Add bundle/backup and buffer/format-at

bundle/backup is needed to make failed reinstalls able to rollback. It
also allows python wheel like functionality, where bundles can be build
on one machine, packaged, and then distributed and installed on other
compatible machines without compilers.

buffer/format-at is to buffer/format as buffer/push-at is to
buffer/push. It allows us to format in the middle of an existing
buffer. Prior, to do this operation and extra buffer creating was
required.

src/boot/boot.janet

@@ -4001,6 +4001,16 @@
     (put manifest :files files)
     files)
 
+  (defn- rmrf
+    "rm -rf in janet"
+    [x]
+    (case (os/stat x :mode)
+      :file (os/rm x)
+      :directory (do
+                   (each y (os/dir x) (rmrf (string x "/" y)))
+                   (os/rmdir x)))
+    nil)
+
   (defn- sync-manifest
     [&opt manifest]
     (default manifest (dyn *bundle-manifest*))
@@ -4050,10 +4060,7 @@
         :file (os/rm file)
         :directory (os/rmdir file)))
     (os/rm (get-manifest-filename bundle-name))
-    (def hf (get-hook-filename bundle-name))
-    (each hook (os/dir hf)
-      (os/rm (string hf "/" hook)))
-    (os/rmdir hf)
+    (rmrf (get-hook-filename bundle-name))
     nil)
 
   (defn bundle/install
@@ -4066,8 +4073,8 @@
     (prime-bundle-paths)
     (def src-hooks (string path "/hooks/"))
     (copy-hooks src-hooks bundle-name)
-    (def man @{:bundle-name bundle-name :local-source path})
-    (when config (merge-into man config))
+    (def man @{:bundle-name bundle-name :local-source path :config config})
+    (merge-into man config)
     (spit (get-manifest-filename bundle-name) (string/format "%j\n" man))
     (edefer (do (print "installation error, uninstalling") (bundle/uninstall bundle-name))
       (bundle/do-hook bundle-name "deps.janet")
@@ -4075,6 +4082,54 @@
       (bundle/do-hook bundle-name "install.janet"))
     nil)
 
+  (defn bundle/backup
+    "Take an installed bundle and create a bundle source directory that can be used to
+     reinstall this bundle on a compatible system. This is used to create backups for installed
+     bundles without rebuilding."
+    [bundle-name dest-dir]
+    (def man (bundle/manifest bundle-name))
+    (def files (get man :files @[]))
+    (assert (os/mkdir dest-dir) (string "could not create directory " dest-dir " (or it already exists)"))
+    (def hooks-dir (string dest-dir "/hooks"))
+    (def install-hook (string dest-dir "/hooks/install.janet"))
+    (edefer (rmrf dest-dir) # don't leave garbage on failure
+      (var i 0)
+      (def install-source @[])
+      (def syspath (os/realpath (dyn *syspath*)))
+      (os/mkdir hooks-dir)
+      (each file files
+        (def {:mode mode :permissions perm} (os/stat file))
+        (def relpath (string/triml (slice file (length syspath) -1) "/"))
+        (case mode
+          :directory (array/push install-source ~(bundle/add-directory ,relpath ,perm))
+          :file (do
+                  (def filename (string/format "file_%04d" (++ i)))
+                  (spit (string dest-dir "/" filename) (slurp file))
+                  (array/push install-source ~(bundle/add-file ,filename ,relpath ,perm)))
+          (errorf "unexpected file %v" file)))
+      (def b @"")
+      (each form install-source (buffer/format b "%j\n" form))
+      (spit install-hook b))
+    dest-dir)
+
+  (defn bundle/reinstall
+    "Reinstall an existing bundle from the local source code. Should not break installation in reinstallation fails."
+    [bundle-name]
+    (def manifest (bundle/manifest bundle-name))
+    (def path (get manifest :local-source))
+    (def config (get manifest :config @{}))
+    (assert (= :directory (os/stat path :mode)) "local source not available")
+
+    (def backup-dir (string (dyn *syspath*) "/.temp_" bundle-name))
+    (def backup-bundle-source (bundle/backup bundle-name backup-dir))
+    (edefer (do
+              (bundle/install bundle-name backup-bundle-source)
+              (rmrf backup-bundle-source))
+      (bundle/uninstall bundle-name)
+      (bundle/install path bundle-name ;(kvs config)))
+    (rmrf backup-bundle-source)
+    bundle-name)
+
   (defn bundle/add-directory
     "Add a directory during the install process relative to `(dyn *syspath*)`"
     [dest &opt chmod-mode]
@@ -4101,7 +4156,7 @@
       (spit absdest (slurp src))
       (array/push files absdest)
       (when chmod-mode
-        (os/chmod dest chmod-mode))
+        (os/chmod absdest chmod-mode))
       (print "adding " absdest)
       absdest))
 
@@ -4112,7 +4167,13 @@
     (if (os/stat d :mode)
       (sort (seq [x :in (os/dir (get-manifest-filename))]
               (string/slice x 0 -5)))
-      @[])))
+      @[]))
+
+  (defn bundle/update-all
+    "Reinstall all bundles"
+    []
+    (each bundle (bundle/list)
+      (bundle/reinstall bundle))))
 
 ###
 ###

src/core/buffer.c

@@ -655,6 +655,27 @@ JANET_CORE_FN(cfun_buffer_format,
     return argv[0];
 }
 
+JANET_CORE_FN(cfun_buffer_format_at,
+              "(buffer/format-at buffer at format & args)",
+              "Snprintf like functionality for printing values into a buffer. Returns "
+              "the modified buffer.") {
+    janet_arity(argc, 2, -1);
+    JanetBuffer *buffer = janet_getbuffer(argv, 0);
+    int32_t at = janet_getinteger(argv, 1);
+    if (at < 0) {
+        at += buffer->count + 1;
+    }
+    if (at > buffer->count) janet_panicf("expected index at to be in range [0, %d), got %d", buffer->count, at);
+    int32_t oldcount = buffer->count;
+    buffer->count = at;
+    const char *strfrmt = (const char *) janet_getstring(argv, 2);
+    janet_buffer_format(buffer, strfrmt, 2, argc, argv);
+    if (buffer->count < oldcount) {
+        buffer->count = oldcount;
+    }
+    return argv[0];
+}
+
 void janet_lib_buffer(JanetTable *env) {
     JanetRegExt buffer_cfuns[] = {
         JANET_CORE_REG("buffer/new", cfun_buffer_new),
@@ -681,6 +702,7 @@ void janet_lib_buffer(JanetTable *env) {
         JANET_CORE_REG("buffer/bit-toggle", cfun_buffer_bittoggle),
         JANET_CORE_REG("buffer/blit", cfun_buffer_blit),
         JANET_CORE_REG("buffer/format", cfun_buffer_format),
+        JANET_CORE_REG("buffer/format-at", cfun_buffer_format_at),
         JANET_REG_END
     };
     janet_core_cfuns_ext(env, NULL, buffer_cfuns);