fish.payara.micro.boot.loader.jar.ZipInflaterInputStream Maven / Gradle / Ivy
/*
* Copyright 2012-2014 the original author or authors.
*
* Licensed 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 fish.payara.micro.boot.loader.jar;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;
/**
* {@link InflaterInputStream} that supports the writing of an extra "dummy" byte (which
* is required with JDK 6) and returns accurate available() results.
*
* @author Phillip Webb
*/
class ZipInflaterInputStream extends InflaterInputStream {
private boolean extraBytesWritten;
private int available;
ZipInflaterInputStream(InputStream inputStream, int size) {
super(inputStream, new Inflater(true), getInflaterBufferSize(size));
this.available = size;
}
@Override
public int available() throws IOException {
if (this.available < 0) {
return super.available();
}
return this.available;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
int result = super.read(b, off, len);
if (result != -1) {
this.available -= result;
}
return result;
}
@Override
protected void fill() throws IOException {
try {
super.fill();
}
catch (EOFException ex) {
if (this.extraBytesWritten) {
throw ex;
}
this.len = 1;
this.buf[0] = 0x0;
this.extraBytesWritten = true;
this.inf.setInput(this.buf, 0, this.len);
}
}
private static int getInflaterBufferSize(long size) {
size += 2; // inflater likes some space
size = (size > 65536 ? 8192 : size);
size = (size <= 0 ? 4096 : size);
return (int) size;
}
}