package org.exist.storage.io;
import java.io.IOException;
import java.io.OutputStream;
import org.apache.log4j.Logger;
import org.exist.util.ByteArray;
import org.exist.util.FastByteBuffer;
import static java.nio.charset.StandardCharsets.UTF_8;
/**
* A byte array output stream using variable byte encoding.
*
* @author wolf
*/
public class VariableByteOutputStream extends OutputStream {
private static final int MAX_BUFFER_SIZE = 65536;
protected FastByteBuffer buf;
private final byte[] temp = new byte[5];
private static final Logger LOG = Logger.getLogger(VariableByteArrayInput.class);
public VariableByteOutputStream() {
super();
buf = new FastByteBuffer(9);
}
public VariableByteOutputStream(int size) {
super();
buf = new FastByteBuffer(size);
}
public void clear() {
if (buf.size() > MAX_BUFFER_SIZE)
{buf = new FastByteBuffer(9);}
else
{buf.setLength(0);}
}
@Override
public void close() throws IOException {
buf = null;
}
public int size() {
return buf.length();
}
@Override
public void flush() throws IOException {
//Nothing to do
}
public int position() {
return buf.size();
}
public byte[] toByteArray() {
final byte[] b = new byte[buf.size()];
buf.copyTo(b, 0);
return b;
}
public ByteArray data() {
return buf;
}
@Override
public void write(int b) throws IOException {
buf.append((byte) b);
}
@Override
public void write(byte[] b) {
buf.append(b);
}
@Override
public void write(byte[] b, int off, int len) throws IOException {
buf.append(b, off, len);
}
public void write(ByteArray b) {
b.copyTo(buf);
}
public void writeByte(byte b) {
buf.append(b);
}
public void writeShort(int s) {
while ((s & ~0177) != 0) {
buf.append((byte) ((s & 0177) | 0200));
s >>>= 7;
}
buf.append((byte) s);
}
public void writeInt(int i) {
int count = 0;
while ((i & ~0177) != 0) {
temp[count++] = (byte) ((i & 0177) | 0200);
i >>>= 7;
}
temp[count++] = (byte) i;
buf.append(temp, 0, count);
}
public void writeFixedInt(int i) {
temp[0] = (byte) ( ( i >>> 0 ) & 0xff );
temp[1] = (byte) ( ( i >>> 8 ) & 0xff );
temp[2] = (byte) ( ( i >>> 16 ) & 0xff );
temp[3] = (byte) ( ( i >>> 24 ) & 0xff );
buf.append(temp, 0, 4);
}
public void writeFixedInt(int position, int i) {
buf.set(position, (byte) ( ( i >>> 0 ) & 0xff ));
buf.set(position + 1, (byte) ( ( i >>> 8 ) & 0xff ));
buf.set(position + 2, (byte) ( ( i >>> 16 ) & 0xff ));
buf.set(position + 3, (byte) ( ( i >>> 24 ) & 0xff ));
}
public void writeInt(int position, int i) {
while ((i & ~0177) != 0) {
buf.set(position++, (byte) ((i & 0177) | 0200));
i >>>= 7;
}
buf.set(position, (byte) i);
}
public void writeLong(long l) {
while ((l & ~0177) != 0) {
buf.append((byte) ((l & 0177) | 0200));
l >>>= 7;
}
buf.append((byte) l);
}
public void writeFixedLong(long l) {
buf.append((byte) ((l >>> 56) & 0xff));
buf.append((byte) ((l >>> 48) & 0xff));
buf.append((byte) ((l >>> 40) & 0xff));
buf.append((byte) ((l >>> 32) & 0xff));
buf.append((byte) ((l >>> 24) & 0xff));
buf.append((byte) ((l >>> 16) & 0xff));
buf.append((byte) ((l >>> 8) & 0xff));
buf.append((byte) ((l >>> 0) & 0xff));
}
public void writeUTF(String s) throws IOException {
byte[] data = s.getBytes(UTF_8);
writeInt(data.length);
write(data, 0, data.length);
}
}