/*
* Copyright (c) 2013 TMate Software Ltd
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* For information on how to redistribute this software under
* the terms of a license other than GNU General Public License
* contact TMate Software at support@hg4j.com
*/
package org.tmatesoft.hg.internal;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import org.tmatesoft.hg.core.HgIOException;
import org.tmatesoft.hg.repo.HgRuntimeException;
/**
* Serialization friend of {@link DataAccess}, similar to OutputStream with few handy methods
*
* @author Artem Tikhomirov
* @author TMate Software Ltd.
*/
@Experimental(reason="Work in progress")
public class DataSerializer {
private byte[] buffer;
public void writeByte(byte... values) throws HgIOException {
write(values, 0, values.length);
}
public void writeInt(int... values) throws HgIOException {
ensureBufferSize(4*values.length); // sizeof(int)
int idx = 0;
for (int v : values) {
bigEndian(v, buffer, idx);
idx += 4;
}
write(buffer, 0, idx);
}
public void write(byte[] data, int offset, int length) throws HgIOException {
throw new HgIOException("Attempt to write to non-existent file", null);
}
public void done() throws HgIOException {
// no-op
}
private void ensureBufferSize(int bytesNeeded) {
if (buffer == null || buffer.length < bytesNeeded) {
buffer = new byte[bytesNeeded];
}
}
/**
* Writes 4 bytes of supplied value into the buffer at given offset, big-endian.
*/
public static final void bigEndian(int value, byte[] buffer, int offset) {
assert offset + 4 <= buffer.length;
buffer[offset++] = (byte) ((value >>> 24) & 0x0ff);
buffer[offset++] = (byte) ((value >>> 16) & 0x0ff);
buffer[offset++] = (byte) ((value >>> 8) & 0x0ff);
buffer[offset++] = (byte) (value & 0x0ff);
}
/**
* Denotes an entity that wants to/could be serialized
*/
@Experimental(reason="Work in progress")
public interface DataSource {
/**
* Invoked once for a single write operation,
* although the source itself may get serialized several times
*/
public void serialize(DataSerializer out) throws HgIOException, HgRuntimeException;
/**
* Hint of data length it would like to writes
* @return -1 if can't answer
*/
public int serializeLength() throws HgRuntimeException;
}
public static class ByteArrayDataSource implements DataSource {
private final byte[] data;
public ByteArrayDataSource(byte[] bytes) {
data = bytes;
}
public void serialize(DataSerializer out) throws HgIOException {
if (data != null) {
out.write(data, 0, data.length);
}
}
public int serializeLength() {
return data == null ? 0 : data.length;
}
}
/**
* Serialize data to byte array
*/
public static class ByteArraySerializer extends DataSerializer {
private final ByteArrayOutputStream out = new ByteArrayOutputStream();
@Override
public void write(byte[] data, int offset, int length) {
out.write(data, offset, length);
}
public byte[] toByteArray() {
return out.toByteArray();
}
}
/**
* Bridge to the world of {@link java.io.OutputStream}.
* Caller instantiates the stream and is responsible to close it as appropriate,
* {@link #done() DataSerializer.done()} doesn't close the stream.
*/
public static class OutputStreamSerializer extends DataSerializer {
private final OutputStream out;
public OutputStreamSerializer(OutputStream outputStream) {
out = outputStream;
}
@Override
public void write(byte[] data, int offset, int length) throws HgIOException {
try {
out.write(data, offset, length);
} catch (IOException ex) {
throw new HgIOException(ex.getMessage(), ex, null);
}
}
}
}