org.apache.activemq.artemis.utils.InflaterReader Maven / Gradle / Ivy
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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.zip.DataFormatException;
import java.util.zip.Inflater;
/**
* InflaterReader
* It takes a compressed input stream and decompressed it as it is being read.
* Not for concurrent use.
*/
public class InflaterReader extends InputStream {
private Inflater inflater = new Inflater();
private InputStream input;
private byte[] readBuffer;
private int pointer;
private int length;
public InflaterReader(InputStream input) {
this(input, 1024);
}
public InflaterReader(InputStream input, int bufferSize) {
this.input = input;
this.readBuffer = new byte[bufferSize];
this.pointer = -1;
}
@Override
public int read() throws IOException {
if (pointer == -1) {
try {
length = doRead(readBuffer, 0, readBuffer.length);
if (length == 0) {
return -1;
}
pointer = 0;
} catch (DataFormatException e) {
throw new IOException(e.getMessage(), e);
}
}
int value = readBuffer[pointer] & 0xFF;
pointer++;
if (pointer == length) {
pointer = -1;
}
return value;
}
/*
* feed inflater more bytes in order to get some
* decompressed output.
* returns number of bytes actually got
*/
private int doRead(byte[] buf, int offset, int len) throws DataFormatException, IOException {
int read = 0;
int n;
byte[] inputBuffer = new byte[len];
while (len > 0) {
n = inflater.inflate(buf, offset, len);
if (n == 0) {
if (inflater.finished()) {
break;
} else if (inflater.needsInput()) {
//feeding
int m = input.read(inputBuffer);
if (m == -1) {
//it shouldn't be here, throw exception
throw new DataFormatException("Input is over while inflater still expecting data");
} else {
//feed the data in
inflater.setInput(inputBuffer, 0, m);
n = inflater.inflate(buf, offset, len);
if (n > 0) {
read += n;
offset += n;
len -= n;
}
}
} else {
//it shouldn't be here, throw
throw new DataFormatException("Inflater is neither finished nor needing input.");
}
} else {
read += n;
offset += n;
len -= n;
}
}
return read;
}
}