--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/internal/RangeSeq.java	Mon Feb 25 18:41:44 2013 +0100
@@ -0,0 +1,175 @@
+/*
+ * 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.Formatter;
+
+/**
+ * Sequence of range pairs (denoted origin and target), {originStart, targetStart, length}, tailored for diff/annotate
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public final class RangeSeq {
+	// XXX smth like IntSliceVector to access triples (or slices of any size, in fact)
+	// with easy indexing, e.g. #get(sliceIndex, indexWithinSlice)
+	// and vect.get(7,2) instead of vect.get(7*SIZEOF_SLICE+2)
+	private final IntVector ranges = new IntVector(3*10, 3*5);
+	private int count;
+	
+	public void add(int start1, int start2, int length) {
+		if (count > 0) {
+			int lastIndex = 3 * (count-1);
+			int lastS1 = ranges.get(lastIndex);
+			int lastS2 = ranges.get(lastIndex + 1);
+			int lastLen = ranges.get(lastIndex + 2);
+			if (start1 == lastS1 + lastLen && start2 == lastS2 + lastLen) {
+				// new range continues the previous one - just increase the length
+				ranges.set(lastIndex + 2, lastLen + length);
+				return;
+			}
+		}
+		ranges.add(start1, start2, length);
+		count++;
+	}
+	
+	public void clear() {
+		ranges.clear();
+		count = 0;
+	}
+
+	public int size() {
+		return count;
+	}
+
+	/**
+	 * find out line index in the target that matches specified origin line
+	 */
+	public int mapLineIndex(int ln) {
+		for (int i = 0; i < ranges.size(); i += 3) {
+			int s1 = ranges.get(i);
+			if (s1 > ln) {
+				return -1;
+			}
+			int l = ranges.get(i+2);
+			if (s1 + l > ln) {
+				int s2 = ranges.get(i + 1);
+				return s2 + (ln - s1);
+			}
+		}
+		return -1;
+	}
+	
+	/**
+	 * find out line index in origin that matches specified target line
+	 */
+	public int reverseMapLine(int targetLine) {
+		for (int i = 0; i < ranges.size(); i +=3) {
+			int ts = ranges.get(i + 1);
+			if (ts > targetLine) {
+				return -1;
+			}
+			int l = ranges.get(i + 2);
+			if (ts + l > targetLine) {
+				int os = ranges.get(i);
+				return os + (targetLine - ts);
+			}
+		}
+		return -1;
+	}
+	
+	public RangeSeq intersect(RangeSeq target) {
+		RangeSeq v = new RangeSeq();
+		for (int i = 0; i < ranges.size(); i += 3) {
+			int originLine = ranges.get(i);
+			int targetLine = ranges.get(i + 1);
+			int length = ranges.get(i + 2);
+			int startTargetLine = -1, startOriginLine = -1, c = 0;
+			for (int j = 0; j < length; j++) {
+				int lnInFinal = target.mapLineIndex(targetLine + j);
+				if (lnInFinal == -1 || (startTargetLine != -1 && lnInFinal != startTargetLine + c)) {
+					// the line is not among "same" in ultimate origin
+					// or belongs to another/next "same" chunk 
+					if (startOriginLine == -1) {
+						continue;
+					}
+					v.add(startOriginLine, startTargetLine, c);
+					c = 0;
+					startOriginLine = startTargetLine = -1;
+					// fall-through to check if it's not complete miss but a next chunk
+				}
+				if (lnInFinal != -1) {
+					if (startOriginLine == -1) {
+						startOriginLine = originLine + j;
+						startTargetLine = lnInFinal;
+						c = 1;
+					} else {
+						// lnInFinal != startTargetLine + s is covered above
+						assert lnInFinal == startTargetLine + c;
+						c++;
+					}
+				}
+			}
+			if (startOriginLine != -1) {
+				assert c > 0;
+				v.add(startOriginLine, startTargetLine, c);
+			}
+		}
+		return v;
+	}
+	
+	// true when specified line in origin is equal to a line in target
+	public boolean includesOriginLine(int ln) {
+		return includes(ln, 0);
+	}
+	
+	// true when specified line in target is equal to a line in origin
+	public boolean includesTargetLine(int ln) {
+		return includes(ln, 1);
+	}
+
+	private boolean includes(int ln, int o) {
+		for (int i = 2; i < ranges.size(); o += 3, i+=3) {
+			int rangeStart = ranges.get(o);
+			if (rangeStart > ln) {
+				return false;
+			}
+			int rangeLen = ranges.get(i);
+			if (rangeStart + rangeLen > ln) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	public CharSequence dump() {
+		StringBuilder sb = new StringBuilder();
+		Formatter f = new Formatter(sb);
+		for (int i = 0; i < ranges.size(); i += 3) {
+			int s1 = ranges.get(i);
+			int s2 = ranges.get(i + 1);
+			int len = ranges.get(i + 2);
+			f.format("[%d..%d) == [%d..%d);  ", s1, s1 + len, s2, s2 + len);
+		}
+		return sb;
+	}
+	
+	@Override
+	public String toString() {
+		return String.format("RangeSeq[%d]", count);
+	}
+}
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