--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/internal/FileRenameHistory.java	Fri Aug 02 23:07:23 2013 +0200
@@ -0,0 +1,162 @@
+/*
+ * Copyright (c) 2013 TMate Software Ltd
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is 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.
+ *
+ * For information on how to redistribute this software under
+ * the terms of a license other than GNU General Public License
+ * contact TMate Software at support@hg4j.com
+ */
+package org.tmatesoft.hg.internal;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+import org.tmatesoft.hg.core.HgFileRevision;
+import org.tmatesoft.hg.core.HgIterateDirection;
+import org.tmatesoft.hg.repo.HgDataFile;
+
+/**
+ * Traces file renames. Quite similar to HgChangesetFileSneaker, although the latter tries different paths
+ * to find origin names, while this class traces first renames found only.
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public final class FileRenameHistory {
+	
+	private final int csetFrom;
+	private final int csetTo;
+	private final List<Chunk> history;
+
+	public FileRenameHistory(int csetStartIndex, int csetEndIndex) {
+		csetFrom = csetStartIndex;
+		csetTo = csetEndIndex;
+		history = new ArrayList<Chunk>(3);
+	}
+	
+	public int startChangeset() {
+		return csetFrom;
+	}
+	
+	public int endChangeset() {
+		return csetTo;
+	}
+	
+	public boolean isOutOfRange(HgDataFile df, int fileRev) {
+		return df.getChangesetRevisionIndex(fileRev) < csetFrom || df.getChangesetRevisionIndex(0) > csetTo;
+	}
+	
+	public void build(HgDataFile df, int fileRev) {
+		assert !isOutOfRange(df, fileRev);
+		LinkedList<Chunk> chunks = new LinkedList<Chunk>();
+		int chunkStart = 0, chunkEnd = fileRev;
+		int csetChunkEnd = -1, csetChunkStart = -1;
+		while (fileRev >= 0) {
+			int cset = df.getChangesetRevisionIndex(fileRev);
+			if (csetChunkEnd == -1) {
+				csetChunkEnd = cset;
+			}
+			if (cset <= csetFrom) {
+				chunkStart = fileRev;
+				csetChunkStart = csetFrom;
+				break;
+			}
+			if (cset > csetTo) {
+				chunkEnd = --fileRev;
+				csetChunkEnd = -1;
+				continue;
+			}
+			csetChunkStart = cset;
+			if (df.isCopy(fileRev)) {
+				chunks.addFirst(new Chunk(df, fileRev, chunkEnd, csetChunkStart, csetChunkEnd));
+				HgFileRevision origin = df.getCopySource(fileRev);
+				df = df.getRepo().getFileNode(origin.getPath());
+				fileRev = chunkEnd = df.getRevisionIndex(origin.getRevision());
+				chunkStart = 0;
+				csetChunkEnd = cset - 1; // if df is copy, cset can't be 0
+				csetChunkStart = -1;
+			} else {
+				fileRev--;
+			}
+		}
+		assert chunkStart >= 0;
+		assert chunkEnd >= 0; // can be negative only if df.cset(0) > csetTo
+		assert csetChunkEnd >= 0;
+		assert csetChunkStart >= 0;
+		chunks.addFirst(new Chunk(df, chunkStart, chunkEnd, csetChunkStart, csetChunkEnd));
+
+		history.clear();
+		history.addAll(chunks);
+	}
+
+	public Iterable<Chunk> iterate(HgIterateDirection order) {
+		if (order == HgIterateDirection.NewToOld) {
+			return ReverseIterator.reversed(history);
+		}
+		assert order == HgIterateDirection.OldToNew;
+		return Collections.unmodifiableList(history);
+	}
+	
+	public int chunks() {
+		return history.size();
+	}
+	
+	public Chunk chunkAt(int cset) {
+		if (cset < csetFrom || cset > csetTo) {
+			return null;
+		}
+		for (Chunk c : history) {
+			if (c.firstCset() > cset) {
+				break;
+			}
+			if (cset <= c.lastCset()) {
+				return c;
+			}
+		}
+		return null;
+	}
+
+
+	/**
+	 * file has changes [firstFileRev..lastFileRev] that have occurred somewhere in [firstCset..lastCset] 
+	 */
+	public static class Chunk {
+		private final HgDataFile df;
+		private final int fileRevFrom;
+		private final int fileRevTo;
+		private final int csetFrom;
+		private final int csetTo;
+		Chunk(HgDataFile file, int fileRevStart, int fileRevEnd, int csetStart, int csetEnd) {
+			df = file;
+			fileRevFrom = fileRevStart;
+			fileRevTo = fileRevEnd;
+			csetFrom = csetStart;
+			csetTo = csetEnd;
+		}
+		public HgDataFile file() {
+			return df;
+		}
+		public int firstFileRev() {
+			return fileRevFrom;
+		}
+		public int lastFileRev() {
+			return fileRevTo;
+		}
+		public int firstCset() {
+			return csetFrom;
+		}
+		public int lastCset() {
+			return csetTo;
+		}
+	}
+}