tikhomirov@107: /*
tikhomirov@107:  * Copyright (c) 2011 TMate Software Ltd
tikhomirov@107:  *  
tikhomirov@107:  * This program is free software; you can redistribute it and/or modify
tikhomirov@107:  * it under the terms of the GNU General Public License as published by
tikhomirov@107:  * the Free Software Foundation; version 2 of the License.
tikhomirov@107:  *
tikhomirov@107:  * This program is distributed in the hope that it will be useful,
tikhomirov@107:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
tikhomirov@107:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
tikhomirov@107:  * GNU General Public License for more details.
tikhomirov@107:  *
tikhomirov@107:  * For information on how to redistribute this software under
tikhomirov@107:  * the terms of a license other than GNU General Public License
tikhomirov@130:  * contact TMate Software at support@hg4j.com
tikhomirov@107:  */
tikhomirov@107: package org.tmatesoft.hg.core;
tikhomirov@107: 
tikhomirov@148: import static org.tmatesoft.hg.repo.HgInternals.wrongLocalRevision;
tikhomirov@107: import static org.tmatesoft.hg.repo.HgRepository.BAD_REVISION;
tikhomirov@107: import static org.tmatesoft.hg.repo.HgRepository.TIP;
tikhomirov@107: 
tikhomirov@107: import java.io.FileNotFoundException;
tikhomirov@148: import java.io.IOException;
tikhomirov@107: 
tikhomirov@107: import org.tmatesoft.hg.repo.HgDataFile;
tikhomirov@107: import org.tmatesoft.hg.repo.HgRepository;
tikhomirov@115: import org.tmatesoft.hg.util.ByteChannel;
tikhomirov@148: import org.tmatesoft.hg.util.CancelledException;
tikhomirov@133: import org.tmatesoft.hg.util.Path;
tikhomirov@107: 
tikhomirov@107: /**
tikhomirov@131:  * Command to obtain content of a file, 'hg cat' counterpart. 
tikhomirov@107:  * 
tikhomirov@107:  * @author Artem Tikhomirov
tikhomirov@107:  * @author TMate Software Ltd.
tikhomirov@107:  */
tikhomirov@131: public class HgCatCommand {
tikhomirov@107: 
tikhomirov@107: 	private final HgRepository repo;
tikhomirov@107: 	private Path file;
tikhomirov@107: 	private int localRevision = TIP;
tikhomirov@107: 	private Nodeid revision;
tikhomirov@107: 
tikhomirov@131: 	public HgCatCommand(HgRepository hgRepo) {
tikhomirov@107: 		repo = hgRepo;
tikhomirov@107: 	}
tikhomirov@107: 
tikhomirov@148: 	/**
tikhomirov@148: 	 * File to read, required parameter 
tikhomirov@148: 	 * @param fname path to a repository file, can't be <code>null</code>
tikhomirov@148: 	 * @return <code>this</code> for convenience
tikhomirov@148: 	 * @throws IllegalArgumentException if supplied fname is null or points to directory
tikhomirov@148: 	 */
tikhomirov@131: 	public HgCatCommand file(Path fname) {
tikhomirov@148: 		if (fname == null || fname.isDirectory()) {
tikhomirov@148: 			throw new IllegalArgumentException(String.valueOf(fname));
tikhomirov@148: 		}
tikhomirov@107: 		file = fname;
tikhomirov@107: 		return this;
tikhomirov@107: 	}
tikhomirov@107: 
tikhomirov@148: 	/**
tikhomirov@148: 	 * Invocation of this method clears revision set with {@link #revision(Nodeid)} or {@link #revision(int)} earlier.
tikhomirov@148: 	 * XXX rev can't be WORKING_COPY (if allowed, need to implement in #execute())
tikhomirov@148: 	 * @param rev local revision number, non-negative, or one of predefined constants. Note, use of {@link HgRepository#BAD_REVISION}, 
tikhomirov@148: 	 * although possible, makes little sense (command would fail if executed).  
tikhomirov@148:  	 * @return <code>this</code> for convenience
tikhomirov@148: 	 */
tikhomirov@131: 	public HgCatCommand revision(int rev) {
tikhomirov@148: 		if (wrongLocalRevision(rev)) {
tikhomirov@148: 			throw new IllegalArgumentException(String.valueOf(rev));
tikhomirov@148: 		}
tikhomirov@107: 		localRevision = rev;
tikhomirov@107: 		revision = null;
tikhomirov@107: 		return this;
tikhomirov@107: 	}
tikhomirov@107: 	
tikhomirov@148: 	/**
tikhomirov@148: 	 * Select revision to read. Invocation of this method clears revision set with {@link #revision(int)} or {@link #revision(Nodeid)} earlier.
tikhomirov@148: 	 * 
tikhomirov@148: 	 * @param nodeid - unique revision identifier, Note, use of <code>null</code> or {@link Nodeid#NULL} is senseless
tikhomirov@148: 	 * @return <code>this</code> for convenience
tikhomirov@148: 	 */
tikhomirov@131: 	public HgCatCommand revision(Nodeid nodeid) {
tikhomirov@148: 		if (nodeid != null && nodeid.isNull()) {
tikhomirov@148: 			nodeid = null;
tikhomirov@148: 		}
tikhomirov@107: 		revision = nodeid;
tikhomirov@107: 		localRevision = BAD_REVISION;
tikhomirov@107: 		return this;
tikhomirov@107: 	}
tikhomirov@107: 
tikhomirov@148: 	/**
tikhomirov@148: 	 * Runs the command with current set of parameters and pipes data to provided sink.
tikhomirov@148: 	 * 
tikhomirov@148: 	 * @param sink output channel to write data to.
tikhomirov@148: 	 * @throws HgDataStreamException 
tikhomirov@148: 	 * @throws IllegalArgumentException when command arguments are incomplete or wrong
tikhomirov@148: 	 */
tikhomirov@148: 	public void execute(ByteChannel sink) throws HgDataStreamException, IOException, CancelledException {
tikhomirov@107: 		if (localRevision == BAD_REVISION && revision == null) {
tikhomirov@107: 			throw new IllegalArgumentException("Either local file revision number or nodeid shall be specified");
tikhomirov@107: 		}
tikhomirov@107: 		if (file == null) {
tikhomirov@107: 			throw new IllegalArgumentException("Name of the file is missing");
tikhomirov@107: 		}
tikhomirov@115: 		if (sink == null) {
tikhomirov@148: 			throw new IllegalArgumentException("Need an output channel");
tikhomirov@107: 		}
tikhomirov@107: 		HgDataFile dataFile = repo.getFileNode(file);
tikhomirov@107: 		if (!dataFile.exists()) {
tikhomirov@148: 			throw new HgDataStreamException(file.toString(), new FileNotFoundException(file.toString()));
tikhomirov@107: 		}
tikhomirov@115: 		int revToExtract;
tikhomirov@107: 		if (revision != null) {
tikhomirov@115: 			revToExtract = dataFile.getLocalRevision(revision);
tikhomirov@107: 		} else {
tikhomirov@115: 			revToExtract = localRevision;
tikhomirov@107: 		}
tikhomirov@157: 		dataFile.contentWithFilters(revToExtract, sink);
tikhomirov@107: 	}
tikhomirov@107: }