org.apache.thrift.transport.TFramedTransport Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.thrift.transport;
import org.apache.thrift.TByteArrayOutputStream;
/**
* TFramedTransport is a buffered TTransport that ensures a fully read message
* every time by preceding messages with a 4-byte frame size.
*/
public class TFramedTransport extends TTransport {
protected static final int DEFAULT_MAX_LENGTH = 16384000;
private int maxLength_;
/**
* Underlying transport
*/
private TTransport transport_ = null;
/**
* Buffer for output
*/
private final TByteArrayOutputStream writeBuffer_ =
new TByteArrayOutputStream(1024);
/**
* Buffer for input
*/
private final TMemoryInputTransport readBuffer_ =
new TMemoryInputTransport(new byte[0]);
public static class Factory extends TTransportFactory {
private int maxLength_;
public Factory() {
maxLength_ = TFramedTransport.DEFAULT_MAX_LENGTH;
}
public Factory(int maxLength) {
maxLength_ = maxLength;
}
@Override
public TTransport getTransport(TTransport base) {
return new TFramedTransport(base, maxLength_);
}
}
/**
* Constructor wraps around another transport
*/
public TFramedTransport(TTransport transport, int maxLength) {
transport_ = transport;
maxLength_ = maxLength;
}
public TFramedTransport(TTransport transport) {
transport_ = transport;
maxLength_ = TFramedTransport.DEFAULT_MAX_LENGTH;
}
public void open() throws TTransportException {
transport_.open();
}
public boolean isOpen() {
return transport_.isOpen();
}
public void close() {
transport_.close();
}
public int read(byte[] buf, int off, int len) throws TTransportException {
int got = readBuffer_.read(buf, off, len);
if (got > 0) {
return got;
}
// Read another frame of data
readFrame();
return readBuffer_.read(buf, off, len);
}
@Override
public byte[] getBuffer() {
return readBuffer_.getBuffer();
}
@Override
public int getBufferPosition() {
return readBuffer_.getBufferPosition();
}
@Override
public int getBytesRemainingInBuffer() {
return readBuffer_.getBytesRemainingInBuffer();
}
@Override
public void consumeBuffer(int len) {
readBuffer_.consumeBuffer(len);
}
public void clear() {
readBuffer_.clear();
}
private final byte[] i32buf = new byte[4];
private void readFrame() throws TTransportException {
transport_.readAll(i32buf, 0, 4);
int size = decodeFrameSize(i32buf);
if (size < 0) {
close();
throw new TTransportException(TTransportException.CORRUPTED_DATA, "Read a negative frame size (" + size + ")!");
}
if (size > maxLength_) {
close();
throw new TTransportException(TTransportException.CORRUPTED_DATA,
"Frame size (" + size + ") larger than max length (" + maxLength_ + ")!");
}
byte[] buff = new byte[size];
transport_.readAll(buff, 0, size);
readBuffer_.reset(buff);
}
public void write(byte[] buf, int off, int len) throws TTransportException {
writeBuffer_.write(buf, off, len);
}
@Override
public void flush() throws TTransportException {
byte[] buf = writeBuffer_.get();
int len = writeBuffer_.len();
writeBuffer_.reset();
encodeFrameSize(len, i32buf);
transport_.write(i32buf, 0, 4);
transport_.write(buf, 0, len);
transport_.flush();
}
public static final void encodeFrameSize(final int frameSize, final byte[] buf) {
buf[0] = (byte)(0xff & (frameSize >> 24));
buf[1] = (byte)(0xff & (frameSize >> 16));
buf[2] = (byte)(0xff & (frameSize >> 8));
buf[3] = (byte)(0xff & (frameSize));
}
public static final int decodeFrameSize(final byte[] buf) {
return
((buf[0] & 0xff) << 24) |
((buf[1] & 0xff) << 16) |
((buf[2] & 0xff) << 8) |
((buf[3] & 0xff));
}
}