--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hg4j/src/main/java/org/tmatesoft/hg/core/HgIncomingCommand.java	Tue May 10 10:52:53 2011 +0200
@@ -0,0 +1,199 @@
+/*
+ * Copyright (c) 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.core;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.tmatesoft.hg.internal.RepositoryComparator;
+import org.tmatesoft.hg.internal.RepositoryComparator.BranchChain;
+import org.tmatesoft.hg.repo.HgBundle;
+import org.tmatesoft.hg.repo.HgChangelog;
+import org.tmatesoft.hg.repo.HgChangelog.RawChangeset;
+import org.tmatesoft.hg.repo.HgRemoteRepository;
+import org.tmatesoft.hg.repo.HgRepository;
+import org.tmatesoft.hg.util.CancelledException;
+
+/**
+ * Command to find out changes available in a remote repository, missing locally.
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public class HgIncomingCommand {
+
+	private final HgRepository localRepo;
+	private HgRemoteRepository remoteRepo;
+	@SuppressWarnings("unused")
+	private boolean includeSubrepo;
+	private RepositoryComparator comparator;
+	private List<BranchChain> missingBranches;
+	private HgChangelog.ParentWalker parentHelper;
+	private Set<String> branches;
+
+	public HgIncomingCommand(HgRepository hgRepo) {
+	 	localRepo = hgRepo;
+	}
+	
+	public HgIncomingCommand against(HgRemoteRepository hgRemote) {
+		remoteRepo = hgRemote;
+		comparator = null;
+		missingBranches = null;
+		return this;
+	}
+
+	/**
+	 * Select specific branch to push.
+	 * Multiple branch specification possible (changeset from any of these would be included in result).
+	 * Note, {@link #executeLite(Object)} does not respect this setting.
+	 * 
+	 * @param branch - branch name, case-sensitive, non-null.
+	 * @return <code>this</code> for convenience
+	 * @throws IllegalArgumentException when branch argument is null
+	 */
+	public HgIncomingCommand branch(String branch) {
+		if (branch == null) {
+			throw new IllegalArgumentException();
+		}
+		if (branches == null) {
+			branches = new TreeSet<String>();
+		}
+		branches.add(branch);
+		return this;
+	}
+	
+	/**
+	 * PLACEHOLDER, NOT IMPLEMENTED YET.
+	 * 
+	 * Whether to include sub-repositories when collecting changes, default is <code>true</code> XXX or false?
+	 * @return <code>this</code> for convenience
+	 */
+	public HgIncomingCommand subrepo(boolean include) {
+		includeSubrepo = include;
+		throw HgRepository.notImplemented();
+	}
+
+	/**
+	 * Lightweight check for incoming changes, gives only list of revisions to pull.
+	 * Reported changes are from any branch (limits set by {@link #branch(String)} are not taken into account. 
+	 *   
+	 * @param context anything hg4j can use to get progress and/or cancel support
+	 * @return list of nodes present at remote and missing locally
+	 * @throws HgException
+	 * @throws CancelledException
+	 */
+	public List<Nodeid> executeLite(Object context) throws HgException, CancelledException {
+		LinkedHashSet<Nodeid> result = new LinkedHashSet<Nodeid>();
+		RepositoryComparator repoCompare = getComparator(context);
+		for (BranchChain bc : getMissingBranches(context)) {
+			List<Nodeid> missing = repoCompare.visitBranches(bc);
+			HashSet<Nodeid> common = new HashSet<Nodeid>(); // ordering is irrelevant  
+			repoCompare.collectKnownRoots(bc, common);
+			// missing could only start with common elements. Once non-common, rest is just distinct branch revision trails.
+			for (Iterator<Nodeid> it = missing.iterator(); it.hasNext() && common.contains(it.next()); it.remove()) ; 
+			result.addAll(missing);
+		}
+		ArrayList<Nodeid> rv = new ArrayList<Nodeid>(result);
+		return rv;
+	}
+
+	/**
+	 * Full information about incoming changes
+	 * 
+	 * @throws HgException
+	 * @throws CancelledException
+	 */
+	public void executeFull(final HgChangesetHandler handler) throws HgException, CancelledException {
+		if (handler == null) {
+			throw new IllegalArgumentException("Delegate can't be null");
+		}
+		final List<Nodeid> common = getCommon(handler);
+		HgBundle changegroup = remoteRepo.getChanges(common);
+		try {
+			changegroup.changes(localRepo, new HgChangelog.Inspector() {
+				private int localIndex;
+				private final HgChangelog.ParentWalker parentHelper;
+				private final ChangesetTransformer transformer;
+			
+				{
+					transformer = new ChangesetTransformer(localRepo, handler, getParentHelper());
+					transformer.limitBranches(branches);
+					parentHelper = getParentHelper();
+					// new revisions, if any, would be added after all existing, and would get numbered started with last+1
+					localIndex = localRepo.getChangelog().getRevisionCount();
+				}
+				
+				public void next(int revisionNumber, Nodeid nodeid, RawChangeset cset) {
+					if (parentHelper.knownNode(nodeid)) {
+						if (!common.contains(nodeid)) {
+							throw new HgBadStateException("Bundle shall not report known nodes other than roots we've supplied");
+						}
+						return;
+					}
+					transformer.next(localIndex++, nodeid, cset);
+				}
+			});
+		} catch (IOException ex) {
+			throw new HgException(ex);
+		}
+	}
+
+	private RepositoryComparator getComparator(Object context) throws HgException, CancelledException {
+		if (remoteRepo == null) {
+			throw new HgBadArgumentException("Shall specify remote repository to compare against", null);
+		}
+		if (comparator == null) {
+			comparator = new RepositoryComparator(getParentHelper(), remoteRepo);
+//			comparator.compare(context); // XXX meanwhile we use distinct path to calculate common  
+		}
+		return comparator;
+	}
+	
+	private HgChangelog.ParentWalker getParentHelper() {
+		if (parentHelper == null) {
+			parentHelper = localRepo.getChangelog().new ParentWalker();
+			parentHelper.init();
+		}
+		return parentHelper;
+	}
+	
+	private List<BranchChain> getMissingBranches(Object context) throws HgException, CancelledException {
+		if (missingBranches == null) {
+			missingBranches = getComparator(context).calculateMissingBranches();
+		}
+		return missingBranches;
+	}
+
+	private List<Nodeid> getCommon(Object context) throws HgException, CancelledException {
+//		return getComparator(context).getCommon();
+		final LinkedHashSet<Nodeid> common = new LinkedHashSet<Nodeid>();
+		// XXX common can be obtained from repoCompare, but at the moment it would almost duplicate work of calculateMissingBranches
+		// once I refactor latter, common shall be taken from repoCompare.
+		RepositoryComparator repoCompare = getComparator(context);
+		for (BranchChain bc : getMissingBranches(context)) {
+			repoCompare.collectKnownRoots(bc, common);
+		}
+		return new LinkedList<Nodeid>(common);
+	}
+}