CC-Tweaked/src/main/java/dan200/computercraft/core/asm/GenericSource.java

101 lines
3.7 KiB
Java

/*
* This file is part of ComputerCraft - http://www.computercraft.info
* Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
* Send enquiries to dratcliffe@gmail.com
*/
package dan200.computercraft.core.asm;
import dan200.computercraft.ComputerCraft;
import dan200.computercraft.api.lua.LuaFunction;
import dan200.computercraft.shared.peripheral.generic.GenericPeripheralProvider;
import net.minecraft.util.ResourceLocation;
import javax.annotation.Nonnull;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
import java.util.ServiceLoader;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;
/**
* A generic source of {@link LuaMethod} functions. This allows for injecting methods onto objects you do not own.
*
* Unlike conventional Lua objects, the annotated methods should be {@code static}, with their target as the first
* parameter.
*
* This is used by the generic peripheral system ({@link GenericPeripheralProvider}) to provide methods for arbitrary
* tile entities. Eventually this'll be be exposed in the public API. Until it is stabilised, it will remain in this
* package - do not use it in external mods!
*/
public interface GenericSource
{
/**
* A unique identifier for this generic source. This may be used in the future to allow disabling specific sources.
*
* @return This source's identifier.
*/
@Nonnull
ResourceLocation id();
/**
* A generic method is a method belonging to a {@link GenericSource} with a known target.
*/
class GenericMethod
{
final Method method;
final LuaFunction annotation;
final Class<?> target;
private static List<GenericMethod> cache;
GenericMethod( Method method, LuaFunction annotation, Class<?> target )
{
this.method = method;
this.annotation = annotation;
this.target = target;
}
/**
* Find all public static methods annotated with {@link LuaFunction} which belong to a {@link GenericSource}.
*
* @return All available generic methods.
*/
static List<GenericMethod> all()
{
if( cache != null ) return cache;
return cache = StreamSupport
.stream( ServiceLoader.load( GenericSource.class, GenericSource.class.getClassLoader() ).spliterator(), false )
.flatMap( x -> Arrays.stream( x.getClass().getDeclaredMethods() ) )
.map( method -> {
LuaFunction annotation = method.getAnnotation( LuaFunction.class );
if( annotation == null ) return null;
if( !Modifier.isStatic( method.getModifiers() ) )
{
ComputerCraft.log.error( "GenericSource method {}.{} should be static.", method.getDeclaringClass(), method.getName() );
return null;
}
Type[] types = method.getGenericParameterTypes();
if( types.length == 0 )
{
ComputerCraft.log.error( "GenericSource method {}.{} has no parameters.", method.getDeclaringClass(), method.getName() );
return null;
}
Class<?> target = Reflect.getRawType( method, types[0], false );
if( target == null ) return null;
return new GenericMethod( method, annotation, target );
} )
.filter( Objects::nonNull )
.collect( Collectors.toList() );
}
}
}