TranscoderSmart.java

/* ========================================================================
 * PlantUML : a free UML diagram generator
 * ========================================================================
 *
 * (C) Copyright 2009-2024, Arnaud Roques
 *
 * Project Info:  https://plantuml.com
 * 
 * If you like this project or if you find it useful, you can support us at:
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 * This file is part of PlantUML.
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 * PlantUML is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
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 * (at your option) any later version.
 *
 * PlantUML 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.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
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 * Original Author:  Arnaud Roques
 *
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 */
package net.sourceforge.plantuml.code;

import java.io.IOException;

public class TranscoderSmart implements Transcoder {

	private final Transcoder zlib = TranscoderImpl.utf8(new AsciiEncoder(), new ArobaseStringCompressor(),
			new CompressionZlib());
	private final Transcoder hexOnly = TranscoderImpl.utf8(new AsciiEncoderHex(), new ArobaseStringCompressor(),
			new CompressionNone());
	// ::comment when __CORE__
	// Legacy encoder
	private final Transcoder oldOne = TranscoderImpl.utf8(new AsciiEncoder(), new ArobaseStringCompressor(),
			new CompressionHuffman());
	private final Transcoder zip = TranscoderImpl.utf8(new AsciiEncoder(), new ArobaseStringCompressor(),
			new CompressionZip());
	private final Transcoder gzip = TranscoderImpl.utf8(new AsciiEncoder(), new ArobaseStringCompressor(),
			new CompressionGZip());
	// ::done

	public String decode(String code) throws NoPlantumlCompressionException {
		// Work in progress
		// See https://github.com/plantuml/plantuml/issues/117

		if (code.startsWith("~0"))
			return zlib.decode(code.substring(2));

		// ::comment when __CORE__
		if (code.startsWith("~1"))
			return oldOne.decode(code.substring(2));
		// ::done

		if (code.startsWith("~h"))
			return hexOnly.decode(code.substring(2));

		if (code.startsWith("~g"))
			return gzip.decode(code.substring(2));

		// ::comment when __CORE__
		if (code.startsWith("~zip~"))
			return zip.decode(code.substring(5));
		// ::done

		// ::comment when __CORE__
		try {
			// ::done
			return zlib.decode(code);
			// ::comment when __CORE__
		} catch (Exception ex) {
			return oldOne.decode(code);
		}
		// ::done
		// return zlib.decode(code);
	}

	public String encode(String text) throws IOException {
		// Right now, we still use the legacy encoding.
		// This will be changed in the incoming months
		return zlib.encode(text);
	}
}