--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hg4j/src/main/java/org/tmatesoft/hg/repo/HgChangelog.java	Tue May 10 10:52:53 2011 +0200
@@ -0,0 +1,351 @@
+/*
+ * Copyright (c) 2010-2011 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.repo;
+
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Calendar;
+import java.util.Collections;
+import java.util.Date;
+import java.util.Formatter;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.TimeZone;
+
+import org.tmatesoft.hg.core.HgBadStateException;
+import org.tmatesoft.hg.core.Nodeid;
+import org.tmatesoft.hg.internal.DataAccess;
+import org.tmatesoft.hg.internal.Pool;
+import org.tmatesoft.hg.internal.RevlogStream;
+
+/**
+ * Representation of the Mercurial changelog file (list of ChangeSets)
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public class HgChangelog extends Revlog {
+
+	/* package-local */HgChangelog(HgRepository hgRepo, RevlogStream content) {
+		super(hgRepo, content);
+	}
+
+	public void all(final HgChangelog.Inspector inspector) {
+		range(0, getLastRevision(), inspector);
+	}
+
+	public void range(int start, int end, final HgChangelog.Inspector inspector) {
+		if (inspector == null) {
+			throw new IllegalArgumentException();
+		}
+		content.iterate(start, end, true, new RawCsetParser(inspector));
+	}
+
+	public List<RawChangeset> range(int start, int end) {
+		final RawCsetCollector c = new RawCsetCollector(end - start + 1);
+		range(start, end, c);
+		return c.result;
+	}
+
+	public void range(final HgChangelog.Inspector inspector, final int... revisions) {
+		if (revisions == null || revisions.length == 0) {
+			return;
+		}
+		RevlogStream.Inspector i = new RevlogStream.Inspector() {
+			private final RawCsetParser delegate = new RawCsetParser(inspector);
+
+			public void next(int revisionNumber, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[] nodeid, DataAccess da) {
+				if (Arrays.binarySearch(revisions, revisionNumber) >= 0) {
+					delegate.next(revisionNumber, actualLen, baseRevision, linkRevision, parent1Revision, parent2Revision, nodeid, da);
+				}
+			}
+		};
+		Arrays.sort(revisions);
+		content.iterate(revisions[0], revisions[revisions.length - 1], true, i);
+	}
+
+	public interface Inspector {
+		// TODO describe whether cset is new instance each time
+		// describe what revisionNumber is when Inspector is used with HgBundle (BAD_REVISION or bundle's local order?) 
+		void next(int revisionNumber, Nodeid nodeid, RawChangeset cset);
+	}
+
+	/**
+	 * Entry in the Changelog
+	 */
+	public static class RawChangeset implements Cloneable /* for those that would like to keep a copy */{
+		// TODO immutable
+		private/* final */Nodeid manifest;
+		private String user;
+		private String comment;
+		private List<String> files; // unmodifiable collection (otherwise #files() and implicit #clone() shall be revised)
+		private Date time;
+		private int timezone;
+		// http://mercurial.selenic.com/wiki/PruningDeadBranches - Closing changesets can be identified by close=1 in the changeset's extra field.
+		private Map<String, String> extras;
+
+		/**
+		 * @see mercurial/changelog.py:read()
+		 * 
+		 *      <pre>
+		 *         format used:
+		 *         nodeid\n        : manifest node in ascii
+		 *         user\n          : user, no \n or \r allowed
+		 *         time tz extra\n : date (time is int or float, timezone is int)
+		 *                         : extra is metadatas, encoded and separated by '\0'
+		 *                         : older versions ignore it
+		 *         files\n\n       : files modified by the cset, no \n or \r allowed
+		 *         (.*)            : comment (free text, ideally utf-8)
+		 * 
+		 *         changelog v0 doesn't use extra
+		 * </pre>
+		 */
+		private RawChangeset() {
+		}
+
+		public Nodeid manifest() {
+			return manifest;
+		}
+
+		public String user() {
+			return user;
+		}
+
+		public String comment() {
+			return comment;
+		}
+
+		public List<String> files() {
+			return files;
+		}
+
+		public Date date() {
+			return time;
+		}
+		
+		/**
+		 * @return time zone value, as is, positive for Western Hemisphere.
+		 */
+		public int timezone() {
+			return timezone;
+		}
+
+		public String dateString() {
+			// XXX keep once formatted? Perhaps, there's faster way to set up calendar/time zone?
+			StringBuilder sb = new StringBuilder(30);
+			Formatter f = new Formatter(sb, Locale.US);
+			TimeZone tz = TimeZone.getTimeZone(TimeZone.getAvailableIDs(timezone * 1000)[0]);
+			// apparently timezone field records number of seconds time differs from UTC,
+			// i.e. value to substract from time to get UTC time. Calendar seems to add
+			// timezone offset to UTC, instead, hence sign change.
+//			tz.setRawOffset(timezone * -1000);
+			Calendar c = Calendar.getInstance(tz, Locale.US);
+			c.setTime(time);
+			f.format("%ta %<tb %<td %<tH:%<tM:%<tS %<tY %<tz", c);
+			return sb.toString();
+		}
+
+		public Map<String, String> extras() {
+			return extras;
+		}
+
+		public String branch() {
+			return extras.get("branch");
+		}
+
+		@Override
+		public String toString() {
+			StringBuilder sb = new StringBuilder();
+			sb.append("Changeset {");
+			sb.append("User: ").append(user).append(", ");
+			sb.append("Comment: ").append(comment).append(", ");
+			sb.append("Manifest: ").append(manifest).append(", ");
+			sb.append("Date: ").append(time).append(", ");
+			sb.append("Files: ").append(files.size());
+			for (String s : files) {
+				sb.append(", ").append(s);
+			}
+			if (extras != null) {
+				sb.append(", Extra: ").append(extras);
+			}
+			sb.append("}");
+			return sb.toString();
+		}
+
+		@Override
+		public RawChangeset clone() {
+			try {
+				return (RawChangeset) super.clone();
+			} catch (CloneNotSupportedException ex) {
+				throw new InternalError(ex.toString());
+			}
+		}
+
+		public static RawChangeset parse(DataAccess da) {
+			try {
+				byte[] data = da.byteArray();
+				RawChangeset rv = new RawChangeset();
+				rv.init(data, 0, data.length, null);
+				return rv;
+			} catch (IOException ex) {
+				throw new HgBadStateException(ex); // FIXME "Error reading changeset data"
+			}
+		}
+
+		// @param usersPool - it's likely user names get repeated again and again throughout repository. can be null
+		/* package-local */void init(byte[] data, int offset, int length, Pool<String> usersPool) {
+			final int bufferEndIndex = offset + length;
+			final byte lineBreak = (byte) '\n';
+			int breakIndex1 = indexOf(data, lineBreak, offset, bufferEndIndex);
+			if (breakIndex1 == -1) {
+				throw new IllegalArgumentException("Bad Changeset data");
+			}
+			Nodeid _nodeid = Nodeid.fromAscii(data, 0, breakIndex1);
+			int breakIndex2 = indexOf(data, lineBreak, breakIndex1 + 1, bufferEndIndex);
+			if (breakIndex2 == -1) {
+				throw new IllegalArgumentException("Bad Changeset data");
+			}
+			String _user = new String(data, breakIndex1 + 1, breakIndex2 - breakIndex1 - 1);
+			if (usersPool != null) {
+				_user = usersPool.unify(_user);
+			}
+			int breakIndex3 = indexOf(data, lineBreak, breakIndex2 + 1, bufferEndIndex);
+			if (breakIndex3 == -1) {
+				throw new IllegalArgumentException("Bad Changeset data");
+			}
+			String _timeString = new String(data, breakIndex2 + 1, breakIndex3 - breakIndex2 - 1);
+			int space1 = _timeString.indexOf(' ');
+			if (space1 == -1) {
+				throw new IllegalArgumentException("Bad Changeset data");
+			}
+			int space2 = _timeString.indexOf(' ', space1 + 1);
+			if (space2 == -1) {
+				space2 = _timeString.length();
+			}
+			long unixTime = Long.parseLong(_timeString.substring(0, space1)); // XXX Float, perhaps
+			int _timezone = Integer.parseInt(_timeString.substring(space1 + 1, space2));
+			// XXX not sure need to add timezone here - I can't figure out whether Hg keeps GMT time, and records timezone just for info, or unixTime is taken local
+			// on commit and timezone is recorded to adjust it to UTC.
+			Date _time = new Date(unixTime * 1000);
+			String _extras = space2 < _timeString.length() ? _timeString.substring(space2 + 1) : null;
+			Map<String, String> _extrasMap;
+			if (_extras == null) {
+				_extrasMap = Collections.singletonMap("branch", "default");
+			} else {
+				_extrasMap = new HashMap<String, String>();
+				for (String pair : _extras.split("\00")) {
+					int eq = pair.indexOf(':');
+					// FIXME need to decode key/value, @see changelog.py:decodeextra
+					_extrasMap.put(pair.substring(0, eq), pair.substring(eq + 1));
+				}
+				if (!_extrasMap.containsKey("branch")) {
+					_extrasMap.put("branch", "default");
+				}
+				_extrasMap = Collections.unmodifiableMap(_extrasMap);
+			}
+
+			//
+			int lastStart = breakIndex3 + 1;
+			int breakIndex4 = indexOf(data, lineBreak, lastStart, bufferEndIndex);
+			ArrayList<String> _files = null;
+			if (breakIndex4 > lastStart) {
+				// if breakIndex4 == lastStart, we already found \n\n and hence there are no files (e.g. merge revision)
+				_files = new ArrayList<String>(5);
+				while (breakIndex4 != -1 && breakIndex4 + 1 < bufferEndIndex) {
+					_files.add(new String(data, lastStart, breakIndex4 - lastStart));
+					lastStart = breakIndex4 + 1;
+					if (data[breakIndex4 + 1] == lineBreak) {
+						// found \n\n
+						break;
+					} else {
+						breakIndex4 = indexOf(data, lineBreak, lastStart, bufferEndIndex);
+					}
+				}
+				if (breakIndex4 == -1 || breakIndex4 >= bufferEndIndex) {
+					throw new IllegalArgumentException("Bad Changeset data");
+				}
+			} else {
+				breakIndex4--;
+			}
+			String _comment;
+			try {
+				_comment = new String(data, breakIndex4 + 2, bufferEndIndex - breakIndex4 - 2, "UTF-8");
+				// FIXME respect ui.fallbackencoding and try to decode if set
+			} catch (UnsupportedEncodingException ex) {
+				_comment = "";
+				throw new IllegalStateException("Could hardly happen");
+			}
+			// change this instance at once, don't leave it partially changes in case of error
+			this.manifest = _nodeid;
+			this.user = _user;
+			this.time = _time;
+			this.timezone = _timezone;
+			this.files = _files == null ? Collections.<String> emptyList() : Collections.unmodifiableList(_files);
+			this.comment = _comment;
+			this.extras = _extrasMap;
+		}
+
+		private static int indexOf(byte[] src, byte what, int startOffset, int endIndex) {
+			for (int i = startOffset; i < endIndex; i++) {
+				if (src[i] == what) {
+					return i;
+				}
+			}
+			return -1;
+		}
+	}
+
+	private static class RawCsetCollector implements Inspector {
+		final ArrayList<RawChangeset> result;
+		
+		public RawCsetCollector(int count) {
+			result = new ArrayList<RawChangeset>(count > 0 ? count : 5);
+		}
+
+		public void next(int revisionNumber, Nodeid nodeid, RawChangeset cset) {
+			result.add(cset.clone());
+		}
+	}
+
+	private static class RawCsetParser implements RevlogStream.Inspector {
+		
+		private final Inspector inspector;
+		private final Pool<String> usersPool;
+		private final RawChangeset cset = new RawChangeset();
+
+		public RawCsetParser(HgChangelog.Inspector delegate) {
+			assert delegate != null;
+			inspector = delegate;
+			usersPool = new Pool<String>();
+		}
+
+		public void next(int revisionNumber, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[] nodeid, DataAccess da) {
+			try {
+				byte[] data = da.byteArray();
+				cset.init(data, 0, data.length, usersPool);
+				// XXX there's no guarantee for Changeset.Callback that distinct instance comes each time, consider instance reuse
+				inspector.next(revisionNumber, Nodeid.fromBinary(nodeid, 0), cset);
+			} catch (Exception ex) {
+				throw new HgBadStateException(ex); // FIXME exception handling
+			}
+		}
+	}
+}