From eecaad8b8e2c447429c31a01d49260ddd6b4ee03 Mon Sep 17 00:00:00 2001
From: Paul Martin <paul@paulsputer.com>
Date: Sat, 16 Apr 2016 17:35:32 -0400
Subject: [PATCH] Proof of concept #1026

---
 src/main/java/com/gitblit/utils/JGitUtils.java |  845 +++++++++++++++++++++++++++++++++++++++++---------------
 1 files changed, 617 insertions(+), 228 deletions(-)

diff --git a/src/main/java/com/gitblit/utils/JGitUtils.java b/src/main/java/com/gitblit/utils/JGitUtils.java
index 0cee70d..adcbb4d 100644
--- a/src/main/java/com/gitblit/utils/JGitUtils.java
+++ b/src/main/java/com/gitblit/utils/JGitUtils.java
@@ -21,6 +21,7 @@
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
@@ -28,6 +29,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import org.apache.commons.io.filefilter.TrueFileFilter;
@@ -35,15 +37,21 @@
 import org.eclipse.jgit.api.FetchCommand;
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.TagCommand;
+import org.eclipse.jgit.api.errors.ConcurrentRefUpdateException;
 import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.api.errors.JGitInternalException;
 import org.eclipse.jgit.diff.DiffEntry;
 import org.eclipse.jgit.diff.DiffEntry.ChangeType;
 import org.eclipse.jgit.diff.DiffFormatter;
 import org.eclipse.jgit.diff.RawTextComparator;
+import org.eclipse.jgit.dircache.DirCache;
+import org.eclipse.jgit.dircache.DirCacheEntry;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
+import org.eclipse.jgit.errors.LargeObjectException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.errors.StopWalkException;
+import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.BlobBasedConfig;
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.Constants;
@@ -61,6 +69,7 @@
 import org.eclipse.jgit.lib.TreeFormatter;
 import org.eclipse.jgit.merge.MergeStrategy;
 import org.eclipse.jgit.merge.RecursiveMerger;
+import org.eclipse.jgit.merge.ThreeWayMerger;
 import org.eclipse.jgit.revwalk.RevBlob;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevObject;
@@ -73,6 +82,7 @@
 import org.eclipse.jgit.transport.CredentialsProvider;
 import org.eclipse.jgit.transport.FetchResult;
 import org.eclipse.jgit.transport.RefSpec;
+import org.eclipse.jgit.treewalk.CanonicalTreeParser;
 import org.eclipse.jgit.treewalk.TreeWalk;
 import org.eclipse.jgit.treewalk.filter.AndTreeFilter;
 import org.eclipse.jgit.treewalk.filter.OrTreeFilter;
@@ -84,12 +94,17 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.gitblit.GitBlit;
 import com.gitblit.GitBlitException;
+import com.gitblit.manager.GitblitManager;
+import com.gitblit.models.FilestoreModel;
 import com.gitblit.models.GitNote;
 import com.gitblit.models.PathModel;
 import com.gitblit.models.PathModel.PathChangeModel;
 import com.gitblit.models.RefModel;
 import com.gitblit.models.SubmoduleModel;
+import com.gitblit.servlet.FilestoreServlet;
+import com.google.common.base.Strings;
 
 /**
  * Collection of static methods for retrieving information from a repository.
@@ -690,7 +705,10 @@
 		if (commit == null) {
 			return new Date(0);
 		}
-		return commit.getAuthorIdent().getWhen();
+		if (commit.getAuthorIdent() != null) {
+			return commit.getAuthorIdent().getWhen();
+		}
+		return getCommitDate(commit);
 	}
 
 	/**
@@ -773,7 +791,7 @@
 			}
 		} finally {
 			rw.dispose();
-			tw.release();
+			tw.close();
 		}
 		return content;
 	}
@@ -884,7 +902,64 @@
 		} catch (IOException e) {
 			error(e, repository, "{0} failed to get files for commit {1}", commit.getName());
 		} finally {
-			tw.release();
+			tw.close();
+		}
+		Collections.sort(list);
+		return list;
+	}
+
+	/**
+	 * Returns the list of files in the specified folder at the specified
+	 * commit. If the repository does not exist or is empty, an empty list is
+	 * returned.
+	 *
+	 * This is modified version that implements path compression feature.
+	 *
+	 * @param repository
+	 * @param path
+	 *            if unspecified, root folder is assumed.
+	 * @param commit
+	 *            if null, HEAD is assumed.
+	 * @return list of files in specified path
+	 */
+	public static List<PathModel> getFilesInPath2(Repository repository, String path, RevCommit commit) {
+
+		List<PathModel> list = new ArrayList<PathModel>();
+		if (!hasCommits(repository)) {
+			return list;
+		}
+		if (commit == null) {
+			commit = getCommit(repository, null);
+		}
+		final TreeWalk tw = new TreeWalk(repository);
+		try {
+
+			tw.addTree(commit.getTree());
+			final boolean isPathEmpty = Strings.isNullOrEmpty(path);
+
+			if (!isPathEmpty) {
+				PathFilter f = PathFilter.create(path);
+				tw.setFilter(f);
+			}
+
+			tw.setRecursive(true);
+			List<String> paths = new ArrayList<>();
+
+			while (tw.next()) {
+					String child = isPathEmpty ? tw.getPathString()
+							: tw.getPathString().replaceFirst(String.format("%s/", path), "");
+					paths.add(child);
+			}
+
+			for(String p: PathUtils.compressPaths(paths)) {
+				String pathString = isPathEmpty ? p : String.format("%s/%s", path, p);
+				list.add(getPathModel(repository, pathString, path, commit));
+			}
+
+		} catch (IOException e) {
+			error(e, repository, "{0} failed to get files for commit {1}", commit.getName());
+		} finally {
+			tw.close();
 		}
 		Collections.sort(list);
 		return list;
@@ -932,23 +1007,40 @@
 				tw.setRecursive(true);
 				tw.addTree(commit.getTree());
 				while (tw.next()) {
-					list.add(new PathChangeModel(tw.getPathString(), tw.getPathString(), 0, tw
-							.getRawMode(0), tw.getObjectId(0).getName(), commit.getId().getName(),
+					long size = 0;
+					FilestoreModel filestoreItem = null;
+					ObjectId objectId = tw.getObjectId(0);
+					
+					try {
+						if (!tw.isSubtree() && (tw.getFileMode(0) != FileMode.GITLINK)) {
+
+							size = tw.getObjectReader().getObjectSize(objectId, Constants.OBJ_BLOB);
+
+							if (isPossibleFilestoreItem(size)) {
+								filestoreItem = getFilestoreItem(tw.getObjectReader().open(objectId));
+							}
+						}
+					} catch (Throwable t) {
+						error(t, null, "failed to retrieve blob size for " + tw.getPathString());
+					}
+					
+					list.add(new PathChangeModel(tw.getPathString(), tw.getPathString(),filestoreItem, size, tw
+							.getRawMode(0), objectId.getName(), commit.getId().getName(),
 							ChangeType.ADD));
 				}
-				tw.release();
+				tw.close();
 			} else {
 				RevCommit parent = rw.parseCommit(commit.getParent(0).getId());
-				DiffStatFormatter df = new DiffStatFormatter(commit.getName());
+				DiffStatFormatter df = new DiffStatFormatter(commit.getName(), repository);
 				df.setRepository(repository);
 				df.setDiffComparator(RawTextComparator.DEFAULT);
 				df.setDetectRenames(true);
 				List<DiffEntry> diffs = df.scan(parent.getTree(), commit.getTree());
 				for (DiffEntry diff : diffs) {
 					// create the path change model
-					PathChangeModel pcm = PathChangeModel.from(diff, commit.getName());
-
-					if (calculateDiffStat) {
+					PathChangeModel pcm = PathChangeModel.from(diff, commit.getName(), repository);
+						
+						if (calculateDiffStat) {
 						// update file diffstats
 						df.format(diff);
 						PathChangeModel pathStat = df.getDiffStat().getPath(pcm.path);
@@ -991,7 +1083,7 @@
 			RevCommit start = rw.parseCommit(startRange);
 			RevCommit end = rw.parseCommit(endRange);
 			list.addAll(getFilesInRange(repository, start, end));
-			rw.release();
+			rw.close();
 		} catch (Throwable t) {
 			error(t, repository, "{0} failed to determine files in range {1}..{2}!", startCommit, endCommit);
 		}
@@ -1022,7 +1114,7 @@
 
 			List<DiffEntry> diffEntries = df.scan(startCommit.getTree(), endCommit.getTree());
 			for (DiffEntry diff : diffEntries) {
-				PathChangeModel pcm = PathChangeModel.from(diff,  endCommit.getName());
+				PathChangeModel pcm = PathChangeModel.from(diff,  endCommit.getName(), repository);
 				list.add(pcm);
 			}
 			Collections.sort(list);
@@ -1089,7 +1181,7 @@
 		} catch (IOException e) {
 			error(e, repository, "{0} failed to get documents for commit {1}", commit.getName());
 		} finally {
-			tw.release();
+			tw.close();
 		}
 		Collections.sort(list);
 		return list;
@@ -1106,22 +1198,100 @@
 	private static PathModel getPathModel(TreeWalk tw, String basePath, RevCommit commit) {
 		String name;
 		long size = 0;
+		
 		if (StringUtils.isEmpty(basePath)) {
 			name = tw.getPathString();
 		} else {
 			name = tw.getPathString().substring(basePath.length() + 1);
 		}
 		ObjectId objectId = tw.getObjectId(0);
+		FilestoreModel filestoreItem = null;
+		
 		try {
 			if (!tw.isSubtree() && (tw.getFileMode(0) != FileMode.GITLINK)) {
+
 				size = tw.getObjectReader().getObjectSize(objectId, Constants.OBJ_BLOB);
+
+				if (isPossibleFilestoreItem(size)) {
+					filestoreItem = getFilestoreItem(tw.getObjectReader().open(objectId));
+				}
 			}
 		} catch (Throwable t) {
 			error(t, null, "failed to retrieve blob size for " + tw.getPathString());
 		}
-		return new PathModel(name, tw.getPathString(), size, tw.getFileMode(0).getBits(),
+		return new PathModel(name, tw.getPathString(), filestoreItem, size, tw.getFileMode(0).getBits(),
 				objectId.getName(), commit.getName());
 	}
+	
+	public static boolean isPossibleFilestoreItem(long size) {
+		return (   (size >= com.gitblit.Constants.LEN_FILESTORE_META_MIN) 
+				&& (size <= com.gitblit.Constants.LEN_FILESTORE_META_MAX));
+	}
+	
+	/**
+	 * 
+	 * @return Representative FilestoreModel if valid, otherwise null
+	 */
+	public static FilestoreModel getFilestoreItem(ObjectLoader obj){
+		try {
+			final byte[] blob = obj.getCachedBytes(com.gitblit.Constants.LEN_FILESTORE_META_MAX);
+			final String meta = new String(blob, "UTF-8");
+		
+			return FilestoreModel.fromMetaString(meta);
+
+		} catch (LargeObjectException e) {
+			//Intentionally failing silent
+		} catch (Exception e) {
+			error(e, null, "failed to retrieve filestoreItem " + obj.toString());
+		}
+		
+		return null;
+	}
+
+	/**
+	 * Returns a path model by path string
+	 *
+	 * @param repo
+	 * @param path
+	 * @param filter
+	 * @param commit
+	 * @return a path model of the specified object
+	 */
+	private static PathModel getPathModel(Repository repo, String path, String filter, RevCommit commit)
+			throws IOException {
+
+		long size = 0;
+		FilestoreModel filestoreItem = null;
+		TreeWalk tw = TreeWalk.forPath(repo, path, commit.getTree());
+		String pathString = path;
+
+		if (!tw.isSubtree() && (tw.getFileMode(0) != FileMode.GITLINK)) {
+
+			pathString = PathUtils.getLastPathComponent(pathString);
+			
+			size = tw.getObjectReader().getObjectSize(tw.getObjectId(0), Constants.OBJ_BLOB);
+			
+			if (isPossibleFilestoreItem(size)) {
+				filestoreItem = getFilestoreItem(tw.getObjectReader().open(tw.getObjectId(0)));
+			}
+		} else if (tw.isSubtree()) {
+
+			// do not display dirs that are behind in the path
+			if (!Strings.isNullOrEmpty(filter)) {
+				pathString = path.replaceFirst(filter + "/", "");
+			}
+
+			// remove the last slash from path in displayed link
+			if (pathString != null && pathString.charAt(pathString.length()-1) == '/') {
+				pathString = pathString.substring(0, pathString.length()-1);
+			}
+		}
+
+		return new PathModel(pathString, tw.getPathString(), filestoreItem, size, tw.getFileMode(0).getBits(),
+				tw.getObjectId(0).getName(), commit.getName());
+
+	}
+
 
 	/**
 	 * Returns a permissions representation of the mode bits.
@@ -1575,13 +1745,9 @@
 	 * @return true if successful
 	 */
 	public static boolean deleteBranchRef(Repository repository, String branch) {
-		String branchName = branch;
-		if (!branchName.startsWith(Constants.R_HEADS)) {
-			branchName = Constants.R_HEADS + branch;
-		}
 
 		try {
-			RefUpdate refUpdate = repository.updateRef(branchName, false);
+			RefUpdate refUpdate = repository.updateRef(branch, false);
 			refUpdate.setForceUpdate(true);
 			RefUpdate.Result result = refUpdate.delete();
 			switch (result) {
@@ -1592,10 +1758,10 @@
 				return true;
 			default:
 				LOGGER.error(MessageFormat.format("{0} failed to delete to {1} returned result {2}",
-						repository.getDirectory().getAbsolutePath(), branchName, result));
+						repository.getDirectory().getAbsolutePath(), branch, result));
 			}
 		} catch (Throwable t) {
-			error(t, repository, "{0} failed to delete {1}", branchName);
+			error(t, repository, "{0} failed to delete {1}", branch);
 		}
 		return false;
 	}
@@ -1665,6 +1831,24 @@
 	 */
 	public static List<RefModel> getTags(Repository repository, boolean fullName, int maxCount) {
 		return getRefs(repository, Constants.R_TAGS, fullName, maxCount);
+	}
+
+	/**
+	 * Returns the list of tags in the repository. If repository does not exist
+	 * or is empty, an empty list is returned.
+	 *
+	 * @param repository
+	 * @param fullName
+	 *            if true, /refs/tags/yadayadayada is returned. If false,
+	 *            yadayadayada is returned.
+	 * @param maxCount
+	 *            if < 0, all tags are returned
+	 * @param offset
+	 *            if maxCount provided sets the starting point of the records to return
+	 * @return list of tags
+	 */
+	public static List<RefModel> getTags(Repository repository, boolean fullName, int maxCount, int offset) {
+		return getRefs(repository, Constants.R_TAGS, fullName, maxCount, offset);
 	}
 
 	/**
@@ -1748,6 +1932,27 @@
 	 */
 	private static List<RefModel> getRefs(Repository repository, String refs, boolean fullName,
 			int maxCount) {
+		return getRefs(repository, refs, fullName, maxCount, 0);
+	}
+
+	/**
+	 * Returns a list of references in the repository matching "refs". If the
+	 * repository is null or empty, an empty list is returned.
+	 *
+	 * @param repository
+	 * @param refs
+	 *            if unspecified, all refs are returned
+	 * @param fullName
+	 *            if true, /refs/something/yadayadayada is returned. If false,
+	 *            yadayadayada is returned.
+	 * @param maxCount
+	 *            if < 0, all references are returned
+	 * @param offset
+	 *            if maxCount provided sets the starting point of the records to return
+	 * @return list of references
+	 */
+	private static List<RefModel> getRefs(Repository repository, String refs, boolean fullName,
+			int maxCount, int offset) {
 		List<RefModel> list = new ArrayList<RefModel>();
 		if (maxCount == 0) {
 			return list;
@@ -1771,7 +1976,14 @@
 			Collections.sort(list);
 			Collections.reverse(list);
 			if (maxCount > 0 && list.size() > maxCount) {
-				list = new ArrayList<RefModel>(list.subList(0, maxCount));
+				if (offset < 0) {
+					offset = 0;
+				}
+				int endIndex = offset + maxCount;
+				if (endIndex > list.size()) {
+					endIndex = list.size();
+				}
+				list = new ArrayList<RefModel>(list.subList(offset, endIndex));
 			}
 		} catch (IOException e) {
 			error(e, repository, "{0} failed to retrieve {1}", refs);
@@ -1900,7 +2112,7 @@
 			error(t, repository, "{0} can't find {1} in commit {2}", path, commit.name());
 		} finally {
 			rw.dispose();
-			tw.release();
+			tw.close();
 		}
 		return commitId;
 	}
@@ -2074,10 +2286,10 @@
 						success = false;
 					}
 				} finally {
-					revWalk.release();
+					revWalk.close();
 				}
 			} finally {
-				odi.release();
+				odi.close();
 			}
 		} catch (Throwable t) {
 			error(t, repository, "Failed to create orphan branch {1} in repository {0}", branchName);
@@ -2148,208 +2360,385 @@
 		}
 		return false;
 	}
-
-	/**
-	 * Returns true if the commit identified by commitId is an ancestor or the
-	 * the commit identified by tipId.
-	 *
-	 * @param repository
-	 * @param commitId
-	 * @param tipId
-	 * @return true if there is the commit is an ancestor of the tip
-	 */
-	public static boolean isMergedInto(Repository repository, String commitId, String tipId) {
-		try {
-			return isMergedInto(repository, repository.resolve(commitId), repository.resolve(tipId));
-		} catch (Exception e) {
-			LOGGER.error("Failed to determine isMergedInto", e);
-		}
-		return false;
-	}
-
-	/**
-	 * Returns true if the commit identified by commitId is an ancestor or the
-	 * the commit identified by tipId.
-	 *
-	 * @param repository
-	 * @param commitId
-	 * @param tipId
-	 * @return true if there is the commit is an ancestor of the tip
-	 */
-	public static boolean isMergedInto(Repository repository, ObjectId commitId, ObjectId tipCommitId) {
-		// traverse the revlog looking for a commit chain between the endpoints
-		RevWalk rw = new RevWalk(repository);
-		try {
-			// must re-lookup RevCommits to workaround undocumented RevWalk bug
-			RevCommit tip = rw.lookupCommit(tipCommitId);
-			RevCommit commit = rw.lookupCommit(commitId);
-			return rw.isMergedInto(commit, tip);
-		} catch (Exception e) {
-			LOGGER.error("Failed to determine isMergedInto", e);
-		} finally {
-			rw.dispose();
-		}
-		return false;
-	}
-
-	/**
-	 * Returns the merge base of two commits or null if there is no common
-	 * ancestry.
-	 *
-	 * @param repository
-	 * @param commitIdA
-	 * @param commitIdB
-	 * @return the commit id of the merge base or null if there is no common base
-	 */
-	public static String getMergeBase(Repository repository, ObjectId commitIdA, ObjectId commitIdB) {
-		RevWalk rw = new RevWalk(repository);
-		try {
-			RevCommit a = rw.lookupCommit(commitIdA);
-			RevCommit b = rw.lookupCommit(commitIdB);
-
-			rw.setRevFilter(RevFilter.MERGE_BASE);
-			rw.markStart(a);
-			rw.markStart(b);
-			RevCommit mergeBase = rw.next();
-			if (mergeBase == null) {
-				return null;
-			}
-			return mergeBase.getName();
-		} catch (Exception e) {
-			LOGGER.error("Failed to determine merge base", e);
-		} finally {
-			rw.dispose();
-		}
-		return null;
-	}
-
-	public static enum MergeStatus {
-		NOT_MERGEABLE, FAILED, ALREADY_MERGED, MERGEABLE, MERGED;
-	}
-
-	/**
-	 * Determines if we can cleanly merge one branch into another.  Returns true
-	 * if we can merge without conflict, otherwise returns false.
-	 *
-	 * @param repository
-	 * @param src
-	 * @param toBranch
-	 * @return true if we can merge without conflict
-	 */
-	public static MergeStatus canMerge(Repository repository, String src, String toBranch) {
-		RevWalk revWalk = null;
-		try {
-			revWalk = new RevWalk(repository);
-			RevCommit branchTip = revWalk.lookupCommit(repository.resolve(toBranch));
-			RevCommit srcTip = revWalk.lookupCommit(repository.resolve(src));
-			if (revWalk.isMergedInto(srcTip, branchTip)) {
-				// already merged
-				return MergeStatus.ALREADY_MERGED;
-			} else if (revWalk.isMergedInto(branchTip, srcTip)) {
-				// fast-forward
-				return MergeStatus.MERGEABLE;
-			}
-			RecursiveMerger merger = (RecursiveMerger) MergeStrategy.RECURSIVE.newMerger(repository, true);
-			boolean canMerge = merger.merge(branchTip, srcTip);
-			if (canMerge) {
-				return MergeStatus.MERGEABLE;
-			}
-		} catch (IOException e) {
-			LOGGER.error("Failed to determine canMerge", e);
-		} finally {
-			revWalk.release();
-		}
-		return MergeStatus.NOT_MERGEABLE;
-	}
-
-
-	public static class MergeResult {
-		public final MergeStatus status;
-		public final String sha;
-
-		MergeResult(MergeStatus status, String sha) {
-			this.status = status;
-			this.sha = sha;
-		}
-	}
-
-	/**
-	 * Tries to merge a commit into a branch.  If there are conflicts, the merge
-	 * will fail.
-	 *
-	 * @param repository
-	 * @param src
-	 * @param toBranch
-	 * @param committer
-	 * @param message
-	 * @return the merge result
-	 */
-	public static MergeResult merge(Repository repository, String src, String toBranch,
-			PersonIdent committer, String message) {
-
-		if (!toBranch.startsWith(Constants.R_REFS)) {
-			// branch ref doesn't start with ref, assume this is a branch head
-			toBranch = Constants.R_HEADS + toBranch;
-		}
-
-		RevWalk revWalk = null;
-		try {
-			revWalk = new RevWalk(repository);
-			RevCommit branchTip = revWalk.lookupCommit(repository.resolve(toBranch));
-			RevCommit srcTip = revWalk.lookupCommit(repository.resolve(src));
-			if (revWalk.isMergedInto(srcTip, branchTip)) {
-				// already merged
-				return new MergeResult(MergeStatus.ALREADY_MERGED, null);
-			}
-			RecursiveMerger merger = (RecursiveMerger) MergeStrategy.RECURSIVE.newMerger(repository, true);
-			boolean merged = merger.merge(branchTip, srcTip);
-			if (merged) {
-				// create a merge commit and a reference to track the merge commit
-				ObjectId treeId = merger.getResultTreeId();
-				ObjectInserter odi = repository.newObjectInserter();
-				try {
-					// Create a commit object
-					CommitBuilder commitBuilder = new CommitBuilder();
-					commitBuilder.setCommitter(committer);
-					commitBuilder.setAuthor(committer);
-					commitBuilder.setEncoding(Constants.CHARSET);
-					if (StringUtils.isEmpty(message)) {
-						message = MessageFormat.format("merge {0} into {1}", srcTip.getName(), branchTip.getName());
-					}
-					commitBuilder.setMessage(message);
-					commitBuilder.setParentIds(branchTip.getId(), srcTip.getId());
-					commitBuilder.setTreeId(treeId);
-
-					// Insert the merge commit into the repository
-					ObjectId mergeCommitId = odi.insert(commitBuilder);
-					odi.flush();
-
-					// set the merge ref to the merge commit
-					RevCommit mergeCommit = revWalk.parseCommit(mergeCommitId);
-					RefUpdate mergeRefUpdate = repository.updateRef(toBranch);
-					mergeRefUpdate.setNewObjectId(mergeCommitId);
-					mergeRefUpdate.setRefLogMessage("commit: " + mergeCommit.getShortMessage(), false);
-					RefUpdate.Result rc = mergeRefUpdate.update();
-					switch (rc) {
-					case FAST_FORWARD:
-						// successful, clean merge
+
+	/**
+	 * Returns true if the commit identified by commitId is an ancestor or the
+	 * the commit identified by tipId.
+	 *
+	 * @param repository
+	 * @param commitId
+	 * @param tipId
+	 * @return true if there is the commit is an ancestor of the tip
+	 */
+	public static boolean isMergedInto(Repository repository, String commitId, String tipId) {
+		try {
+			return isMergedInto(repository, repository.resolve(commitId), repository.resolve(tipId));
+		} catch (Exception e) {
+			LOGGER.error("Failed to determine isMergedInto", e);
+		}
+		return false;
+	}
+
+	/**
+	 * Returns true if the commit identified by commitId is an ancestor or the
+	 * the commit identified by tipId.
+	 *
+	 * @param repository
+	 * @param commitId
+	 * @param tipId
+	 * @return true if there is the commit is an ancestor of the tip
+	 */
+	public static boolean isMergedInto(Repository repository, ObjectId commitId, ObjectId tipCommitId) {
+		// traverse the revlog looking for a commit chain between the endpoints
+		RevWalk rw = new RevWalk(repository);
+		try {
+			// must re-lookup RevCommits to workaround undocumented RevWalk bug
+			RevCommit tip = rw.lookupCommit(tipCommitId);
+			RevCommit commit = rw.lookupCommit(commitId);
+			return rw.isMergedInto(commit, tip);
+		} catch (Exception e) {
+			LOGGER.error("Failed to determine isMergedInto", e);
+		} finally {
+			rw.dispose();
+		}
+		return false;
+	}
+
+	/**
+	 * Returns the merge base of two commits or null if there is no common
+	 * ancestry.
+	 *
+	 * @param repository
+	 * @param commitIdA
+	 * @param commitIdB
+	 * @return the commit id of the merge base or null if there is no common base
+	 */
+	public static String getMergeBase(Repository repository, ObjectId commitIdA, ObjectId commitIdB) {
+		RevWalk rw = new RevWalk(repository);
+		try {
+			RevCommit a = rw.lookupCommit(commitIdA);
+			RevCommit b = rw.lookupCommit(commitIdB);
+
+			rw.setRevFilter(RevFilter.MERGE_BASE);
+			rw.markStart(a);
+			rw.markStart(b);
+			RevCommit mergeBase = rw.next();
+			if (mergeBase == null) {
+				return null;
+			}
+			return mergeBase.getName();
+		} catch (Exception e) {
+			LOGGER.error("Failed to determine merge base", e);
+		} finally {
+			rw.dispose();
+		}
+		return null;
+	}
+
+	public static enum MergeStatus {
+		MISSING_INTEGRATION_BRANCH, MISSING_SRC_BRANCH, NOT_MERGEABLE, FAILED, ALREADY_MERGED, MERGEABLE, MERGED;
+	}
+
+	/**
+	 * Determines if we can cleanly merge one branch into another.  Returns true
+	 * if we can merge without conflict, otherwise returns false.
+	 *
+	 * @param repository
+	 * @param src
+	 * @param toBranch
+	 * @return true if we can merge without conflict
+	 */
+	public static MergeStatus canMerge(Repository repository, String src, String toBranch) {
+		RevWalk revWalk = null;
+		try {
+			revWalk = new RevWalk(repository);
+			ObjectId branchId = repository.resolve(toBranch);
+			if (branchId == null) {
+				return MergeStatus.MISSING_INTEGRATION_BRANCH;
+			}
+			ObjectId srcId = repository.resolve(src);
+			if (srcId == null) {
+				return MergeStatus.MISSING_SRC_BRANCH;
+			}
+			RevCommit branchTip = revWalk.lookupCommit(branchId);
+			RevCommit srcTip = revWalk.lookupCommit(srcId);
+			if (revWalk.isMergedInto(srcTip, branchTip)) {
+				// already merged
+				return MergeStatus.ALREADY_MERGED;
+			} else if (revWalk.isMergedInto(branchTip, srcTip)) {
+				// fast-forward
+				return MergeStatus.MERGEABLE;
+			}
+			RecursiveMerger merger = (RecursiveMerger) MergeStrategy.RECURSIVE.newMerger(repository, true);
+			boolean canMerge = merger.merge(branchTip, srcTip);
+			if (canMerge) {
+				return MergeStatus.MERGEABLE;
+			}
+		} catch (NullPointerException e) {
+			LOGGER.error("Failed to determine canMerge", e);
+		} catch (IOException e) {
+			LOGGER.error("Failed to determine canMerge", e);
+		} finally {
+			if (revWalk != null) {
+				revWalk.close();
+			}
+		}
+		return MergeStatus.NOT_MERGEABLE;
+	}
+
+
+	public static class MergeResult {
+		public final MergeStatus status;
+		public final String sha;
+
+		MergeResult(MergeStatus status, String sha) {
+			this.status = status;
+			this.sha = sha;
+		}
+	}
+
+	/**
+	 * Tries to merge a commit into a branch.  If there are conflicts, the merge
+	 * will fail.
+	 *
+	 * @param repository
+	 * @param src
+	 * @param toBranch
+	 * @param committer
+	 * @param message
+	 * @return the merge result
+	 */
+	public static MergeResult merge(Repository repository, String src, String toBranch,
+			PersonIdent committer, String message) {
+
+		if (!toBranch.startsWith(Constants.R_REFS)) {
+			// branch ref doesn't start with ref, assume this is a branch head
+			toBranch = Constants.R_HEADS + toBranch;
+		}
+
+		RevWalk revWalk = null;
+		try {
+			revWalk = new RevWalk(repository);
+			RevCommit branchTip = revWalk.lookupCommit(repository.resolve(toBranch));
+			RevCommit srcTip = revWalk.lookupCommit(repository.resolve(src));
+			if (revWalk.isMergedInto(srcTip, branchTip)) {
+				// already merged
+				return new MergeResult(MergeStatus.ALREADY_MERGED, null);
+			}
+			RecursiveMerger merger = (RecursiveMerger) MergeStrategy.RECURSIVE.newMerger(repository, true);
+			boolean merged = merger.merge(branchTip, srcTip);
+			if (merged) {
+				// create a merge commit and a reference to track the merge commit
+				ObjectId treeId = merger.getResultTreeId();
+				ObjectInserter odi = repository.newObjectInserter();
+				try {
+					// Create a commit object
+					CommitBuilder commitBuilder = new CommitBuilder();
+					commitBuilder.setCommitter(committer);
+					commitBuilder.setAuthor(committer);
+					commitBuilder.setEncoding(Constants.CHARSET);
+					if (StringUtils.isEmpty(message)) {
+						message = MessageFormat.format("merge {0} into {1}", srcTip.getName(), branchTip.getName());
+					}
+					commitBuilder.setMessage(message);
+					commitBuilder.setParentIds(branchTip.getId(), srcTip.getId());
+					commitBuilder.setTreeId(treeId);
+
+					// Insert the merge commit into the repository
+					ObjectId mergeCommitId = odi.insert(commitBuilder);
+					odi.flush();
+
+					// set the merge ref to the merge commit
+					RevCommit mergeCommit = revWalk.parseCommit(mergeCommitId);
+					RefUpdate mergeRefUpdate = repository.updateRef(toBranch);
+					mergeRefUpdate.setNewObjectId(mergeCommitId);
+					mergeRefUpdate.setRefLogMessage("commit: " + mergeCommit.getShortMessage(), false);
+					RefUpdate.Result rc = mergeRefUpdate.update();
+					switch (rc) {
+					case FAST_FORWARD:
+						// successful, clean merge
 						break;
-					default:
-						throw new GitBlitException(MessageFormat.format("Unexpected result \"{0}\" when merging commit {1} into {2} in {3}",
-								rc.name(), srcTip.getName(), branchTip.getName(), repository.getDirectory()));
-					}
-
-					// return the merge commit id
-					return new MergeResult(MergeStatus.MERGED, mergeCommitId.getName());
-				} finally {
-					odi.release();
-				}
-			}
-		} catch (IOException e) {
-			LOGGER.error("Failed to merge", e);
-		} finally {
-			revWalk.release();
-		}
-		return new MergeResult(MergeStatus.FAILED, null);
-	}
+					default:
+						throw new GitBlitException(MessageFormat.format("Unexpected result \"{0}\" when merging commit {1} into {2} in {3}",
+								rc.name(), srcTip.getName(), branchTip.getName(), repository.getDirectory()));
+					}
+
+					// return the merge commit id
+					return new MergeResult(MergeStatus.MERGED, mergeCommitId.getName());
+				} finally {
+					odi.close();
+				}
+			}
+		} catch (IOException e) {
+			LOGGER.error("Failed to merge", e);
+		} finally {
+			if (revWalk != null) {
+				revWalk.close();
+			}
+		}
+		return new MergeResult(MergeStatus.FAILED, null);
+	}
+	
+	
+	/**
+	 * Returns the LFS URL for the given oid 
+	 * Currently assumes that the Gitblit Filestore is used 
+	 *
+	 * @param baseURL
+	 * @param repository name
+	 * @param oid of lfs item
+	 * @return the lfs item URL
+	 */
+	public static String getLfsRepositoryUrl(String baseURL, String repositoryName, String oid) {
+		
+		if (baseURL.length() > 0 && baseURL.charAt(baseURL.length() - 1) == '/') {
+			baseURL = baseURL.substring(0, baseURL.length() - 1);
+		}
+		
+		return baseURL + com.gitblit.Constants.R_PATH 
+					   + repositoryName + "/" 
+					   + com.gitblit.Constants.R_LFS 
+					   + "objects/" + oid;
+		
+	}
+	
+	/**
+	 * Returns all tree entries that do not match the ignore paths.
+	 *
+	 * @param db
+	 * @param ignorePaths
+	 * @param dcBuilder
+	 * @throws IOException
+	 */
+	public static List<DirCacheEntry> getTreeEntries(Repository db, String branch, Collection<String> ignorePaths) throws IOException {
+		List<DirCacheEntry> list = new ArrayList<DirCacheEntry>();
+		TreeWalk tw = null;
+		try {
+			ObjectId treeId = db.resolve(branch + "^{tree}");
+			if (treeId == null) {
+				// branch does not exist yet
+				return list;
+			}
+			tw = new TreeWalk(db);
+			int hIdx = tw.addTree(treeId);
+			tw.setRecursive(true);
+
+			while (tw.next()) {
+				String path = tw.getPathString();
+				CanonicalTreeParser hTree = null;
+				if (hIdx != -1) {
+					hTree = tw.getTree(hIdx, CanonicalTreeParser.class);
+				}
+				if (!ignorePaths.contains(path)) {
+					// add all other tree entries
+					if (hTree != null) {
+						final DirCacheEntry entry = new DirCacheEntry(path);
+						entry.setObjectId(hTree.getEntryObjectId());
+						entry.setFileMode(hTree.getEntryFileMode());
+						list.add(entry);
+					}
+				}
+			}
+		} finally {
+			if (tw != null) {
+				tw.close();
+			}
+		}
+		return list;
+	}
+	
+	public static boolean commitIndex(Repository db, String branch, DirCache index,
+									  ObjectId parentId, boolean forceCommit,
+									  String author, String authorEmail, String message) throws IOException, ConcurrentRefUpdateException {
+		boolean success = false;
+
+		ObjectId headId = db.resolve(branch + "^{commit}");
+		ObjectId baseId = parentId;
+		if (baseId == null || headId == null) { return false; }
+		
+		ObjectInserter odi = db.newObjectInserter();
+		try {
+			// Create the in-memory index of the new/updated ticket
+			ObjectId indexTreeId = index.writeTree(odi);
+
+			// Create a commit object
+			PersonIdent ident = new PersonIdent(author, authorEmail);
+			
+			if (forceCommit == false) {
+				ThreeWayMerger merger = MergeStrategy.RECURSIVE.newMerger(db, true);
+				merger.setObjectInserter(odi);
+				merger.setBase(baseId);
+				boolean mergeSuccess = merger.merge(indexTreeId, headId);
+				
+				if (mergeSuccess) {
+					indexTreeId = merger.getResultTreeId();
+				 } else {
+					//Manual merge required
+					return false; 
+				 }
+			}
+			
+			CommitBuilder commit = new CommitBuilder();
+			commit.setAuthor(ident);
+			commit.setCommitter(ident);
+			commit.setEncoding(com.gitblit.Constants.ENCODING);
+			commit.setMessage(message);
+			commit.setParentId(headId);
+			commit.setTreeId(indexTreeId);
+
+			// Insert the commit into the repository
+			ObjectId commitId = odi.insert(commit);
+			odi.flush();
+
+			RevWalk revWalk = new RevWalk(db);
+			try {
+				RevCommit revCommit = revWalk.parseCommit(commitId);
+				RefUpdate ru = db.updateRef(branch);
+				ru.setForceUpdate(forceCommit);
+				ru.setNewObjectId(commitId);
+				ru.setExpectedOldObjectId(headId);
+				ru.setRefLogMessage("commit: " + revCommit.getShortMessage(), false);
+				Result rc = ru.update();
+
+				switch (rc) {
+				case NEW:
+				case FORCED:
+				case FAST_FORWARD:
+					success = true;
+					break;
+				case REJECTED:
+				case LOCK_FAILURE:
+					throw new ConcurrentRefUpdateException(JGitText.get().couldNotLockHEAD,
+							ru.getRef(), rc);
+				default:
+					throw new JGitInternalException(MessageFormat.format(
+							JGitText.get().updatingRefFailed, branch, commitId.toString(),
+							rc));
+				}
+			} finally {
+				revWalk.close();
+			}
+		} finally {
+			odi.close();
+		}
+		return success;
+	}
+	
+	/**
+	 * Returns true if the commit identified by commitId is at the tip of it's branch.
+	 *
+	 * @param repository
+	 * @param commitId
+	 * @return true if the given commit is the tip
+	 */
+	public static boolean isTip(Repository repository, String commitId) {
+		try {
+			RefModel tip = getBranch(repository, commitId);
+			return (tip != null);	
+		} catch (Exception e) {
+			LOGGER.error("Failed to determine isTip", e);
+		}
+		return false;
+	}
+
 }

--
Gitblit v1.9.1