tikhomirov@320: /*
tikhomirov@412:  * Copyright (c) 2011-2012 TMate Software Ltd
tikhomirov@320:  *  
tikhomirov@320:  * This program is free software; you can redistribute it and/or modify
tikhomirov@320:  * it under the terms of the GNU General Public License as published by
tikhomirov@320:  * the Free Software Foundation; version 2 of the License.
tikhomirov@320:  *
tikhomirov@320:  * This program is distributed in the hope that it will be useful,
tikhomirov@320:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
tikhomirov@320:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
tikhomirov@320:  * GNU General Public License for more details.
tikhomirov@320:  *
tikhomirov@320:  * For information on how to redistribute this software under
tikhomirov@320:  * the terms of a license other than GNU General Public License
tikhomirov@320:  * contact TMate Software at support@hg4j.com
tikhomirov@320:  */
tikhomirov@320: package org.tmatesoft.hg.internal;
tikhomirov@320: 
tikhomirov@412: import java.nio.ByteBuffer;
tikhomirov@415: import java.nio.CharBuffer;
tikhomirov@412: import java.nio.charset.CharacterCodingException;
tikhomirov@412: import java.nio.charset.Charset;
tikhomirov@412: import java.nio.charset.CharsetDecoder;
tikhomirov@412: import java.nio.charset.CharsetEncoder;
tikhomirov@320: 
tikhomirov@415: import org.tmatesoft.hg.core.SessionContext;
tikhomirov@415: 
tikhomirov@320: /**
tikhomirov@320:  * Keep all encoding-related issues in the single place
tikhomirov@415:  * NOT thread-safe (encoder and decoder requires synchronized access)
tikhomirov@320:  * @author Artem Tikhomirov
tikhomirov@320:  * @author TMate Software Ltd.
tikhomirov@320:  */
tikhomirov@320: public class EncodingHelper {
tikhomirov@320: 	// XXX perhaps, shall not be full of statics, but rather an instance coming from e.g. HgRepository?
tikhomirov@412: 	/*
tikhomirov@412: 	 * To understand what Mercurial thinks of UTF-8 and Unix byte approach to names, see
tikhomirov@412: 	 * http://mercurial.808500.n3.nabble.com/Unicode-support-request-td3430704.html
tikhomirov@412: 	 */
tikhomirov@412: 	
tikhomirov@415: 	private final SessionContext sessionContext;
tikhomirov@412: 	private final CharsetEncoder encoder;
tikhomirov@412: 	private final CharsetDecoder decoder;
tikhomirov@412: 	
tikhomirov@415: 	EncodingHelper(Charset fsEncoding, SessionContext ctx) {
tikhomirov@415: 		sessionContext = ctx;
tikhomirov@412: 		decoder = fsEncoding.newDecoder();
tikhomirov@412: 		encoder = fsEncoding.newEncoder();
tikhomirov@412: 	}
tikhomirov@320: 
tikhomirov@418: 	/**
tikhomirov@418: 	 * Translate file names from manifest to amazing Unicode string 
tikhomirov@418: 	 */
tikhomirov@412: 	public String fromManifest(byte[] data, int start, int length) {
tikhomirov@418: 		return decodeWithSystemDefaultFallback(data, start, length);
tikhomirov@320: 	}
tikhomirov@418: 	
tikhomirov@415: 	/**
tikhomirov@415: 	 * @return byte representation of the string directly comparable to bytes in manifest
tikhomirov@415: 	 */
tikhomirov@415: 	public byte[] toManifest(String s) {
tikhomirov@415: 		if (s == null) {
tikhomirov@415: 			// perhaps, can return byte[0] in this case?
tikhomirov@415: 			throw new IllegalArgumentException();
tikhomirov@415: 		}
tikhomirov@415: 		try {
tikhomirov@415: 			// synchonized(encoder) {
tikhomirov@415: 			ByteBuffer bb = encoder.encode(CharBuffer.wrap(s));
tikhomirov@415: 			// }
tikhomirov@415: 			byte[] rv = new byte[bb.remaining()];
tikhomirov@415: 			bb.get(rv, 0, rv.length);
tikhomirov@415: 			return rv;
tikhomirov@415: 		} catch (CharacterCodingException ex) {
tikhomirov@415: 			sessionContext.getLog().error(getClass(), ex, String.format("Use of charset %s failed, resort to system default", charset().name()));
tikhomirov@415: 			// resort to system-default
tikhomirov@415: 			return s.getBytes();
tikhomirov@415: 		}
tikhomirov@415: 	}
tikhomirov@415: 
tikhomirov@418: 	/**
tikhomirov@418: 	 * Translate file names from dirstate to amazing Unicode string 
tikhomirov@418: 	 */
tikhomirov@418: 	public String fromDirstate(byte[] data, int start, int length) {
tikhomirov@418: 		return decodeWithSystemDefaultFallback(data, start, length);
tikhomirov@412: 	}
tikhomirov@412: 
tikhomirov@418: 	private String decodeWithSystemDefaultFallback(byte[] data, int start, int length) {
tikhomirov@418: 		try {
tikhomirov@418: 			return decoder.decode(ByteBuffer.wrap(data, start, length)).toString();
tikhomirov@418: 		} catch (CharacterCodingException ex) {
tikhomirov@418: 			sessionContext.getLog().error(getClass(), ex, String.format("Use of charset %s failed, resort to system default", charset().name()));
tikhomirov@418: 			// resort to system-default
tikhomirov@418: 			return new String(data, start, length);
tikhomirov@418: 		}
tikhomirov@418: 	}
tikhomirov@418: 
tikhomirov@418: 	private Charset charset() {
tikhomirov@412: 		return encoder.charset();
tikhomirov@412: 	}
tikhomirov@415: 
tikhomirov@320: }