tikhomirov@534: /*
tikhomirov@534:  * Copyright (c) 2013 TMate Software Ltd
tikhomirov@534:  *  
tikhomirov@534:  * This program is free software; you can redistribute it and/or modify
tikhomirov@534:  * it under the terms of the GNU General Public License as published by
tikhomirov@534:  * the Free Software Foundation; version 2 of the License.
tikhomirov@534:  *
tikhomirov@534:  * This program is distributed in the hope that it will be useful,
tikhomirov@534:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
tikhomirov@534:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
tikhomirov@534:  * GNU General Public License for more details.
tikhomirov@534:  *
tikhomirov@534:  * For information on how to redistribute this software under
tikhomirov@534:  * the terms of a license other than GNU General Public License
tikhomirov@534:  * contact TMate Software at support@hg4j.com
tikhomirov@534:  */
tikhomirov@534: package org.tmatesoft.hg.internal;
tikhomirov@534: 
tikhomirov@618: import java.io.ByteArrayOutputStream;
tikhomirov@618: 
tikhomirov@618: import org.tmatesoft.hg.core.HgIOException;
tikhomirov@534: 
tikhomirov@534: /**
tikhomirov@534:  * Serialization friend of {@link DataAccess}
tikhomirov@534:  * 
tikhomirov@534:  * @author Artem Tikhomirov
tikhomirov@534:  * @author TMate Software Ltd.
tikhomirov@534:  */
tikhomirov@534: @Experimental(reason="Work in progress")
tikhomirov@534: public class DataSerializer {
tikhomirov@618: 	private byte[] buffer;
tikhomirov@534: 	
tikhomirov@618: 	public void writeByte(byte... values) throws HgIOException {
tikhomirov@534: 		write(values, 0, values.length);
tikhomirov@534: 	}
tikhomirov@534: 
tikhomirov@618: 	public void writeInt(int... values) throws HgIOException {
tikhomirov@618: 		ensureBufferSize(4*values.length); // sizeof(int)
tikhomirov@618: 		int idx = 0;
tikhomirov@534: 		for (int v : values) {
tikhomirov@618: 			bigEndian(v, buffer, idx);
tikhomirov@618: 			idx += 4;
tikhomirov@618: 		}
tikhomirov@618: 		write(buffer, 0, idx);
tikhomirov@618: 	}
tikhomirov@618: 
tikhomirov@618: 	public void write(byte[] data, int offset, int length) throws HgIOException {
tikhomirov@618: 		throw new HgIOException("Attempt to write to non-existent file", null);
tikhomirov@618: 	}
tikhomirov@618: 
tikhomirov@618: 	public void done() throws HgIOException {
tikhomirov@618: 		// no-op
tikhomirov@618: 	}
tikhomirov@618: 	
tikhomirov@618: 	private void ensureBufferSize(int bytesNeeded) {
tikhomirov@618: 		if (buffer == null || buffer.length < bytesNeeded) {
tikhomirov@618: 			buffer = new byte[bytesNeeded];
tikhomirov@534: 		}
tikhomirov@534: 	}
tikhomirov@534: 
tikhomirov@534: 	/**
tikhomirov@534: 	 * Writes 4 bytes of supplied value into the buffer at given offset, big-endian. 
tikhomirov@534: 	 */
tikhomirov@534: 	public static final void bigEndian(int value, byte[] buffer, int offset) {
tikhomirov@534: 		assert offset + 4 <= buffer.length; 
tikhomirov@534: 		buffer[offset++] = (byte) ((value >>> 24) & 0x0ff);
tikhomirov@534: 		buffer[offset++] = (byte) ((value >>> 16) & 0x0ff);
tikhomirov@534: 		buffer[offset++] = (byte) ((value >>> 8) & 0x0ff);
tikhomirov@534: 		buffer[offset++] = (byte) (value & 0x0ff);
tikhomirov@534: 	}
tikhomirov@534: 	
tikhomirov@556: 	/**
tikhomirov@556: 	 * Denotes an entity that wants to/could be serialized
tikhomirov@556: 	 */
tikhomirov@534: 	@Experimental(reason="Work in progress")
tikhomirov@534: 	interface DataSource {
tikhomirov@618: 		/**
tikhomirov@618: 		 * Invoked once for a single write operation, 
tikhomirov@618: 		 * although the source itself may get serialized several times
tikhomirov@618: 		 */
tikhomirov@618: 		public void serialize(DataSerializer out) throws HgIOException;
tikhomirov@534: 
tikhomirov@534: 		/**
tikhomirov@534: 		 * Hint of data length it would like to writes
tikhomirov@534: 		 * @return -1 if can't answer
tikhomirov@534: 		 */
tikhomirov@534: 		public int serializeLength();
tikhomirov@534: 	}
tikhomirov@534: 	
tikhomirov@534: 	public static class ByteArrayDataSource implements DataSource {
tikhomirov@534: 		
tikhomirov@534: 		private final byte[] data;
tikhomirov@534: 
tikhomirov@534: 		public ByteArrayDataSource(byte[] bytes) {
tikhomirov@534: 			data = bytes;
tikhomirov@534: 		}
tikhomirov@534: 
tikhomirov@618: 		public void serialize(DataSerializer out) throws HgIOException {
tikhomirov@534: 			if (data != null) {
tikhomirov@534: 				out.write(data, 0, data.length);
tikhomirov@534: 			}
tikhomirov@534: 		}
tikhomirov@534: 
tikhomirov@534: 		public int serializeLength() {
tikhomirov@534: 			return data == null ? 0 : data.length;
tikhomirov@534: 		}
tikhomirov@618: 	}
tikhomirov@618: 	
tikhomirov@618: 	public static class ByteArrayDataSerializer extends DataSerializer {
tikhomirov@618: 		private final ByteArrayOutputStream out = new ByteArrayOutputStream();
tikhomirov@618: 
tikhomirov@618: 		@Override
tikhomirov@618: 		public void write(byte[] data, int offset, int length) {
tikhomirov@618: 			out.write(data, offset, length);
tikhomirov@618: 		}
tikhomirov@534: 		
tikhomirov@618: 		public byte[] toByteArray() {
tikhomirov@618: 			return out.toByteArray();
tikhomirov@618: 		}
tikhomirov@534: 	}
tikhomirov@534: }