Make the fuchsia mojo/public repo the source of truth.

mojo/public/java/bindings/src/org/chromium/mojo/bindings/Connector.java

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package org.chromium.mojo.bindings;
-
-import org.chromium.mojo.system.AsyncWaiter;
-import org.chromium.mojo.system.Core;
-import org.chromium.mojo.system.MessagePipeHandle;
-import org.chromium.mojo.system.MessagePipeHandle.ReadMessageResult;
-import org.chromium.mojo.system.MojoException;
-import org.chromium.mojo.system.MojoResult;
-import org.chromium.mojo.system.ResultAnd;
-
-import java.nio.ByteBuffer;
-
-/**
- * A {@link Connector} owns a {@link MessagePipeHandle} and will send any received messages to the
- * registered {@link MessageReceiver}. It also acts as a {@link MessageReceiver} and will send any
- * message through the handle.
- * <p>
- * The method |start| must be called before the {@link Connector} will start listening to incoming
- * messages.
- */
-public class Connector implements MessageReceiver, HandleOwner<MessagePipeHandle> {
-
-    /**
-     * The callback that is notified when the state of the owned handle changes.
-     */
-    private final AsyncWaiterCallback mAsyncWaiterCallback = new AsyncWaiterCallback();
-
-    /**
-     * The owned message pipe.
-     */
-    private final MessagePipeHandle mMessagePipeHandle;
-
-    /**
-     * A waiter which is notified when a new message is available on the owned message pipe.
-     */
-    private final AsyncWaiter mAsyncWaiter;
-
-    /**
-     * The {@link MessageReceiver} to which received messages are sent.
-     */
-    private MessageReceiver mIncomingMessageReceiver;
-
-    /**
-     * The Cancellable for the current wait. Is |null| when not currently waiting for new messages.
-     */
-    private AsyncWaiter.Cancellable mCancellable;
-
-    /**
-     * The error handler to notify of errors.
-     */
-    private ConnectionErrorHandler mErrorHandler;
-
-    /**
-     * Create a new connector over a |messagePipeHandle|. The created connector will use the default
-     * {@link AsyncWaiter} from the {@link Core} implementation of |messagePipeHandle|.
-     */
-    public Connector(MessagePipeHandle messagePipeHandle) {
-        this(messagePipeHandle, BindingsHelper.getDefaultAsyncWaiterForHandle(messagePipeHandle));
-    }
-
-    /**
-     * Create a new connector over a |messagePipeHandle| using the given {@link AsyncWaiter} to get
-     * notified of changes on the handle.
-     */
-    public Connector(MessagePipeHandle messagePipeHandle, AsyncWaiter asyncWaiter) {
-        mCancellable = null;
-        mMessagePipeHandle = messagePipeHandle;
-        mAsyncWaiter = asyncWaiter;
-    }
-
-    /**
-     * Set the {@link MessageReceiver} that will receive message from the owned message pipe.
-     */
-    public void setIncomingMessageReceiver(MessageReceiver incomingMessageReceiver) {
-        mIncomingMessageReceiver = incomingMessageReceiver;
-    }
-
-    /**
-     * Set the {@link ConnectionErrorHandler} that will be notified of errors on the owned message
-     * pipe.
-     */
-    public void setErrorHandler(ConnectionErrorHandler errorHandler) {
-        mErrorHandler = errorHandler;
-    }
-
-    /**
-     * Start listening for incoming messages.
-     */
-    public void start() {
-        assert mCancellable == null;
-        registerAsyncWaiterForRead();
-    }
-
-    /**
-     * @see MessageReceiver#accept(Message)
-     */
-    @Override
-    public boolean accept(Message message) {
-        try {
-            mMessagePipeHandle.writeMessage(message.getData(),
-                    message.getHandles(), MessagePipeHandle.WriteFlags.NONE);
-            return true;
-        } catch (MojoException e) {
-            onError(e);
-            return false;
-        }
-    }
-
-    /**
-     * Pass the owned handle of the connector. After this, the connector is disconnected. It cannot
-     * accept new message and it isn't listening to the handle anymore.
-     *
-     * @see org.chromium.mojo.bindings.HandleOwner#passHandle()
-     */
-    @Override
-    public MessagePipeHandle passHandle() {
-        cancelIfActive();
-        MessagePipeHandle handle = mMessagePipeHandle.pass();
-        if (mIncomingMessageReceiver != null) {
-            mIncomingMessageReceiver.close();
-        }
-        return handle;
-    }
-
-    /**
-     * @see java.io.Closeable#close()
-     */
-    @Override
-    public void close() {
-        cancelIfActive();
-        mMessagePipeHandle.close();
-        if (mIncomingMessageReceiver != null) {
-            MessageReceiver incomingMessageReceiver = mIncomingMessageReceiver;
-            mIncomingMessageReceiver = null;
-            incomingMessageReceiver.close();
-        }
-    }
-
-    private class AsyncWaiterCallback implements AsyncWaiter.Callback {
-
-        /**
-         * @see org.chromium.mojo.system.AsyncWaiter.Callback#onResult(int)
-         */
-        @Override
-        public void onResult(int result) {
-            Connector.this.onAsyncWaiterResult(result);
-        }
-
-        /**
-         * @see org.chromium.mojo.system.AsyncWaiter.Callback#onError(MojoException)
-         */
-        @Override
-        public void onError(MojoException exception) {
-            mCancellable = null;
-            Connector.this.onError(exception);
-        }
-
-    }
-
-    /**
-     * @see org.chromium.mojo.system.AsyncWaiter.Callback#onResult(int)
-     */
-    private void onAsyncWaiterResult(int result) {
-        mCancellable = null;
-        if (result == MojoResult.OK) {
-            readOutstandingMessages();
-        } else {
-            onError(new MojoException(result));
-        }
-    }
-
-    private void onError(MojoException exception) {
-        close();
-        assert mCancellable == null;
-        if (mErrorHandler != null) {
-            mErrorHandler.onConnectionError(exception);
-        }
-    }
-
-    /**
-     * Register to be called back when a new message is available on the owned message pipe.
-     */
-    private void registerAsyncWaiterForRead() {
-        assert mCancellable == null;
-        if (mAsyncWaiter != null) {
-            mCancellable = mAsyncWaiter.asyncWait(mMessagePipeHandle, Core.HandleSignals.READABLE,
-                    Core.DEADLINE_INFINITE, mAsyncWaiterCallback);
-        } else {
-            onError(new MojoException(MojoResult.INVALID_ARGUMENT));
-        }
-    }
-
-    /**
-     * Read all available messages on the owned message pipe.
-     */
-    private void readOutstandingMessages() {
-        ResultAnd<Boolean> result;
-        do {
-            try {
-                result = readAndDispatchMessage(mMessagePipeHandle, mIncomingMessageReceiver);
-            } catch (MojoException e) {
-                onError(e);
-                return;
-            }
-        } while (result.getValue());
-        if (result.getMojoResult() == MojoResult.SHOULD_WAIT) {
-            registerAsyncWaiterForRead();
-        } else {
-            onError(new MojoException(result.getMojoResult()));
-        }
-    }
-
-    private void cancelIfActive() {
-        if (mCancellable != null) {
-            mCancellable.cancel();
-            mCancellable = null;
-        }
-    }
-
-    /**
-     * Read a message, and pass it to the given |MessageReceiver| if not null. If the
-     * |MessageReceiver| is null, the message is lost.
-     *
-     * @param receiver The {@link MessageReceiver} that will receive the read {@link Message}. Can
-     *            be <code>null</code>, in which case the message is discarded.
-     */
-    static ResultAnd<Boolean> readAndDispatchMessage(
-            MessagePipeHandle handle, MessageReceiver receiver) {
-        // TODO(qsr) Allow usage of a pool of pre-allocated buffer for performance.
-        ResultAnd<ReadMessageResult> result =
-                handle.readMessage(null, 0, MessagePipeHandle.ReadFlags.NONE);
-        if (result.getMojoResult() != MojoResult.RESOURCE_EXHAUSTED) {
-            return new ResultAnd<Boolean>(result.getMojoResult(), false);
-        }
-        ReadMessageResult readResult = result.getValue();
-        assert readResult != null;
-        ByteBuffer buffer = ByteBuffer.allocateDirect(readResult.getMessageSize());
-        result = handle.readMessage(
-                buffer, readResult.getHandlesCount(), MessagePipeHandle.ReadFlags.NONE);
-        if (receiver != null && result.getMojoResult() == MojoResult.OK) {
-            boolean accepted = receiver.accept(new Message(buffer, result.getValue().getHandles()));
-            return new ResultAnd<Boolean>(result.getMojoResult(), accepted);
-        }
-        return new ResultAnd<Boolean>(result.getMojoResult(), false);
-    }
-}