org.apache.activemq.artemis.utils.DeflaterReader 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.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();
}
}
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