org.apache.activemq.artemis.utils.DeflaterReader Maven / Gradle / Ivy
Go to download
This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* 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.artemis.utils;
import java.io.IOException;
import java.io.InputStream;
import java.util.concurrent.atomic.AtomicLong;
import java.util.zip.Deflater;
/**
* A DeflaterReader
* The reader takes an inputstream and compress it.
* Not for concurrent use.
*/
public class DeflaterReader extends InputStream {
private final Deflater deflater = new Deflater();
private boolean isFinished = false;
private boolean compressDone = false;
private InputStream input;
private final AtomicLong bytesRead;
public DeflaterReader(final InputStream inData, final AtomicLong bytesRead) {
input = inData;
this.bytesRead = bytesRead;
}
@Override
public int read() throws IOException {
byte[] buffer = new byte[1];
int n = read(buffer, 0, 1);
if (n == 1) {
return buffer[0] & 0xFF;
}
if (n == -1 || n == 0) {
return -1;
}
throw new IOException("Error reading data, invalid n: " + n);
}
/**
* Try to fill the buffer with compressed bytes. Except the last effective read,
* this method always returns with a full buffer of compressed data.
*
* @param buffer the buffer to fill compressed bytes
* @return the number of bytes really filled, -1 indicates end.
* @throws IOException
*/
@Override
public int read(final byte[] buffer, int offset, int len) throws IOException {
if (compressDone) {
return -1;
}
//buffer for reading input stream
byte[] readBuffer = new byte[2 * len];
int n;
int read = 0;
while (len > 0) {
n = deflater.deflate(buffer, offset, len);
if (n == 0) {
if (isFinished) {
deflater.end();
compressDone = true;
break;
} else if (deflater.needsInput()) {
// read some data from inputstream
int m = input.read(readBuffer);
if (m == -1) {
deflater.finish();
isFinished = true;
} else {
if (bytesRead != null) {
bytesRead.addAndGet(m);
}
deflater.setInput(readBuffer, 0, m);
}
} else {
deflater.finish();
isFinished = true;
}
} else {
read += n;
offset += n;
len -= n;
}
}
return read;
}
public void closeStream() throws IOException {
super.close();
input.close();
}
public long getTotalSize() {
return bytesRead.get();
}
}