io.nebo.thrift.TNiftyTransport.java Source code

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Here is the source code for io.nebo.thrift.TNiftyTransport.java

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/*
 * Copyright (C) 2012-2013 Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.nebo.thrift;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import org.apache.thrift.transport.TTransport;
import org.apache.thrift.transport.TTransportException;

/**
 * Wraps incoming channel buffer into TTransport and provides a output buffer.
 */
public class TNiftyTransport extends TTransport {
    private final Channel channel;
    private final ByteBuf in;
    private ByteBuf out;
    private static final int DEFAULT_OUTPUT_BUFFER_SIZE = 1024;
    private final int initialReaderIndex;
    private final int initialBufferPosition;
    private int bufferPosition;
    private int bufferEnd;
    private final byte[] buffer;
    private final ThriftTransportType thriftTransportType;

    public TNiftyTransport(Channel channel, ByteBuf in, ThriftTransportType thriftTransportType) {
        this.channel = channel;
        this.in = in;
        this.out = Unpooled.buffer(DEFAULT_OUTPUT_BUFFER_SIZE);
        this.thriftTransportType = thriftTransportType;
        this.initialReaderIndex = in.readerIndex();

        if (!in.hasArray()) {
            buffer = null;
            bufferPosition = 0;
            initialBufferPosition = bufferEnd = -1;
        } else {
            buffer = in.array();
            initialBufferPosition = bufferPosition = in.arrayOffset() + in.readerIndex();
            bufferEnd = bufferPosition + in.readableBytes();
            // Without this, reading from a !in.hasArray() buffer will advance the readerIndex
            // of the buffer, while reading from a in.hasArray() buffer will not advance the
            // readerIndex, and this has led to subtle bugs. This should help to identify
            // those problems by making things more consistent.
            in.readerIndex(in.readerIndex() + in.readableBytes());
        }
    }

    @Override
    public boolean isOpen() {
        return channel.isOpen();
    }

    @Override
    public void open() throws TTransportException {
        // no-op
    }

    @Override
    public void close() {
        // no-op
        channel.close();
    }

    @Override
    public int read(byte[] bytes, int offset, int length) throws TTransportException {
        if (getBytesRemainingInBuffer() >= 0) {
            int _read = Math.min(getBytesRemainingInBuffer(), length);
            System.arraycopy(getBuffer(), getBufferPosition(), bytes, offset, _read);
            consumeBuffer(_read);
            return _read;
        } else {
            int _read = Math.min(in.readableBytes(), length);
            in.readBytes(bytes, offset, _read);
            return _read;
        }
    }

    @Override
    public int readAll(byte[] bytes, int offset, int length) throws TTransportException {
        if (read(bytes, offset, length) < length) {
            throw new TTransportException("Buffer doesn't have enough bytes to read");
        }
        return length;
    }

    @Override
    public void write(byte[] bytes, int offset, int length) throws TTransportException {
        out.writeBytes(bytes, offset, length);
    }

    public ByteBuf getOutputBuffer() {
        return out;
    }

    public void setOutputBuffer(ByteBuf buf) {
        out = buf;
    }

    @Override
    public void flush() throws TTransportException {
        // Flush is a no-op: NiftyDispatcher will write the response to the Channel, in order to
        // guarantee ordering of responses when required.
    }

    @Override
    public void consumeBuffer(int len) {
        bufferPosition += len;
    }

    @Override
    public byte[] getBuffer() {
        return buffer;
    }

    @Override
    public int getBufferPosition() {
        return bufferPosition;
    }

    @Override
    public int getBytesRemainingInBuffer() {
        return bufferEnd - bufferPosition;
    }

    public int getReadByteCount() {
        if (getBytesRemainingInBuffer() >= 0) {
            return getBufferPosition() - initialBufferPosition;
        } else {
            return in.readerIndex() - initialReaderIndex;
        }
    }

    public int getWrittenByteCount() {
        return getOutputBuffer().writerIndex();
    }
}