--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/internal/diff/ForwardAnnotateInspector.java	Wed Aug 14 14:51:51 2013 +0200
@@ -0,0 +1,145 @@
+/*
+ * 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.diff;
+
+import org.tmatesoft.hg.core.HgAnnotateCommand.Inspector;
+import org.tmatesoft.hg.core.HgBlameInspector;
+import org.tmatesoft.hg.core.HgCallbackTargetException;
+import org.tmatesoft.hg.core.HgIterateDirection;
+import org.tmatesoft.hg.internal.IntMap;
+import org.tmatesoft.hg.internal.IntSliceSeq;
+import org.tmatesoft.hg.internal.IntTuple;
+import org.tmatesoft.hg.util.CancelSupport;
+import org.tmatesoft.hg.util.CancelledException;
+import org.tmatesoft.hg.util.ProgressSupport;
+
+/**
+ * Annotate file history iterating from parents to children
+ * 
+ * At the moment, doesn't handle start from any revision but 0
+ * 
+ * (+) May report annotate for any revision (with actual file change) in the visited range.
+ * 
+ * @see ReverseAnnotateInspector
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public class ForwardAnnotateInspector implements HgBlameInspector, HgBlameInspector.RevisionDescriptor.Recipient {
+	final IntMap<IntSliceSeq> all = new IntMap<IntSliceSeq>(100);
+	// revision->map(lineNumber->lineContent)
+	private final IntMap<IntMap<byte[]>> lineContent = new IntMap<IntMap<byte[]>>(100);
+	private IntSliceSeq current;
+	private RevisionDescriptor revDescriptor;
+
+	/**
+	 * @return desired order of iteration for diff
+	 */
+	public HgIterateDirection iterateDirection() {
+		return HgIterateDirection.OldToNew;
+	}
+
+	public void report(int revision, Inspector insp, ProgressSupport progress, CancelSupport cancel) throws HgCallbackTargetException, CancelledException {
+		int totalLines = 0;
+		if (!all.containsKey(revision)) {
+			throw new IllegalArgumentException(String.format("Revision %d has not been visited", revision));
+		}
+		for (IntTuple t : all.get(revision)) {
+			totalLines += t.at(0);
+		}
+		progress.start(totalLines);
+		LineImpl li = new LineImpl();
+		int line = 1;
+		for (IntTuple t : all.get(revision)) {
+			IntMap<byte[]> revLines = lineContent.get(t.at(1));
+			for (int i = 0, x = t.at(0); i < x; i++) {
+				final int lineInRev = t.at(2) + i;
+				final byte[] lc = revLines.get(lineInRev);
+				li.init(line++, lineInRev+1, t.at(1), lc);
+				insp.next(li);
+				progress.worked(1);
+				cancel.checkCancelled();
+			}
+		}
+		progress.done();
+	}
+
+	public void start(RevisionDescriptor rd) throws HgCallbackTargetException {
+		all.put(rd.targetChangesetIndex(), current = new IntSliceSeq(3));
+		revDescriptor = rd;
+	}
+
+	public void done(RevisionDescriptor rd) throws HgCallbackTargetException {
+		revDescriptor = null;
+	}
+
+	public void same(EqualBlock block) throws HgCallbackTargetException {
+		copyBlock(block.originChangesetIndex(), block.originStart(), block.length());
+	}
+
+	public void added(AddBlock block) throws HgCallbackTargetException {
+		if (revDescriptor.isMerge() && block.originChangesetIndex() == revDescriptor.mergeChangesetIndex()) {
+			copyBlock(block.originChangesetIndex(), block.insertedAt(), block.totalAddedLines());
+			return;
+		}
+		BlockData addedLines = block.addedLines();
+		IntMap<byte[]> revLines = lineContent.get(block.targetChangesetIndex());
+		if (revLines == null) {
+			lineContent.put(block.targetChangesetIndex(), revLines = new IntMap<byte[]>(block.totalAddedLines()));
+		}
+		for (int i = 0; i < block.totalAddedLines(); i++) {
+			revLines.put(block.firstAddedLine() + i, addedLines.elementAt(i).asArray());
+		}
+		current.add(block.totalAddedLines(), block.targetChangesetIndex(), block.firstAddedLine());
+	}
+
+	public void changed(ChangeBlock block) throws HgCallbackTargetException {
+		added(block);
+	}
+
+	public void deleted(DeleteBlock block) throws HgCallbackTargetException {
+	}
+	
+	private void copyBlock(int originChangesetIndex, int blockStart, int length) {
+		IntSliceSeq origin = all.get(originChangesetIndex);
+		assert origin != null; // shall visit parents before came to this child
+		int originPos = 0;
+		int targetBlockLen = length;
+		for (IntTuple t : origin) {
+			int originBlockLen = t.at(0);
+			int originBlockEnd = originPos + originBlockLen;
+			if (originBlockEnd > blockStart) {
+				// part of origin block from blockStart up to originBlockEnd, but not more
+				// than size of the block (when blockStart is out of block start, i.e. < originPos)
+				int originBlockOverlap = Math.min(originBlockLen, originBlockEnd - blockStart);
+				assert originBlockOverlap > 0;
+				// eat as much as there's left in the block being copied
+				int originBlockConsumed = Math.min(originBlockOverlap, targetBlockLen);
+				int originBlockLine = t.at(2);
+				if (originPos < blockStart) {
+					originBlockLine += originBlockLen-originBlockOverlap;
+				}
+				// copy fragment of original block;
+				current.add(originBlockConsumed, t.at(1), originBlockLine);
+				targetBlockLen -= originBlockConsumed;
+				if (targetBlockLen == 0) {
+					break;
+				}
+			}
+			originPos += originBlockLen;
+		}
+	}
+}
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