kitaev@213: /*
kitaev@213:  * Copyright (c) 2011 TMate Software Ltd
kitaev@213:  *  
kitaev@213:  * This program is free software; you can redistribute it and/or modify
kitaev@213:  * it under the terms of the GNU General Public License as published by
kitaev@213:  * the Free Software Foundation; version 2 of the License.
kitaev@213:  *
kitaev@213:  * This program is distributed in the hope that it will be useful,
kitaev@213:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
kitaev@213:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
kitaev@213:  * GNU General Public License for more details.
kitaev@213:  *
kitaev@213:  * For information on how to redistribute this software under
kitaev@213:  * the terms of a license other than GNU General Public License
kitaev@213:  * contact TMate Software at support@hg4j.com
kitaev@213:  */
kitaev@213: package org.tmatesoft.hg.internal;
kitaev@213: 
kitaev@213: import java.util.TreeMap;
kitaev@213: 
kitaev@213: import org.tmatesoft.hg.repo.HgChangelog.RawChangeset;
kitaev@213: import org.tmatesoft.hg.repo.HgDataFile;
kitaev@213: import org.tmatesoft.hg.repo.HgInternals;
kitaev@213: import org.tmatesoft.hg.repo.HgRepository;
kitaev@213: import org.tmatesoft.hg.util.Path;
kitaev@213: 
kitaev@213: /**
kitaev@213:  *
kitaev@213:  * @author Artem Tikhomirov
kitaev@213:  * @author TMate Software Ltd.
kitaev@213:  */
kitaev@213: public class ChangelogHelper {
kitaev@213: 	private final int leftBoundary;
kitaev@213: 	private final HgRepository repo;
kitaev@213: 	private final TreeMap<Integer, RawChangeset> cache = new TreeMap<Integer, RawChangeset>();
kitaev@213: 	private String nextCommitAuthor;
kitaev@213: 
kitaev@213: 	/**
kitaev@213: 	 * @param hgRepo
kitaev@213: 	 * @param leftBoundaryRevision walker never visits revisions with local numbers less than specified,
kitaev@213: 	 * IOW only revisions [leftBoundaryRevision..TIP] are considered.
kitaev@213: 	 */
kitaev@213: 	public ChangelogHelper(HgRepository hgRepo, int leftBoundaryRevision) {
kitaev@213: 		repo = hgRepo;
kitaev@213: 		leftBoundary = leftBoundaryRevision;
kitaev@213: 	}
kitaev@213: 	
kitaev@213: 	/**
kitaev@213: 	 * @return the repo
kitaev@213: 	 */
kitaev@213: 	public HgRepository getRepo() {
kitaev@213: 		return repo;
kitaev@213: 	}
kitaev@213: 
kitaev@213: 	/**
kitaev@213: 	 * Walks changelog in reverse order
kitaev@213: 	 * @param file
kitaev@213: 	 * @return changeset where specified file is mentioned among affected files, or 
kitaev@213: 	 * <code>null</code> if none found up to leftBoundary 
kitaev@213: 	 */
kitaev@213: 	public RawChangeset findLatestChangeWith(Path file) {
kitaev@213: 		HgDataFile df = repo.getFileNode(file);
kitaev@213: 		int changelogRev = df.getChangesetLocalRevision(HgRepository.TIP);
kitaev@213: 		if (changelogRev >= leftBoundary) {
kitaev@213: 			// the method is likely to be invoked for different files, 
kitaev@213: 			// while changesets might be the same. Cache 'em not to read too much. 
kitaev@213: 			RawChangeset cs = cache.get(changelogRev);
kitaev@213: 			if (cs == null) {
kitaev@213: 				cs = repo.getChangelog().range(changelogRev, changelogRev).get(0);
kitaev@213: 				cache.put(changelogRev, cs);
kitaev@213: 			}
kitaev@213: 			return cs;
kitaev@213: 		}
kitaev@213: 		return null;
kitaev@213: 	}
kitaev@213: 
kitaev@213: 	public String getNextCommitUsername() {
kitaev@213: 		if (nextCommitAuthor == null) {
kitaev@213: 			nextCommitAuthor = new HgInternals(repo).getNextCommitUsername();
kitaev@213: 		}
kitaev@213: 		return nextCommitAuthor;
kitaev@213: 	}
kitaev@213: }