/**
* 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.activemq.transport.tcp;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* An optimized buffered outputstream for Tcp
*
*
*/
public class TcpBufferedOutputStream extends FilterOutputStream implements TimeStampStream {
private static final int BUFFER_SIZE = 8192;
private byte[] buffer;
private int bufferlen;
private int count;
private volatile long writeTimestamp = -1;//concurrent reads of this value
/**
* Constructor
*
* @param out
*/
public TcpBufferedOutputStream(OutputStream out) {
this(out, BUFFER_SIZE);
}
/**
* Creates a new buffered output stream to write data to the specified
* underlying output stream with the specified buffer size.
*
* @param out the underlying output stream.
* @param size the buffer size.
* @throws IllegalArgumentException if size <= 0.
*/
public TcpBufferedOutputStream(OutputStream out, int size) {
super(out);
if (size <= 0) {
throw new IllegalArgumentException("Buffer size <= 0");
}
buffer = new byte[size];
bufferlen = size;
}
/**
* write a byte on to the stream
*
* @param b - byte to write
* @throws IOException
*/
public void write(int b) throws IOException {
if ((bufferlen - count) < 1) {
flush();
}
buffer[count++] = (byte)b;
}
/**
* write a byte array to the stream
*
* @param b the byte buffer
* @param off the offset into the buffer
* @param len the length of data to write
* @throws IOException
*/
public void write(byte b[], int off, int len) throws IOException {
if (b != null) {
if ((bufferlen - count) < len) {
flush();
}
if (buffer.length >= len) {
System.arraycopy(b, off, buffer, count, len);
count += len;
} else {
try {
writeTimestamp = System.currentTimeMillis();
out.write(b, off, len);
} finally {
writeTimestamp = -1;
}
}
}
}
/**
* flush the data to the output stream This doesn't call flush on the
* underlying outputstream, because Tcp is particularly efficent at doing
* this itself ....
*
* @throws IOException
*/
public void flush() throws IOException {
if (count > 0 && out != null) {
try {
writeTimestamp = System.currentTimeMillis();
out.write(buffer, 0, count);
} finally {
writeTimestamp = -1;
}
count = 0;
}
}
/**
* close this stream
*
* @throws IOException
*/
public void close() throws IOException {
super.close();
}
/* (non-Javadoc)
* @see org.apache.activemq.transport.tcp.TimeStampStream#isWriting()
*/
public boolean isWriting() {
return writeTimestamp > 0;
}
/* (non-Javadoc)
* @see org.apache.activemq.transport.tcp.TimeStampStream#getWriteTimestamp()
*/
public long getWriteTimestamp() {
return writeTimestamp;
}
}