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Truffle is a multi-language framework for executing dynamic languages
that achieves high performance when combined with Graal.
/*
* Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* The Universal Permissive License (UPL), Version 1.0
*
* Subject to the condition set forth below, permission is hereby granted to any
* person obtaining a copy of this software, associated documentation and/or
* data (collectively the "Software"), free of charge and under any and all
* copyright rights in the Software, and any and all patent rights owned or
* freely licensable by each licensor hereunder covering either (i) the
* unmodified Software as contributed to or provided by such licensor, or (ii)
* the Larger Works (as defined below), to deal in both
*
* (a) the Software, and
*
* (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
* one is included with the Software each a "Larger Work" to which the Software
* is contributed by such licensors),
*
* without restriction, including without limitation the rights to copy, create
* derivative works of, display, perform, and distribute the Software and make,
* use, sell, offer for sale, import, export, have made, and have sold the
* Software and the Larger Work(s), and to sublicense the foregoing rights on
* either these or other terms.
*
* This license is subject to the following condition:
*
* The above copyright notice and either this complete permission notice or at a
* minimum a reference to the UPL must be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package com.oracle.truffle.api.library;
import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.library.GenerateLibrary.Abstract;
import com.oracle.truffle.api.library.GenerateLibrary.DefaultExport;
/**
* The reflection library allows to send to and proxy messages of receivers. The reflection library
* may be used for any receiver object. If a sent message is not implemented by the target receiver
* then the default library export will be used, otherwise it is forwarded to the resolved exported
* message. If the reflection library is exported by a receiver directly then the reflection
* behavior can be customized. This allows, for example, to proxy all messages to a delegate
* instance.
*
* Sending Messages
*
* Messages can be sent to receivers by first {@link Message#resolve(Class, String) resolving} a
* target message. Then the message can be sent to a receiver that may implement that message. The
* message name and class may be resolved dynamically.
*
* Usage example
*
*
* String messageName = "isArray";
* Message message = Message.resolve(ArrayLibrary.class, messageName);
* Object receiver = 42;
* try {
* ReflectionLibrary.getFactory().getUncached().send(receiver, message);
* } catch (Exception e) {
* // handle error
* }
*
*
* Proxies
*
* It is possible to proxy library messages to a delegate object. To achieve that the reflection
* library can be exported by a receiver type.
*
* Usage example
*
*
* @ExportLibrary(ReflectionLibrary.class)
* static class AgnosticWrapper {
*
* final Object delegate;
*
* AgnosticWrapper(Object delegate) {
* this.delegate = delegate;
* }
*
* @ExportMessage
* final Object send(Message message, Object[] args,
* @CachedLibrary("this.delegate") ReflectionLibrary reflection) throws Exception {
* // do before
* Object result = reflection.send(delegate, message, args);
* // do after
* return result;
* }
* }
*
*
*
* @since 19.0
*/
@GenerateLibrary
@DefaultExport(ReflectionLibraryDefault.class)
public abstract class ReflectionLibrary extends Library {
/**
* Constructor for generated subclasses. Subclasses of this class are generated, do not extend
* this class directly.
*
* @since 19.0
*/
protected ReflectionLibrary() {
}
/**
* Sends a given message to the target receiver with the provided arguments. The provided
* receiver and message must not be null. If the argument types don't match the expected message
* signature then an {@link IllegalArgumentException} will be thrown.
*
* @since 19.0
*/
@Abstract
@SuppressWarnings("unused")
@TruffleBoundary
public Object send(Object receiver, Message message, Object... args) throws Exception {
throw new AbstractMethodError();
}
private static final LibraryFactory FACTORY = LibraryFactory.resolve(ReflectionLibrary.class);
static final ReflectionLibrary UNCACHED = FACTORY.getUncached();
/**
* Returns the library factory for {@link ReflectionLibrary}.
*
* @since 19.0
*/
public static LibraryFactory getFactory() {
return FACTORY;
}
/**
* Returns the uncached automatically dispatched version of the reflection library. This is a
* short-cut for calling ReflectionLibrary.getFactory().getUncached().
*
* @see LibraryFactory#getUncached()
* @since 21.3
*/
public static ReflectionLibrary getUncached() {
return UNCACHED;
}
/**
* Returns the uncached manually dispatched version of the reflection library. This is a
* short-cut for calling ReflectionLibrary.getFactory().getUncached(v).
*
* @see LibraryFactory#getUncached(Object)
* @since 21.3
*/
public static ReflectionLibrary getUncached(Object v) {
return FACTORY.getUncached(v);
}
}
@ExportLibrary(value = ReflectionLibrary.class, receiverType = Object.class)
final class ReflectionLibraryDefault {
static final int LIMIT = 8;
@ExportMessage
static class Send {
@Specialization(guards = {"message == cachedMessage", "cachedLibrary.accepts(receiver)"}, limit = "LIMIT")
static Object doSendCached(Object receiver, @SuppressWarnings("unused") Message message, Object[] args,
@Cached("message") Message cachedMessage,
@Cached("createLibrary(message, receiver)") Library cachedLibrary) throws Exception {
return cachedMessage.getFactory().genericDispatch(cachedLibrary, receiver, cachedMessage, args, 0);
}
static Library createLibrary(Message message, Object receiver) {
return message.getFactory().create(receiver);
}
@Specialization(replaces = "doSendCached")
@TruffleBoundary
static Object doSendGeneric(Object receiver, Message message, Object[] args) throws Exception {
LibraryFactory lib = message.getFactory();
return lib.genericDispatch(lib.getUncached(receiver), receiver, message, args, 0);
}
}
}