--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/internal/PhasesHelper.java	Tue Jun 05 20:50:06 2012 +0200
@@ -0,0 +1,194 @@
+/*
+ * Copyright (c) 2012 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 static org.tmatesoft.hg.repo.HgPhase.Draft;
+import static org.tmatesoft.hg.repo.HgPhase.Secret;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+
+import org.tmatesoft.hg.core.HgChangeset;
+import org.tmatesoft.hg.core.HgInvalidControlFileException;
+import org.tmatesoft.hg.core.Nodeid;
+import org.tmatesoft.hg.repo.HgChangelog;
+import org.tmatesoft.hg.repo.HgInternals;
+import org.tmatesoft.hg.repo.HgPhase;
+import org.tmatesoft.hg.repo.HgRepository;
+
+/**
+ * Support to deal with phases feature fo Mercurial (as of Mercutial version 2.1)
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public final class PhasesHelper {
+
+	private final HgRepository hgRepo;
+	private final HgChangelog.ParentWalker parentHelper;
+	private Boolean repoSupporsPhases;
+	private List<Nodeid> draftPhaseRoots;
+	private List<Nodeid> secretPhaseRoots;
+
+	public PhasesHelper(HgRepository repo) {
+		this(repo, null);
+	}
+
+	public PhasesHelper(HgRepository repo, HgChangelog.ParentWalker pw) {
+		hgRepo = repo;
+		parentHelper = pw;
+	}
+
+	public boolean isCapableOfPhases() throws HgInvalidControlFileException {
+		if (null == repoSupporsPhases) {
+			repoSupporsPhases = readRoots();
+		}
+		return repoSupporsPhases.booleanValue();
+	}
+
+
+	public HgPhase getPhase(HgChangeset cset) throws HgInvalidControlFileException {
+		final Nodeid csetRev = cset.getNodeid();
+		final int csetRevIndex = cset.getRevision();
+		return getPhase(csetRevIndex, csetRev);
+	}
+
+	public HgPhase getPhase(final int csetRevIndex, Nodeid csetRev) throws HgInvalidControlFileException {
+		if (!isCapableOfPhases()) {
+			return HgPhase.Undefined;
+		}
+		if (csetRev == null || csetRev.isNull()) {
+			csetRev = hgRepo.getChangelog().getRevision(csetRevIndex);
+		}
+					
+		for (HgPhase phase : new HgPhase[] {HgPhase.Secret, HgPhase.Draft }) {
+			List<Nodeid> roots = getPhaseRoots(phase);
+			if (roots.isEmpty()) {
+				continue;
+			}
+			if (roots.contains(csetRev)) {
+				return phase;
+			}
+			if (parentHelper != null) {
+				if (parentHelper.childrenOf(roots).contains(csetRev)) {
+					return phase;
+				}
+			} else {
+				// no parent helper
+				// search all descendants
+				int[] rootIndexes = toIndexes(roots);
+				Arrays.sort(rootIndexes);
+				if (rootIndexes[0] > csetRevIndex) {
+					// this phase started later than our changeset was added, try another phase
+					continue;
+				}
+				/*
+				 * TODO descendants() method to build a BitSet with 1 at index of those that are descendants
+				 * wrap it into a class with root nodeid to 
+				 * (a) collect only for a subset of repository, 
+				 * (b) be able to answer isDescendant(int csetRevIndex) using absolute indexing (i.e bitAt(csetRevIndex - rootRevIndex))  
+				 */
+				final HashSet<Nodeid> parents2consider = new HashSet<Nodeid>(roots);
+				final boolean[] result = new boolean[] { false };
+				hgRepo.getChangelog().walk(rootIndexes[0], csetRevIndex, new HgChangelog.ParentInspector() {
+					
+					public void next(int revisionIndex, Nodeid revision, int parent1, int parent2, Nodeid nidParent1, Nodeid nidParent2) {
+						boolean descendant = false;
+						if (!nidParent1.isNull() && parents2consider.contains(nidParent1)) {
+							parents2consider.add(nidParent1);
+							descendant = true;
+						}
+						if (!nidParent2.isNull() && parents2consider.contains(nidParent2)) {
+							parents2consider.add(nidParent2);
+							descendant = true;
+						}
+						if (descendant && revisionIndex == csetRevIndex) {
+							// revision of interest descends from one of the roots
+							result[0] = true;
+						}
+					}
+				});
+				if (result[0]) {
+					return phase;
+				}
+			}
+		}
+		return HgPhase.Public;
+
+	}
+
+	
+	private int[] toIndexes(List<Nodeid> roots) throws HgInvalidControlFileException {
+		int[] rv = new int[roots.size()];
+		for (int i = 0; i < rv.length; i++) {
+			rv[i] = hgRepo.getChangelog().getRevisionIndex(roots.get(i));
+		}
+		return rv;
+	}
+
+	private Boolean readRoots() throws HgInvalidControlFileException {
+		// FIXME shall access phaseroots through HgRepository#repoPathHelper
+		File phaseroots = new File(HgInternals.getRepositoryDir(hgRepo), "store/phaseroots");
+		try {
+			if (!phaseroots.exists()) {
+				return Boolean.FALSE;
+			}
+			HashMap<HgPhase, List<Nodeid>> phase2roots = new HashMap<HgPhase, List<Nodeid>>();
+			BufferedReader br = new BufferedReader(new FileReader(phaseroots));
+			String line;
+			while ((line = br.readLine()) != null) {
+				String[] lc = line.trim().split("\\s+");
+				if (lc.length == 0) {
+					continue;
+				}
+				if (lc.length != 2) {
+					HgInternals.getContext(hgRepo).getLog().warn(getClass(), "Bad line in phaseroots:%s", line);
+					continue;
+				}
+				int phaseIndex = Integer.parseInt(lc[0]);
+				Nodeid rootRev = Nodeid.fromAscii(lc[1]);
+				HgPhase phase = HgPhase.parse(phaseIndex);
+				List<Nodeid> roots = phase2roots.get(phase);
+				if (roots == null) {
+					phase2roots.put(phase, roots = new LinkedList<Nodeid>());
+				}
+				roots.add(rootRev);
+			}
+			draftPhaseRoots = phase2roots.containsKey(Draft) ? phase2roots.get(Draft) : Collections.<Nodeid>emptyList();
+			secretPhaseRoots = phase2roots.containsKey(Secret) ? phase2roots.get(Secret) : Collections.<Nodeid>emptyList();
+		} catch (IOException ex) {
+			throw new HgInvalidControlFileException(ex.toString(), ex, phaseroots);
+		}
+		return Boolean.TRUE;
+	}
+
+	private List<Nodeid> getPhaseRoots(HgPhase phase) {
+		switch (phase) {
+		case Draft : return draftPhaseRoots;
+		case Secret : return secretPhaseRoots;
+		}
+		return Collections.emptyList();
+	}
+}