Bump CC:T to 1.109.7

Hopefully will help debug #1739. Maybe.

.gitignore

@@ -7,7 +7,9 @@
 /logs
 /build
 /projects/*/logs
+/projects/fabric/fabricloader.log
 /projects/*/build
+/projects/*/src/test/generated_tests/
 /buildSrc/build
 /out
 /buildSrc/out

README.md

@@ -42,7 +42,6 @@ repositories {
     url "https://squiddev.cc/maven/"
     content {
       includeGroup("cc.tweaked")
-      includeModule("org.squiddev", "Cobalt")
     }
   }
 }
@@ -76,8 +75,8 @@ minecraft {
 ```
 
 You should also be careful to only use classes within the `dan200.computercraft.api` package. Non-API classes are
-subject to change at any point. If you depend on functionality outside the API, file an issue, and we can look into
-exposing more features.
+subject to change at any point. If you depend on functionality outside the API (or need to mixin to CC:T), please file
+an issue to let me know!
 
 We bundle the API sources with the jar, so documentation should be easily viewable within your editor. Alternatively,
 the generated documentation [can be browsed online](https://tweaked.cc/javadoc/).

build.gradle.kts

@@ -13,6 +13,8 @@ plugins {
     publishing
     alias(libs.plugins.taskTree)
     alias(libs.plugins.githubRelease)
+    alias(libs.plugins.gradleVersions)
+    alias(libs.plugins.versionCatalogUpdate)
     id("org.jetbrains.gradle.plugin.idea-ext")
     id("cc-tweaked")
 }
@@ -102,3 +104,9 @@ idea.project.settings.compiler.javac {
         }
         .toMap()
 }
+
+versionCatalogUpdate {
+    sortByKey.set(false)
+    pin { versions.addAll("fastutil", "guava", "netty", "slf4j") }
+    keep { keepUnusedLibraries.set(true) }
+}

buildSrc/build.gradle.kts

@@ -5,6 +5,8 @@
 plugins {
     `java-gradle-plugin`
     `kotlin-dsl`
+    alias(libs.plugins.gradleVersions)
+    alias(libs.plugins.versionCatalogUpdate)
 }
 
 // Duplicated in settings.gradle.kts
@@ -27,19 +29,19 @@ repositories {
         }
     }
 
-    maven("https://repo.spongepowered.org/repository/maven-public/") {
-        name = "Sponge"
-        content {
-            includeGroup("org.spongepowered")
-        }
-    }
-
     maven("https://maven.fabricmc.net/") {
         name = "Fabric"
         content {
             includeGroup("net.fabricmc")
         }
     }
+
+    maven("https://squiddev.cc/maven") {
+        name = "SquidDev"
+        content {
+            includeGroup("cc.tweaked.vanilla-extract")
+        }
+    }
 }
 
 dependencies {
@@ -53,8 +55,7 @@ dependencies {
     implementation(libs.ideaExt)
     implementation(libs.librarian)
     implementation(libs.minotaur)
-    implementation(libs.vanillaGradle)
-    implementation(libs.vineflower)
+    implementation(libs.vanillaExtract)
 }
 
 gradlePlugin {
@@ -75,3 +76,9 @@ gradlePlugin {
         }
     }
 }
+
+versionCatalogUpdate {
+    sortByKey.set(false)
+    keep { keepUnusedLibraries.set(true) }
+    catalogFile.set(file("../gradle/libs.versions.toml"))
+}

buildSrc/src/main/kotlin/cc-tweaked.fabric.gradle.kts

@@ -12,7 +12,6 @@ import cc.tweaked.gradle.MinecraftConfigurations
 plugins {
     `java-library`
     id("fabric-loom")
-    id("io.github.juuxel.loom-vineflower")
     id("cc-tweaked.java-convention")
 }
 

buildSrc/src/main/kotlin/cc-tweaked.java-convention.gradle.kts

@@ -76,6 +76,12 @@ dependencies {
     val libs = project.extensions.getByType<VersionCatalogsExtension>().named("libs")
     checkstyle(libs.findLibrary("checkstyle").get())
 
+    constraints {
+        checkstyle("org.codehaus.plexus:plexus-container-default:2.1.1") {
+            because("2.1.0 depends on deprecated Google collections module")
+        }
+    }
+
     errorprone(libs.findLibrary("errorProne-core").get())
     errorprone(libs.findLibrary("nullAway").get())
 }
@@ -201,6 +207,7 @@ spotless {
     val ktlintConfig = mapOf(
         "ktlint_standard_no-wildcard-imports" to "disabled",
         "ktlint_standard_class-naming" to "disabled",
+        "ktlint_standard_function-naming" to "disabled",
         "ij_kotlin_allow_trailing_comma" to "true",
         "ij_kotlin_allow_trailing_comma_on_call_site" to "true",
     )

buildSrc/src/main/kotlin/cc-tweaked.vanilla.gradle.kts

@@ -10,25 +10,31 @@ import cc.tweaked.gradle.MinecraftConfigurations
 
 plugins {
     id("cc-tweaked.java-convention")
-    id("org.spongepowered.gradle.vanilla")
+    id("cc.tweaked.vanilla-extract")
 }
 
 plugins.apply(CCTweakedPlugin::class.java)
 
 val mcVersion: String by extra
 
+val libs = project.extensions.getByType<VersionCatalogsExtension>().named("libs")
+
 minecraft {
     version(mcVersion)
+
+    mappings {
+        parchment(libs.findVersion("parchmentMc").get().toString(), libs.findVersion("parchment").get().toString())
+    }
+
+    unpick(libs.findLibrary("yarn").get())
 }
 
 dependencies {
-    val libs = project.extensions.getByType<VersionCatalogsExtension>().named("libs")
-
     // Depend on error prone annotations to silence a lot of compile warnings.
-    compileOnlyApi(libs.findLibrary("errorProne.annotations").get())
+    compileOnly(libs.findLibrary("errorProne.annotations").get())
 }
 
-MinecraftConfigurations.setup(project)
+MinecraftConfigurations.setupBasic(project)
 
 extensions.configure(CCTweakedExtension::class.java) {
     linters(minecraft = true, loader = null)

buildSrc/src/main/kotlin/cc/tweaked/gradle/CCTweakedExtension.kt

@@ -10,9 +10,11 @@ import org.gradle.api.GradleException
 import org.gradle.api.NamedDomainObjectProvider
 import org.gradle.api.Project
 import org.gradle.api.Task
+import org.gradle.api.artifacts.Dependency
 import org.gradle.api.attributes.TestSuiteType
 import org.gradle.api.file.FileSystemOperations
 import org.gradle.api.plugins.JavaPluginExtension
+import org.gradle.api.provider.ListProperty
 import org.gradle.api.provider.Provider
 import org.gradle.api.provider.SetProperty
 import org.gradle.api.reporting.ReportingExtension
@@ -73,11 +75,17 @@ abstract class CCTweakedExtension(
      */
     val sourceDirectories: SetProperty<SourceSetReference> = project.objects.setProperty(SourceSetReference::class.java)
 
+    /**
+     * Dependencies excluded from published artifacts.
+     */
+    private val excludedDeps: ListProperty<Dependency> = project.objects.listProperty(Dependency::class.java)
+
     /** All source sets referenced by this project. */
     val sourceSets = sourceDirectories.map { x -> x.map { it.sourceSet } }
 
     init {
         sourceDirectories.finalizeValueOnRead()
+        excludedDeps.finalizeValueOnRead()
         project.afterEvaluate { sourceDirectories.disallowChanges() }
     }
 
@@ -246,6 +254,20 @@ abstract class CCTweakedExtension(
         ).resolve().single()
     }
 
+    /**
+     * Exclude a dependency from being published in Maven.
+     */
+    fun exclude(dep: Dependency) {
+        excludedDeps.add(dep)
+    }
+
+    /**
+     * Configure a [MavenDependencySpec].
+     */
+    fun configureExcludes(spec: MavenDependencySpec) {
+        for (dep in excludedDeps.get()) spec.exclude(dep)
+    }
+
     companion object {
         private val COMMIT_COUNTS = Pattern.compile("""^\s*[0-9]+\s+(.*)$""")
         private val IGNORED_USERS = setOf(

buildSrc/src/main/kotlin/cc/tweaked/gradle/DependencyCheck.kt

@@ -0,0 +1,92 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package cc.tweaked.gradle
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.GradleException
+import org.gradle.api.artifacts.Configuration
+import org.gradle.api.artifacts.MinimalExternalModuleDependency
+import org.gradle.api.artifacts.component.ModuleComponentIdentifier
+import org.gradle.api.artifacts.component.ModuleComponentSelector
+import org.gradle.api.artifacts.component.ProjectComponentIdentifier
+import org.gradle.api.artifacts.result.DependencyResult
+import org.gradle.api.artifacts.result.ResolvedDependencyResult
+import org.gradle.api.provider.ListProperty
+import org.gradle.api.provider.MapProperty
+import org.gradle.api.provider.Provider
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.TaskAction
+import org.gradle.language.base.plugins.LifecycleBasePlugin
+
+abstract class DependencyCheck : DefaultTask() {
+    @get:Input
+    abstract val configuration: ListProperty<Configuration>
+
+    /**
+     * A mapping of module coordinates (`group:module`) to versions, overriding the requested version.
+     */
+    @get:Input
+    abstract val overrides: MapProperty<String, String>
+
+    init {
+        description = "Check :core's dependencies are consistent with Minecraft's."
+        group = LifecycleBasePlugin.VERIFICATION_GROUP
+
+        configuration.finalizeValueOnRead()
+        overrides.finalizeValueOnRead()
+    }
+
+    /**
+     * Override a module with a different version.
+     */
+    fun override(module: Provider<MinimalExternalModuleDependency>, version: String) {
+        overrides.putAll(project.provider { mutableMapOf(module.get().module.toString() to version) })
+    }
+
+    @TaskAction
+    fun run() {
+        var ok = true
+        for (configuration in configuration.get()) {
+            configuration.incoming.resolutionResult.allDependencies {
+                if (!check(this@allDependencies)) ok = false
+            }
+        }
+
+        if (!ok) {
+            throw GradleException("Mismatched versions in Minecraft dependencies. gradle/libs.versions.toml may need updating.")
+        }
+    }
+
+    private fun check(dependency: DependencyResult): Boolean {
+        if (dependency !is ResolvedDependencyResult) {
+            logger.warn("Found unexpected dependency result {}", dependency)
+            return false
+        }
+
+        // Skip dependencies on non-modules.
+        val requested = dependency.requested
+        if (requested !is ModuleComponentSelector) return true
+
+        // If this dependency is specified within some project (so is non-transitive), or is pulled in via Minecraft,
+        // then check for consistency.
+        // It would be nice to be smarter about transitive dependencies, but avoiding false positives is hard.
+        val from = dependency.from.id
+        if (
+            from is ProjectComponentIdentifier ||
+            from is ModuleComponentIdentifier && (from.group == "net.minecraft" || from.group == "io.netty")
+        ) {
+            // If the version is different between the requested and selected version, report an error.
+            val selected = dependency.selected.moduleVersion!!.version
+            val requestedVersion = overrides.get()["${requested.group}:${requested.module}"] ?: requested.version
+            if (requestedVersion != selected) {
+                logger.error("Requested dependency {} (via {}) but got version {}", requested, from, selected)
+                return false
+            }
+
+            return true
+        }
+        return true
+    }
+}

buildSrc/src/main/kotlin/cc/tweaked/gradle/Extensions.kt

@@ -6,7 +6,6 @@ package cc.tweaked.gradle
 
 import org.gradle.api.artifacts.dsl.DependencyHandler
 import org.gradle.api.file.FileSystemLocation
-import org.gradle.api.file.FileSystemLocationProperty
 import org.gradle.api.provider.Property
 import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.JavaExec
@@ -129,3 +128,30 @@ fun <T> Property<T>.setProvider(provider: Provider<out T>) = set(provider)
 
 /** Short-cut method to get the absolute path of a [FileSystemLocation] provider. */
 fun Provider<out FileSystemLocation>.getAbsolutePath(): String = get().asFile.absolutePath
+
+/**
+ * Get the version immediately after the provided version.
+ *
+ * For example, given "1.2.3", this will return "1.2.4".
+ */
+fun getNextVersion(version: String): String {
+    // Split a version like x.y.z-SNAPSHOT into x.y.z and -SNAPSHOT
+    val dashIndex = version.indexOf('-')
+    val mainVersion = if (dashIndex < 0) version else version.substring(0, dashIndex)
+
+    // Find the last component in x.y.z and increment it.
+    val lastIndex = mainVersion.lastIndexOf('.')
+    if (lastIndex < 0) throw IllegalArgumentException("Cannot parse version format \"$version\"")
+    val lastVersion = try {
+        version.substring(lastIndex + 1).toInt()
+    } catch (e: NumberFormatException) {
+        throw IllegalArgumentException("Cannot parse version format \"$version\"", e)
+    }
+
+    // Then append all components together.
+    val out = StringBuilder()
+    out.append(version, 0, lastIndex + 1)
+    out.append(lastVersion + 1)
+    if (dashIndex >= 0) out.append(version, dashIndex, version.length)
+    return out.toString()
+}

buildSrc/src/main/kotlin/cc/tweaked/gradle/MavenDependencySpec.kt

@@ -6,6 +6,8 @@ package cc.tweaked.gradle
 
 import org.gradle.api.artifacts.Dependency
 import org.gradle.api.artifacts.MinimalExternalModuleDependency
+import org.gradle.api.artifacts.ProjectDependency
+import org.gradle.api.plugins.BasePluginExtension
 import org.gradle.api.publish.maven.MavenPublication
 import org.gradle.api.specs.Spec
 
@@ -26,8 +28,13 @@ class MavenDependencySpec {
 
     fun exclude(dep: Dependency) {
         exclude {
+            // We have to cheat a little for project dependencies, as the project name doesn't match the artifact group.
+            val name = when (dep) {
+                is ProjectDependency -> dep.dependencyProject.extensions.getByType(BasePluginExtension::class.java).archivesName.get()
+                else -> dep.name
+            }
             (dep.group.isNullOrEmpty() || dep.group == it.groupId) &&
-                (dep.name.isNullOrEmpty() || dep.name == it.artifactId) &&
+                (name.isNullOrEmpty() || name == it.artifactId) &&
                 (dep.version.isNullOrEmpty() || dep.version == it.version)
         }
     }

buildSrc/src/main/kotlin/cc/tweaked/gradle/MinecraftConfigurations.kt

@@ -4,23 +4,17 @@
 
 package cc.tweaked.gradle
 
+import cc.tweaked.vanillaextract.configurations.Capabilities
+import cc.tweaked.vanillaextract.configurations.MinecraftSetup
 import org.gradle.api.Project
-import org.gradle.api.artifacts.Configuration
 import org.gradle.api.artifacts.ModuleDependency
 import org.gradle.api.artifacts.dsl.DependencyHandler
-import org.gradle.api.attributes.Bundling
-import org.gradle.api.attributes.Category
-import org.gradle.api.attributes.LibraryElements
-import org.gradle.api.attributes.Usage
-import org.gradle.api.attributes.java.TargetJvmVersion
-import org.gradle.api.capabilities.Capability
 import org.gradle.api.plugins.BasePlugin
 import org.gradle.api.plugins.JavaPluginExtension
 import org.gradle.api.tasks.SourceSet
 import org.gradle.api.tasks.bundling.Jar
 import org.gradle.api.tasks.javadoc.Javadoc
 import org.gradle.kotlin.dsl.get
-import org.gradle.kotlin.dsl.named
 
 /**
  * This sets up a separate client-only source set, and extends that and the main/common source set with additional
@@ -59,31 +53,13 @@ class MinecraftConfigurations private constructor(private val project: Project)
         }
         configurations.named(client.implementationConfigurationName) { extendsFrom(clientApi) }
 
-        /*
-          Now add outgoing variants for the main and common source sets that we can consume downstream. This is possibly
-          the worst way to do things, but unfortunately the alternatives don't actually work very well:
-
-           - Just using source set outputs: This means dependencies don't propagate, which means when :fabric depends
-             on :fabric-api, we don't inherit the fake :common-api in IDEA.
-
-           - Having separate common/main jars: Nice in principle, but unfortunately Forge needs a separate deobf jar
-             task (as the original jar is obfuscated), and IDEA is not able to map its output back to a source set.
-
-          This works for now, but is incredibly brittle. It's part of the reason we can't use testFixtures inside our
-          MC projects, as that adds a project(self) -> test dependency, which would pull in the jar instead.
-
-          Note we register a fake client jar here. It's not actually needed, but is there to make sure IDEA has
-          a way to tell that client classes are needed at runtime.
-
-          I'm so sorry, deeply aware how cursed this is.
-        */
-        setupOutgoing(main, "CommonOnly")
         project.tasks.register(client.jarTaskName, Jar::class.java) {
             description = "An empty jar standing in for the client classes."
             group = BasePlugin.BUILD_GROUP
             archiveClassifier.set("client")
         }
-        setupOutgoing(client)
+
+        MinecraftSetup(project).setupOutgoingConfigurations()
 
         // Reset the client classpath (Loom configures it slightly differently to this) and add a main -> client
         // dependency. Here we /can/ use source set outputs as we add transitive deps by patching the classpath. Nasty,
@@ -106,88 +82,39 @@ class MinecraftConfigurations private constructor(private val project: Project)
         project.tasks.named("jar", Jar::class.java) { from(client.output) }
         project.tasks.named("sourcesJar", Jar::class.java) { from(client.allSource) }
 
+        setupBasic()
+    }
+
+    private fun setupBasic() {
+        val client = sourceSets["client"]
+
         project.extensions.configure(CCTweakedExtension::class.java) {
             sourceDirectories.add(SourceSetReference.internal(client))
         }
-    }
 
-    private fun setupOutgoing(sourceSet: SourceSet, suffix: String = "") {
-        setupOutgoing("${sourceSet.apiElementsConfigurationName}$suffix", sourceSet, objects.named(Usage.JAVA_API)) {
-            description = "API elements for ${sourceSet.name}"
-            extendsFrom(configurations[sourceSet.apiConfigurationName])
-        }
-
-        setupOutgoing("${sourceSet.runtimeElementsConfigurationName}$suffix", sourceSet, objects.named(Usage.JAVA_RUNTIME)) {
-            description = "Runtime elements for ${sourceSet.name}"
-            extendsFrom(configurations[sourceSet.implementationConfigurationName], configurations[sourceSet.runtimeOnlyConfigurationName])
-        }
-    }
-
-    /**
-     * Set up an outgoing configuration for a specific source set. We set an additional "main" or "client" capability
-     * (depending on the source set name) which allows downstream projects to consume them separately (see
-     * [DependencyHandler.commonClasses] and [DependencyHandler.clientClasses]).
-     */
-    private fun setupOutgoing(name: String, sourceSet: SourceSet, usage: Usage, configure: Configuration.() -> Unit) {
-        configurations.register(name) {
-            isVisible = false
-            isCanBeConsumed = true
-            isCanBeResolved = false
-
-            configure(this)
-
-            attributes {
-                attribute(Category.CATEGORY_ATTRIBUTE, objects.named(Category.LIBRARY))
-                attribute(Usage.USAGE_ATTRIBUTE, usage)
-                attribute(Bundling.BUNDLING_ATTRIBUTE, objects.named(Bundling.EXTERNAL))
-                attributeProvider(
-                    TargetJvmVersion.TARGET_JVM_VERSION_ATTRIBUTE,
-                    java.toolchain.languageVersion.map { it.asInt() },
-                )
-                attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, objects.named(LibraryElements.JAR))
+        // Register a task to check there are no conflicts with the core project.
+        val checkDependencyConsistency =
+            project.tasks.register("checkDependencyConsistency", DependencyCheck::class.java) {
+                // We need to check both the main and client classpath *configurations*, as the actual configuration
+                configuration.add(configurations.named(main.runtimeClasspathConfigurationName))
+                configuration.add(configurations.named(client.runtimeClasspathConfigurationName))
             }
-
-            outgoing {
-                capability(BasicOutgoingCapability(project, sourceSet.name))
-
-                // We have two outgoing variants here: the original jar and the classes.
-                artifact(project.tasks.named(sourceSet.jarTaskName))
-
-                variants.create("classes") {
-                    attributes.attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, objects.named(LibraryElements.CLASSES))
-                    sourceSet.output.classesDirs.forEach { artifact(it) { builtBy(sourceSet.output) } }
-                }
-            }
-        }
+        project.tasks.named("check") { dependsOn(checkDependencyConsistency) }
     }
 
     companion object {
+        fun setupBasic(project: Project) {
+            MinecraftConfigurations(project).setupBasic()
+        }
+
         fun setup(project: Project) {
             MinecraftConfigurations(project).setup()
         }
     }
 }
 
-private class BasicIncomingCapability(private val module: ModuleDependency, private val name: String) : Capability {
-    override fun getGroup(): String = module.group!!
-    override fun getName(): String = "${module.name}-$name"
-    override fun getVersion(): String? = null
-}
+fun DependencyHandler.clientClasses(notation: Any): ModuleDependency =
+    Capabilities.clientClasses(create(notation) as ModuleDependency)
 
-private class BasicOutgoingCapability(private val project: Project, private val name: String) : Capability {
-    override fun getGroup(): String = project.group.toString()
-    override fun getName(): String = "${project.name}-$name"
-    override fun getVersion(): String = project.version.toString()
-}
-
-fun DependencyHandler.clientClasses(notation: Any): ModuleDependency {
-    val dep = create(notation) as ModuleDependency
-    dep.capabilities { requireCapability(BasicIncomingCapability(dep, "client")) }
-    return dep
-}
-
-fun DependencyHandler.commonClasses(notation: Any): ModuleDependency {
-    val dep = create(notation) as ModuleDependency
-    dep.capabilities { requireCapability(BasicIncomingCapability(dep, "main")) }
-    return dep
-}
+fun DependencyHandler.commonClasses(notation: Any): ModuleDependency =
+    Capabilities.commonClasses(create(notation) as ModuleDependency)

doc/reference/breaking_changes.md

@@ -21,7 +21,7 @@ of the mod should run fine on later versions.
 However, some changes to the underlying game, or CC: Tweaked's own internals may break some programs. This page serves
 as documentation for breaking changes and "gotchas" one should look out for between versions.
 
-## CC: Tweaked 1.109.0 {#cct-1.109}
+## CC: Tweaked 1.109.0 to 1.109.3 {#cct-1.109}
 
  - Update to Lua 5.2:
    - Support for Lua 5.0's pseudo-argument `arg` has been removed. You should always use `...` for varargs.
@@ -31,6 +31,7 @@ as documentation for breaking changes and "gotchas" one should look out for betw
    - `load`/`loadstring` defaults to using the global environment (`_G`) rather than the current coroutine's
      environment.
    - Support for dumping functions (`string.dump`) and loading binary chunks has been removed.
+   - `math.random` now uses Lua 5.4's random number generator.
 
  - File handles, HTTP requests and websockets now always use the original bytes rather than encoding/decoding to UTF-8.
 
@@ -75,6 +76,6 @@ as documentation for breaking changes and "gotchas" one should look out for betw
  - Programs containing `/` are looked up in the current directory and are no longer looked up on the path. For instance,
    you can no longer type `turtle/excavate` to run `/rom/programs/turtle/excavate.lua`.
 
-[flattening]: https://minecraft.wiki.com/w/Java_Edition_1.13/Flattening
+[flattening]: https://minecraft.wiki/w/Java_Edition_1.13/Flattening
 [legal_data_pack]: https://minecraft.gamepedia.com/Tutorials/Creating_a_data_pack#Legal_characters
 [datapack-example]: https://github.com/cc-tweaked/datapack-example "An example datapack for CC: Tweaked"

gradle.properties

@@ -9,8 +9,8 @@ kotlin.stdlib.default.dependency=false
 kotlin.jvm.target.validation.mode=error
 
 # Mod properties
-isUnstable=true
-modVersion=1.109.0
+isUnstable=false
+modVersion=1.109.7
 
 # Minecraft properties: We want to configure this here so we can read it in settings.gradle
 mcVersion=1.20.1

gradle/libs.versions.toml

@@ -10,28 +10,30 @@
 fabric-api = "0.86.1+1.20.1"
 fabric-loader = "0.14.21"
 forge = "47.1.0"
-forgeSpi = "6.0.0"
+forgeSpi = "7.0.1"
 mixin = "0.8.5"
 parchment = "2023.08.20"
 parchmentMc = "1.20.1"
+yarn = "1.20.1+build.10"
 
-# Normal dependencies
-asm = "9.5"
-autoService = "1.1.1"
-checkerFramework = "3.32.0"
-cobalt = "0.8.0"
-cobalt-next = "0.8.1" # Not a real version, used to constrain the version we accept.
-commonsCli = "1.3.1"
+# Core dependencies (these versions are tied to the version Minecraft uses)
 fastutil = "8.5.9"
 guava = "31.1-jre"
-jetbrainsAnnotations = "24.0.1"
+netty = "4.1.82.Final"
+slf4j = "2.0.1"
+
+# Core dependencies (independent of Minecraft)
+asm = "9.6"
+autoService = "1.1.1"
+checkerFramework = "3.42.0"
+cobalt = "0.9.1"
+commonsCli = "1.6.0"
+jetbrainsAnnotations = "24.1.0"
 jsr305 = "3.0.2"
 jzlib = "1.1.3"
-kotlin = "1.8.10"
-kotlin-coroutines = "1.6.4"
-netty = "4.1.82.Final"
+kotlin = "1.9.21"
+kotlin-coroutines = "1.7.3"
 nightConfig = "3.6.7"
-slf4j = "2.0.1"
 
 # Minecraft mods
 emi = "1.0.8+1.20.1"
@@ -47,30 +49,32 @@ sodium = "mc1.20-0.4.10"
 
 # Testing
 hamcrest = "2.2"
-jqwik = "1.7.4"
-junit = "5.10.0"
+jqwik = "1.8.2"
+junit = "5.10.1"
+jmh = "1.37"
 
 # Build tools
-cctJavadoc = "1.8.1"
-checkstyle = "10.12.3"
+cctJavadoc = "1.8.2"
+checkstyle = "10.12.6"
 curseForgeGradle = "1.0.14"
-errorProne-core = "2.21.1"
+errorProne-core = "2.23.0"
 errorProne-plugin = "3.1.0"
-fabric-loom = "1.3.7"
-forgeGradle = "6.0.8"
-githubRelease = "2.4.1"
+fabric-loom = "1.5.7"
+forgeGradle = "6.0.20"
+githubRelease = "2.5.2"
+gradleVersions = "0.50.0"
 ideaExt = "1.1.7"
 illuaminate = "0.1.0-44-g9ee0055"
 librarian = "1.+"
-lwjgl = "3.3.1"
+lwjgl = "3.3.3"
 minotaur = "2.+"
-mixinGradle = "0.7.+"
+mixinGradle = "0.7.38"
 nullAway = "0.9.9"
-spotless = "6.21.0"
+spotless = "6.23.3"
 taskTree = "2.1.1"
-teavm = "0.10.0-SQUID.1"
-vanillaGradle = "0.2.1-SNAPSHOT"
-vineflower = "1.11.0"
+teavm = "0.10.0-SQUID.2"
+vanillaExtract = "0.1.1"
+versionCatalogUpdate = "0.8.1"
 
 [libraries]
 # Normal dependencies
@@ -124,6 +128,8 @@ junit-jupiter-api = { module = "org.junit.jupiter:junit-jupiter-api", version.re
 junit-jupiter-engine = { module = "org.junit.jupiter:junit-jupiter-engine", version.ref = "junit" }
 junit-jupiter-params = { module = "org.junit.jupiter:junit-jupiter-params", version.ref = "junit" }
 slf4j-simple = { module = "org.slf4j:slf4j-simple", version.ref = "slf4j" }
+jmh = { module = "org.openjdk.jmh:jmh-core", version.ref = "jmh" }
+jmh-processor = { module = "org.openjdk.jmh:jmh-generator-annprocess", version.ref = "jmh" }
 
 # LWJGL
 lwjgl-bom = { module = "org.lwjgl:lwjgl-bom", version.ref = "lwjgl" }
@@ -156,16 +162,18 @@ teavm-metaprogramming-api = { module = "org.teavm:teavm-metaprogramming-api", ve
 teavm-metaprogramming-impl = { module = "org.teavm:teavm-metaprogramming-impl", version.ref = "teavm" }
 teavm-platform = { module = "org.teavm:teavm-platform", version.ref = "teavm" }
 teavm-tooling = { module = "org.teavm:teavm-tooling", version.ref = "teavm" }
-vanillaGradle = { module = "org.spongepowered:vanillagradle", version.ref = "vanillaGradle" }
-vineflower = { module = "io.github.juuxel:loom-vineflower", version.ref = "vineflower" }
+vanillaExtract = { module = "cc.tweaked.vanilla-extract:plugin", version.ref = "vanillaExtract" }
+yarn = { module = "net.fabricmc:yarn", version.ref = "yarn" }
 
 [plugins]
 forgeGradle = { id = "net.minecraftforge.gradle", version.ref = "forgeGradle" }
 githubRelease = { id = "com.github.breadmoirai.github-release", version.ref = "githubRelease" }
+gradleVersions = { id = "com.github.ben-manes.versions", version.ref = "gradleVersions" }
 kotlin = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
 librarian = { id = "org.parchmentmc.librarian.forgegradle", version.ref = "librarian" }
 mixinGradle = { id = "org.spongepowered.mixin", version.ref = "mixinGradle" }
 taskTree = { id = "com.dorongold.task-tree", version.ref = "taskTree" }
+versionCatalogUpdate = { id = "nl.littlerobots.version-catalog-update", version.ref = "versionCatalogUpdate" }
 
 [bundles]
 annotations = ["jsr305", "checkerFramework", "jetbrainsAnnotations"]
@@ -175,7 +183,6 @@ kotlin = ["kotlin-stdlib", "kotlin-coroutines"]
 externalMods-common = ["jei-api", "nightConfig-core", "nightConfig-toml"]
 externalMods-forge-compile = ["moreRed", "oculus", "jei-api"]
 externalMods-forge-runtime = ["jei-forge"]
-externalMods-fabric = ["nightConfig-core", "nightConfig-toml"]
 externalMods-fabric-compile = ["fabricPermissions", "iris", "jei-api", "rei-api", "rei-builtin"]
 externalMods-fabric-runtime = ["jei-fabric", "modmenu"]
 
@@ -184,5 +191,5 @@ test = ["junit-jupiter-api", "junit-jupiter-params", "hamcrest", "jqwik-api"]
 testRuntime = ["junit-jupiter-engine", "jqwik-engine"]
 
 # Build tools
-teavm-api = [ "teavm-jso", "teavm-jso-apis", "teavm-platform", "teavm-classlib", "teavm-metaprogramming-api" ]
-teavm-tooling = [ "teavm-tooling", "teavm-metaprogramming-impl", "teavm-jso-impl" ]
+teavm-api = ["teavm-jso", "teavm-jso-apis", "teavm-platform", "teavm-classlib", "teavm-metaprogramming-api"]
+teavm-tooling = ["teavm-tooling", "teavm-metaprogramming-impl", "teavm-jso-impl"]

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.1.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
 networkTimeout=10000
+validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradlew

@@ -83,7 +83,8 @@ done
 # This is normally unused
 # shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -130,10 +131,13 @@ location of your Java installation."
     fi
 else
     JAVACMD=java
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.
@@ -141,7 +145,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
         # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
@@ -149,7 +153,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
       '' | soft) :;; #(
       *)
         # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -198,11 +202,11 @@ fi
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \

illuaminate.sexp

@@ -6,7 +6,7 @@
 
 (sources
   /doc/
-  /projects/forge/build/docs/luaJavadoc/
+  /projects/common/build/docs/luaJavadoc/
   /projects/core/src/main/resources/data/computercraft/lua/bios.lua
   /projects/core/src/main/resources/data/computercraft/lua/rom/
   /projects/core/src/test/resources/test-rom
@@ -36,7 +36,7 @@
 
   (library-path
     /doc/stub/
-    /projects/forge/build/docs/luaJavadoc/
+    /projects/common/build/docs/luaJavadoc/
 
     /projects/core/src/main/resources/data/computercraft/lua/rom/apis/
     /projects/core/src/main/resources/data/computercraft/lua/rom/apis/command/
@@ -88,7 +88,7 @@
   (/doc/stub/
    /projects/core/src/main/resources/data/computercraft/lua/bios.lua
    /projects/core/src/main/resources/data/computercraft/lua/rom/apis/
-   /projects/forge/build/docs/luaJavadoc/)
+   /projects/common/build/docs/luaJavadoc/)
   (linters -var:unused-global)
   (lint (allow-toplevel-global true)))
 
@@ -105,6 +105,10 @@
    /projects/core/src/main/resources/data/computercraft/lua/rom/apis/turtle/turtle.lua)
   (linters -var:deprecated))
 
+;; Suppress unused variable warnings in the parser.
+(at /projects/core/src/main/resources/data/computercraft/lua/rom/modules/main/cc/internal/syntax/parser.lua
+  (linters -var:unused))
+
 (at /projects/core/src/test/resources/test-rom
   ; We should still be able to test deprecated members.
   (linters -var:deprecated)

package.json

@@ -23,7 +23,7 @@
     "rehype-highlight": "^7.0.0",
     "rehype-react": "^8.0.0",
     "rollup": "^4.0.0",
-    "tsx": "^3.12.10",
+    "tsx": "^4.7.0",
     "typescript": "^5.2.2"
   }
 }

projects/common-api/src/client/java/dan200/computercraft/api/client/ComputerCraftAPIClient.java

@@ -27,8 +27,13 @@ public final class ComputerCraftAPIClient {
      * @param serialiser The turtle upgrade serialiser.
      * @param modeller   The upgrade modeller.
      * @param <T>        The type of the turtle upgrade.
+     * @deprecated This method can lead to confusing load behaviour on Forge. Use
+     * {@code dan200.computercraft.api.client.FabricComputerCraftAPIClient#registerTurtleUpgradeModeller} on Fabric, or
+     * {@code dan200.computercraft.api.client.turtle.RegisterTurtleModellersEvent} on Forge.
      */
+    @Deprecated(forRemoval = true)
     public static <T extends ITurtleUpgrade> void registerTurtleUpgradeModeller(TurtleUpgradeSerialiser<T> serialiser, TurtleUpgradeModeller<T> modeller) {
+        // TODO(1.20.4): Remove this
         getInstance().registerTurtleUpgradeModeller(serialiser, modeller);
     }
 

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/RegisterTurtleUpgradeModeller.java

@@ -0,0 +1,26 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.api.client.turtle;
+
+import dan200.computercraft.api.turtle.ITurtleUpgrade;
+import dan200.computercraft.api.turtle.TurtleUpgradeSerialiser;
+
+/**
+ * A functional interface to register a {@link TurtleUpgradeModeller} for a class of turtle upgrades.
+ * <p>
+ * This interface is largely intended to be used from multi-loader code, to allow sharing registration code between
+ * multiple loaders.
+ */
+@FunctionalInterface
+public interface RegisterTurtleUpgradeModeller {
+    /**
+     * Register a {@link TurtleUpgradeModeller}.
+     *
+     * @param serialiser The turtle upgrade serialiser.
+     * @param modeller   The upgrade modeller.
+     * @param <T>        The type of the turtle upgrade.
+     */
+    <T extends ITurtleUpgrade> void register(TurtleUpgradeSerialiser<T> serialiser, TurtleUpgradeModeller<T> modeller);
+}

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/TurtleUpgradeModeller.java

@@ -4,12 +4,10 @@
 
 package dan200.computercraft.api.client.turtle;
 
-import dan200.computercraft.api.client.ComputerCraftAPIClient;
 import dan200.computercraft.api.client.TransformedModel;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
-import dan200.computercraft.api.turtle.TurtleUpgradeSerialiser;
 import net.minecraft.client.resources.model.ModelResourceLocation;
 import net.minecraft.client.resources.model.UnbakedModel;
 import net.minecraft.nbt.CompoundTag;
@@ -21,9 +19,13 @@ import java.util.List;
 
 /**
  * Provides models for a {@link ITurtleUpgrade}.
+ * <p>
+ * Use {@code dan200.computercraft.api.client.FabricComputerCraftAPIClient#registerTurtleUpgradeModeller} to register a
+ * modeller on Fabric and {@code dan200.computercraft.api.client.turtle.RegisterTurtleModellersEvent} to register one
+ * on Forge
  *
  * @param <T> The type of turtle upgrade this modeller applies to.
- * @see ComputerCraftAPIClient#registerTurtleUpgradeModeller(TurtleUpgradeSerialiser, TurtleUpgradeModeller) To register a modeller.
+ * @see RegisterTurtleUpgradeModeller For multi-loader registration support.
  */
 public interface TurtleUpgradeModeller<T extends ITurtleUpgrade> {
     /**

projects/common-api/src/main/java/dan200/computercraft/api/network/wired/WiredNetwork.java

@@ -5,6 +5,7 @@
 package dan200.computercraft.api.network.wired;
 
 import dan200.computercraft.api.peripheral.IPeripheral;
+import org.jetbrains.annotations.ApiStatus;
 
 import java.util.Map;
 
@@ -22,6 +23,7 @@ import java.util.Map;
  *
  * @see WiredNode#getNetwork()
  */
+@ApiStatus.NonExtendable
 public interface WiredNetwork {
     /**
      * Create a connection between two nodes.
@@ -35,7 +37,9 @@ public interface WiredNetwork {
      * @throws IllegalArgumentException If {@code left} and {@code right} are equal.
      * @see WiredNode#connectTo(WiredNode)
      * @see WiredNetwork#connect(WiredNode, WiredNode)
+     * @deprecated Use {@link WiredNode#connectTo(WiredNode)}
      */
+    @Deprecated
     boolean connect(WiredNode left, WiredNode right);
 
     /**
@@ -50,7 +54,9 @@ public interface WiredNetwork {
      * @throws IllegalArgumentException If {@code left} and {@code right} are equal.
      * @see WiredNode#disconnectFrom(WiredNode)
      * @see WiredNetwork#connect(WiredNode, WiredNode)
+     * @deprecated Use {@link WiredNode#disconnectFrom(WiredNode)}
      */
+    @Deprecated
     boolean disconnect(WiredNode left, WiredNode right);
 
     /**
@@ -64,7 +70,9 @@ public interface WiredNetwork {
      * only element.
      * @throws IllegalArgumentException If the node is not in the network.
      * @see WiredNode#remove()
+     * @deprecated Use {@link WiredNode#remove()}
      */
+    @Deprecated
     boolean remove(WiredNode node);
 
     /**
@@ -77,6 +85,8 @@ public interface WiredNetwork {
      * @param peripherals The new peripherals for this node.
      * @throws IllegalArgumentException If the node is not in the network.
      * @see WiredNode#updatePeripherals(Map)
+     * @deprecated Use {@link WiredNode#updatePeripherals(Map)}
      */
+    @Deprecated
     void updatePeripherals(WiredNode node, Map<String, IPeripheral> peripherals);
 }

projects/common-api/src/main/java/dan200/computercraft/api/network/wired/WiredNode.java

@@ -6,6 +6,7 @@ package dan200.computercraft.api.network.wired;
 
 import dan200.computercraft.api.network.PacketNetwork;
 import dan200.computercraft.api.peripheral.IPeripheral;
+import org.jetbrains.annotations.ApiStatus;
 
 import java.util.Map;
 
@@ -22,6 +23,7 @@ import java.util.Map;
  * Wired nodes also provide several convenience methods for interacting with a wired network. These should only ever
  * be used on the main server thread.
  */
+@ApiStatus.NonExtendable
 public interface WiredNode extends PacketNetwork {
     /**
      * The associated element for this network node.
@@ -37,7 +39,9 @@ public interface WiredNode extends PacketNetwork {
      * This should only be used on the server thread.
      *
      * @return This node's network.
+     * @deprecated Use the connect/disconnect/remove methods on {@link WiredNode}.
      */
+    @Deprecated
     WiredNetwork getNetwork();
 
     /**
@@ -47,12 +51,9 @@ public interface WiredNode extends PacketNetwork {
      *
      * @param node The other node to connect to.
      * @return {@code true} if a connection was created or {@code false} if the connection already exists.
-     * @see WiredNetwork#connect(WiredNode, WiredNode)
      * @see WiredNode#disconnectFrom(WiredNode)
      */
-    default boolean connectTo(WiredNode node) {
-        return getNetwork().connect(this, node);
-    }
+    boolean connectTo(WiredNode node);
 
     /**
      * Destroy a connection between this node and another.
@@ -61,13 +62,9 @@ public interface WiredNode extends PacketNetwork {
      *
      * @param node The other node to disconnect from.
      * @return {@code true} if a connection was destroyed or {@code false} if no connection exists.
-     * @throws IllegalArgumentException If {@code node} is not on the same network.
-     * @see WiredNetwork#disconnect(WiredNode, WiredNode)
      * @see WiredNode#connectTo(WiredNode)
      */
-    default boolean disconnectFrom(WiredNode node) {
-        return getNetwork().disconnect(this, node);
-    }
+    boolean disconnectFrom(WiredNode node);
 
     /**
      * Sever all connections this node has, removing it from this network.
@@ -78,11 +75,8 @@ public interface WiredNode extends PacketNetwork {
      * @return Whether this node was removed from the network. One cannot remove a node from a network where it is the
      * only element.
      * @throws IllegalArgumentException If the node is not in the network.
-     * @see WiredNetwork#remove(WiredNode)
      */
-    default boolean remove() {
-        return getNetwork().remove(this);
-    }
+    boolean remove();
 
     /**
      * Mark this node's peripherals as having changed.
@@ -91,9 +85,6 @@ public interface WiredNode extends PacketNetwork {
      * that your network element owns.
      *
      * @param peripherals The new peripherals for this node.
-     * @see WiredNetwork#updatePeripherals(WiredNode, Map)
      */
-    default void updatePeripherals(Map<String, IPeripheral> peripherals) {
-        getNetwork().updatePeripherals(this, peripherals);
-    }
+    void updatePeripherals(Map<String, IPeripheral> peripherals);
 }

projects/common-api/src/main/java/dan200/computercraft/api/turtle/TurtleUpgradeSerialiser.java

@@ -48,13 +48,8 @@ import java.util.function.Function;
  * }
  * }</pre>
  * <p>
- * Finally, we need to register a model for our upgrade. This is done with
- * {@link dan200.computercraft.api.client.ComputerCraftAPIClient#registerTurtleUpgradeModeller}:
- *
- * <pre>{@code
- * // Register our model inside FMLClientSetupEvent
- * ComputerCraftAPIClient.registerTurtleUpgradeModeller(MY_UPGRADE.get(), TurtleUpgradeModeller.flatItem())
- * }</pre>
+ * Finally, we need to register a model for our upgrade. The way to do this varies on mod loader, see
+ * {@link dan200.computercraft.api.client.turtle.TurtleUpgradeModeller} for more information.
  * <p>
  * {@link TurtleUpgradeDataProvider} provides a data provider to aid with generating these JSON files.
  *

projects/common/build.gradle.kts

@@ -2,13 +2,12 @@
 //
 // SPDX-License-Identifier: MPL-2.0
 
-import cc.tweaked.gradle.annotationProcessorEverywhere
-import cc.tweaked.gradle.clientClasses
-import cc.tweaked.gradle.commonClasses
+import cc.tweaked.gradle.*
 
 plugins {
     id("cc-tweaked.vanilla")
     id("cc-tweaked.gametest")
+    id("cc-tweaked.illuaminate")
     id("cc-tweaked.publishing")
 }
 
@@ -19,6 +18,18 @@ minecraft {
     )
 }
 
+configurations {
+    register("cctJavadoc")
+}
+
+repositories {
+    maven("https://maven.minecraftforge.net/") {
+        content {
+            includeModule("org.spongepowered", "mixin")
+        }
+    }
+}
+
 dependencies {
     // Pull in our other projects. See comments in MinecraftConfigurations on this nastiness.
     implementation(project(":core"))
@@ -28,7 +39,6 @@ dependencies {
     compileOnly(libs.bundles.externalMods.common)
     clientCompileOnly(variantOf(libs.emi) { classifier("api") })
 
-    compileOnly(libs.mixin)
     annotationProcessorEverywhere(libs.autoService)
     testFixturesAnnotationProcessor(libs.autoService)
 
@@ -36,9 +46,62 @@ dependencies {
     testImplementation(libs.bundles.test)
     testRuntimeOnly(libs.bundles.testRuntime)
 
+    testImplementation(libs.jmh)
+    testAnnotationProcessor(libs.jmh.processor)
+
+    testModCompileOnly(libs.mixin)
     testModImplementation(testFixtures(project(":core")))
     testModImplementation(testFixtures(project(":common")))
     testModImplementation(libs.bundles.kotlin)
 
     testFixturesImplementation(testFixtures(project(":core")))
+
+    "cctJavadoc"(libs.cctJavadoc)
+}
+
+illuaminate {
+    version.set(libs.versions.illuaminate)
+}
+
+val luaJavadoc by tasks.registering(Javadoc::class) {
+    description = "Generates documentation for Java-side Lua functions."
+    group = JavaBasePlugin.DOCUMENTATION_GROUP
+
+    val sourceSets = listOf(sourceSets.main.get(), project(":core").sourceSets.main.get())
+    for (sourceSet in sourceSets) {
+        source(sourceSet.java)
+        classpath += sourceSet.compileClasspath
+    }
+
+    destinationDir = layout.buildDirectory.dir("docs/luaJavadoc").get().asFile
+
+    val options = options as StandardJavadocDocletOptions
+    options.docletpath = configurations["cctJavadoc"].files.toList()
+    options.doclet = "cc.tweaked.javadoc.LuaDoclet"
+    options.addStringOption("project-root", rootProject.file(".").absolutePath)
+    options.noTimestamp(false)
+
+    javadocTool.set(
+        javaToolchains.javadocToolFor {
+            languageVersion.set(CCTweakedPlugin.JAVA_VERSION)
+        },
+    )
+}
+
+val lintLua by tasks.registering(IlluaminateExec::class) {
+    group = JavaBasePlugin.VERIFICATION_GROUP
+    description = "Lint Lua (and Lua docs) with illuaminate"
+
+    // Config files
+    inputs.file(rootProject.file("illuaminate.sexp")).withPropertyName("illuaminate.sexp")
+    // Sources
+    inputs.files(rootProject.fileTree("doc")).withPropertyName("docs")
+    inputs.files(project(":core").fileTree("src/main/resources/data/computercraft/lua")).withPropertyName("lua rom")
+    inputs.files(luaJavadoc)
+
+    args = listOf("lint")
+    workingDir = rootProject.projectDir
+
+    doFirst { if (System.getenv("GITHUB_ACTIONS") != null) println("::add-matcher::.github/matchers/illuaminate.json") }
+    doLast { if (System.getenv("GITHUB_ACTIONS") != null) println("::remove-matcher owner=illuaminate::") }
 }

projects/common/src/client/java/dan200/computercraft/client/ClientHooks.java

@@ -17,8 +17,6 @@ import dan200.computercraft.client.render.monitor.MonitorRenderState;
 import dan200.computercraft.client.sound.SpeakerManager;
 import dan200.computercraft.shared.CommonHooks;
 import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.command.CommandComputerCraft;
-import dan200.computercraft.shared.computer.core.ServerContext;
 import dan200.computercraft.shared.media.items.PrintoutItem;
 import dan200.computercraft.shared.peripheral.modem.wired.CableBlock;
 import dan200.computercraft.shared.peripheral.modem.wired.CableModemVariant;
@@ -28,7 +26,6 @@ import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import dan200.computercraft.shared.turtle.blocks.TurtleBlockEntity;
 import dan200.computercraft.shared.util.PauseAwareTimer;
 import dan200.computercraft.shared.util.WorldUtil;
-import net.minecraft.Util;
 import net.minecraft.client.Camera;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.MultiBufferSource;
@@ -43,7 +40,6 @@ import net.minecraft.world.phys.BlockHitResult;
 import net.minecraft.world.phys.HitResult;
 
 import javax.annotation.Nullable;
-import java.io.File;
 import java.util.function.Consumer;
 
 /**
@@ -71,10 +67,6 @@ public final class ClientHooks {
         ClientPocketComputers.reset();
     }
 
-    public static boolean onChatMessage(String message) {
-        return handleOpenComputerCommand(message);
-    }
-
     public static boolean drawHighlight(PoseStack transform, MultiBufferSource bufferSource, Camera camera, BlockHitResult hit) {
         return CableHighlightRenderer.drawHighlight(transform, bufferSource, camera, hit)
             || MonitorHighlightRenderer.drawHighlight(transform, bufferSource, camera, hit);
@@ -109,34 +101,6 @@ public final class ClientHooks {
         SpeakerManager.onPlayStreaming(engine, channel, stream);
     }
 
-    /**
-     * Handle the {@link CommandComputerCraft#OPEN_COMPUTER} "clientside command". This isn't a true command, as we
-     * don't want it to actually be visible to the user.
-     *
-     * @param message The current chat message.
-     * @return Whether to cancel sending this message.
-     */
-    private static boolean handleOpenComputerCommand(String message) {
-        if (!message.startsWith(CommandComputerCraft.OPEN_COMPUTER)) return false;
-
-        var server = Minecraft.getInstance().getSingleplayerServer();
-        if (server == null) return false;
-
-        var idStr = message.substring(CommandComputerCraft.OPEN_COMPUTER.length()).trim();
-        int id;
-        try {
-            id = Integer.parseInt(idStr);
-        } catch (NumberFormatException ignore) {
-            return false;
-        }
-
-        var file = new File(ServerContext.get(server).storageDir().toFile(), "computer/" + id);
-        if (!file.isDirectory()) return false;
-
-        Util.getPlatform().openFile(file);
-        return true;
-    }
-
     /**
      * Add additional information about the currently targeted block to the debug screen.
      *

projects/common/src/client/java/dan200/computercraft/client/ClientRegistry.java

@@ -4,8 +4,12 @@
 
 package dan200.computercraft.client;
 
+import com.mojang.brigadier.CommandDispatcher;
+import com.mojang.brigadier.arguments.IntegerArgumentType;
+import com.mojang.brigadier.builder.LiteralArgumentBuilder;
+import com.mojang.brigadier.builder.RequiredArgumentBuilder;
 import dan200.computercraft.api.ComputerCraftAPI;
-import dan200.computercraft.api.client.ComputerCraftAPIClient;
+import dan200.computercraft.api.client.turtle.RegisterTurtleUpgradeModeller;
 import dan200.computercraft.api.client.turtle.TurtleUpgradeModeller;
 import dan200.computercraft.client.gui.*;
 import dan200.computercraft.client.pocket.ClientPocketComputers;
@@ -16,11 +20,14 @@ import dan200.computercraft.client.turtle.TurtleModemModeller;
 import dan200.computercraft.client.turtle.TurtleUpgradeModellers;
 import dan200.computercraft.core.util.Colour;
 import dan200.computercraft.shared.ModRegistry;
+import dan200.computercraft.shared.command.CommandComputerCraft;
 import dan200.computercraft.shared.common.IColouredItem;
+import dan200.computercraft.shared.computer.core.ServerContext;
 import dan200.computercraft.shared.computer.inventory.AbstractComputerMenu;
 import dan200.computercraft.shared.computer.inventory.ViewComputerMenu;
 import dan200.computercraft.shared.media.items.DiskItem;
 import dan200.computercraft.shared.media.items.TreasureDiskItem;
+import net.minecraft.Util;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.color.item.ItemColor;
 import net.minecraft.client.gui.screens.MenuScreens;
@@ -30,6 +37,7 @@ import net.minecraft.client.renderer.blockentity.BlockEntityRendererProvider;
 import net.minecraft.client.renderer.blockentity.BlockEntityRenderers;
 import net.minecraft.client.renderer.item.ClampedItemPropertyFunction;
 import net.minecraft.client.renderer.item.ItemProperties;
+import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.packs.resources.PreparableReloadListener;
 import net.minecraft.server.packs.resources.ResourceProvider;
@@ -39,6 +47,7 @@ import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.ItemLike;
 
 import javax.annotation.Nullable;
+import java.io.File;
 import java.io.IOException;
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;
@@ -60,18 +69,6 @@ public final class ClientRegistry {
      * Register any client-side objects which don't have to be done on the main thread.
      */
     public static void register() {
-        ComputerCraftAPIClient.registerTurtleUpgradeModeller(ModRegistry.TurtleSerialisers.SPEAKER.get(), TurtleUpgradeModeller.sided(
-            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_speaker_left"),
-            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_speaker_right")
-        ));
-        ComputerCraftAPIClient.registerTurtleUpgradeModeller(ModRegistry.TurtleSerialisers.WORKBENCH.get(), TurtleUpgradeModeller.sided(
-            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_crafting_table_left"),
-            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_crafting_table_right")
-        ));
-        ComputerCraftAPIClient.registerTurtleUpgradeModeller(ModRegistry.TurtleSerialisers.WIRELESS_MODEM_NORMAL.get(), new TurtleModemModeller(false));
-        ComputerCraftAPIClient.registerTurtleUpgradeModeller(ModRegistry.TurtleSerialisers.WIRELESS_MODEM_ADVANCED.get(), new TurtleModemModeller(true));
-        ComputerCraftAPIClient.registerTurtleUpgradeModeller(ModRegistry.TurtleSerialisers.TOOL.get(), TurtleUpgradeModeller.flatItem());
-
         BlockEntityRenderers.register(ModRegistry.BlockEntities.MONITOR_NORMAL.get(), MonitorBlockEntityRenderer::new);
         BlockEntityRenderers.register(ModRegistry.BlockEntities.MONITOR_ADVANCED.get(), MonitorBlockEntityRenderer::new);
         BlockEntityRenderers.register(ModRegistry.BlockEntities.TURTLE_NORMAL.get(), TurtleBlockEntityRenderer::new);
@@ -103,6 +100,20 @@ public final class ClientRegistry {
         );
     }
 
+    public static void registerTurtleModellers(RegisterTurtleUpgradeModeller register) {
+        register.register(ModRegistry.TurtleSerialisers.SPEAKER.get(), TurtleUpgradeModeller.sided(
+            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_speaker_left"),
+            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_speaker_right")
+        ));
+        register.register(ModRegistry.TurtleSerialisers.WORKBENCH.get(), TurtleUpgradeModeller.sided(
+            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_crafting_table_left"),
+            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_crafting_table_right")
+        ));
+        register.register(ModRegistry.TurtleSerialisers.WIRELESS_MODEM_NORMAL.get(), new TurtleModemModeller(false));
+        register.register(ModRegistry.TurtleSerialisers.WIRELESS_MODEM_ADVANCED.get(), new TurtleModemModeller(true));
+        register.register(ModRegistry.TurtleSerialisers.TOOL.get(), TurtleUpgradeModeller.flatItem());
+    }
+
     @SafeVarargs
     private static void registerItemProperty(String name, ClampedItemPropertyFunction getter, Supplier<? extends Item>... items) {
         var id = new ResourceLocation(ComputerCraftAPI.MOD_ID, name);
@@ -179,4 +190,45 @@ public final class ClientRegistry {
             return function.unclampedCall(stack, level, entity, layer);
         }
     }
+
+    /**
+     * Register client-side commands.
+     *
+     * @param dispatcher The dispatcher to register the commands to.
+     * @param sendError  A function to send an error message.
+     * @param <T>        The type of the client-side command context.
+     */
+    public static <T> void registerClientCommands(CommandDispatcher<T> dispatcher, BiConsumer<T, Component> sendError) {
+        dispatcher.register(LiteralArgumentBuilder.<T>literal(CommandComputerCraft.CLIENT_OPEN_FOLDER)
+            .requires(x -> Minecraft.getInstance().getSingleplayerServer() != null)
+            .then(RequiredArgumentBuilder.<T, Integer>argument("computer_id", IntegerArgumentType.integer(0))
+                .executes(c -> handleOpenComputerCommand(c.getSource(), sendError, c.getArgument("computer_id", Integer.class)))
+            ));
+    }
+
+    /**
+     * Handle the {@link CommandComputerCraft#CLIENT_OPEN_FOLDER} command.
+     *
+     * @param context   The command context.
+     * @param sendError A function to send an error message.
+     * @param id        The computer's id.
+     * @param <T>       The type of the client-side command context.
+     * @return {@code 1} if a folder was opened, {@code 0} otherwise.
+     */
+    private static <T> int handleOpenComputerCommand(T context, BiConsumer<T, Component> sendError, int id) {
+        var server = Minecraft.getInstance().getSingleplayerServer();
+        if (server == null) {
+            sendError.accept(context, Component.literal("Not on a single-player server"));
+            return 0;
+        }
+
+        var file = new File(ServerContext.get(server).storageDir().toFile(), "computer/" + id);
+        if (!file.isDirectory()) {
+            sendError.accept(context, Component.literal("Computer's folder does not exist"));
+            return 0;
+        }
+
+        Util.getPlatform().openFile(file);
+        return 1;
+    }
 }

projects/common/src/client/java/dan200/computercraft/client/gui/AbstractComputerScreen.java

@@ -7,7 +7,7 @@ package dan200.computercraft.client.gui;
 import dan200.computercraft.client.gui.widgets.ComputerSidebar;
 import dan200.computercraft.client.gui.widgets.DynamicImageButton;
 import dan200.computercraft.client.gui.widgets.TerminalWidget;
-import dan200.computercraft.client.platform.ClientPlatformHelper;
+import dan200.computercraft.client.network.ClientNetworking;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.core.InputHandler;
@@ -19,6 +19,7 @@ import dan200.computercraft.shared.network.server.UploadFileMessage;
 import net.minecraft.ChatFormatting;
 import net.minecraft.Util;
 import net.minecraft.client.gui.GuiGraphics;
+import net.minecraft.client.gui.components.events.GuiEventListener;
 import net.minecraft.client.gui.screens.inventory.AbstractContainerScreen;
 import net.minecraft.network.chat.Component;
 import net.minecraft.world.entity.player.Inventory;
@@ -144,6 +145,11 @@ public abstract class AbstractComputerScreen<T extends AbstractComputerMenu> ext
             || super.mouseDragged(x, y, button, deltaX, deltaY);
     }
 
+    @Override
+    public void setFocused(@Nullable GuiEventListener listener) {
+        // Don't clear and re-focus if we're already focused.
+        if (listener != getFocused()) super.setFocused(listener);
+    }
 
     @Override
     protected void renderLabels(GuiGraphics graphics, int mouseX, int mouseY) {
@@ -201,7 +207,7 @@ public abstract class AbstractComputerScreen<T extends AbstractComputerMenu> ext
             return;
         }
 
-        if (toUpload.size() > 0) UploadFileMessage.send(menu, toUpload, ClientPlatformHelper.get()::sendToServer);
+        if (toUpload.size() > 0) UploadFileMessage.send(menu, toUpload, ClientNetworking::sendToServer);
     }
 
     public void uploadResult(UploadResult result, @Nullable Component message) {

projects/common/src/client/java/dan200/computercraft/client/gui/ClientInputHandler.java

@@ -4,7 +4,7 @@
 
 package dan200.computercraft.client.gui;
 
-import dan200.computercraft.client.platform.ClientPlatformHelper;
+import dan200.computercraft.client.network.ClientNetworking;
 import dan200.computercraft.shared.computer.core.InputHandler;
 import dan200.computercraft.shared.computer.menu.ComputerMenu;
 import dan200.computercraft.shared.network.server.ComputerActionServerMessage;
@@ -29,51 +29,51 @@ public final class ClientInputHandler implements InputHandler {
 
     @Override
     public void turnOn() {
-        ClientPlatformHelper.get().sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.TURN_ON));
+        ClientNetworking.sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.TURN_ON));
     }
 
     @Override
     public void shutdown() {
-        ClientPlatformHelper.get().sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.SHUTDOWN));
+        ClientNetworking.sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.SHUTDOWN));
     }
 
     @Override
     public void reboot() {
-        ClientPlatformHelper.get().sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.REBOOT));
+        ClientNetworking.sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.REBOOT));
     }
 
     @Override
     public void queueEvent(String event, @Nullable Object[] arguments) {
-        ClientPlatformHelper.get().sendToServer(new QueueEventServerMessage(menu, event, arguments));
+        ClientNetworking.sendToServer(new QueueEventServerMessage(menu, event, arguments));
     }
 
     @Override
     public void keyDown(int key, boolean repeat) {
-        ClientPlatformHelper.get().sendToServer(new KeyEventServerMessage(menu, repeat ? KeyEventServerMessage.TYPE_REPEAT : KeyEventServerMessage.TYPE_DOWN, key));
+        ClientNetworking.sendToServer(new KeyEventServerMessage(menu, repeat ? KeyEventServerMessage.TYPE_REPEAT : KeyEventServerMessage.TYPE_DOWN, key));
     }
 
     @Override
     public void keyUp(int key) {
-        ClientPlatformHelper.get().sendToServer(new KeyEventServerMessage(menu, KeyEventServerMessage.TYPE_UP, key));
+        ClientNetworking.sendToServer(new KeyEventServerMessage(menu, KeyEventServerMessage.TYPE_UP, key));
     }
 
     @Override
     public void mouseClick(int button, int x, int y) {
-        ClientPlatformHelper.get().sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_CLICK, button, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_CLICK, button, x, y));
     }
 
     @Override
     public void mouseUp(int button, int x, int y) {
-        ClientPlatformHelper.get().sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_UP, button, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_UP, button, x, y));
     }
 
     @Override
     public void mouseDrag(int button, int x, int y) {
-        ClientPlatformHelper.get().sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_DRAG, button, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_DRAG, button, x, y));
     }
 
     @Override
     public void mouseScroll(int direction, int x, int y) {
-        ClientPlatformHelper.get().sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_SCROLL, direction, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_SCROLL, direction, x, y));
     }
 }

projects/common/src/client/java/dan200/computercraft/client/gui/widgets/TerminalWidget.java

@@ -246,7 +246,7 @@ public class TerminalWidget extends AbstractWidget {
             keysDown.clear();
 
             // When blurring, we should make the last mouse button go up
-            if (lastMouseButton > 0) {
+            if (lastMouseButton >= 0) {
                 computer.mouseUp(lastMouseButton + 1, lastMouseX + 1, lastMouseY + 1);
                 lastMouseButton = -1;
             }

projects/common/src/client/java/dan200/computercraft/client/network/ClientNetworking.java

@@ -0,0 +1,28 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.client.network;
+
+import dan200.computercraft.client.platform.ClientPlatformHelper;
+import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.server.ServerNetworkContext;
+import net.minecraft.client.Minecraft;
+
+/**
+ * Methods for sending packets from clients to the server.
+ */
+public final class ClientNetworking {
+    private ClientNetworking() {
+    }
+
+    /**
+     * Send a network message to the server.
+     *
+     * @param message The message to send.
+     */
+    public static void sendToServer(NetworkMessage<ServerNetworkContext> message) {
+        var connection = Minecraft.getInstance().getConnection();
+        if (connection != null) connection.send(ClientPlatformHelper.get().createPacket(message));
+    }
+}

projects/common/src/client/java/dan200/computercraft/client/platform/ClientNetworkContextImpl.java

@@ -4,6 +4,7 @@
 
 package dan200.computercraft.client.platform;
 
+import com.google.auto.service.AutoService;
 import dan200.computercraft.client.ClientTableFormatter;
 import dan200.computercraft.client.gui.AbstractComputerScreen;
 import dan200.computercraft.client.gui.OptionScreen;
@@ -17,30 +18,30 @@ import dan200.computercraft.shared.computer.upload.UploadResult;
 import dan200.computercraft.shared.network.client.ClientNetworkContext;
 import dan200.computercraft.shared.peripheral.monitor.MonitorBlockEntity;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
-import io.netty.buffer.ByteBuf;
 import net.minecraft.client.Minecraft;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.sounds.SoundEvent;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.level.Level;
 
 import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
 import java.util.UUID;
 
 /**
- * The base implementation of {@link ClientNetworkContext}.
- * <p>
- * This should be extended by mod loader specific modules with the remaining abstract methods.
+ * The client-side implementation of {@link ClientNetworkContext}.
  */
-public abstract class AbstractClientNetworkContext implements ClientNetworkContext {
+@AutoService(ClientNetworkContext.class)
+public final class ClientNetworkContextImpl implements ClientNetworkContext {
     @Override
-    public final void handleChatTable(TableBuilder table) {
+    public void handleChatTable(TableBuilder table) {
         ClientTableFormatter.INSTANCE.display(table);
     }
 
     @Override
-    public final void handleComputerTerminal(int containerId, TerminalState terminal) {
+    public void handleComputerTerminal(int containerId, TerminalState terminal) {
         Player player = Minecraft.getInstance().player;
         if (player != null && player.containerMenu.containerId == containerId && player.containerMenu instanceof ComputerMenu menu) {
             menu.updateTerminal(terminal);
@@ -48,7 +49,7 @@ public abstract class AbstractClientNetworkContext implements ClientNetworkConte
     }
 
     @Override
-    public final void handleMonitorData(BlockPos pos, TerminalState terminal) {
+    public void handleMonitorData(BlockPos pos, TerminalState terminal) {
         var player = Minecraft.getInstance().player;
         if (player == null) return;
 
@@ -59,44 +60,46 @@ public abstract class AbstractClientNetworkContext implements ClientNetworkConte
     }
 
     @Override
-    public final void handlePocketComputerData(int instanceId, ComputerState state, int lightState, TerminalState terminal) {
+    public void handlePlayRecord(BlockPos pos, @Nullable SoundEvent sound, @Nullable String name) {
+        var mc = Minecraft.getInstance();
+        ClientPlatformHelper.get().playStreamingMusic(pos, sound);
+        if (name != null) mc.gui.setNowPlaying(Component.literal(name));
+    }
+
+    @Override
+    public void handlePocketComputerData(int instanceId, ComputerState state, int lightState, TerminalState terminal) {
         var computer = ClientPocketComputers.get(instanceId, terminal.colour);
         computer.setState(state, lightState);
         if (terminal.hasTerminal()) computer.setTerminal(terminal);
     }
 
     @Override
-    public final void handlePocketComputerDeleted(int instanceId) {
+    public void handlePocketComputerDeleted(int instanceId) {
         ClientPocketComputers.remove(instanceId);
     }
 
     @Override
-    public final void handleSpeakerAudio(UUID source, SpeakerPosition.Message position, float volume) {
-        SpeakerManager.getSound(source).playAudio(reifyPosition(position), volume);
+    public void handleSpeakerAudio(UUID source, SpeakerPosition.Message position, float volume, ByteBuffer buffer) {
+        SpeakerManager.getSound(source).playAudio(reifyPosition(position), volume, buffer);
     }
 
     @Override
-    public final void handleSpeakerAudioPush(UUID source, ByteBuf buffer) {
-        SpeakerManager.getSound(source).pushAudio(buffer);
-    }
-
-    @Override
-    public final void handleSpeakerMove(UUID source, SpeakerPosition.Message position) {
+    public void handleSpeakerMove(UUID source, SpeakerPosition.Message position) {
         SpeakerManager.moveSound(source, reifyPosition(position));
     }
 
     @Override
-    public final void handleSpeakerPlay(UUID source, SpeakerPosition.Message position, ResourceLocation sound, float volume, float pitch) {
+    public void handleSpeakerPlay(UUID source, SpeakerPosition.Message position, ResourceLocation sound, float volume, float pitch) {
         SpeakerManager.getSound(source).playSound(reifyPosition(position), sound, volume, pitch);
     }
 
     @Override
-    public final void handleSpeakerStop(UUID source) {
+    public void handleSpeakerStop(UUID source) {
         SpeakerManager.stopSound(source);
     }
 
     @Override
-    public final void handleUploadResult(int containerId, UploadResult result, @Nullable Component errorMessage) {
+    public void handleUploadResult(int containerId, UploadResult result, @Nullable Component errorMessage) {
         var minecraft = Minecraft.getInstance();
 
         var screen = OptionScreen.unwrap(minecraft.screen);

projects/common/src/client/java/dan200/computercraft/client/platform/ClientPlatformHelper.java

@@ -9,6 +9,10 @@ import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.server.ServerNetworkContext;
 import net.minecraft.client.renderer.MultiBufferSource;
 import net.minecraft.client.resources.model.BakedModel;
+import net.minecraft.core.BlockPos;
+import net.minecraft.network.protocol.Packet;
+import net.minecraft.network.protocol.game.ServerGamePacketListener;
+import net.minecraft.sounds.SoundEvent;
 
 import javax.annotation.Nullable;
 
@@ -18,11 +22,12 @@ public interface ClientPlatformHelper extends dan200.computercraft.impl.client.C
     }
 
     /**
-     * Send a network message to the server.
+     * Convert a serverbound {@link NetworkMessage} to a Minecraft {@link Packet}.
      *
-     * @param message The message to send.
+     * @param message The messsge to convert.
+     * @return The converted message.
      */
-    void sendToServer(NetworkMessage<ServerNetworkContext> message);
+    Packet<ServerGamePacketListener> createPacket(NetworkMessage<ServerNetworkContext> message);
 
     /**
      * Render a {@link BakedModel}, using any loader-specific hooks.
@@ -35,4 +40,13 @@ public interface ClientPlatformHelper extends dan200.computercraft.impl.client.C
      * @param tints         Block colour tints to apply to the model.
      */
     void renderBakedModel(PoseStack transform, MultiBufferSource buffers, BakedModel model, int lightmapCoord, int overlayLight, @Nullable int[] tints);
+
+    /**
+     * Play a record at a particular position.
+     *
+     * @param pos   The position to play this record.
+     * @param sound The record to play, or {@code null} to stop it.
+     * @see net.minecraft.client.renderer.LevelRenderer#playStreamingMusic(SoundEvent, BlockPos)
+     */
+    void playStreamingMusic(BlockPos pos, @Nullable SoundEvent sound);
 }

projects/common/src/client/java/dan200/computercraft/client/render/TurtleBlockEntityRenderer.java

@@ -11,7 +11,6 @@ import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.turtle.TurtleSide;
 import dan200.computercraft.client.platform.ClientPlatformHelper;
 import dan200.computercraft.client.turtle.TurtleUpgradeModellers;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.turtle.blocks.TurtleBlockEntity;
 import dan200.computercraft.shared.util.Holiday;
 import net.minecraft.client.Minecraft;
@@ -21,7 +20,6 @@ import net.minecraft.client.renderer.blockentity.BlockEntityRenderDispatcher;
 import net.minecraft.client.renderer.blockentity.BlockEntityRenderer;
 import net.minecraft.client.renderer.blockentity.BlockEntityRendererProvider;
 import net.minecraft.client.resources.model.BakedModel;
-import net.minecraft.client.resources.model.ModelResourceLocation;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.phys.BlockHitResult;
 import net.minecraft.world.phys.HitResult;
@@ -29,8 +27,6 @@ import net.minecraft.world.phys.HitResult;
 import javax.annotation.Nullable;
 
 public class TurtleBlockEntityRenderer implements BlockEntityRenderer<TurtleBlockEntity> {
-    private static final ModelResourceLocation NORMAL_TURTLE_MODEL = new ModelResourceLocation(ComputerCraftAPI.MOD_ID, "turtle_normal", "inventory");
-    private static final ModelResourceLocation ADVANCED_TURTLE_MODEL = new ModelResourceLocation(ComputerCraftAPI.MOD_ID, "turtle_advanced", "inventory");
     private static final ResourceLocation COLOUR_TURTLE_MODEL = new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_colour");
     private static final ResourceLocation ELF_OVERLAY_MODEL = new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_elf_overlay");
 
@@ -42,13 +38,6 @@ public class TurtleBlockEntityRenderer implements BlockEntityRenderer<TurtleBloc
         font = context.getFont();
     }
 
-    public static ResourceLocation getTurtleModel(ComputerFamily family, boolean coloured) {
-        return switch (family) {
-            default -> coloured ? COLOUR_TURTLE_MODEL : NORMAL_TURTLE_MODEL;
-            case ADVANCED -> coloured ? COLOUR_TURTLE_MODEL : ADVANCED_TURTLE_MODEL;
-        };
-    }
-
     public static @Nullable ResourceLocation getTurtleOverlayModel(@Nullable ResourceLocation overlay, boolean christmas) {
         if (overlay != null) return overlay;
         if (christmas) return ELF_OVERLAY_MODEL;
@@ -78,7 +67,6 @@ public class TurtleBlockEntityRenderer implements BlockEntityRenderer<TurtleBloc
             var matrix = transform.last().pose();
             var opacity = (int) (mc.options.getBackgroundOpacity(0.25f) * 255) << 24;
             var width = -font.width(label) / 2.0f;
-            // TODO: Check this looks okay
             font.drawInBatch(label, width, (float) 0, 0x20ffffff, false, matrix, buffers, Font.DisplayMode.SEE_THROUGH, opacity, lightmapCoord);
             font.drawInBatch(label, width, (float) 0, 0xffffffff, false, matrix, buffers, Font.DisplayMode.NORMAL, 0, lightmapCoord);
 
@@ -96,10 +84,18 @@ public class TurtleBlockEntityRenderer implements BlockEntityRenderer<TurtleBloc
 
         // Render the turtle
         var colour = turtle.getColour();
-        var family = turtle.getFamily();
         var overlay = turtle.getOverlay();
 
-        renderModel(transform, buffers, lightmapCoord, overlayLight, getTurtleModel(family, colour != -1), colour == -1 ? null : new int[]{ colour });
+        if (colour == -1) {
+            // Render the turtle using its item model.
+            var modelManager = Minecraft.getInstance().getItemRenderer().getItemModelShaper();
+            var model = modelManager.getItemModel(turtle.getBlockState().getBlock().asItem());
+            if (model == null) model = modelManager.getModelManager().getMissingModel();
+            renderModel(transform, buffers, lightmapCoord, overlayLight, model, null);
+        } else {
+            // Otherwise render it using the colour item.
+            renderModel(transform, buffers, lightmapCoord, overlayLight, COLOUR_TURTLE_MODEL, new int[]{ colour });
+        }
 
         // Render the overlay
         var overlayModel = getTurtleOverlayModel(overlay, Holiday.getCurrent() == Holiday.CHRISTMAS);

projects/common/src/client/java/dan200/computercraft/client/render/monitor/MonitorBlockEntityRenderer.java

@@ -58,9 +58,9 @@ public class MonitorBlockEntityRenderer implements BlockEntityRenderer<MonitorBl
     @Override
     public void render(MonitorBlockEntity monitor, float partialTicks, PoseStack transform, MultiBufferSource bufferSource, int lightmapCoord, int overlayLight) {
         // Render from the origin monitor
-        var originTerminal = monitor.getClientMonitor();
-
+        var originTerminal = monitor.getOriginClientMonitor();
         if (originTerminal == null) return;
+
         var origin = originTerminal.getOrigin();
         var renderState = originTerminal.getRenderState(MonitorRenderState::new);
         var monitorPos = monitor.getBlockPos();

projects/common/src/client/java/dan200/computercraft/client/sound/DfpwmStream.java

@@ -6,7 +6,7 @@ package dan200.computercraft.client.sound;
 
 import com.mojang.blaze3d.audio.Channel;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPeripheral;
-import io.netty.buffer.ByteBuf;
+import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
 import net.minecraft.client.sounds.AudioStream;
 import net.minecraft.client.sounds.SoundEngine;
 import org.lwjgl.BufferUtils;
@@ -36,7 +36,7 @@ class DfpwmStream implements AudioStream {
     /**
      * The {@link Channel} which this sound is playing on.
      *
-     * @see SpeakerInstance#pushAudio(ByteBuf)
+     * @see SpeakerInstance#playAudio(SpeakerPosition, float, ByteBuffer)
      */
     @Nullable
     Channel channel;
@@ -44,7 +44,7 @@ class DfpwmStream implements AudioStream {
     /**
      * The underlying {@link SoundEngine} executor.
      *
-     * @see SpeakerInstance#pushAudio(ByteBuf)
+     * @see SpeakerInstance#playAudio(SpeakerPosition, float, ByteBuffer)
      * @see SoundEngine#executor
      */
     @Nullable
@@ -58,12 +58,12 @@ class DfpwmStream implements AudioStream {
     DfpwmStream() {
     }
 
-    void push(ByteBuf input) {
-        var readable = input.readableBytes();
+    void push(ByteBuffer input) {
+        var readable = input.remaining();
         var output = ByteBuffer.allocate(readable * 8).order(ByteOrder.nativeOrder());
 
         for (var i = 0; i < readable; i++) {
-            var inputByte = input.readByte();
+            var inputByte = input.get();
             for (var j = 0; j < 8; j++) {
                 var currentBit = (inputByte & 1) != 0;
                 var target = currentBit ? 127 : -128;

projects/common/src/client/java/dan200/computercraft/client/sound/SpeakerInstance.java

@@ -7,11 +7,11 @@ package dan200.computercraft.client.sound;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.core.util.Nullability;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
-import io.netty.buffer.ByteBuf;
 import net.minecraft.client.Minecraft;
 import net.minecraft.resources.ResourceLocation;
 
 import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
 
 /**
  * An instance of a speaker, which is either playing a {@link DfpwmStream} stream or a normal sound.
@@ -25,7 +25,7 @@ public class SpeakerInstance {
     SpeakerInstance() {
     }
 
-    public synchronized void pushAudio(ByteBuf buffer) {
+    private void pushAudio(ByteBuffer buffer) {
         var sound = this.sound;
 
         var stream = currentStream;
@@ -43,7 +43,9 @@ public class SpeakerInstance {
         }
     }
 
-    public void playAudio(SpeakerPosition position, float volume) {
+    public void playAudio(SpeakerPosition position, float volume, ByteBuffer buffer) {
+        pushAudio(buffer);
+
         var soundManager = Minecraft.getInstance().getSoundManager();
 
         if (sound != null && sound.stream != currentStream) {

projects/common/src/client/java/dan200/computercraft/client/turtle/TurtleUpgradeModellers.java

@@ -11,11 +11,14 @@ import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
 import dan200.computercraft.api.turtle.TurtleUpgradeSerialiser;
+import dan200.computercraft.impl.PlatformHelper;
 import dan200.computercraft.impl.TurtleUpgrades;
 import dan200.computercraft.impl.UpgradeManager;
 import net.minecraft.client.Minecraft;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.resources.ResourceLocation;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.Map;
 import java.util.WeakHashMap;
@@ -24,14 +27,15 @@ import java.util.stream.Stream;
 
 /**
  * A registry of {@link TurtleUpgradeModeller}s.
- *
- * @see dan200.computercraft.api.client.ComputerCraftAPIClient#registerTurtleUpgradeModeller(TurtleUpgradeSerialiser, TurtleUpgradeModeller)
  */
 public final class TurtleUpgradeModellers {
+    private static final Logger LOG = LoggerFactory.getLogger(TurtleUpgradeModellers.class);
+
     private static final TurtleUpgradeModeller<ITurtleUpgrade> NULL_TURTLE_MODELLER = (upgrade, turtle, side) ->
         new TransformedModel(Minecraft.getInstance().getModelManager().getMissingModel(), Transformation.identity());
 
     private static final Map<TurtleUpgradeSerialiser<?>, TurtleUpgradeModeller<?>> turtleModels = new ConcurrentHashMap<>();
+    private static volatile boolean fetchedModels;
 
     /**
      * In order to avoid a double lookup of {@link ITurtleUpgrade} to {@link UpgradeManager.UpgradeWrapper} to
@@ -45,12 +49,18 @@ public final class TurtleUpgradeModellers {
     }
 
     public static <T extends ITurtleUpgrade> void register(TurtleUpgradeSerialiser<T> serialiser, TurtleUpgradeModeller<T> modeller) {
-        synchronized (turtleModels) {
-            if (turtleModels.containsKey(serialiser)) {
-                throw new IllegalStateException("Modeller already registered for serialiser");
-            }
+        if (fetchedModels) {
+            // TODO(1.20.4): Replace with an error.
+            LOG.warn(
+                "Turtle upgrade serialiser {} was registered too late, its models may not be loaded correctly. If you are " +
+                    "the mod author, you may be using a deprecated API - see https://github.com/cc-tweaked/CC-Tweaked/pull/1684 " +
+                    "for further information.",
+                PlatformHelper.get().getRegistryKey(TurtleUpgradeSerialiser.registryId(), serialiser)
+            );
+        }
 
-            turtleModels.put(serialiser, modeller);
+        if (turtleModels.putIfAbsent(serialiser, modeller) != null) {
+            throw new IllegalStateException("Modeller already registered for serialiser");
         }
     }
 
@@ -75,6 +85,7 @@ public final class TurtleUpgradeModellers {
     }
 
     public static Stream<ResourceLocation> getDependencies() {
+        fetchedModels = true;
         return turtleModels.values().stream().flatMap(x -> x.getDependencies().stream());
     }
 }

projects/common/src/client/resources/computercraft-client.mixins.json

@@ -1,13 +0,0 @@
-{
-    "required": true,
-    "package": "dan200.computercraft.mixin.client",
-    "minVersion": "0.8",
-    "compatibilityLevel": "JAVA_17",
-    "injectors": {
-        "defaultRequire": 1
-    },
-    "client": [
-        "ClientPacketListenerMixin"
-    ],
-    "refmap": "client-computercraft.refmap.json"
-}

projects/common/src/main/java/dan200/computercraft/data/PrettyDataProvider.java

@@ -0,0 +1,48 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.data;
+
+import com.google.common.hash.HashCode;
+import com.google.common.hash.HashFunction;
+import com.google.common.hash.Hashing;
+import net.minecraft.data.CachedOutput;
+import net.minecraft.data.DataProvider;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * Wraps an existing {@link DataProvider}, passing generated JSON through {@link PrettyJsonWriter}.
+ *
+ * @param provider The provider to wrap.
+ * @param <T>      The type of the provider to wrap.
+ */
+public record PrettyDataProvider<T extends DataProvider>(T provider) implements DataProvider {
+    @Override
+    public CompletableFuture<?> run(CachedOutput cachedOutput) {
+        return provider.run(new Output(cachedOutput));
+    }
+
+    @Override
+    public String getName() {
+        return provider.getName();
+    }
+
+    private record Output(CachedOutput output) implements CachedOutput {
+        @SuppressWarnings("deprecation")
+        private static final HashFunction HASH_FUNCTION = Hashing.sha1();
+
+        @Override
+        public void writeIfNeeded(Path path, byte[] bytes, HashCode hashCode) throws IOException {
+            if (path.getFileName().toString().endsWith(".json")) {
+                bytes = PrettyJsonWriter.reformat(bytes);
+                hashCode = HASH_FUNCTION.hashBytes(bytes);
+            }
+
+            output.writeIfNeeded(path, bytes, hashCode);
+        }
+    }
+}

projects/common/src/main/java/dan200/computercraft/data/PrettyJsonWriter.java

@@ -22,11 +22,10 @@ import java.util.List;
 
 /**
  * Alternative version of {@link JsonWriter} which attempts to lay out the JSON in a more compact format.
- * <p>
- * Yes, this is at least a little deranged.
+ *
+ * @see PrettyDataProvider
  */
 public class PrettyJsonWriter extends JsonWriter {
-    public static final boolean ENABLED = System.getProperty("cct.pretty-json") != null;
     private static final Gson GSON = new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create();
 
     private static final int MAX_WIDTH = 120;
@@ -44,17 +43,6 @@ public class PrettyJsonWriter extends JsonWriter {
         this.out = out;
     }
 
-    /**
-     * Create a JSON writer. This will either be a pretty or normal version, depending on whether the global flag is
-     * set.
-     *
-     * @param out The writer to emit to.
-     * @return The constructed JSON writer.
-     */
-    public static JsonWriter createWriter(Writer out) {
-        return ENABLED ? new PrettyJsonWriter(out) : new JsonWriter(out);
-    }
-
     /**
      * Reformat a JSON string with our pretty printer.
      *
@@ -62,8 +50,6 @@ public class PrettyJsonWriter extends JsonWriter {
      * @return The reformatted string.
      */
     public static byte[] reformat(byte[] contents) {
-        if (!ENABLED) return contents;
-
         JsonElement object;
         try (var reader = new InputStreamReader(new ByteArrayInputStream(contents), StandardCharsets.UTF_8)) {
             object = GSON.fromJson(reader, JsonElement.class);

projects/common/src/main/java/dan200/computercraft/data/RecipeProvider.java

@@ -13,7 +13,6 @@ import dan200.computercraft.api.upgrades.UpgradeData;
 import dan200.computercraft.core.util.Colour;
 import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.common.IColouredItem;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.platform.PlatformHelper;
 import dan200.computercraft.shared.platform.RecipeIngredients;
 import dan200.computercraft.shared.platform.RegistryWrappers;
@@ -38,7 +37,6 @@ import net.minecraft.world.level.ItemLike;
 import net.minecraft.world.level.block.Blocks;
 
 import java.util.List;
-import java.util.Locale;
 import java.util.UUID;
 import java.util.function.Consumer;
 
@@ -106,14 +104,13 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
     private void turtleUpgrades(Consumer<FinishedRecipe> add) {
         for (var turtleItem : turtleItems()) {
             var base = turtleItem.create(-1, null, -1, null, null, 0, null);
-
-            var nameId = turtleItem.getFamily().name().toLowerCase(Locale.ROOT);
+            var name = RegistryWrappers.ITEMS.getKey(turtleItem);
 
             for (var upgrade : turtleUpgrades.getGeneratedUpgrades()) {
                 var result = turtleItem.create(-1, null, -1, null, UpgradeData.ofDefault(upgrade), -1, null);
                 ShapedRecipeBuilder
                     .shaped(RecipeCategory.REDSTONE, result.getItem())
-                    .group(String.format("%s:turtle_%s", ComputerCraftAPI.MOD_ID, nameId))
+                    .group(name.toString())
                     .pattern("#T")
                     .define('T', base.getItem())
                     .define('#', upgrade.getCraftingItem().getItem())
@@ -121,9 +118,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
                         inventoryChange(base.getItem(), upgrade.getCraftingItem().getItem()))
                     .save(
                         RecipeWrapper.wrap(ModRegistry.RecipeSerializers.IMPOSTOR_SHAPED.get(), add).withResultTag(result.getTag()),
-                        new ResourceLocation(ComputerCraftAPI.MOD_ID, String.format("turtle_%s/%s/%s",
-                            nameId, upgrade.getUpgradeID().getNamespace(), upgrade.getUpgradeID().getPath()
-                        ))
+                        name.withSuffix(String.format("/%s/%s", upgrade.getUpgradeID().getNamespace(), upgrade.getUpgradeID().getPath()))
                     );
             }
         }
@@ -141,15 +136,13 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
     private void pocketUpgrades(Consumer<FinishedRecipe> add) {
         for (var pocket : pocketComputerItems()) {
             var base = pocket.create(-1, null, -1, null);
-            if (base.isEmpty()) continue;
-
-            var nameId = pocket.getFamily().name().toLowerCase(Locale.ROOT);
+            var name = RegistryWrappers.ITEMS.getKey(pocket).withPath(x -> x.replace("pocket_computer_", "pocket_"));
 
             for (var upgrade : pocketUpgrades.getGeneratedUpgrades()) {
                 var result = pocket.create(-1, null, -1, UpgradeData.ofDefault(upgrade));
                 ShapedRecipeBuilder
                     .shaped(RecipeCategory.REDSTONE, result.getItem())
-                    .group(String.format("%s:pocket_%s", ComputerCraftAPI.MOD_ID, nameId))
+                    .group(name.toString())
                     .pattern("#")
                     .pattern("P")
                     .define('P', base.getItem())
@@ -158,9 +151,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
                         inventoryChange(base.getItem(), upgrade.getCraftingItem().getItem()))
                     .save(
                         RecipeWrapper.wrap(ModRegistry.RecipeSerializers.IMPOSTOR_SHAPED.get(), add).withResultTag(result.getTag()),
-                        new ResourceLocation(ComputerCraftAPI.MOD_ID, String.format("pocket_%s/%s/%s",
-                            nameId, upgrade.getUpgradeID().getNamespace(), upgrade.getUpgradeID().getPath()
-                        ))
+                        name.withSuffix(String.format("/%s/%s", upgrade.getUpgradeID().getNamespace(), upgrade.getUpgradeID().getPath()))
                     );
             }
         }
@@ -190,12 +181,10 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
     private void turtleOverlay(Consumer<FinishedRecipe> add, String overlay, Consumer<ShapelessRecipeBuilder> build) {
         for (var turtleItem : turtleItems()) {
             var base = turtleItem.create(-1, null, -1, null, null, 0, null);
-
-            var nameId = turtleItem.getFamily().name().toLowerCase(Locale.ROOT);
-            var group = "%s:turtle_%s_overlay".formatted(ComputerCraftAPI.MOD_ID, nameId);
+            var name = RegistryWrappers.ITEMS.getKey(turtleItem);
 
             var builder = ShapelessRecipeBuilder.shapeless(RecipeCategory.REDSTONE, base.getItem())
-                .group(group)
+                .group(name.withSuffix("_overlay").toString())
                 .unlockedBy("has_turtle", inventoryChange(base.getItem()));
             build.accept(builder);
             builder
@@ -204,7 +193,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
                     RecipeWrapper
                         .wrap(ModRegistry.RecipeSerializers.TURTLE_OVERLAY.get(), add)
                         .withExtraData(x -> x.addProperty("overlay", new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/" + overlay).toString())),
-                    new ResourceLocation(ComputerCraftAPI.MOD_ID, "turtle_%s_overlays/%s".formatted(nameId, overlay))
+                    name.withSuffix("_overlays/" + overlay)
                 );
         }
     }
@@ -253,7 +242,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
             .define('C', ModRegistry.Items.COMPUTER_NORMAL.get())
             .unlockedBy("has_components", inventoryChange(itemPredicate(ModRegistry.Items.COMPUTER_NORMAL.get()), itemPredicate(ingredients.goldIngot())))
             .save(
-                RecipeWrapper.wrap(ModRegistry.RecipeSerializers.COMPUTER_UPGRADE.get(), add).withExtraData(family(ComputerFamily.ADVANCED)),
+                RecipeWrapper.wrap(ModRegistry.RecipeSerializers.COMPUTER_UPGRADE.get(), add),
                 new ResourceLocation(ComputerCraftAPI.MOD_ID, "computer_advanced_upgrade")
             );
 
@@ -277,7 +266,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
             .define('C', ModRegistry.Items.COMPUTER_NORMAL.get())
             .define('I', ingredients.woodenChest())
             .unlockedBy("has_computer", inventoryChange(ModRegistry.Items.COMPUTER_NORMAL.get()))
-            .save(RecipeWrapper.wrap(ModRegistry.RecipeSerializers.TURTLE.get(), add).withExtraData(family(ComputerFamily.NORMAL)));
+            .save(RecipeWrapper.wrap(ModRegistry.RecipeSerializers.TURTLE.get(), add));
 
         ShapedRecipeBuilder
             .shaped(RecipeCategory.REDSTONE, ModRegistry.Blocks.TURTLE_ADVANCED.get())
@@ -288,7 +277,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
             .define('C', ModRegistry.Items.COMPUTER_ADVANCED.get())
             .define('I', ingredients.woodenChest())
             .unlockedBy("has_computer", inventoryChange(ModRegistry.Items.COMPUTER_NORMAL.get()))
-            .save(RecipeWrapper.wrap(ModRegistry.RecipeSerializers.TURTLE.get(), add).withExtraData(family(ComputerFamily.ADVANCED)));
+            .save(RecipeWrapper.wrap(ModRegistry.RecipeSerializers.TURTLE.get(), add));
 
         ShapedRecipeBuilder
             .shaped(RecipeCategory.REDSTONE, ModRegistry.Blocks.TURTLE_ADVANCED.get())
@@ -300,7 +289,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
             .define('B', ingredients.goldBlock())
             .unlockedBy("has_components", inventoryChange(itemPredicate(ModRegistry.Items.TURTLE_NORMAL.get()), itemPredicate(ingredients.goldIngot())))
             .save(
-                RecipeWrapper.wrap(ModRegistry.RecipeSerializers.COMPUTER_UPGRADE.get(), add).withExtraData(family(ComputerFamily.ADVANCED)),
+                RecipeWrapper.wrap(ModRegistry.RecipeSerializers.COMPUTER_UPGRADE.get(), add),
                 new ResourceLocation(ComputerCraftAPI.MOD_ID, "turtle_advanced_upgrade")
             );
 
@@ -367,7 +356,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
             .define('C', ModRegistry.Items.POCKET_COMPUTER_NORMAL.get())
             .unlockedBy("has_components", inventoryChange(itemPredicate(ModRegistry.Items.POCKET_COMPUTER_NORMAL.get()), itemPredicate(ingredients.goldIngot())))
             .save(
-                RecipeWrapper.wrap(ModRegistry.RecipeSerializers.COMPUTER_UPGRADE.get(), add).withExtraData(family(ComputerFamily.ADVANCED)),
+                RecipeWrapper.wrap(ModRegistry.RecipeSerializers.COMPUTER_UPGRADE.get(), add),
                 new ResourceLocation(ComputerCraftAPI.MOD_ID, "pocket_computer_advanced_upgrade")
             );
 
@@ -519,10 +508,6 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
         return tag;
     }
 
-    private static Consumer<JsonObject> family(ComputerFamily family) {
-        return json -> json.addProperty("family", family.getSerializedName());
-    }
-
     private static void addSpecial(Consumer<FinishedRecipe> add, SimpleCraftingRecipeSerializer<?> special) {
         SpecialRecipeBuilder.special(special).save(add, RegistryWrappers.RECIPE_SERIALIZERS.getKey(special).toString());
     }

projects/common/src/main/java/dan200/computercraft/data/TagProvider.java

@@ -58,7 +58,10 @@ class TagProvider {
 
         tags.tag(ComputerCraftTags.Blocks.TURTLE_SWORD_BREAKABLE).addTag(BlockTags.WOOL).add(Blocks.COBWEB);
 
-        tags.tag(ComputerCraftTags.Blocks.TURTLE_CAN_USE).addTag(BlockTags.CAULDRONS).addTag(BlockTags.BEEHIVES);
+        tags.tag(ComputerCraftTags.Blocks.TURTLE_CAN_USE)
+            .addTag(BlockTags.BEEHIVES)
+            .addTag(BlockTags.CAULDRONS)
+            .add(Blocks.COMPOSTER);
 
         // Make all blocks aside from command computer mineable.
         tags.tag(BlockTags.MINEABLE_WITH_PICKAXE).add(
@@ -76,6 +79,8 @@ class TagProvider {
             ModRegistry.Blocks.WIRED_MODEM_FULL.get(),
             ModRegistry.Blocks.CABLE.get()
         );
+
+        tags.tag(BlockTags.WITHER_IMMUNE).add(ModRegistry.Blocks.COMPUTER_COMMAND.get());
     }
 
     public static void itemTags(ItemTagConsumer tags) {

projects/common/src/main/java/dan200/computercraft/impl/UpgradeManager.java

@@ -123,7 +123,7 @@ public class UpgradeManager<R extends UpgradeSerialiser<? extends T>, T extends
         // TODO: Can we track which mod this resource came from and use that instead? It's theoretically possible,
         //  but maybe not ideal for datapacks.
         var modId = id.getNamespace();
-        if (modId.equals("minecraft") || modId.equals("")) modId = ComputerCraftAPI.MOD_ID;
+        if (modId.equals("minecraft") || modId.isEmpty()) modId = ComputerCraftAPI.MOD_ID;
 
         var upgrade = serialiser.fromJson(id, root);
         if (!upgrade.getUpgradeID().equals(id)) {

projects/common/src/main/java/dan200/computercraft/impl/network/wired/InvariantChecker.java

@@ -4,45 +4,66 @@
 
 package dan200.computercraft.impl.network.wired;
 
+import org.jetbrains.annotations.Contract;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.annotation.Nullable;
+
 /**
- * Verifies certain elements of a network are "well formed".
+ * Verifies certain elements of a network are well-formed.
  * <p>
- * This adds substantial overhead to network modification, and so should only be enabled
- * in a development environment.
+ * This adds substantial overhead to network modification, and so is only enabled when assertions are enabled.
  */
-public final class InvariantChecker {
+final class InvariantChecker {
     private static final Logger LOG = LoggerFactory.getLogger(InvariantChecker.class);
-    private static final boolean ENABLED = false;
 
     private InvariantChecker() {
     }
 
-    public static void checkNode(WiredNodeImpl node) {
-        if (!ENABLED) return;
+    static void checkNode(WiredNodeImpl node) {
+        assert checkNodeImpl(node) : "Node invariants failed. See logs.";
+    }
 
-        var network = node.network;
-        if (network == null) {
-            LOG.error("Node's network is null", new Exception());
-            return;
+    private static boolean checkNodeImpl(WiredNodeImpl node) {
+        var okay = true;
+
+        if (node.currentSet != null) {
+            okay = false;
+            LOG.error("{}: currentSet was not cleared.", node);
         }
 
-        if (network.nodes == null || !network.nodes.contains(node)) {
-            LOG.error("Node's network does not contain node", new Exception());
+        var network = makeNullable(node.network);
+        if (network == null) {
+            okay = false;
+            LOG.error("{}: Node's network is null.", node);
+        } else if (makeNullable(network.nodes) == null || !network.nodes.contains(node)) {
+            okay = false;
+            LOG.error("{}: Node's network does not contain node.", node);
         }
 
         for (var neighbour : node.neighbours) {
             if (!neighbour.neighbours.contains(node)) {
-                LOG.error("Neighbour is missing node", new Exception());
+                okay = false;
+                LOG.error("{}: Neighbour {}'s neighbour set does not contain origianl node.", node, neighbour);
             }
         }
+
+        return okay;
     }
 
-    public static void checkNetwork(WiredNetworkImpl network) {
-        if (!ENABLED) return;
+    static void checkNetwork(WiredNetworkImpl network) {
+        assert checkNetworkImpl(network) : "Network invariants failed. See logs.";
+    }
 
-        for (var node : network.nodes) checkNode(node);
+    private static boolean checkNetworkImpl(WiredNetworkImpl network) {
+        var okay = true;
+        for (var node : network.nodes) okay &= checkNodeImpl(node);
+        return okay;
+    }
+
+    @Contract("")
+    private static <T> @Nullable T makeNullable(T object) {
+        return object;
     }
 }

projects/common/src/main/java/dan200/computercraft/impl/network/wired/NodeSet.java

@@ -0,0 +1,100 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.impl.network.wired;
+
+import dan200.computercraft.api.network.wired.WiredNode;
+
+import javax.annotation.Nullable;
+import java.util.Objects;
+
+/**
+ * A disjoint-set/union-find of {@link WiredNodeImpl}s.
+ * <p>
+ * Rather than actually maintaining a list of included nodes, wired nodes store {@linkplain WiredNodeImpl#currentSet the
+ * set they're part of}. This means that we can only have one disjoint-set at once, but that is not a problem in
+ * practice.
+ *
+ * @see WiredNodeImpl#currentSet
+ * @see WiredNetworkImpl#remove(WiredNode)
+ * @see <a href="https://en.wikipedia.org/wiki/Disjoint-set_data_structure">Disjoint-set data structure</a>
+ */
+class NodeSet {
+    private NodeSet parent = this;
+    private int size = 1;
+    private @Nullable WiredNetworkImpl network;
+
+    private boolean isRoot() {
+        return parent == this;
+    }
+
+    /**
+     * Resolve this union, finding the root {@link NodeSet}.
+     *
+     * @return The root union.
+     */
+    NodeSet find() {
+        var self = this;
+        while (!self.isRoot()) self = self.parent = self.parent.parent;
+        return self;
+    }
+
+    /**
+     * Get the size of this node set.
+     *
+     * @return The size of the set.
+     */
+    int size() {
+        return find().size;
+    }
+
+    /**
+     * Add a node to this {@link NodeSet}.
+     *
+     * @param node The node to add to the set.
+     */
+    void addNode(WiredNodeImpl node) {
+        if (!isRoot()) throw new IllegalStateException("Cannot grow a non-root set.");
+        if (node.currentSet != null) throw new IllegalArgumentException("Node is already in a set.");
+
+        node.currentSet = this;
+        size++;
+    }
+
+    /**
+     * Merge two nodes sets together.
+     *
+     * @param left  The first union.
+     * @param right The second union.
+     * @return The union which was subsumed.
+     */
+    public static NodeSet merge(NodeSet left, NodeSet right) {
+        if (!left.isRoot() || !right.isRoot()) throw new IllegalArgumentException("Cannot union a non-root set.");
+        if (left == right) throw new IllegalArgumentException("Cannot merge a node into itself.");
+
+        return left.size >= right.size ? mergeInto(left, right) : mergeInto(right, left);
+    }
+
+    private static NodeSet mergeInto(NodeSet root, NodeSet child) {
+        assert root.size > child.size;
+        child.parent = root;
+        root.size += child.size;
+        return child;
+    }
+
+    void setNetwork(WiredNetworkImpl network) {
+        if (!isRoot()) throw new IllegalStateException("Set is not the root.");
+        if (this.network != null) throw new IllegalStateException("Set already has a network.");
+        this.network = network;
+    }
+
+    /**
+     * Get the associated network.
+     *
+     * @return The associated network.
+     */
+    WiredNetworkImpl network() {
+        return Objects.requireNonNull(find().network);
+    }
+}

projects/common/src/main/java/dan200/computercraft/impl/network/wired/WiredNetworkImpl.java

@@ -8,6 +8,7 @@ import dan200.computercraft.api.network.Packet;
 import dan200.computercraft.api.network.wired.WiredNetwork;
 import dan200.computercraft.api.network.wired.WiredNode;
 import dan200.computercraft.api.peripheral.IPeripheral;
+import dan200.computercraft.core.util.Nullability;
 
 import java.util.*;
 import java.util.concurrent.locks.ReadWriteLock;
@@ -187,10 +188,76 @@ final class WiredNetworkImpl implements WiredNetwork {
                 return true;
             }
 
-            var reachable = reachableNodes(neighbours.iterator().next());
+            assert neighbours.size() >= 2 : "Must have more than one neighbour.";
+
+            /*
+             Otherwise we need to find all sets of connected nodes within the graph, and split them off into their own
+             networks.
+
+             With our current graph representation[^1], this requires a traversal of the graph, taking O(|V| + |E))
+             time, which can get quite expensive for large graphs. We try to avoid this traversal where possible, by
+             optimising for the case where the graph remains fully connected after removing this node, for instance,
+             removing "A" here:
+
+               A---B            B
+               |   |    =>      |
+               C---D        C---D
+
+             We observe that these sorts of loops tend to be local, and so try to identify them as quickly as possible.
+             To do this, we do a standard breadth-first traversal of the graph starting at the neighbours of the
+             removed node, building sets of connected nodes.
+
+             If, at any point, all nodes visited so far are connected to each other, then we know all remaining nodes
+             will also be connected. This allows us to abort our traversal of the graph, and just remove the node (much
+             like we do in the single neighbour case above).
+
+             Otherwise, we then just create a new network for each disjoint set of connected nodes.
+
+             {^1]:
+               There are efficient (near-logarithmic) algorithms for this (e.g. https://arxiv.org/pdf/1609.05867.pdf),
+               but they are significantly more complex to implement.
+            */
+
+            // Create a new set of nodes for each neighbour, and add them to our queue of nodes to visit.
+            List<WiredNodeImpl> queue = new ArrayList<>();
+            Set<NodeSet> nodeSets = new HashSet<>(neighbours.size());
+            for (var neighbour : neighbours) {
+                nodeSets.add(neighbour.currentSet = new NodeSet());
+                queue.add(neighbour);
+            }
+
+            // Perform a breadth-first search of the graph, starting from the neighbours.
+            graphSearch:
+            for (var i = 0; i < queue.size(); i++) {
+                var enqueuedNode = queue.get(i);
+                for (var neighbour : enqueuedNode.neighbours) {
+                    var nodeSet = Nullability.assertNonNull(enqueuedNode.currentSet).find();
+
+                    // The neighbour has no set and so has not been visited yet. Add it to the current set and enqueue
+                    // it to be visited.
+                    if (neighbour.currentSet == null) {
+                        nodeSet.addNode(neighbour);
+                        queue.add(neighbour);
+                        continue;
+                    }
+
+                    // Otherwise, take the union of the two nodes' sets if needed. If we've only got a single node set
+                    // left, then we know the whole graph is network is connected (even if not all nodes have been
+                    // visited) and so can abort early.
+                    var neighbourSet = neighbour.currentSet.find();
+                    if (nodeSet != neighbourSet) {
+                        var removed = nodeSets.remove(NodeSet.merge(nodeSet, neighbourSet));
+                        assert removed : "Merged set should have been ";
+                        if (nodeSets.size() == 1) break graphSearch;
+                    }
+                }
+            }
+
+            // If we have a single subset, then all nodes are reachable - just clear the set and exit.
+            if (nodeSets.size() == 1) {
+                assert nodeSets.iterator().next().size() == queue.size();
+                for (var neighbour : queue) neighbour.currentSet = null;
 
-            // If all nodes are reachable then exit.
-            if (reachable.size() == nodes.size()) {
                 // Broadcast our simple peripheral changes
                 removeSingleNode(wired, wiredNetwork);
                 InvariantChecker.checkNode(wired);
@@ -198,43 +265,46 @@ final class WiredNetworkImpl implements WiredNetwork {
                 return true;
             }
 
-            // A split may cause 2..neighbours.size() separate networks, so we
-            // iterate through our neighbour list, generating child networks.
-            neighbours.removeAll(reachable);
-            var maximals = new ArrayList<WiredNetworkImpl>(neighbours.size() + 1);
-            maximals.add(wiredNetwork);
-            maximals.add(new WiredNetworkImpl(reachable));
+            assert queue.size() == nodes.size() : "Expected queue to contain all nodes.";
 
-            while (!neighbours.isEmpty()) {
-                reachable = reachableNodes(neighbours.iterator().next());
-                neighbours.removeAll(reachable);
-                maximals.add(new WiredNetworkImpl(reachable));
+            // Otherwise we need to create our new networks.
+            var networks = new ArrayList<WiredNetworkImpl>(1 + nodeSets.size());
+            // Add the network we've created for the removed node.
+            networks.add(wiredNetwork);
+            //  And then create a new network for each disjoint subset.
+            for (var set : nodeSets) {
+                var network = new WiredNetworkImpl(new HashSet<>(set.size()));
+                set.setNetwork(network);
+                networks.add(network);
             }
 
-            for (var network : maximals) network.lock.writeLock().lock();
+            for (var network : networks) network.lock.writeLock().lock();
 
             try {
                 // We special case the original node: detaching all peripherals when needed.
                 wired.network = wiredNetwork;
                 wired.peripherals = Map.of();
+                wired.neighbours.clear();
 
-                // Ensure every network is finalised
-                for (var network : maximals) {
-                    for (var child : network.nodes) {
-                        child.network = network;
-                        network.peripherals.putAll(child.peripherals);
-                    }
+                // Add all nodes to their appropriate network.
+                for (var child : queue) {
+                    var network = Nullability.assertNonNull(child.currentSet).network();
+                    child.currentSet = null;
+
+                    child.network = network;
+                    network.nodes.add(child);
+                    network.peripherals.putAll(child.peripherals);
                 }
 
-                for (var network : maximals) InvariantChecker.checkNetwork(network);
+                for (var network : networks) InvariantChecker.checkNetwork(network);
                 InvariantChecker.checkNode(wired);
 
                 // Then broadcast network changes once all nodes are finalised
-                for (var network : maximals) {
+                for (var network : networks) {
                     WiredNetworkChangeImpl.changeOf(peripherals, network.peripherals).broadcast(network.nodes);
                 }
             } finally {
-                for (var network : maximals) network.lock.writeLock().unlock();
+                for (var network : networks) network.lock.writeLock().unlock();
             }
 
             nodes.clear();
@@ -373,22 +443,4 @@ final class WiredNetworkImpl implements WiredNetwork {
             throw new IllegalArgumentException("Unknown implementation of IWiredNode: " + node);
         }
     }
-
-    private static Set<WiredNodeImpl> reachableNodes(WiredNodeImpl start) {
-        Queue<WiredNodeImpl> enqueued = new ArrayDeque<>();
-        var reachable = new HashSet<WiredNodeImpl>();
-
-        reachable.add(start);
-        enqueued.add(start);
-
-        WiredNodeImpl node;
-        while ((node = enqueued.poll()) != null) {
-            for (var neighbour : node.neighbours) {
-                // Otherwise attempt to enqueue this neighbour as well.
-                if (reachable.add(neighbour)) enqueued.add(neighbour);
-            }
-        }
-
-        return reachable;
-    }
 }

projects/common/src/main/java/dan200/computercraft/impl/network/wired/WiredNodeImpl.java

@@ -27,11 +27,39 @@ public final class WiredNodeImpl implements WiredNode {
     final HashSet<WiredNodeImpl> neighbours = new HashSet<>();
     volatile WiredNetworkImpl network;
 
+    /**
+     * A temporary field used when checking network connectivity.
+     *
+     * @see WiredNetworkImpl#remove(WiredNode)
+     */
+    @Nullable
+    NodeSet currentSet;
+
     public WiredNodeImpl(WiredElement element) {
         this.element = element;
         network = new WiredNetworkImpl(this);
     }
 
+    @Override
+    public boolean connectTo(WiredNode node) {
+        return network.connect(this, node);
+    }
+
+    @Override
+    public boolean disconnectFrom(WiredNode node) {
+        return network == ((WiredNodeImpl) node).network && network.disconnect(this, node);
+    }
+
+    @Override
+    public boolean remove() {
+        return network.remove(this);
+    }
+
+    @Override
+    public void updatePeripherals(Map<String, IPeripheral> peripherals) {
+        network.updatePeripherals(this, peripherals);
+    }
+
     @Override
     public synchronized void addReceiver(PacketReceiver receiver) {
         if (receivers == null) receivers = new HashSet<>();

projects/common/src/main/java/dan200/computercraft/mixin/CacheUpdaterMixin.java

@@ -1,25 +0,0 @@
-// SPDX-FileCopyrightText: 2022 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.mixin;
-
-import dan200.computercraft.data.PrettyJsonWriter;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.ModifyArg;
-
-@Mixin(targets = "net/minecraft/data/HashCache$CacheUpdater")
-public class CacheUpdaterMixin {
-    @SuppressWarnings("UnusedMethod")
-    @ModifyArg(
-        method = "writeIfNeeded",
-        at = @At(value = "INVOKE", target = "Ljava/nio/file/Files;write(Ljava/nio/file/Path;[B[Ljava/nio/file/OpenOption;)Ljava/nio/file/Path;"),
-        require = 0
-    )
-    private byte[] reformatJson(byte[] contents) {
-        // It would be cleaner to do this inside DataProvider.saveStable, but Forge's version of Mixin doesn't allow us
-        // to inject into interfaces.
-        return PrettyJsonWriter.reformat(contents);
-    }
-}

projects/common/src/main/java/dan200/computercraft/shared/CommonHooks.java

@@ -14,12 +14,16 @@ import dan200.computercraft.shared.computer.metrics.ComputerMBean;
 import dan200.computercraft.shared.peripheral.monitor.MonitorWatcher;
 import dan200.computercraft.shared.util.DropConsumer;
 import dan200.computercraft.shared.util.TickScheduler;
+import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.dedicated.DedicatedServer;
+import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.server.packs.resources.PreparableReloadListener;
 import net.minecraft.world.entity.Entity;
+import net.minecraft.world.item.CreativeModeTab;
+import net.minecraft.world.item.CreativeModeTabs;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.chunk.LevelChunk;
 import net.minecraft.world.level.storage.loot.BuiltInLootTables;
@@ -69,10 +73,19 @@ public final class CommonHooks {
         NetworkUtils.reset();
     }
 
+    public static void onServerChunkUnload(LevelChunk chunk) {
+        if (!(chunk.getLevel() instanceof ServerLevel)) throw new IllegalArgumentException("Not a server chunk.");
+        TickScheduler.onChunkUnload(chunk);
+    }
+
     public static void onChunkWatch(LevelChunk chunk, ServerPlayer player) {
         MonitorWatcher.onWatch(chunk, player);
     }
 
+    public static void onChunkTicketLevelChanged(ServerLevel level, long chunkPos, int oldLevel, int newLevel) {
+        TickScheduler.onChunkTicketChanged(level, chunkPos, oldLevel, newLevel);
+    }
+
     public static final ResourceLocation TREASURE_DISK_LOOT = new ResourceLocation(ComputerCraftAPI.MOD_ID, "treasure_disk");
 
     private static final Set<ResourceLocation> TREASURE_DISK_LOOT_TABLES = Set.of(
@@ -111,4 +124,17 @@ public final class CommonHooks {
     public static boolean onLivingDrop(Entity entity, ItemStack stack) {
         return DropConsumer.onLivingDrop(entity, stack);
     }
+
+    /**
+     * Add items to an existing creative tab.
+     *
+     * @param key     The {@link ResourceKey} for this creative tab.
+     * @param context Additional parameters used for building the contents.
+     * @param out     The creative tab output to append items to.
+     */
+    public static void onBuildCreativeTab(ResourceKey<CreativeModeTab> key, CreativeModeTab.ItemDisplayParameters context, CreativeModeTab.Output out) {
+        if (key == CreativeModeTabs.OP_BLOCKS && context.hasPermissions()) {
+            out.accept(ModRegistry.Items.COMPUTER_COMMAND.get());
+        }
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/ModRegistry.java

@@ -34,6 +34,7 @@ import dan200.computercraft.shared.computer.inventory.ViewComputerMenu;
 import dan200.computercraft.shared.computer.items.CommandComputerItem;
 import dan200.computercraft.shared.computer.items.ComputerItem;
 import dan200.computercraft.shared.computer.recipe.ComputerUpgradeRecipe;
+import dan200.computercraft.shared.config.Config;
 import dan200.computercraft.shared.data.BlockNamedEntityLootCondition;
 import dan200.computercraft.shared.data.ConstantLootConditionSerializer;
 import dan200.computercraft.shared.data.HasComputerIdLootCondition;
@@ -139,19 +140,17 @@ public final class ModRegistry {
         }
 
         public static final RegistryEntry<ComputerBlock<ComputerBlockEntity>> COMPUTER_NORMAL = REGISTRY.register("computer_normal",
-            () -> new ComputerBlock<>(computerProperties().mapColor(MapColor.STONE), ComputerFamily.NORMAL, BlockEntities.COMPUTER_NORMAL));
+            () -> new ComputerBlock<>(computerProperties().mapColor(MapColor.STONE), BlockEntities.COMPUTER_NORMAL));
         public static final RegistryEntry<ComputerBlock<ComputerBlockEntity>> COMPUTER_ADVANCED = REGISTRY.register("computer_advanced",
-            () -> new ComputerBlock<>(computerProperties().mapColor(MapColor.GOLD), ComputerFamily.ADVANCED, BlockEntities.COMPUTER_ADVANCED));
+            () -> new ComputerBlock<>(computerProperties().mapColor(MapColor.GOLD), BlockEntities.COMPUTER_ADVANCED));
 
-        public static final RegistryEntry<ComputerBlock<CommandComputerBlockEntity>> COMPUTER_COMMAND = REGISTRY.register("computer_command", () -> new CommandComputerBlock<>(
-            computerProperties().strength(-1, 6000000.0F),
-            ComputerFamily.COMMAND, BlockEntities.COMPUTER_COMMAND
-        ));
+        public static final RegistryEntry<ComputerBlock<CommandComputerBlockEntity>> COMPUTER_COMMAND = REGISTRY.register("computer_command",
+            () -> new CommandComputerBlock<>(computerProperties().strength(-1, 6000000.0F), BlockEntities.COMPUTER_COMMAND));
 
         public static final RegistryEntry<TurtleBlock> TURTLE_NORMAL = REGISTRY.register("turtle_normal",
-            () -> new TurtleBlock(turtleProperties().mapColor(MapColor.STONE), ComputerFamily.NORMAL, BlockEntities.TURTLE_NORMAL));
+            () -> new TurtleBlock(turtleProperties().mapColor(MapColor.STONE), BlockEntities.TURTLE_NORMAL));
         public static final RegistryEntry<TurtleBlock> TURTLE_ADVANCED = REGISTRY.register("turtle_advanced",
-            () -> new TurtleBlock(turtleProperties().mapColor(MapColor.GOLD), ComputerFamily.ADVANCED, BlockEntities.TURTLE_ADVANCED));
+            () -> new TurtleBlock(turtleProperties().mapColor(MapColor.GOLD).explosionResistance(TurtleBlock.IMMUNE_EXPLOSION_RESISTANCE), BlockEntities.TURTLE_ADVANCED));
 
         public static final RegistryEntry<SpeakerBlock> SPEAKER = REGISTRY.register("speaker", () -> new SpeakerBlock(properties().mapColor(MapColor.STONE)));
         public static final RegistryEntry<DiskDriveBlock> DISK_DRIVE = REGISTRY.register("disk_drive", () -> new DiskDriveBlock(properties().mapColor(MapColor.STONE)));
@@ -192,9 +191,9 @@ public final class ModRegistry {
             ofBlock(Blocks.COMPUTER_COMMAND, (p, s) -> new CommandComputerBlockEntity(BlockEntities.COMPUTER_COMMAND.get(), p, s));
 
         public static final RegistryEntry<BlockEntityType<TurtleBlockEntity>> TURTLE_NORMAL =
-            ofBlock(Blocks.TURTLE_NORMAL, (p, s) -> new TurtleBlockEntity(BlockEntities.TURTLE_NORMAL.get(), p, s, ComputerFamily.NORMAL));
+            ofBlock(Blocks.TURTLE_NORMAL, (p, s) -> new TurtleBlockEntity(BlockEntities.TURTLE_NORMAL.get(), p, s, () -> Config.turtleFuelLimit, ComputerFamily.NORMAL));
         public static final RegistryEntry<BlockEntityType<TurtleBlockEntity>> TURTLE_ADVANCED =
-            ofBlock(Blocks.TURTLE_ADVANCED, (p, s) -> new TurtleBlockEntity(BlockEntities.TURTLE_ADVANCED.get(), p, s, ComputerFamily.ADVANCED));
+            ofBlock(Blocks.TURTLE_ADVANCED, (p, s) -> new TurtleBlockEntity(BlockEntities.TURTLE_ADVANCED.get(), p, s, () -> Config.advancedTurtleFuelLimit, ComputerFamily.ADVANCED));
 
         public static final RegistryEntry<BlockEntityType<SpeakerBlockEntity>> SPEAKER =
             ofBlock(Blocks.SPEAKER, (p, s) -> new SpeakerBlockEntity(BlockEntities.SPEAKER.get(), p, s));
@@ -311,7 +310,10 @@ public final class ModRegistry {
             () -> new MenuType<>(PrinterMenu::new, FeatureFlags.VANILLA_SET));
 
         public static final RegistryEntry<MenuType<HeldItemMenu>> PRINTOUT = REGISTRY.register("printout",
-            () -> ContainerData.toType(HeldItemContainerData::new, HeldItemMenu::createPrintout));
+            () -> ContainerData.toType(
+                HeldItemContainerData::new,
+                (id, inventory, data) -> new HeldItemMenu(Menus.PRINTOUT.get(), id, inventory.player, data.getHand())
+            ));
 
         public static final RegistryEntry<MenuType<ViewComputerMenu>> VIEW_COMPUTER = REGISTRY.register("view_computer",
             () -> ContainerData.toType(ComputerContainerData::new, ViewComputerMenu::new));
@@ -371,11 +373,11 @@ public final class ModRegistry {
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<ClearColourRecipe>> DYEABLE_ITEM_CLEAR = simple("clear_colour", ClearColourRecipe::new);
         public static final RegistryEntry<RecipeSerializer<TurtleRecipe>> TURTLE = REGISTRY.register("turtle", () -> TurtleRecipe.validatingSerialiser(TurtleRecipe::of));
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<TurtleUpgradeRecipe>> TURTLE_UPGRADE = simple("turtle_upgrade", TurtleUpgradeRecipe::new);
-        public static final RegistryEntry<RecipeSerializer<TurtleOverlayRecipe>> TURTLE_OVERLAY = REGISTRY.register("turtle_overlay", TurtleOverlayRecipe.Serializer::new);
+        public static final RegistryEntry<RecipeSerializer<TurtleOverlayRecipe>> TURTLE_OVERLAY = REGISTRY.register("turtle_overlay", TurtleOverlayRecipe.Serialiser::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<PocketComputerUpgradeRecipe>> POCKET_COMPUTER_UPGRADE = simple("pocket_computer_upgrade", PocketComputerUpgradeRecipe::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<PrintoutRecipe>> PRINTOUT = simple("printout", PrintoutRecipe::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<DiskRecipe>> DISK = simple("disk", DiskRecipe::new);
-        public static final RegistryEntry<RecipeSerializer<ComputerUpgradeRecipe>> COMPUTER_UPGRADE = REGISTRY.register("computer_upgrade", ComputerUpgradeRecipe.Serializer::new);
+        public static final RegistryEntry<RecipeSerializer<ComputerUpgradeRecipe>> COMPUTER_UPGRADE = REGISTRY.register("computer_upgrade", () -> CustomShapedRecipe.validatingSerialiser(ComputerUpgradeRecipe::of));
     }
 
     public static class Permissions {
@@ -464,8 +466,8 @@ public final class ModRegistry {
      * Register any objects which must be done on the main thread.
      */
     public static void registerMainThread() {
-        CauldronInteraction.WATER.put(ModRegistry.Items.TURTLE_NORMAL.get(), TurtleItem.CAULDRON_INTERACTION);
-        CauldronInteraction.WATER.put(ModRegistry.Items.TURTLE_ADVANCED.get(), TurtleItem.CAULDRON_INTERACTION);
+        CauldronInteraction.WATER.put(Items.TURTLE_NORMAL.get(), TurtleItem.CAULDRON_INTERACTION);
+        CauldronInteraction.WATER.put(Items.TURTLE_ADVANCED.get(), TurtleItem.CAULDRON_INTERACTION);
     }
 
     private static void addTurtle(CreativeModeTab.Output out, TurtleItem turtle) {

projects/common/src/main/java/dan200/computercraft/shared/command/CommandComputerCraft.java

@@ -54,7 +54,12 @@ import static net.minecraft.commands.Commands.literal;
 
 public final class CommandComputerCraft {
     public static final UUID SYSTEM_UUID = new UUID(0, 0);
-    public static final String OPEN_COMPUTER = "computercraft open-computer ";
+
+    /**
+     * The client-side command to open the folder. Ideally this would live under the main {@code computercraft}
+     * namespace, but unfortunately that overrides commands, rather than merging them.
+     */
+    public static final String CLIENT_OPEN_FOLDER = "computercraft-computer-folder";
 
     private CommandComputerCraft() {
     }
@@ -389,7 +394,7 @@ public final class CommandComputerCraft {
 
         return link(
             text("\u270E"),
-            "/" + OPEN_COMPUTER + id,
+            "/" + CLIENT_OPEN_FOLDER + " " + id,
             Component.translatable("commands.computercraft.dump.open_path")
         );
     }

projects/common/src/main/java/dan200/computercraft/shared/command/text/TableBuilder.java

@@ -7,7 +7,7 @@ package dan200.computercraft.shared.command.text;
 import dan200.computercraft.core.util.Nullability;
 import dan200.computercraft.shared.command.CommandUtils;
 import dan200.computercraft.shared.network.client.ChatTableClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import net.minecraft.commands.CommandSourceStack;
 import net.minecraft.network.chat.Component;
 import net.minecraft.server.level.ServerPlayer;
@@ -105,7 +105,7 @@ public class TableBuilder {
         if (CommandUtils.isPlayer(source)) {
             trim(18);
             var player = (ServerPlayer) Nullability.assertNonNull(source.getEntity());
-            PlatformHelper.get().sendToPlayer(new ChatTableClientMessage(this), player);
+            ServerNetworking.sendToPlayer(new ChatTableClientMessage(this), player);
         } else {
             trim(100);
             new ServerTableFormatter(source).display(this);

projects/common/src/main/java/dan200/computercraft/shared/common/HeldItemMenu.java

@@ -4,8 +4,6 @@
 
 package dan200.computercraft.shared.common;
 
-import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.network.container.HeldItemContainerData;
 import net.minecraft.network.chat.Component;
 import net.minecraft.world.InteractionHand;
 import net.minecraft.world.MenuProvider;
@@ -28,10 +26,6 @@ public class HeldItemMenu extends AbstractContainerMenu {
         stack = player.getItemInHand(hand).copy();
     }
 
-    public static HeldItemMenu createPrintout(int id, Inventory inventory, HeldItemContainerData data) {
-        return new HeldItemMenu(ModRegistry.Menus.PRINTOUT.get(), id, inventory.player, data.getHand());
-    }
-
     public ItemStack getStack() {
         return stack;
     }

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/AbstractComputerBlock.java

@@ -7,7 +7,6 @@ package dan200.computercraft.shared.computer.blocks;
 import dan200.computercraft.annotations.ForgeOverride;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.shared.common.IBundledRedstoneBlock;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.items.IComputerItem;
 import dan200.computercraft.shared.platform.RegistryEntry;
 import dan200.computercraft.shared.util.BlockEntityHelpers;
@@ -42,13 +41,11 @@ import javax.annotation.Nullable;
 public abstract class AbstractComputerBlock<T extends AbstractComputerBlockEntity> extends HorizontalDirectionalBlock implements IBundledRedstoneBlock, EntityBlock {
     private static final ResourceLocation DROP = new ResourceLocation(ComputerCraftAPI.MOD_ID, "computer");
 
-    private final ComputerFamily family;
     protected final RegistryEntry<BlockEntityType<T>> type;
     private final BlockEntityTicker<T> serverTicker = (level, pos, state, computer) -> computer.serverTick();
 
-    protected AbstractComputerBlock(Properties settings, ComputerFamily family, RegistryEntry<BlockEntityType<T>> type) {
+    protected AbstractComputerBlock(Properties settings, RegistryEntry<BlockEntityType<T>> type) {
         super(settings);
-        this.family = family;
         this.type = type;
     }
 
@@ -82,10 +79,6 @@ public abstract class AbstractComputerBlock<T extends AbstractComputerBlockEntit
 
     protected abstract ItemStack getItem(AbstractComputerBlockEntity tile);
 
-    public ComputerFamily getFamily() {
-        return family;
-    }
-
     @Override
     @Deprecated
     public int getSignal(BlockState state, BlockGetter world, BlockPos pos, Direction incomingSide) {

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/AbstractComputerBlockEntity.java

@@ -25,7 +25,6 @@ import net.minecraft.core.Direction;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.game.ClientboundBlockEntityDataPacket;
-import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.*;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.ItemStack;
@@ -51,7 +50,7 @@ public abstract class AbstractComputerBlockEntity extends BlockEntity implements
     private boolean fresh = false;
 
     private int invalidSides = 0;
-    private final ComponentAccess<IPeripheral> peripherals = PlatformHelper.get().createPeripheralAccess(d -> invalidSides |= 1 << d.ordinal());
+    private final ComponentAccess<IPeripheral> peripherals = PlatformHelper.get().createPeripheralAccess(this, d -> invalidSides |= 1 << d.ordinal());
 
     private LockCode lockCode = LockCode.NO_LOCK;
 
@@ -114,16 +113,13 @@ public abstract class AbstractComputerBlockEntity extends BlockEntity implements
         return InteractionResult.PASS;
     }
 
-    public void neighborChanged(BlockPos neighbour) {
-        updateInputAt(neighbour);
-    }
-
     protected void serverTick() {
         if (getLevel().isClientSide) return;
         if (computerID < 0 && !startOn) return; // Don't tick if we don't need a computer!
 
         var computer = createServerComputer();
 
+        // Update any peripherals that have changed.
         if (invalidSides != 0) {
             for (var direction : DirectionUtil.FACINGS) {
                 if ((invalidSides & (1 << direction.ordinal())) != 0) refreshPeripheral(computer, direction);
@@ -140,16 +136,30 @@ public abstract class AbstractComputerBlockEntity extends BlockEntity implements
 
         fresh = false;
         computerID = computer.getID();
-        label = computer.getLabel();
-        on = computer.isOn();
 
-        // Update the block state if needed. We don't fire a block update intentionally,
-        // as this only really is needed on the client side.
+        // If the on state has changed, mark as as dirty.
+        var newOn = computer.isOn();
+        if (on != newOn) {
+            on = newOn;
+            setChanged();
+        }
+
+        // If the label has changed, mark as dirty and sync to client.
+        var newLabel = computer.getLabel();
+        if (!Objects.equals(label, newLabel)) {
+            label = newLabel;
+            BlockEntityHelpers.updateBlock(this);
+        }
+
+        // Update the block state if needed.
         updateBlockState(computer.getState());
 
-        // TODO: This should ideally be split up into label/id/on (which should save NBT and sync to client) and
-        //  redstone (which should update outputs)
-        if (computer.hasOutputChanged()) updateOutput();
+        var changes = computer.pollAndResetChanges();
+        if (changes != 0) {
+            for (var direction : DirectionUtil.FACINGS) {
+                if ((changes & (1 << remapToLocalSide(direction).ordinal())) != 0) updateRedstoneTo(direction);
+            }
+        }
     }
 
     protected abstract void updateBlockState(ComputerState newState);
@@ -199,11 +209,15 @@ public abstract class AbstractComputerBlockEntity extends BlockEntity implements
         return localSide;
     }
 
-    private void updateRedstoneInputs(ServerComputer computer) {
-        var pos = getBlockPos();
-        for (var dir : DirectionUtil.FACINGS) updateRedstoneInput(computer, dir, pos.relative(dir));
-    }
-
+    /**
+     * Update the redstone input on a particular side.
+     * <p>
+     * This is called <em>immediately</em> when a neighbouring block changes (see {@link #neighborChanged(BlockPos)}).
+     *
+     * @param computer  The current server computer.
+     * @param dir       The direction to update in.
+     * @param targetPos The position of the adjacent block, equal to {@code getBlockPos().offset(dir)}.
+     */
     private void updateRedstoneInput(ServerComputer computer, Direction dir, BlockPos targetPos) {
         var offsetSide = dir.getOpposite();
         var localDir = remapToLocalSide(dir);
@@ -212,13 +226,22 @@ public abstract class AbstractComputerBlockEntity extends BlockEntity implements
         computer.setBundledRedstoneInput(localDir, BundledRedstone.getOutput(getLevel(), targetPos, offsetSide));
     }
 
+    /**
+     * Update the peripheral on a particular side.
+     * <p>
+     * This is called from {@link #serverTick()}, after a peripheral has been marked as invalid (such as in
+     * {@link #neighborChanged(BlockPos)})
+     *
+     * @param computer The current server computer.
+     * @param dir      The direction to update in.
+     */
     private void refreshPeripheral(ServerComputer computer, Direction dir) {
         invalidSides &= ~(1 << dir.ordinal());
 
         var localDir = remapToLocalSide(dir);
         if (isPeripheralBlockedOnSide(localDir)) return;
 
-        var peripheral = peripherals.get((ServerLevel) getLevel(), getBlockPos(), dir);
+        var peripheral = peripherals.get(dir);
         computer.setPeripheral(localDir, peripheral);
     }
 
@@ -244,7 +267,18 @@ public abstract class AbstractComputerBlockEntity extends BlockEntity implements
         }
     }
 
-    private void updateInputAt(BlockPos neighbour) {
+    /**
+     * Called when a neighbour block changes.
+     * <p>
+     * This finds the side the neighbour block is on, and updates the inputs accordingly.
+     * <p>
+     * We do <strong>NOT</strong> update the peripheral immediately. Blocks and block entities are sometimes
+     * inconsistent at the point where an update is received, and so we instead just mark that side as dirty (see
+     * {@link #invalidSides}) and refresh it {@linkplain #serverTick() next tick}.
+     *
+     * @param neighbour The position of the neighbour block.
+     */
+    public void neighborChanged(BlockPos neighbour) {
         var computer = getServerComputer();
         if (computer == null) return;
 
@@ -259,22 +293,28 @@ public abstract class AbstractComputerBlockEntity extends BlockEntity implements
 
         // If the position is not any adjacent one, update all inputs. This is pretty terrible, but some redstone mods
         // handle this incorrectly.
-        updateRedstoneInputs(computer);
+        for (var dir : DirectionUtil.FACINGS) updateRedstoneInput(computer, dir, getBlockPos().relative(dir));
         invalidSides = (1 << 6) - 1; // Mark all peripherals as dirty.
     }
 
     /**
-     * Update the block's state and propagate redstone output.
+     * Update outputs in a specific direction.
+     *
+     * @param direction The direction to propagate outputs in.
      */
-    public void updateOutput() {
-        BlockEntityHelpers.updateBlock(this);
-        for (var dir : DirectionUtil.FACINGS) RedstoneUtil.propagateRedstoneOutput(getLevel(), getBlockPos(), dir);
+    protected void updateRedstoneTo(Direction direction) {
+        RedstoneUtil.propagateRedstoneOutput(getLevel(), getBlockPos(), direction);
 
         var computer = getServerComputer();
-        if (computer != null) updateRedstoneInputs(computer);
+        if (computer != null) updateRedstoneInput(computer, direction, getBlockPos().relative(direction));
     }
 
-    protected abstract ServerComputer createComputer(int id);
+    /**
+     * Update all redstone outputs.
+     */
+    public void updateRedstone() {
+        for (var dir : DirectionUtil.FACINGS) updateRedstoneTo(dir);
+    }
 
     @Override
     public final int getComputerID() {
@@ -332,6 +372,8 @@ public abstract class AbstractComputerBlockEntity extends BlockEntity implements
         return computer;
     }
 
+    protected abstract ServerComputer createComputer(int id);
+
     @Nullable
     public ServerComputer getServerComputer() {
         return getLevel().isClientSide || getLevel().getServer() == null ? null : ServerContext.get(getLevel().getServer()).registry().get(instanceID);

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/CommandComputerBlock.java

@@ -4,7 +4,6 @@
 
 package dan200.computercraft.shared.computer.blocks;
 
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.platform.RegistryEntry;
 import net.minecraft.world.level.block.GameMasterBlock;
 import net.minecraft.world.level.block.entity.BlockEntityType;
@@ -17,7 +16,7 @@ import net.minecraft.world.level.block.entity.BlockEntityType;
  * @see dan200.computercraft.shared.computer.items.CommandComputerItem
  */
 public class CommandComputerBlock<T extends CommandComputerBlockEntity> extends ComputerBlock<T> implements GameMasterBlock {
-    public CommandComputerBlock(Properties settings, ComputerFamily family, RegistryEntry<BlockEntityType<T>> type) {
-        super(settings, family, type);
+    public CommandComputerBlock(Properties settings, RegistryEntry<BlockEntityType<T>> type) {
+        super(settings, type);
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/CommandComputerBlockEntity.java

@@ -20,28 +20,24 @@ import net.minecraft.world.level.block.state.BlockState;
 import net.minecraft.world.phys.Vec2;
 import net.minecraft.world.phys.Vec3;
 
-import java.util.HashMap;
-import java.util.Map;
+import java.util.ArrayList;
+import java.util.List;
 
 public class CommandComputerBlockEntity extends ComputerBlockEntity {
     public class CommandReceiver implements CommandSource {
-        private final Map<Integer, String> output = new HashMap<>();
+        private final List<String> output = new ArrayList<>();
 
         public void clearOutput() {
             output.clear();
         }
 
-        public Map<Integer, String> getOutput() {
-            return output;
-        }
-
-        public Map<Integer, String> copyOutput() {
-            return new HashMap<>(output);
+        public List<String> copyOutput() {
+            return new ArrayList<>(output);
         }
 
         @Override
         public void sendSystemMessage(Component textComponent) {
-            output.put(output.size() + 1, textComponent.getString());
+            output.add(textComponent.getString());
         }
 
         @Override

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/ComputerBlock.java

@@ -4,9 +4,8 @@
 
 package dan200.computercraft.shared.computer.blocks;
 
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.core.ComputerState;
-import dan200.computercraft.shared.computer.items.ComputerItemFactory;
+import dan200.computercraft.shared.computer.items.ComputerItem;
 import dan200.computercraft.shared.platform.RegistryEntry;
 import net.minecraft.core.Direction;
 import net.minecraft.world.item.ItemStack;
@@ -25,8 +24,8 @@ public class ComputerBlock<T extends ComputerBlockEntity> extends AbstractComput
     public static final EnumProperty<ComputerState> STATE = EnumProperty.create("state", ComputerState.class);
     public static final DirectionProperty FACING = BlockStateProperties.HORIZONTAL_FACING;
 
-    public ComputerBlock(Properties settings, ComputerFamily family, RegistryEntry<BlockEntityType<T>> type) {
-        super(settings, family, type);
+    public ComputerBlock(Properties settings, RegistryEntry<BlockEntityType<T>> type) {
+        super(settings, type);
         registerDefaultState(defaultBlockState()
             .setValue(FACING, Direction.NORTH)
             .setValue(STATE, ComputerState.OFF)
@@ -46,6 +45,9 @@ public class ComputerBlock<T extends ComputerBlockEntity> extends AbstractComput
 
     @Override
     protected ItemStack getItem(AbstractComputerBlockEntity tile) {
-        return tile instanceof ComputerBlockEntity ? ComputerItemFactory.create((ComputerBlockEntity) tile) : ItemStack.EMPTY;
+        if (!(tile instanceof ComputerBlockEntity computer)) return ItemStack.EMPTY;
+        if (!(asItem() instanceof ComputerItem item)) return ItemStack.EMPTY;
+
+        return item.create(computer.getComputerID(), computer.getLabel());
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/ComputerBlockEntity.java

@@ -32,11 +32,9 @@ public class ComputerBlockEntity extends AbstractComputerBlockEntity {
 
     @Override
     protected ServerComputer createComputer(int id) {
-        var family = getFamily();
         return new ServerComputer(
             (ServerLevel) getLevel(), getBlockPos(), id, label,
-            family, Config.computerTermWidth,
-            Config.computerTermHeight
+            getFamily(), Config.computerTermWidth, Config.computerTermHeight
         );
     }
 
@@ -53,7 +51,7 @@ public class ComputerBlockEntity extends AbstractComputerBlockEntity {
     protected void updateBlockState(ComputerState newState) {
         var existing = getBlockState();
         if (existing.getValue(ComputerBlock.STATE) != newState) {
-            getLevel().setBlock(getBlockPos(), existing.setValue(ComputerBlock.STATE, newState), 3);
+            getLevel().setBlock(getBlockPos(), existing.setValue(ComputerBlock.STATE, newState), ComputerBlock.UPDATE_CLIENTS);
         }
     }
 

projects/common/src/main/java/dan200/computercraft/shared/computer/core/ComputerFamily.java

@@ -4,33 +4,8 @@
 
 package dan200.computercraft.shared.computer.core;
 
-import com.google.gson.JsonObject;
-import com.google.gson.JsonSyntaxException;
-import net.minecraft.util.GsonHelper;
-import net.minecraft.util.StringRepresentable;
-
-public enum ComputerFamily implements StringRepresentable {
-    NORMAL("normal"),
-    ADVANCED("advanced"),
-    COMMAND("command");
-
-    private final String name;
-
-    ComputerFamily(String name) {
-        this.name = name;
-    }
-
-    public static ComputerFamily getFamily(JsonObject json, String name) {
-        var familyName = GsonHelper.getAsString(json, name);
-        for (var family : values()) {
-            if (family.getSerializedName().equalsIgnoreCase(familyName)) return family;
-        }
-
-        throw new JsonSyntaxException("Unknown computer family '" + familyName + "' for field " + name);
-    }
-
-    @Override
-    public String getSerializedName() {
-        return name;
-    }
+public enum ComputerFamily {
+    NORMAL,
+    ADVANCED,
+    COMMAND,
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/core/ServerComputer.java

@@ -20,7 +20,7 @@ import dan200.computercraft.shared.config.Config;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.client.ClientNetworkContext;
 import dan200.computercraft.shared.network.client.ComputerTerminalClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import net.minecraft.core.BlockPos;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.inventory.AbstractContainerMenu;
@@ -42,7 +42,6 @@ public class ServerComputer implements InputHandler, ComputerEnvironment {
     private final NetworkedTerminal terminal;
     private final AtomicBoolean terminalChanged = new AtomicBoolean(false);
 
-    private boolean changedLastFrame;
     private int ticksSincePing;
 
     public ServerComputer(
@@ -96,10 +95,7 @@ public class ServerComputer implements InputHandler, ComputerEnvironment {
 
     public void tickServer() {
         ticksSincePing++;
-
         computer.tick();
-
-        changedLastFrame = computer.pollAndResetChanged();
         if (terminalChanged.getAndSet(false)) onTerminalChanged();
     }
 
@@ -119,8 +115,8 @@ public class ServerComputer implements InputHandler, ComputerEnvironment {
         return ticksSincePing > 100;
     }
 
-    public boolean hasOutputChanged() {
-        return changedLastFrame;
+    public int pollAndResetChanges() {
+        return computer.pollAndResetChanges();
     }
 
     public int register() {
@@ -142,7 +138,7 @@ public class ServerComputer implements InputHandler, ComputerEnvironment {
 
         for (var player : server.getPlayerList().getPlayers()) {
             if (player.containerMenu instanceof ComputerMenu && ((ComputerMenu) player.containerMenu).getComputer() == this) {
-                PlatformHelper.get().sendToPlayer(createPacket.apply(player.containerMenu), player);
+                ServerNetworking.sendToPlayer(createPacket.apply(player.containerMenu), player);
             }
         }
     }
@@ -167,7 +163,7 @@ public class ServerComputer implements InputHandler, ComputerEnvironment {
     }
 
     public ComputerState getState() {
-        if (!isOn()) return ComputerState.OFF;
+        if (!computer.isOn()) return ComputerState.OFF;
         return computer.isBlinking() ? ComputerState.BLINKING : ComputerState.ON;
     }
 

projects/common/src/main/java/dan200/computercraft/shared/computer/items/AbstractComputerItem.java

@@ -8,7 +8,6 @@ import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.filesystem.Mount;
 import dan200.computercraft.api.media.IMedia;
 import dan200.computercraft.shared.computer.blocks.AbstractComputerBlock;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.config.Config;
 import net.minecraft.ChatFormatting;
 import net.minecraft.network.chat.Component;
@@ -22,11 +21,8 @@ import javax.annotation.Nullable;
 import java.util.List;
 
 public abstract class AbstractComputerItem extends BlockItem implements IComputerItem, IMedia {
-    private final ComputerFamily family;
-
     public AbstractComputerItem(AbstractComputerBlock<?> block, Properties settings) {
         super(block, settings);
-        family = block.getFamily();
     }
 
     @Override
@@ -45,13 +41,6 @@ public abstract class AbstractComputerItem extends BlockItem implements ICompute
         return IComputerItem.super.getLabel(stack);
     }
 
-    @Override
-    public final ComputerFamily getFamily() {
-        return family;
-    }
-
-    // IMedia implementation
-
     @Override
     public boolean setLabel(ItemStack stack, @Nullable String label) {
         if (label != null) {

projects/common/src/main/java/dan200/computercraft/shared/computer/items/ComputerItem.java

@@ -5,8 +5,8 @@
 package dan200.computercraft.shared.computer.items;
 
 import dan200.computercraft.shared.computer.blocks.ComputerBlock;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import net.minecraft.network.chat.Component;
+import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 
 import javax.annotation.Nullable;
@@ -24,9 +24,9 @@ public class ComputerItem extends AbstractComputerItem {
     }
 
     @Override
-    public ItemStack withFamily(ItemStack stack, ComputerFamily family) {
-        var result = ComputerItemFactory.create(getComputerID(stack), null, family);
-        if (stack.hasCustomHoverName()) result.setHoverName(stack.getHoverName());
-        return result;
+    public ItemStack changeItem(ItemStack stack, Item newItem) {
+        return newItem instanceof ComputerItem computer
+            ? computer.create(getComputerID(stack), getLabel(stack))
+            : ItemStack.EMPTY;
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/items/ComputerItemFactory.java

@@ -1,29 +0,0 @@
-// Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
-//
-// SPDX-License-Identifier: LicenseRef-CCPL
-
-package dan200.computercraft.shared.computer.items;
-
-import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.computer.blocks.ComputerBlockEntity;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
-import net.minecraft.world.item.ItemStack;
-
-import javax.annotation.Nullable;
-
-public final class ComputerItemFactory {
-    private ComputerItemFactory() {
-    }
-
-    public static ItemStack create(ComputerBlockEntity tile) {
-        return create(tile.getComputerID(), tile.getLabel(), tile.getFamily());
-    }
-
-    public static ItemStack create(int id, @Nullable String label, ComputerFamily family) {
-        return switch (family) {
-            case NORMAL -> ModRegistry.Items.COMPUTER_NORMAL.get().create(id, label);
-            case ADVANCED -> ModRegistry.Items.COMPUTER_ADVANCED.get().create(id, label);
-            case COMMAND -> ModRegistry.Items.COMPUTER_COMMAND.get().create(id, label);
-        };
-    }
-}

projects/common/src/main/java/dan200/computercraft/shared/computer/items/IComputerItem.java

@@ -4,7 +4,7 @@
 
 package dan200.computercraft.shared.computer.items;
 
-import dan200.computercraft.shared.computer.core.ComputerFamily;
+import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 
 import javax.annotation.Nullable;
@@ -21,7 +21,15 @@ public interface IComputerItem {
         return stack.hasCustomHoverName() ? stack.getHoverName().getString() : null;
     }
 
-    ComputerFamily getFamily();
-
-    ItemStack withFamily(ItemStack stack, ComputerFamily family);
+    /**
+     * Create a new stack, changing the underlying item.
+     * <p>
+     * This should copy the computer's data to a different item of the same type (for instance, converting a normal
+     * computer to an advanced one).
+     *
+     * @param stack   The current computer stack.
+     * @param newItem The new item.
+     * @return The new stack, possibly {@linkplain ItemStack#EMPTY empty} if {@code newItem} is of the same type.
+     */
+    ItemStack changeItem(ItemStack stack, Item newItem);
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/menu/ServerInputState.java

@@ -11,7 +11,7 @@ import dan200.computercraft.shared.computer.upload.FileSlice;
 import dan200.computercraft.shared.computer.upload.FileUpload;
 import dan200.computercraft.shared.computer.upload.UploadResult;
 import dan200.computercraft.shared.network.client.UploadResultMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
 import it.unimi.dsi.fastutil.ints.IntSet;
 import net.minecraft.network.chat.Component;
@@ -138,7 +138,7 @@ public class ServerInputState<T extends AbstractContainerMenu & ComputerMenu> im
             return;
         }
 
-        PlatformHelper.get().sendToPlayer(finishUpload(uploader), uploader);
+        ServerNetworking.sendToPlayer(finishUpload(uploader), uploader);
     }
 
     private UploadResultMessage finishUpload(ServerPlayer player) {
@@ -159,7 +159,7 @@ public class ServerInputState<T extends AbstractContainerMenu & ComputerMenu> im
                 toUpload.stream().map(x -> new TransferredFile(x.getName(), new ByteBufferChannel(x.getBytes()))).toList(),
                 () -> {
                     if (player.isAlive() && player.containerMenu == owner) {
-                        PlatformHelper.get().sendToPlayer(UploadResultMessage.consumed(owner), player);
+                        ServerNetworking.sendToPlayer(UploadResultMessage.consumed(owner), player);
                     }
                 }),
         });

projects/common/src/main/java/dan200/computercraft/shared/computer/metrics/GlobalMetrics.java

@@ -46,12 +46,14 @@ public final class GlobalMetrics {
      * Add a new global metrics observer. This will receive metrics data for all computers.
      *
      * @param tracker The observer to add.
+     * @return Whether the observer was added. {@code false} if the observer was already registered.
      */
-    public void addObserver(ComputerMetricsObserver tracker) {
+    public boolean addObserver(ComputerMetricsObserver tracker) {
         synchronized (lock) {
-            if (trackers.contains(tracker)) return;
+            if (trackers.contains(tracker)) return false;
             trackers.add(tracker);
             enabled = true;
+            return true;
         }
     }
 
@@ -59,11 +61,13 @@ public final class GlobalMetrics {
      * Remove a previously-registered global metrics observer.
      *
      * @param tracker The observer to add.
+     * @return Whether the observer was removed. {@code false} if the observer was not registered.
      */
-    public void removeObserver(ComputerMetricsObserver tracker) {
+    public boolean removeObserver(ComputerMetricsObserver tracker) {
         synchronized (lock) {
-            trackers.remove(tracker);
+            var changed = trackers.remove(tracker);
             enabled = !trackers.isEmpty();
+            return changed;
         }
     }
 

projects/common/src/main/java/dan200/computercraft/shared/computer/metrics/basic/BasicComputerMetricsObserver.java

@@ -10,6 +10,7 @@ import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.computer.metrics.ComputerMetricsObserver;
 import dan200.computercraft.shared.computer.metrics.GlobalMetrics;
 
+import javax.annotation.concurrent.GuardedBy;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -21,29 +22,31 @@ import java.util.Map;
  */
 public class BasicComputerMetricsObserver implements ComputerMetricsObserver {
     private final GlobalMetrics owner;
-    private boolean tracking = false;
 
+    @GuardedBy("this")
     private final List<ComputerMetrics> timings = new ArrayList<>();
+
+    @GuardedBy("this")
     private final Map<ServerComputer, ComputerMetrics> timingLookup = new MapMaker().weakKeys().makeMap();
 
     public BasicComputerMetricsObserver(GlobalMetrics owner) {
         this.owner = owner;
     }
 
-    public synchronized void start() {
-        if (!tracking) owner.addObserver(this);
-        tracking = true;
+    public void start() {
+        if (!owner.addObserver(this)) return;
 
-        timings.clear();
-        timingLookup.clear();
+        synchronized (this) {
+            timings.clear();
+            timingLookup.clear();
+        }
     }
 
-    public synchronized boolean stop() {
-        if (!tracking) return false;
-
-        owner.removeObserver(this);
-        tracking = false;
-        timingLookup.clear();
+    public boolean stop() {
+        if (!owner.removeObserver(this)) return false;
+        synchronized (this) {
+            timingLookup.clear();
+        }
         return true;
     }
 
@@ -57,6 +60,7 @@ public class BasicComputerMetricsObserver implements ComputerMetricsObserver {
         return new ArrayList<>(timings);
     }
 
+    @GuardedBy("this")
     private ComputerMetrics getMetrics(ServerComputer computer) {
         var existing = timingLookup.get(computer);
         if (existing != null) return existing;

projects/common/src/main/java/dan200/computercraft/shared/computer/recipe/ComputerUpgradeRecipe.java

@@ -4,57 +4,44 @@
 
 package dan200.computercraft.shared.computer.recipe;
 
-import com.google.gson.JsonObject;
+import com.mojang.serialization.DataResult;
 import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.items.IComputerItem;
 import dan200.computercraft.shared.recipe.ShapedRecipeSpec;
-import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.crafting.RecipeSerializer;
 
 /**
- * A recipe which "upgrades" a {@linkplain IComputerItem computer}, converting it from one {@linkplain ComputerFamily
- * family} to another.
+ * A recipe which "upgrades" a {@linkplain IComputerItem computer}, converting to it a new item (for instance a normal
+ * turtle to an advanced one).
+ *
+ * @see IComputerItem#changeItem(ItemStack, Item)
  */
 public final class ComputerUpgradeRecipe extends ComputerConvertRecipe {
-    private final ComputerFamily family;
+    private final Item result;
 
-    private ComputerUpgradeRecipe(ResourceLocation identifier, ShapedRecipeSpec recipe, ComputerFamily family) {
+    private ComputerUpgradeRecipe(ResourceLocation identifier, ShapedRecipeSpec recipe) {
         super(identifier, recipe);
-        this.family = family;
+        this.result = recipe.result().getItem();
+    }
+
+    public static DataResult<ComputerUpgradeRecipe> of(ResourceLocation id, ShapedRecipeSpec recipe) {
+        if (!(recipe.result().getItem() instanceof IComputerItem)) {
+            return DataResult.error(() -> recipe.result().getItem() + " is not a computer item");
+        }
+
+        return DataResult.success(new ComputerUpgradeRecipe(id, recipe));
     }
 
     @Override
     protected ItemStack convert(IComputerItem item, ItemStack stack) {
-        return item.withFamily(stack, family);
+        return item.changeItem(stack, result);
     }
 
     @Override
     public RecipeSerializer<ComputerUpgradeRecipe> getSerializer() {
         return ModRegistry.RecipeSerializers.COMPUTER_UPGRADE.get();
     }
-
-    public static class Serializer implements RecipeSerializer<ComputerUpgradeRecipe> {
-        @Override
-        public ComputerUpgradeRecipe fromJson(ResourceLocation identifier, JsonObject json) {
-            var recipe = ShapedRecipeSpec.fromJson(json);
-            var family = ComputerFamily.getFamily(json, "family");
-            return new ComputerUpgradeRecipe(identifier, recipe, family);
-        }
-
-        @Override
-        public ComputerUpgradeRecipe fromNetwork(ResourceLocation identifier, FriendlyByteBuf buf) {
-            var recipe = ShapedRecipeSpec.fromNetwork(buf);
-            var family = buf.readEnum(ComputerFamily.class);
-            return new ComputerUpgradeRecipe(identifier, recipe, family);
-        }
-
-        @Override
-        public void toNetwork(FriendlyByteBuf buf, ComputerUpgradeRecipe recipe) {
-            recipe.toSpec().toNetwork(buf);
-            buf.writeEnum(recipe.family);
-        }
-    }
 }

projects/common/src/main/java/dan200/computercraft/shared/config/ConfigSpec.java

@@ -224,7 +224,7 @@ public final class ConfigSpec {
                 .defineInRange("max_requests", CoreConfig.httpMaxRequests, 0, Integer.MAX_VALUE);
 
             httpMaxWebsockets = builder
-                .comment("The number of websockets a computer can have open at one time. Set to 0 for unlimited.")
+                .comment("The number of websockets a computer can have open at one time.")
                 .defineInRange("max_websockets", CoreConfig.httpMaxWebsockets, 1, Integer.MAX_VALUE);
 
             builder

projects/common/src/main/java/dan200/computercraft/shared/network/MessageType.java

@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.network;
+
+/**
+ * A type of message to send over the network.
+ * <p>
+ * Much like recipe or argument serialisers, each type of {@link NetworkMessage} should have a unique type associated
+ * with it. This holds platform-specific information about how the packet should be sent over the network.
+ *
+ * @param <T> The type of message to send
+ * @see NetworkMessages
+ * @see NetworkMessage#type()
+ */
+public interface MessageType<T extends NetworkMessage<?>> {
+}

projects/common/src/main/java/dan200/computercraft/shared/network/NetworkMessage.java

@@ -17,6 +17,13 @@ import net.minecraft.network.FriendlyByteBuf;
  * @see ServerNetworkContext
  */
 public interface NetworkMessage<T> {
+    /**
+     * Get the type of this message.
+     *
+     * @return The type of this message.
+     */
+    MessageType<?> type();
+
     /**
      * Write this packet to a buffer.
      * <p>
@@ -24,7 +31,7 @@ public interface NetworkMessage<T> {
      *
      * @param buf The buffer to write data to.
      */
-    void toBytes(FriendlyByteBuf buf);
+    void write(FriendlyByteBuf buf);
 
     /**
      * Handle this {@link NetworkMessage}.

projects/common/src/main/java/dan200/computercraft/shared/network/NetworkMessages.java

@@ -4,48 +4,84 @@
 
 package dan200.computercraft.shared.network;
 
+import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.shared.network.client.*;
 import dan200.computercraft.shared.network.server.*;
 import dan200.computercraft.shared.platform.PlatformHelper;
+import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
+import it.unimi.dsi.fastutil.ints.IntSet;
 import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.resources.ResourceLocation;
 
-import java.util.function.Function;
+import java.util.*;
 
 /**
- * Registry for all packets provided by CC: Tweaked.
+ * List of all {@link MessageType}s provided by CC: Tweaked.
  *
  * @see PlatformHelper The platform helper is used to send packets.
  */
 public final class NetworkMessages {
+    private static final IntSet seenIds = new IntOpenHashSet();
+    private static final Set<String> seenChannel = new HashSet<>();
+    private static final List<MessageType<? extends NetworkMessage<ServerNetworkContext>>> serverMessages = new ArrayList<>();
+    private static final List<MessageType<? extends NetworkMessage<ClientNetworkContext>>> clientMessages = new ArrayList<>();
+
+    public static final MessageType<ComputerActionServerMessage> COMPUTER_ACTION = registerServerbound(0, "computer_action", ComputerActionServerMessage.class, ComputerActionServerMessage::new);
+    public static final MessageType<QueueEventServerMessage> QUEUE_EVENT = registerServerbound(1, "queue_event", QueueEventServerMessage.class, QueueEventServerMessage::new);
+    public static final MessageType<KeyEventServerMessage> KEY_EVENT = registerServerbound(2, "key_event", KeyEventServerMessage.class, KeyEventServerMessage::new);
+    public static final MessageType<MouseEventServerMessage> MOUSE_EVENT = registerServerbound(3, "mouse_event", MouseEventServerMessage.class, MouseEventServerMessage::new);
+    public static final MessageType<UploadFileMessage> UPLOAD_FILE = registerServerbound(4, "upload_file", UploadFileMessage.class, UploadFileMessage::new);
+
+    public static final MessageType<ChatTableClientMessage> CHAT_TABLE = registerClientbound(10, "chat_table", ChatTableClientMessage.class, ChatTableClientMessage::new);
+    public static final MessageType<PocketComputerDataMessage> POCKET_COMPUTER_DATA = registerClientbound(11, "pocket_computer_data", PocketComputerDataMessage.class, PocketComputerDataMessage::new);
+    public static final MessageType<PocketComputerDeletedClientMessage> POCKET_COMPUTER_DELETED = registerClientbound(12, "pocket_computer_deleted", PocketComputerDeletedClientMessage.class, PocketComputerDeletedClientMessage::new);
+    public static final MessageType<ComputerTerminalClientMessage> COMPUTER_TERMINAL = registerClientbound(13, "computer_terminal", ComputerTerminalClientMessage.class, ComputerTerminalClientMessage::new);
+    public static final MessageType<PlayRecordClientMessage> PLAY_RECORD = registerClientbound(14, "play_record", PlayRecordClientMessage.class, PlayRecordClientMessage::new);
+    public static final MessageType<MonitorClientMessage> MONITOR_CLIENT = registerClientbound(15, "monitor_client", MonitorClientMessage.class, MonitorClientMessage::new);
+    public static final MessageType<SpeakerAudioClientMessage> SPEAKER_AUDIO = registerClientbound(16, "speaker_audio", SpeakerAudioClientMessage.class, SpeakerAudioClientMessage::new);
+    public static final MessageType<SpeakerMoveClientMessage> SPEAKER_MOVE = registerClientbound(17, "speaker_move", SpeakerMoveClientMessage.class, SpeakerMoveClientMessage::new);
+    public static final MessageType<SpeakerPlayClientMessage> SPEAKER_PLAY = registerClientbound(18, "speaker_play", SpeakerPlayClientMessage.class, SpeakerPlayClientMessage::new);
+    public static final MessageType<SpeakerStopClientMessage> SPEAKER_STOP = registerClientbound(19, "speaker_stop", SpeakerStopClientMessage.class, SpeakerStopClientMessage::new);
+    public static final MessageType<UploadResultMessage> UPLOAD_RESULT = registerClientbound(20, "upload_result", UploadResultMessage.class, UploadResultMessage::new);
+    public static final MessageType<UpgradesLoadedMessage> UPGRADES_LOADED = registerClientbound(21, "upgrades_loaded", UpgradesLoadedMessage.class, UpgradesLoadedMessage::new);
+
     private NetworkMessages() {
     }
 
-    public interface PacketRegistry {
-        <T extends NetworkMessage<ClientNetworkContext>> void registerClientbound(int id, Class<T> type, Function<FriendlyByteBuf, T> decoder);
-
-        <T extends NetworkMessage<ServerNetworkContext>> void registerServerbound(int id, Class<T> type, Function<FriendlyByteBuf, T> decoder);
+    private static <C, T extends NetworkMessage<C>> MessageType<T> register(
+        List<MessageType<? extends NetworkMessage<C>>> messages,
+        int id, String channel, Class<T> klass, FriendlyByteBuf.Reader<T> reader
+    ) {
+        if (!seenIds.add(id)) throw new IllegalArgumentException("Duplicate id " + id);
+        if (!seenChannel.add(channel)) throw new IllegalArgumentException("Duplicate channel " + channel);
+        var type = PlatformHelper.get().createMessageType(id, new ResourceLocation(ComputerCraftAPI.MOD_ID, channel), klass, reader);
+        messages.add(type);
+        return type;
     }
 
-    public static void register(PacketRegistry registry) {
-        // Server messages
-        registry.registerServerbound(0, ComputerActionServerMessage.class, ComputerActionServerMessage::new);
-        registry.registerServerbound(1, QueueEventServerMessage.class, QueueEventServerMessage::new);
-        registry.registerServerbound(2, KeyEventServerMessage.class, KeyEventServerMessage::new);
-        registry.registerServerbound(3, MouseEventServerMessage.class, MouseEventServerMessage::new);
-        registry.registerServerbound(4, UploadFileMessage.class, UploadFileMessage::new);
+    private static <T extends NetworkMessage<ServerNetworkContext>> MessageType<T> registerServerbound(int id, String channel, Class<T> klass, FriendlyByteBuf.Reader<T> reader) {
+        return register(serverMessages, id, channel, klass, reader);
+    }
 
-        // Client messages
-        registry.registerClientbound(10, ChatTableClientMessage.class, ChatTableClientMessage::new);
-        registry.registerClientbound(11, PocketComputerDataMessage.class, PocketComputerDataMessage::new);
-        registry.registerClientbound(12, PocketComputerDeletedClientMessage.class, PocketComputerDeletedClientMessage::new);
-        registry.registerClientbound(13, ComputerTerminalClientMessage.class, ComputerTerminalClientMessage::new);
-        registry.registerClientbound(14, PlayRecordClientMessage.class, PlayRecordClientMessage::new);
-        registry.registerClientbound(15, MonitorClientMessage.class, MonitorClientMessage::new);
-        registry.registerClientbound(16, SpeakerAudioClientMessage.class, SpeakerAudioClientMessage::new);
-        registry.registerClientbound(17, SpeakerMoveClientMessage.class, SpeakerMoveClientMessage::new);
-        registry.registerClientbound(18, SpeakerPlayClientMessage.class, SpeakerPlayClientMessage::new);
-        registry.registerClientbound(19, SpeakerStopClientMessage.class, SpeakerStopClientMessage::new);
-        registry.registerClientbound(20, UploadResultMessage.class, UploadResultMessage::new);
-        registry.registerClientbound(21, UpgradesLoadedMessage.class, UpgradesLoadedMessage::new);
+    private static <T extends NetworkMessage<ClientNetworkContext>> MessageType<T> registerClientbound(int id, String channel, Class<T> klass, FriendlyByteBuf.Reader<T> reader) {
+        return register(clientMessages, id, channel, klass, reader);
+    }
+
+    /**
+     * Get all serverbound message types.
+     *
+     * @return An unmodifiable sequence of all serverbound message types.
+     */
+    public static Collection<MessageType<? extends NetworkMessage<ServerNetworkContext>>> getServerbound() {
+        return Collections.unmodifiableCollection(serverMessages);
+    }
+
+    /**
+     * Get all clientbound message types.
+     *
+     * @return An unmodifiable sequence of all clientbound message types.
+     */
+    public static Collection<MessageType<? extends NetworkMessage<ClientNetworkContext>>> getClientbound() {
+        return Collections.unmodifiableCollection(clientMessages);
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/ChatTableClientMessage.java

@@ -5,7 +5,9 @@
 package dan200.computercraft.shared.network.client;
 
 import dan200.computercraft.shared.command.text.TableBuilder;
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.network.chat.Component;
 
@@ -43,7 +45,7 @@ public class ChatTableClientMessage implements NetworkMessage<ClientNetworkConte
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeUtf(table.getId(), MAX_LEN);
         buf.writeVarInt(table.getColumns());
         buf.writeBoolean(table.getHeaders() != null);
@@ -63,4 +65,9 @@ public class ChatTableClientMessage implements NetworkMessage<ClientNetworkConte
     public void handle(ClientNetworkContext context) {
         context.handleChatTable(table);
     }
+
+    @Override
+    public MessageType<ChatTableClientMessage> type() {
+        return NetworkMessages.CHAT_TABLE;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/ClientNetworkContext.java

@@ -4,30 +4,24 @@
 
 package dan200.computercraft.shared.network.client;
 
-import dan200.computercraft.impl.Services;
 import dan200.computercraft.shared.command.text.TableBuilder;
 import dan200.computercraft.shared.computer.core.ComputerState;
 import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.computer.upload.UploadResult;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
-import io.netty.buffer.ByteBuf;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.sounds.SoundEvent;
 
 import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
 import java.util.UUID;
 
 /**
  * The context under which clientbound packets are evaluated.
  */
 public interface ClientNetworkContext {
-    static ClientNetworkContext get() {
-        var instance = Instance.INSTANCE;
-        return instance == null ? Services.raise(ClientNetworkContext.class, Instance.ERROR) : instance;
-    }
-
     void handleChatTable(TableBuilder table);
 
     void handleComputerTerminal(int containerId, TerminalState terminal);
@@ -40,9 +34,7 @@ public interface ClientNetworkContext {
 
     void handlePocketComputerDeleted(int instanceId);
 
-    void handleSpeakerAudio(UUID source, SpeakerPosition.Message position, float volume);
-
-    void handleSpeakerAudioPush(UUID source, ByteBuf buffer);
+    void handleSpeakerAudio(UUID source, SpeakerPosition.Message position, float volume, ByteBuffer audio);
 
     void handleSpeakerMove(UUID source, SpeakerPosition.Message position);
 
@@ -51,18 +43,4 @@ public interface ClientNetworkContext {
     void handleSpeakerStop(UUID source);
 
     void handleUploadResult(int containerId, UploadResult result, @Nullable Component errorMessage);
-
-    final class Instance {
-        static final @Nullable ClientNetworkContext INSTANCE;
-        static final @Nullable Throwable ERROR;
-
-        static {
-            var helper = Services.tryLoad(ClientNetworkContext.class);
-            INSTANCE = helper.instance();
-            ERROR = helper.error();
-        }
-
-        private Instance() {
-        }
-    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/ComputerTerminalClientMessage.java

@@ -5,7 +5,9 @@
 package dan200.computercraft.shared.network.client;
 
 import dan200.computercraft.shared.computer.terminal.TerminalState;
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 
@@ -25,7 +27,7 @@ public class ComputerTerminalClientMessage implements NetworkMessage<ClientNetwo
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeVarInt(containerId);
         terminal.write(buf);
     }
@@ -34,4 +36,9 @@ public class ComputerTerminalClientMessage implements NetworkMessage<ClientNetwo
     public void handle(ClientNetworkContext context) {
         context.handleComputerTerminal(containerId, terminal);
     }
+
+    @Override
+    public MessageType<ComputerTerminalClientMessage> type() {
+        return NetworkMessages.COMPUTER_TERMINAL;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/MonitorClientMessage.java

@@ -5,7 +5,9 @@
 package dan200.computercraft.shared.network.client;
 
 import dan200.computercraft.shared.computer.terminal.TerminalState;
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.FriendlyByteBuf;
 
@@ -25,7 +27,7 @@ public class MonitorClientMessage implements NetworkMessage<ClientNetworkContext
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeBlockPos(pos);
         state.write(buf);
     }
@@ -34,4 +36,9 @@ public class MonitorClientMessage implements NetworkMessage<ClientNetworkContext
     public void handle(ClientNetworkContext context) {
         context.handleMonitorData(pos, state);
     }
+
+    @Override
+    public MessageType<MonitorClientMessage> type() {
+        return NetworkMessages.MONITOR_CLIENT;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/PlayRecordClientMessage.java

@@ -4,7 +4,9 @@
 
 package dan200.computercraft.shared.network.client;
 
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import dan200.computercraft.shared.peripheral.diskdrive.DiskDriveBlockEntity;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.FriendlyByteBuf;
@@ -43,7 +45,7 @@ public class PlayRecordClientMessage implements NetworkMessage<ClientNetworkCont
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeBlockPos(pos);
         buf.writeNullable(soundEvent, (b, e) -> e.writeToNetwork(b));
         buf.writeNullable(name, FriendlyByteBuf::writeUtf);
@@ -53,4 +55,9 @@ public class PlayRecordClientMessage implements NetworkMessage<ClientNetworkCont
     public void handle(ClientNetworkContext context) {
         context.handlePlayRecord(pos, soundEvent, name);
     }
+
+    @Override
+    public MessageType<PlayRecordClientMessage> type() {
+        return NetworkMessages.PLAY_RECORD;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/PocketComputerDataMessage.java

@@ -7,7 +7,9 @@ package dan200.computercraft.shared.network.client;
 import dan200.computercraft.shared.computer.core.ComputerState;
 import dan200.computercraft.shared.computer.terminal.NetworkedTerminal;
 import dan200.computercraft.shared.computer.terminal.TerminalState;
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import dan200.computercraft.shared.pocket.core.PocketServerComputer;
 import net.minecraft.network.FriendlyByteBuf;
 
@@ -35,7 +37,7 @@ public class PocketComputerDataMessage implements NetworkMessage<ClientNetworkCo
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeVarInt(instanceId);
         buf.writeEnum(state);
         buf.writeVarInt(lightState);
@@ -46,4 +48,9 @@ public class PocketComputerDataMessage implements NetworkMessage<ClientNetworkCo
     public void handle(ClientNetworkContext context) {
         context.handlePocketComputerData(instanceId, state, lightState, terminal);
     }
+
+    @Override
+    public MessageType<PocketComputerDataMessage> type() {
+        return NetworkMessages.POCKET_COMPUTER_DATA;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/PocketComputerDeletedClientMessage.java

@@ -4,7 +4,9 @@
 
 package dan200.computercraft.shared.network.client;
 
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import net.minecraft.network.FriendlyByteBuf;
 
 
@@ -20,7 +22,7 @@ public class PocketComputerDeletedClientMessage implements NetworkMessage<Client
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeVarInt(instanceId);
     }
 
@@ -28,4 +30,9 @@ public class PocketComputerDeletedClientMessage implements NetworkMessage<Client
     public void handle(ClientNetworkContext context) {
         context.handlePocketComputerDeleted(instanceId);
     }
+
+    @Override
+    public MessageType<PocketComputerDeletedClientMessage> type() {
+        return NetworkMessages.POCKET_COMPUTER_DELETED;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/SpeakerAudioClientMessage.java

@@ -4,17 +4,16 @@
 
 package dan200.computercraft.shared.network.client;
 
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerBlockEntity;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
 import net.minecraft.network.FriendlyByteBuf;
 
-import javax.annotation.Nullable;
 import java.nio.ByteBuffer;
 import java.util.UUID;
 
-import static dan200.computercraft.core.util.Nullability.assertNonNull;
-
 /**
  * Starts a sound on the client.
  * <p>
@@ -25,7 +24,7 @@ import static dan200.computercraft.core.util.Nullability.assertNonNull;
 public class SpeakerAudioClientMessage implements NetworkMessage<ClientNetworkContext> {
     private final UUID source;
     private final SpeakerPosition.Message pos;
-    private final @Nullable ByteBuffer content;
+    private final ByteBuffer content;
     private final float volume;
 
     public SpeakerAudioClientMessage(UUID source, SpeakerPosition pos, float volume, ByteBuffer content) {
@@ -40,22 +39,26 @@ public class SpeakerAudioClientMessage implements NetworkMessage<ClientNetworkCo
         pos = SpeakerPosition.Message.read(buf);
         volume = buf.readFloat();
 
-        // TODO: Remove this, so we no longer need a getter for ClientNetworkContext. However, doing so without
-        //  leaking or redundantly copying the buffer is hard.
-        ClientNetworkContext.get().handleSpeakerAudioPush(source, buf);
-        content = null;
+        var bytes = new byte[buf.readableBytes()];
+        buf.readBytes(bytes);
+        content = ByteBuffer.wrap(bytes);
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeUUID(source);
         pos.write(buf);
         buf.writeFloat(volume);
-        buf.writeBytes(assertNonNull(content).duplicate());
+        buf.writeBytes(content.duplicate());
     }
 
     @Override
     public void handle(ClientNetworkContext context) {
-        context.handleSpeakerAudio(source, pos, volume);
+        context.handleSpeakerAudio(source, pos, volume, content);
+    }
+
+    @Override
+    public MessageType<SpeakerAudioClientMessage> type() {
+        return NetworkMessages.SPEAKER_AUDIO;
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/SpeakerMoveClientMessage.java

@@ -4,7 +4,9 @@
 
 package dan200.computercraft.shared.network.client;
 
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerBlockEntity;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
 import net.minecraft.network.FriendlyByteBuf;
@@ -33,7 +35,7 @@ public class SpeakerMoveClientMessage implements NetworkMessage<ClientNetworkCon
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeUUID(source);
         pos.write(buf);
     }
@@ -42,4 +44,9 @@ public class SpeakerMoveClientMessage implements NetworkMessage<ClientNetworkCon
     public void handle(ClientNetworkContext context) {
         context.handleSpeakerMove(source, pos);
     }
+
+    @Override
+    public MessageType<SpeakerMoveClientMessage> type() {
+        return NetworkMessages.SPEAKER_MOVE;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/SpeakerPlayClientMessage.java

@@ -4,7 +4,9 @@
 
 package dan200.computercraft.shared.network.client;
 
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerBlockEntity;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
 import net.minecraft.network.FriendlyByteBuf;
@@ -43,7 +45,7 @@ public class SpeakerPlayClientMessage implements NetworkMessage<ClientNetworkCon
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeUUID(source);
         pos.write(buf);
         buf.writeResourceLocation(sound);
@@ -55,4 +57,9 @@ public class SpeakerPlayClientMessage implements NetworkMessage<ClientNetworkCon
     public void handle(ClientNetworkContext context) {
         context.handleSpeakerPlay(source, pos, sound, volume, pitch);
     }
+
+    @Override
+    public MessageType<SpeakerPlayClientMessage> type() {
+        return NetworkMessages.SPEAKER_PLAY;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/SpeakerStopClientMessage.java

@@ -4,7 +4,9 @@
 
 package dan200.computercraft.shared.network.client;
 
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerBlockEntity;
 import net.minecraft.network.FriendlyByteBuf;
 
@@ -29,7 +31,7 @@ public class SpeakerStopClientMessage implements NetworkMessage<ClientNetworkCon
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeUUID(source);
     }
 
@@ -37,4 +39,9 @@ public class SpeakerStopClientMessage implements NetworkMessage<ClientNetworkCon
     public void handle(ClientNetworkContext context) {
         context.handleSpeakerStop(source);
     }
+
+    @Override
+    public MessageType<SpeakerStopClientMessage> type() {
+        return NetworkMessages.SPEAKER_STOP;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/UpgradesLoadedMessage.java

@@ -13,7 +13,9 @@ import dan200.computercraft.api.upgrades.UpgradeSerialiser;
 import dan200.computercraft.impl.PocketUpgrades;
 import dan200.computercraft.impl.TurtleUpgrades;
 import dan200.computercraft.impl.UpgradeManager;
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import dan200.computercraft.shared.platform.PlatformHelper;
 import net.minecraft.core.Registry;
 import net.minecraft.network.FriendlyByteBuf;
@@ -27,7 +29,7 @@ import java.util.Objects;
 /**
  * Syncs turtle and pocket upgrades to the client.
  */
-public class UpgradesLoadedMessage implements NetworkMessage<ClientNetworkContext> {
+public final class UpgradesLoadedMessage implements NetworkMessage<ClientNetworkContext> {
     private final Map<String, UpgradeManager.UpgradeWrapper<TurtleUpgradeSerialiser<?>, ITurtleUpgrade>> turtleUpgrades;
     private final Map<String, UpgradeManager.UpgradeWrapper<PocketUpgradeSerialiser<?>, IPocketUpgrade>> pocketUpgrades;
 
@@ -65,7 +67,7 @@ public class UpgradesLoadedMessage implements NetworkMessage<ClientNetworkContex
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         toBytes(buf, TurtleUpgradeSerialiser.registryId(), turtleUpgrades);
         toBytes(buf, PocketUpgradeSerialiser.registryId(), pocketUpgrades);
     }
@@ -95,4 +97,9 @@ public class UpgradesLoadedMessage implements NetworkMessage<ClientNetworkContex
         TurtleUpgrades.instance().loadFromNetwork(turtleUpgrades);
         PocketUpgrades.instance().loadFromNetwork(pocketUpgrades);
     }
+
+    @Override
+    public MessageType<UpgradesLoadedMessage> type() {
+        return NetworkMessages.UPGRADES_LOADED;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/UploadResultMessage.java

@@ -6,7 +6,9 @@ package dan200.computercraft.shared.network.client;
 
 import dan200.computercraft.core.util.Nullability;
 import dan200.computercraft.shared.computer.upload.UploadResult;
+import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.NetworkMessages;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.network.chat.Component;
 import net.minecraft.world.inventory.AbstractContainerMenu;
@@ -43,7 +45,7 @@ public class UploadResultMessage implements NetworkMessage<ClientNetworkContext>
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeVarInt(containerId);
         buf.writeEnum(result);
         if (result == UploadResult.ERROR) buf.writeComponent(Nullability.assertNonNull(errorMessage));
@@ -53,4 +55,9 @@ public class UploadResultMessage implements NetworkMessage<ClientNetworkContext>
     public void handle(ClientNetworkContext context) {
         context.handleUploadResult(containerId, result, errorMessage);
     }
+
+    @Override
+    public MessageType<UploadResultMessage> type() {
+        return NetworkMessages.UPLOAD_RESULT;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/server/ComputerActionServerMessage.java

@@ -5,6 +5,8 @@
 package dan200.computercraft.shared.network.server;
 
 import dan200.computercraft.shared.computer.menu.ComputerMenu;
+import dan200.computercraft.shared.network.MessageType;
+import dan200.computercraft.shared.network.NetworkMessages;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 
@@ -23,8 +25,8 @@ public class ComputerActionServerMessage extends ComputerServerMessage {
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
-        super.toBytes(buf);
+    public void write(FriendlyByteBuf buf) {
+        super.write(buf);
         buf.writeEnum(action);
     }
 
@@ -37,6 +39,11 @@ public class ComputerActionServerMessage extends ComputerServerMessage {
         }
     }
 
+    @Override
+    public MessageType<ComputerActionServerMessage> type() {
+        return NetworkMessages.COMPUTER_ACTION;
+    }
+
     public enum Action {
         TURN_ON,
         SHUTDOWN,

projects/common/src/main/java/dan200/computercraft/shared/network/server/ComputerServerMessage.java

@@ -28,7 +28,7 @@ public abstract class ComputerServerMessage implements NetworkMessage<ServerNetw
 
     @Override
     @OverridingMethodsMustInvokeSuper
-    public void toBytes(FriendlyByteBuf buf) {
+    public void write(FriendlyByteBuf buf) {
         buf.writeVarInt(containerId);
     }
 

projects/common/src/main/java/dan200/computercraft/shared/network/server/KeyEventServerMessage.java

@@ -5,6 +5,8 @@
 package dan200.computercraft.shared.network.server;
 
 import dan200.computercraft.shared.computer.menu.ComputerMenu;
+import dan200.computercraft.shared.network.MessageType;
+import dan200.computercraft.shared.network.NetworkMessages;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 
@@ -30,8 +32,8 @@ public class KeyEventServerMessage extends ComputerServerMessage {
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
-        super.toBytes(buf);
+    public void write(FriendlyByteBuf buf) {
+        super.write(buf);
         buf.writeByte(type);
         buf.writeVarInt(key);
     }
@@ -45,4 +47,9 @@ public class KeyEventServerMessage extends ComputerServerMessage {
             input.keyDown(key, type == TYPE_REPEAT);
         }
     }
+
+    @Override
+    public MessageType<KeyEventServerMessage> type() {
+        return NetworkMessages.KEY_EVENT;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/server/MouseEventServerMessage.java

@@ -5,6 +5,8 @@
 package dan200.computercraft.shared.network.server;
 
 import dan200.computercraft.shared.computer.menu.ComputerMenu;
+import dan200.computercraft.shared.network.MessageType;
+import dan200.computercraft.shared.network.NetworkMessages;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 
@@ -37,8 +39,8 @@ public class MouseEventServerMessage extends ComputerServerMessage {
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
-        super.toBytes(buf);
+    public void write(FriendlyByteBuf buf) {
+        super.write(buf);
         buf.writeByte(type);
         buf.writeVarInt(arg);
         buf.writeVarInt(x);
@@ -55,4 +57,9 @@ public class MouseEventServerMessage extends ComputerServerMessage {
             case TYPE_SCROLL -> input.mouseScroll(arg, x, y);
         }
     }
+
+    @Override
+    public MessageType<MouseEventServerMessage> type() {
+        return NetworkMessages.MOUSE_EVENT;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/server/QueueEventServerMessage.java

@@ -7,6 +7,8 @@ package dan200.computercraft.shared.network.server;
 import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.computer.menu.ComputerMenu;
 import dan200.computercraft.shared.computer.menu.ServerInputHandler;
+import dan200.computercraft.shared.network.MessageType;
+import dan200.computercraft.shared.network.NetworkMessages;
 import dan200.computercraft.shared.util.NBTUtil;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.world.inventory.AbstractContainerMenu;
@@ -37,8 +39,8 @@ public class QueueEventServerMessage extends ComputerServerMessage {
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
-        super.toBytes(buf);
+    public void write(FriendlyByteBuf buf) {
+        super.write(buf);
         buf.writeUtf(event);
         buf.writeNbt(args == null ? null : NBTUtil.encodeObjects(args));
     }
@@ -47,4 +49,9 @@ public class QueueEventServerMessage extends ComputerServerMessage {
     protected void handle(ServerNetworkContext context, ComputerMenu container) {
         container.getInput().queueEvent(event, args);
     }
+
+    @Override
+    public MessageType<QueueEventServerMessage> type() {
+        return NetworkMessages.QUEUE_EVENT;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/server/ServerNetworking.java

@@ -0,0 +1,82 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.network.server;
+
+import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.client.ClientNetworkContext;
+import dan200.computercraft.shared.platform.PlatformHelper;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ServerChunkCache;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.phys.Vec3;
+
+import java.util.Collection;
+
+/**
+ * Methods for sending network messages from the server to clients.
+ */
+public final class ServerNetworking {
+    private ServerNetworking() {
+    }
+
+    /**
+     * Send a message to a specific player.
+     *
+     * @param message The message to send.
+     * @param player  The player to send it to.
+     */
+    public static void sendToPlayer(NetworkMessage<ClientNetworkContext> message, ServerPlayer player) {
+        player.connection.send(PlatformHelper.get().createPacket(message));
+    }
+
+    /**
+     * Send a message to a set of players.
+     *
+     * @param message The message to send.
+     * @param players The players to send it to.
+     */
+    public static void sendToPlayers(NetworkMessage<ClientNetworkContext> message, Collection<ServerPlayer> players) {
+        if (players.isEmpty()) return;
+        var packet = PlatformHelper.get().createPacket(message);
+        for (var player : players) player.connection.send(packet);
+    }
+
+    /**
+     * Send a message to all players.
+     *
+     * @param message The message to send.
+     * @param server  The current server.
+     */
+    public static void sendToAllPlayers(NetworkMessage<ClientNetworkContext> message, MinecraftServer server) {
+        server.getPlayerList().broadcastAll(PlatformHelper.get().createPacket(message));
+    }
+
+    /**
+     * Send a message to all players around a point.
+     *
+     * @param message  The message to send.
+     * @param level    The level the point is in.
+     * @param pos      The centre position.
+     * @param distance The distance to the centre players must be within.
+     */
+    public static void sendToAllAround(NetworkMessage<ClientNetworkContext> message, ServerLevel level, Vec3 pos, float distance) {
+        level.getServer().getPlayerList().broadcast(null, pos.x, pos.y, pos.z, distance, level.dimension(), PlatformHelper.get().createPacket(message));
+    }
+
+    /**
+     * Send a message to all players tracking a chunk.
+     *
+     * @param message The message to send.
+     * @param chunk   The chunk players must be tracking.
+     */
+    public static void sendToAllTracking(NetworkMessage<ClientNetworkContext> message, LevelChunk chunk) {
+        var packet = PlatformHelper.get().createPacket(message);
+        for (var player : ((ServerChunkCache) chunk.getLevel().getChunkSource()).chunkMap.getPlayers(chunk.getPos(), false)) {
+            player.connection.send(packet);
+        }
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/network/server/UploadFileMessage.java

@@ -9,6 +9,8 @@ import dan200.computercraft.shared.computer.menu.ComputerMenu;
 import dan200.computercraft.shared.computer.upload.FileSlice;
 import dan200.computercraft.shared.computer.upload.FileUpload;
 import dan200.computercraft.shared.config.Config;
+import dan200.computercraft.shared.network.MessageType;
+import dan200.computercraft.shared.network.NetworkMessages;
 import io.netty.handler.codec.DecoderException;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.world.inventory.AbstractContainerMenu;
@@ -91,8 +93,8 @@ public class UploadFileMessage extends ComputerServerMessage {
     }
 
     @Override
-    public void toBytes(FriendlyByteBuf buf) {
-        super.toBytes(buf);
+    public void write(FriendlyByteBuf buf) {
+        super.write(buf);
         buf.writeUUID(uuid);
         buf.writeByte(flag);
 
@@ -166,4 +168,9 @@ public class UploadFileMessage extends ComputerServerMessage {
         input.continueUpload(uuid, slices);
         if ((flag & FLAG_LAST) != 0) input.finishUpload(player, uuid);
     }
+
+    @Override
+    public MessageType<UploadFileMessage> type() {
+        return NetworkMessages.UPLOAD_FILE;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/peripheral/diskdrive/DiskDriveBlockEntity.java

@@ -7,11 +7,12 @@ package dan200.computercraft.shared.peripheral.diskdrive;
 import com.google.errorprone.annotations.concurrent.GuardedBy;
 import dan200.computercraft.api.filesystem.Mount;
 import dan200.computercraft.api.filesystem.WritableMount;
+import dan200.computercraft.api.media.IMedia;
 import dan200.computercraft.api.peripheral.IComputerAccess;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.shared.common.AbstractContainerBlockEntity;
 import dan200.computercraft.shared.network.client.PlayRecordClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import dan200.computercraft.shared.util.WorldUtil;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
@@ -32,6 +33,28 @@ import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
 
+/**
+ * The underlying block entity for disk drives. This holds the main logic for the {@linkplain DiskDrivePeripheral disk
+ * drive peripheral}, such as handling mounts and {@linkplain DiskDrivePeripheral#playAudio() playing audio}.
+ * <p>
+ * Most disk drive peripheral methods execute on the computer thread (largely due to historic reasons). This causes some
+ * problems, as the disk item could be read by both the computer thread (via peripheral calls) and main thread (via
+ * Minecraft inventory interaction).
+ * <p>
+ * To solve this, we use an immutable {@link MediaStack}, which holds an immutable version of the current
+ * {@link ItemStack} (and its corresponding {@link IMedia}). When the {@linkplain #setChanged() inventory is changed},
+ * we {@linkplain #updateMedia() update the media stack} and recompute mounts.
+ * <p>
+ * This is somewhat complicated by {@link #attach(IComputerAccess)}. As that can happen on the computer thread and
+ * may mutate the stack (when {@link IMedia#createDataMount(ItemStack, ServerLevel)} assigns an ID for the first time),
+ * we need a way to safely update the inventory. To solve this, all internal non-inventory interactions with disk drives
+ * treat the media stack as the "primary" stack. This allows us to atomically update it, and then sync it back to the
+ * main inventory ({@link #updateMediaStack(ItemStack, boolean)}) either directly ({@link #updateDiskFromMedia()}) or
+ * on the next block tick ({@link #stackDirty}). This does mean there's a one-tick delay where the inventory may be
+ * out-of-date, but that should happen very rarely.
+ *
+ * @see DiskDrivePeripheral
+ */
 public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
     private static final String NBT_ITEM = "Item";
 
@@ -42,11 +65,13 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
 
     private final DiskDrivePeripheral peripheral = new DiskDrivePeripheral(this);
 
-    private final @GuardedBy("this") Map<IComputerAccess, MountInfo> computers = new HashMap<>();
-
     private final NonNullList<ItemStack> inventory = NonNullList.withSize(1, ItemStack.EMPTY);
 
+    @GuardedBy("this")
+    private final Map<IComputerAccess, MountInfo> computers = new HashMap<>();
+    @GuardedBy("this")
     private MediaStack media = MediaStack.EMPTY;
+    @GuardedBy("this")
     private @Nullable Mount mount;
 
     private boolean recordPlaying = false;
@@ -54,7 +79,12 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
     // then read them when ticking.
     private final AtomicReference<RecordCommand> recordQueued = new AtomicReference<>(null);
     private final AtomicBoolean ejectQueued = new AtomicBoolean(false);
-    private final AtomicBoolean mountQueued = new AtomicBoolean(false);
+
+    /**
+     * Whether the stack in {@link #media} has been modified on the computer thread, and needs to be written back to the
+     * inventory on the main thread.
+     */
+    private final AtomicBoolean stackDirty = new AtomicBoolean(false);
 
     public DiskDriveBlockEntity(BlockEntityType<DiskDriveBlockEntity> type, BlockPos pos, BlockState state) {
         super(type, pos, state);
@@ -66,7 +96,7 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
 
     @Override
     public void clearRemoved() {
-        updateItem();
+        updateMedia();
     }
 
     @Override
@@ -93,12 +123,14 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
     }
 
     void serverTick() {
+        if (stackDirty.getAndSet(false)) updateDiskFromMedia();
         if (ejectQueued.getAndSet(false)) ejectContents();
 
         var recordQueued = this.recordQueued.getAndSet(null);
         if (recordQueued != null) {
             switch (recordQueued) {
                 case PLAY -> {
+                    var media = getMedia();
                     var record = media.getAudio();
                     if (record != null) {
                         recordPlaying = true;
@@ -112,12 +144,6 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
                 }
             }
         }
-
-        if (mountQueued.get()) {
-            synchronized (this) {
-                mountAll();
-            }
-        }
     }
 
     @Override
@@ -127,38 +153,46 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
 
     @Override
     public void setChanged() {
-        if (level != null && !level.isClientSide) updateItem();
+        if (level != null && !level.isClientSide) updateMedia();
         super.setChanged();
     }
 
-    private void updateItem() {
-        var newDisk = getDiskStack();
-        if (ItemStack.isSameItemSameTags(newDisk, media.stack)) return;
+    /**
+     * Called on the server after the item has changed. This unmounts the old media and mounts the new one.
+     */
+    private synchronized void updateMedia() {
+        var newStack = getDiskStack();
+        if (ItemStack.isSameItemSameTags(newStack, media.stack())) return;
 
-        var media = MediaStack.of(newDisk);
+        var newMedia = MediaStack.of(newStack);
 
-        if (newDisk.isEmpty()) {
+        if (newStack.isEmpty()) {
             updateBlockState(DiskDriveState.EMPTY);
         } else {
-            updateBlockState(media.media != null ? DiskDriveState.FULL : DiskDriveState.INVALID);
+            updateBlockState(newMedia.media() != null ? DiskDriveState.FULL : DiskDriveState.INVALID);
         }
 
-        synchronized (this) {
-            // Unmount old disk
-            if (!this.media.stack.isEmpty()) {
-                for (var computer : computers.entrySet()) unmountDisk(computer.getKey(), computer.getValue());
+        // Unmount old disk
+        if (!media.stack().isEmpty()) {
+            for (var computer : computers.entrySet()) unmountDisk(computer.getKey(), computer.getValue());
+        }
+
+        // Stop music
+        if (recordPlaying) {
+            stopRecord();
+            recordPlaying = false;
+        }
+
+        // Use our new media, and (if needed) mount the new disk.
+        mount = null;
+        media = newMedia;
+        stackDirty.set(false);
+
+        if (!newStack.isEmpty() && !computers.isEmpty()) {
+            var mount = getOrCreateMount(true);
+            for (var entry : computers.entrySet()) {
+                mountDisk(entry.getKey(), entry.getValue(), mount);
             }
-
-            // Stop music
-            if (recordPlaying) {
-                stopRecord();
-                recordPlaying = false;
-            }
-
-            mount = null;
-            this.media = media;
-
-            mountAll();
         }
     }
 
@@ -166,7 +200,7 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
         return getItem(0);
     }
 
-    MediaStack getMedia() {
+    synchronized MediaStack getMedia() {
         return media;
     }
 
@@ -181,16 +215,31 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
     }
 
     /**
-     * Update the current disk stack, assuming the underlying item does not change. Unlike
-     * {@link #setDiskStack(ItemStack)} this will not change any mounts.
-     *
-     * @param stack The new disk stack.
+     * Update the inventory's disk stack from the media stack. Unlike {@link #setDiskStack(ItemStack)} this will not
+     * change any mounts.
      */
-    void updateDiskStack(ItemStack stack) {
-        setItem(0, stack);
-        if (!ItemStack.isSameItemSameTags(stack, media.stack)) {
-            media = MediaStack.of(stack);
-            super.setChanged();
+    private synchronized void updateDiskFromMedia() {
+        // Write back the item to the main inventory, and then mark it as dirty.
+        setItem(0, media.stack().copy());
+        super.setChanged();
+    }
+
+    /**
+     * Atomically update {@link #media}'s stack, then sync it back to the main inventory.
+     *
+     * @param stack     The original stack.
+     * @param immediate Whether to do this immediately (when called from the main thread) or asynchronously (when called
+     *                  from the computer thread).
+     */
+    @GuardedBy("this")
+    private void updateMediaStack(ItemStack stack, boolean immediate) {
+        if (ItemStack.isSameItemSameTags(media.stack(), stack)) return;
+        media = new MediaStack(stack, media.media());
+
+        if (immediate) {
+            updateDiskFromMedia();
+        } else {
+            stackDirty.set(true);
         }
     }
 
@@ -212,7 +261,9 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
         synchronized (this) {
             var info = new MountInfo();
             computers.put(computer, info);
-            mountQueued.set(true);
+            if (!media.stack().isEmpty()) {
+                mountDisk(computer, info, getOrCreateMount(level instanceof ServerLevel l && l.getServer().isSameThread()));
+            }
         }
     }
 
@@ -234,53 +285,50 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
         ejectQueued.set(true);
     }
 
-    /**
-     * Add our mount to all computers.
-     */
-    @GuardedBy("this")
-    private void mountAll() {
-        doMountAll();
-        mountQueued.set(false);
+    synchronized MountResult setDiskLabel(@Nullable String label) {
+        if (media.media() == null) return MountResult.NO_MEDIA;
+
+        // Set the label, and write it back to the media stack.
+        var stack = media.stack().copy();
+        if (!media.media().setLabel(stack, label)) return MountResult.NOT_ALLOWED;
+        updateMediaStack(stack, true);
+
+        return MountResult.CHANGED;
     }
 
-    /**
-     * The worker for {@link #mountAll()}. This is responsible for creating the mount and placing it on all computers.
-     */
     @GuardedBy("this")
-    private void doMountAll() {
-        if (computers.isEmpty() || media.media == null) return;
+    private @Nullable Mount getOrCreateMount(boolean immediate) {
+        if (media.media() == null) return null;
+        if (mount != null) return mount;
 
-        if (mount == null) {
-            var stack = getDiskStack();
-            mount = media.media.createDataMount(stack, (ServerLevel) level);
-            setDiskStack(stack);
-        }
+        // Set the id (if needed) and write it back to the media stack.
+        var stack = media.stack().copy();
+        mount = media.media().createDataMount(stack, (ServerLevel) level);
+        updateMediaStack(stack, immediate);
 
-        if (mount == null) return;
+        return mount;
+    }
 
-        for (var entry : computers.entrySet()) {
-            var computer = entry.getKey();
-            var info = entry.getValue();
-            if (info.mountPath != null) continue;
-
-            if (mount instanceof WritableMount writable) {
-                // Try mounting at the lowest numbered "disk" name we can
-                var n = 1;
-                while (info.mountPath == null) {
-                    info.mountPath = computer.mountWritable(n == 1 ? "disk" : "disk" + n, writable);
-                    n++;
-                }
-            } else {
-                // Try mounting at the lowest numbered "disk" name we can
-                var n = 1;
-                while (info.mountPath == null) {
-                    info.mountPath = computer.mount(n == 1 ? "disk" : "disk" + n, mount);
-                    n++;
-                }
+    private static void mountDisk(IComputerAccess computer, MountInfo info, @Nullable Mount mount) {
+        if (mount instanceof WritableMount writable) {
+            // Try mounting at the lowest numbered "disk" name we can
+            var n = 1;
+            while (info.mountPath == null) {
+                info.mountPath = computer.mountWritable(n == 1 ? "disk" : "disk" + n, writable);
+                n++;
             }
-
-            computer.queueEvent("disk", computer.getAttachmentName());
+        } else if (mount != null) {
+            // Try mounting at the lowest numbered "disk" name we can
+            var n = 1;
+            while (info.mountPath == null) {
+                info.mountPath = computer.mount(n == 1 ? "disk" : "disk" + n, mount);
+                n++;
+            }
+        } else {
+            assert info.mountPath == null : "Mount path should be null";
         }
+
+        computer.queueEvent("disk", computer.getAttachmentName());
     }
 
     private static void unmountDisk(IComputerAccess computer, MountInfo info) {
@@ -315,7 +363,7 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
     }
 
     private void sendMessage(PlayRecordClientMessage message) {
-        PlatformHelper.get().sendToAllAround(message, (ServerLevel) getLevel(), Vec3.atCenterOf(getBlockPos()), 64);
+        ServerNetworking.sendToAllAround(message, (ServerLevel) getLevel(), Vec3.atCenterOf(getBlockPos()), 64);
     }
 
     @Override
@@ -327,4 +375,10 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
         PLAY,
         STOP,
     }
+
+    enum MountResult {
+        NO_MEDIA,
+        NOT_ALLOWED,
+        CHANGED,
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/peripheral/diskdrive/DiskDrivePeripheral.java

@@ -51,7 +51,7 @@ public class DiskDrivePeripheral implements IPeripheral {
      */
     @LuaFunction
     public final boolean isDiskPresent() {
-        return !diskDrive.getMedia().stack.isEmpty();
+        return !diskDrive.getMedia().stack().isEmpty();
     }
 
     /**
@@ -64,7 +64,7 @@ public class DiskDrivePeripheral implements IPeripheral {
     @LuaFunction
     public final Object[] getDiskLabel() {
         var media = diskDrive.getMedia();
-        return media.media == null ? null : new Object[]{ media.media.getLabel(media.stack) };
+        return media.media() == null ? null : new Object[]{ media.media().getLabel(media.stack()) };
     }
 
     /**
@@ -80,15 +80,11 @@ public class DiskDrivePeripheral implements IPeripheral {
      */
     @LuaFunction(mainThread = true)
     public final void setDiskLabel(Optional<String> label) throws LuaException {
-        var media = diskDrive.getMedia();
-        if (media.media == null) return;
-
-        // We're on the main thread so the stack and media should be in sync.
-        var stack = diskDrive.getDiskStack();
-        if (!media.media.setLabel(stack, label.map(StringUtil::normaliseLabel).orElse(null))) {
-            throw new LuaException("Disk label cannot be changed");
+        switch (diskDrive.setDiskLabel(label.map(StringUtil::normaliseLabel).orElse(null))) {
+            case NOT_ALLOWED -> throw new LuaException("Disk label cannot be changed");
+            case CHANGED, NO_MEDIA -> {
+            }
         }
-        diskDrive.updateDiskStack(stack);
     }
 
     /**
@@ -172,7 +168,7 @@ public class DiskDrivePeripheral implements IPeripheral {
     @Nullable
     @LuaFunction
     public final Object[] getDiskID() {
-        var disk = diskDrive.getMedia().stack;
+        var disk = diskDrive.getMedia().stack();
         return disk.getItem() instanceof DiskItem ? new Object[]{ DiskItem.getDiskID(disk) } : null;
     }
 

projects/common/src/main/java/dan200/computercraft/shared/peripheral/diskdrive/MediaStack.java

@@ -13,19 +13,14 @@ import javax.annotation.Nullable;
 
 /**
  * An immutable snapshot of the current disk. This allows us to read the stack in a thread-safe manner.
+ *
+ * @param stack An immutable {@link ItemStack}.
+ * @param media The associated {@link IMedia} instance for this stack.
  */
-final class MediaStack {
+record MediaStack(ItemStack stack, @Nullable IMedia media) {
     static final MediaStack EMPTY = new MediaStack(ItemStack.EMPTY, null);
 
-    final ItemStack stack;
-    final @Nullable IMedia media;
-
-    private MediaStack(ItemStack stack, @Nullable IMedia media) {
-        this.stack = stack;
-        this.media = media;
-    }
-
-    public static MediaStack of(ItemStack stack) {
+    static MediaStack of(ItemStack stack) {
         if (stack.isEmpty()) return EMPTY;
 
         var freshStack = stack.copy();