--- a/src/org/tmatesoft/hg/repo/HgChangelog.java	Wed Feb 16 20:13:41 2011 +0100
+++ b/src/org/tmatesoft/hg/repo/HgChangelog.java	Wed Feb 16 20:32:29 2011 +0100
@@ -16,9 +16,16 @@
  */
 package org.tmatesoft.hg.repo;
 
+import java.io.UnsupportedEncodingException;
 import java.util.ArrayList;
 import java.util.Arrays;
+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 org.tmatesoft.hg.core.Nodeid;
 import org.tmatesoft.hg.internal.RevlogStream;
@@ -36,11 +43,11 @@
 		super(hgRepo, content);
 	}
 
-	public void all(final Changeset.Inspector inspector) {
+	public void all(final HgChangelog.Inspector inspector) {
 		range(0, content.revisionCount() - 1, inspector);
 	}
 
-	public void range(int start, int end, final Changeset.Inspector inspector) {
+	public void range(int start, int end, final HgChangelog.Inspector inspector) {
 		RevlogStream.Inspector i = new RevlogStream.Inspector() {
 			
 			public void next(int revisionNumber, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[] nodeid, byte[] data) {
@@ -65,7 +72,7 @@
 		return rv; 
 	}
 
-	public void range(final Changeset.Inspector inspector, final int... revisions) {
+	public void range(final HgChangelog.Inspector inspector, final int... revisions) {
 		if (revisions == null || revisions.length == 0) {
 			return;
 		}
@@ -81,4 +88,212 @@
 		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
+		void next(int revisionNumber, Nodeid nodeid, Changeset cset);
+	}
+
+
+	/**
+	 * Entry in the Changelog
+	 */
+	public static class Changeset 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; // not sure it's of any use
+			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 Changeset() {
+					}
+
+					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;
+					}
+
+					public String dateString() {
+						StringBuilder sb = new StringBuilder(30);
+						Formatter f = new Formatter(sb, Locale.US);
+						f.format("%ta %<tb %<td %<tH:%<tM:%<tS %<tY %<tz", time);
+						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 Changeset clone() {
+						try {
+							return (Changeset) super.clone();
+						} catch (CloneNotSupportedException ex) {
+							throw new InternalError(ex.toString());
+						}
+					}
+
+					public static Changeset parse(byte[] data, int offset, int length) {
+						Changeset rv = new Changeset();
+						rv.init(data, offset, length);
+						return rv;
+					}
+
+					/* package-local */void init(byte[] data, int offset, int length) {
+						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);
+						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;
+					}
+	}
+
 }