Revert of DevTools socket tunnel.

components/devtools_bridge/android/java/src/org/chromium/components/devtools_bridge/SocketTunnelBase.java

Index: components/devtools_bridge/android/java/src/org/chromium/components/devtools_bridge/SocketTunnelBase.java
diff --git a/components/devtools_bridge/android/java/src/org/chromium/components/devtools_bridge/SocketTunnelBase.java b/components/devtools_bridge/android/java/src/org/chromium/components/devtools_bridge/SocketTunnelBase.java
deleted file mode 100644
index 7c1439a516fbc17f246053737649936bf6c15f8e..0000000000000000000000000000000000000000
--- a/components/devtools_bridge/android/java/src/org/chromium/components/devtools_bridge/SocketTunnelBase.java
+++ /dev/null
@@ -1,396 +0,0 @@
-// 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.components.devtools_bridge;
-
-import android.net.LocalSocket;
-import android.net.LocalSocketAddress;
-
-import java.io.IOException;
-import java.nio.ByteBuffer;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.atomic.AtomicReference;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReadWriteLock;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
-
-/**
- * Base class for client and server that tunnels DevToolsServer's UNIX socket
- * over WebRTC data channel.
- *
- * Server runs on a android device with Chromium (or alike). Client runs where socket
- * needed to be accesses (it could be the same device if socket names are different; this
- * configuration useful for testing).
- *
- * Client listens LocalServerSocket and each time it receives connection it forwards
- * CLIENT_OPEN packet to the server with newly assigned connection id. On receiving this packet
- * server tries to connect to DevToolsServer socket. If succeeded it sends back SERVER_OPEN_ACK
- * with the same connection id. If failed it sends SERVER_CLOSE.
- *
- * When input stream on client shuts down it sends CLIENT_CLOSE. The same with SERVER_CLOSE
- * on the server side (only if SERVER_OPEN_ACK had sent). Between CLIENT_OPEN and CLIENT_CLOSE
- * any amount of data packets may be transferred (the same for SERVER_OPEN_ACK/SERVER_CLOSE
- * on the server side).
- *
- * Since all communication is reliable and ordered it's safe for client to assume that
- * if CLIENT_CLOSE has sent and SERVER_CLOSE has received with the same connection ID this
- * ID is safe to be reused.
- */
-public abstract class SocketTunnelBase {
-    // Data channel is threadsafe but access to the reference needs synchromization.
-    private final ReadWriteLock mDataChanneliReferenceLock = new ReentrantReadWriteLock();
-    private volatile AbstractDataChannel mDataChannel;
-
-    // Packet structure encapsulated in buildControlPacket, buildDataPacket and PacketDecoderBase.
-    // Structure of control packet:
-    // 1-st byte: CONTROL_CONNECTION_ID.
-    // 2-d byte: op code.
-    // 3-d byte: connection id.
-    //
-    // Structure of data packet:
-    // 1-st byte: connection id.
-    // 2..n: data.
-
-    private static final int CONTROL_PACKET_SIZE = 3;
-
-    // Client to server control packets.
-    protected static final byte CLIENT_OPEN = (byte) 0;
-    protected static final byte CLIENT_CLOSE = (byte) 1;
-
-    // Server to client control packets.
-    protected static final byte SERVER_OPEN_ACK = (byte) 0;
-    protected static final byte SERVER_CLOSE = (byte) 1;
-
-    // Must not exceed WebRTC limit. Exceeding it closes
-    // data channel automatically. TODO(serya): WebRTC limit supposed to be removed.
-    static final int READING_BUFFER_SIZE = 4 * 1024;
-
-    private static final int CONTROL_CONNECTION_ID = 0;
-
-    // DevTools supports up to ~10 connections at the time. A few extra IDs usefull for
-    // delays in closing acknowledgement.
-    protected static final int MIN_CONNECTION_ID = 1;
-    protected static final int MAX_CONNECTION_ID = 64;
-
-    // Signaling thread isn't accessible via API. Assumes that first caller
-    // checkCalledOnSignalingThread is called on it indeed. It also works well for tests.
-    private final AtomicReference<Thread> mSignalingThread = new AtomicReference<Thread>();
-
-    // For writing in socket without blocking signaling thread.
-    private final ExecutorService mWritingThread = Executors.newSingleThreadExecutor();
-
-    public boolean isBound() {
-        final Lock lock = mDataChanneliReferenceLock.readLock();
-        lock.lock();
-        try {
-            return mDataChannel != null;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Binds the tunnel to the data channel. Tunnel starts its activity when data channel
-     * open.
-     */
-    public void bind(AbstractDataChannel dataChannel) {
-        // Observer registrution must not be done in constructor.
-        final Lock lock = mDataChanneliReferenceLock.writeLock();
-        lock.lock();
-        try {
-            mDataChannel = dataChannel;
-        } finally {
-            lock.unlock();
-        }
-        dataChannel.registerObserver(new DataChannelObserver());
-    }
-
-    /**
-     * Stops all tunnel activity and returns the prevously bound data channel.
-     * It's safe to dispose the data channel after it.
-     */
-    public AbstractDataChannel unbind() {
-        final Lock lock = mDataChanneliReferenceLock.writeLock();
-        lock.lock();
-        final AbstractDataChannel dataChannel;
-        try {
-            dataChannel = mDataChannel;
-            mDataChannel = null;
-        } finally {
-            lock.unlock();
-        }
-        dataChannel.unregisterObserver();
-        mSignalingThread.set(null);
-        mWritingThread.shutdownNow();
-        return dataChannel;
-    }
-
-    protected void checkCalledOnSignalingThread() {
-        if (!mSignalingThread.compareAndSet(null, Thread.currentThread())) {
-            if (mSignalingThread.get() != Thread.currentThread()) {
-                throw new RuntimeException("Must be called on signaling thread");
-            }
-        }
-    }
-
-    protected static void checkConnectionId(int connectionId) throws ProtocolError {
-        if (connectionId < MIN_CONNECTION_ID || connectionId > MAX_CONNECTION_ID) {
-            throw new ProtocolError("Invalid connection id: " + Integer.toString(connectionId));
-        }
-    }
-
-    protected void onProtocolError(ProtocolError e) {
-        checkCalledOnSignalingThread();
-
-        // When integrity of data channel is broken then best way to survive is to close it.
-        final Lock lock = mDataChanneliReferenceLock.readLock();
-        lock.lock();
-        try {
-            mDataChannel.close();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    protected abstract void onReceivedDataPacket(int connectionId, byte[] data)
-            throws ProtocolError;
-    protected abstract void onReceivedControlPacket(int connectionId, byte opCode)
-            throws ProtocolError;
-    protected void onSocketException(IOException e, int connectionId) {}
-    protected void onDataChannelOpened() {}
-    protected void onDataChannelClosed() {}
-
-    static ByteBuffer buildControlPacket(int connectionId, byte opCode) {
-        ByteBuffer packet = ByteBuffer.allocateDirect(CONTROL_PACKET_SIZE);
-        packet.put((byte) CONTROL_CONNECTION_ID);
-        packet.put(opCode);
-        packet.put((byte) connectionId);
-        return packet;
-    }
-
-    static ByteBuffer buildDataPacket(int connectionId, byte[] buffer, int count) {
-        ByteBuffer packet = ByteBuffer.allocateDirect(count + 1);
-        packet.put((byte) connectionId);
-        packet.put(buffer, 0, count);
-        return packet;
-    }
-
-    protected void sendToDataChannel(ByteBuffer packet) {
-        packet.limit(packet.position());
-        packet.position(0);
-        final Lock lock = mDataChanneliReferenceLock.readLock();
-        lock.lock();
-        try {
-            if (mDataChannel != null) {
-                mDataChannel.send(packet, AbstractDataChannel.MessageType.BINARY);
-            }
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Packet decoding exposed for tests.
-     */
-    abstract static class PacketDecoderBase {
-        protected void decodePacket(ByteBuffer packet) throws ProtocolError {
-            if (packet.remaining() == 0) {
-                throw new ProtocolError("Empty packet");
-            }
-
-            int connectionId = packet.get();
-            if (connectionId != CONTROL_CONNECTION_ID) {
-                checkConnectionId(connectionId);
-                byte[] data = new byte[packet.remaining()];
-                packet.get(data);
-                onReceivedDataPacket(connectionId, data);
-            } else {
-                if (packet.remaining() != CONTROL_PACKET_SIZE - 1) {
-                    throw new ProtocolError("Invalid control packet size");
-                }
-
-                byte opCode = packet.get();
-                connectionId = packet.get();
-                checkConnectionId(connectionId);
-                onReceivedControlPacket(connectionId, opCode);
-            }
-        }
-
-        protected abstract void onReceivedDataPacket(int connectionId, byte[] data)
-                throws ProtocolError;
-        protected abstract void onReceivedControlPacket(int connectionId, byte opcode)
-                throws ProtocolError;
-    }
-
-    private final class DataChannelObserver
-            extends PacketDecoderBase implements AbstractDataChannel.Observer {
-        @Override
-        public void onStateChange(AbstractDataChannel.State state) {
-            checkCalledOnSignalingThread();
-
-            if (state == AbstractDataChannel.State.OPEN) {
-                onDataChannelOpened();
-            } else {
-                onDataChannelClosed();
-            }
-        }
-
-        @Override
-        public void onMessage(ByteBuffer message) {
-            checkCalledOnSignalingThread();
-
-            try {
-                decodePacket(message);
-            } catch (ProtocolError e) {
-                onProtocolError(e);
-            }
-        }
-
-        @Override
-        protected void onReceivedDataPacket(int connectionId, byte[] data) throws ProtocolError {
-            checkCalledOnSignalingThread();
-
-            SocketTunnelBase.this.onReceivedDataPacket(connectionId, data);
-        }
-
-        @Override
-        protected void onReceivedControlPacket(int connectionId, byte opCode) throws ProtocolError {
-            checkCalledOnSignalingThread();
-
-            SocketTunnelBase.this.onReceivedControlPacket(connectionId, opCode);
-        }
-    }
-
-    /**
-     * Any problem happened while handling incoming message that breaks state integrity.
-     */
-    static class ProtocolError extends Exception {
-        public ProtocolError(String description) {
-            super(description);
-        }
-    }
-
-    /**
-     * Base utility class for client and server connections.
-     */
-    protected abstract class ConnectionBase {
-        protected final int mId;
-        protected final LocalSocket mSocket;
-        private final AtomicInteger mOpenedStreams = new AtomicInteger(2); // input and output.
-        private volatile boolean mConnected;
-        private byte[] mBuffer;
-
-        private ConnectionBase(int id, LocalSocket socket, boolean preconnected) {
-            mId = id;
-            mSocket = socket;
-            mConnected = preconnected;
-        }
-
-        protected ConnectionBase(int id, LocalSocket socket) {
-            this(id, socket, true);
-        }
-
-        protected ConnectionBase(int id) {
-            this(id, new LocalSocket(), false);
-        }
-
-        protected boolean connect(LocalSocketAddress address) {
-            assert !mConnected;
-            try {
-                mSocket.connect(address);
-                mConnected = true;
-                return true;
-            } catch (IOException e) {
-                onSocketException(e, mId);
-                return false;
-            }
-        }
-
-        protected void runReadingLoop() {
-            mBuffer = new byte[READING_BUFFER_SIZE];
-            try {
-                boolean open;
-                do {
-                    open = pump();
-                } while (open);
-            } catch (IOException e) {
-                onSocketException(e, mId);
-            } finally {
-                mBuffer = null;
-            }
-        }
-
-        private boolean pump() throws IOException {
-            int count = mSocket.getInputStream().read(mBuffer);
-            if (count <= 0)
-                return false;
-            sendToDataChannel(buildDataPacket(mId, mBuffer, count));
-            return true;
-        }
-
-        protected void writeData(byte[] data) {
-            // Called on writing thread.
-            try {
-                mSocket.getOutputStream().write(data);
-            } catch (IOException e) {
-                onSocketException(e, mId);
-            }
-        }
-
-        public void onReceivedDataPacket(final byte[] data) {
-            mWritingThread.execute(new Runnable() {
-                @Override
-                public void run() {
-                    writeData(data);
-                }
-            });
-        }
-
-        public void terminate() {
-            close();
-        }
-
-        protected void shutdownOutput() {
-            // Shutdown output on writing thread to make sure all pending writes finished.
-            mWritingThread.execute(new Runnable() {
-                @Override
-                public void run() {
-                    shutdownOutputOnWritingThread();
-                }
-            });
-        }
-
-        private void shutdownOutputOnWritingThread() {
-            try {
-                if (mConnected) mSocket.shutdownOutput();
-            } catch (IOException e) {
-                onSocketException(e, mId);
-            }
-            releaseStream();
-        }
-
-        protected void shutdownInput() {
-            try {
-                if (mConnected) mSocket.shutdownInput();
-            } catch (IOException e) {
-                onSocketException(e, mId);
-            }
-            releaseStream();
-        }
-
-        private void releaseStream() {
-            if (mOpenedStreams.decrementAndGet() == 0) close();
-        }
-
-        protected void close() {
-            try {
-                mSocket.close();
-            } catch (IOException e) {
-                onSocketException(e, mId);
-            }
-        }
-    }
-}