com.yahoo.compress.ZstdOutputStream Maven / Gradle / Ivy
// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.compress;
import java.io.IOException;
import java.io.OutputStream;
/**
* @author bjorncs
*/
public class ZstdOutputStream extends OutputStream {
private final ZstdCompressor compressor = new ZstdCompressor();
public static final int DEFAULT_INPUT_BUFFER_SIZE = 8*1024;
private final OutputStream out;
private final byte[] inputBuffer;
private final byte[] outputBuffer;
private int inputPosition = 0;
private boolean isClosed = false;
public ZstdOutputStream(OutputStream out, int inputBufferSize) {
this.out = out;
this.inputBuffer = new byte[inputBufferSize];
this.outputBuffer = new byte[ZstdCompressor.getMaxCompressedLength(inputBufferSize)];
}
public ZstdOutputStream(OutputStream out) {
this(out, DEFAULT_INPUT_BUFFER_SIZE);
}
@Override
public void write(int b) throws IOException {
throwIfClosed();
inputBuffer[inputPosition++] = (byte) b;
flushIfFull();
}
@Override
public void write(byte[] b) throws IOException {
write(b, 0, b.length);
}
@Override
public void write(byte[] b, int off, int len) throws IOException {
throwIfClosed();
int end = off + len;
while (off < end) {
int copyLength = Math.min(end - off, inputBuffer.length - inputPosition);
System.arraycopy(b, off, inputBuffer, inputPosition, copyLength);
off += copyLength;
inputPosition += copyLength;
flushIfFull();
}
}
@Override
public void flush() throws IOException {
flushInternal();
out.flush();
}
@Override
public void close() throws IOException {
throwIfClosed();
flush();
out.close();
isClosed = true;
}
private void flushInternal() throws IOException {
throwIfClosed();
int compressedLength = compressor.compress(inputBuffer, 0, inputPosition, outputBuffer, 0, outputBuffer.length);
out.write(outputBuffer, 0, compressedLength);
inputPosition = 0;
}
private void flushIfFull() throws IOException {
if (inputPosition == inputBuffer.length) {
flushInternal();
}
}
private void throwIfClosed() {
if (isClosed) throw new IllegalArgumentException("Output stream is already closed");
}
}