Merge pull request #2 from JakeGinnivan/cache-merge-base

Additional refactoring for caching.

Author: DanielRose

src/GitVersionCore.Tests/IntegrationTests/FeatureBranchScenarios.cs

@@ -514,9 +514,8 @@ public void PickUpVersionFromMasterMarkedWithIsTracksReleaseBranches()
             fixture.AssertFullSemver(config, "0.10.1-pre.1+1");
 
             // create a feature branch from master and verify the version
-            // TODO this will pass once default becomes inherit
-            //fixture.BranchTo("MyFeatureD");
-            //fixture.AssertFullSemver(config, "0.10.1-MyFeatureD.1+1");
+            fixture.BranchTo("MyFeatureD");
+            fixture.AssertFullSemver(config, "0.10.1-MyFeatureD.1+1");
         }
     }
 }

src/GitVersionCore/BranchConfigurationCalculator.cs

@@ -12,9 +12,9 @@ public class BranchConfigurationCalculator
         /// <summary>
         /// Gets the <see cref="BranchConfig"/> for the current commit.
         /// </summary>
-        public static BranchConfig GetBranchConfiguration(Commit currentCommit, IRepository repository, bool onlyEvaluateTrackedBranches, Config config, Branch currentBranch, IList<Branch> excludedInheritBranches = null)
+        public static BranchConfig GetBranchConfiguration(GitVersionContext context, Branch targetBranch, IList<Branch> excludedInheritBranches = null)
         {
-            var matchingBranches = LookupBranchConfiguration(config, currentBranch).ToArray();
+            var matchingBranches = LookupBranchConfiguration(context.FullConfiguration, targetBranch).ToArray();
 
             BranchConfig branchConfiguration;
             if (matchingBranches.Length > 0)
@@ -25,7 +25,7 @@ public static BranchConfig GetBranchConfiguration(Commit currentCommit, IReposit
                 {
                     Logger.WriteWarning(string.Format(
                         "Multiple branch configurations match the current branch branchName of '{0}'. Using the first matching configuration, '{1}'. Matching configurations include: '{2}'",
-                        currentBranch.FriendlyName,
+                        targetBranch.FriendlyName,
                         branchConfiguration.Name,
                         string.Join("', '", matchingBranches.Select(b => b.Name))));
                 }
@@ -34,14 +34,14 @@ public static BranchConfig GetBranchConfiguration(Commit currentCommit, IReposit
             {
                 Logger.WriteInfo(string.Format(
                     "No branch configuration found for branch {0}, falling back to default configuration",
-                    currentBranch.FriendlyName));
+                    targetBranch.FriendlyName));
 
                 branchConfiguration = new BranchConfig { Name = string.Empty };
-                ConfigurationProvider.ApplyBranchDefaults(config, branchConfiguration, "");
+                ConfigurationProvider.ApplyBranchDefaults(context.FullConfiguration, branchConfiguration, "");
             }
 
             return branchConfiguration.Increment == IncrementStrategy.Inherit ?
-                InheritBranchConfiguration(onlyEvaluateTrackedBranches, repository, currentCommit, currentBranch, branchConfiguration, config, excludedInheritBranches) :
+                InheritBranchConfiguration(context, targetBranch, branchConfiguration, excludedInheritBranches) :
                 branchConfiguration;
         }
 
@@ -60,16 +60,18 @@ static IEnumerable<BranchConfig> LookupBranchConfiguration([NotNull] Config conf
             return config.Branches.Where(b => Regex.IsMatch(currentBranch.FriendlyName, "^" + b.Value.Regex, RegexOptions.IgnoreCase)).Select(kvp => kvp.Value);
         }
 
-        static BranchConfig InheritBranchConfiguration(bool onlyEvaluateTrackedBranches, IRepository repository, Commit currentCommit, Branch currentBranch, BranchConfig branchConfiguration, Config config, IList<Branch> excludedInheritBranches)
+        static BranchConfig InheritBranchConfiguration(GitVersionContext context, Branch targetBranch, BranchConfig branchConfiguration, IList<Branch> excludedInheritBranches)
         {
+            var repository = context.Repository;
+            var config = context.FullConfiguration;
             using (Logger.IndentLog("Attempting to inherit branch configuration from parent branch"))
             {
-                var excludedBranches = new[] { currentBranch };
+                var excludedBranches = new[] { targetBranch };
                 // Check if we are a merge commit. If so likely we are a pull request
-                var parentCount = currentCommit.Parents.Count();
+                var parentCount = context.CurrentCommit.Parents.Count();
                 if (parentCount == 2)
                 {
-                    excludedBranches = CalculateWhenMultipleParents(repository, currentCommit, ref currentBranch, excludedBranches);
+                    excludedBranches = CalculateWhenMultipleParents(repository, context.CurrentCommit, ref targetBranch, excludedBranches);
                 }
 
                 if (excludedInheritBranches == null)
@@ -90,22 +92,25 @@ static BranchConfig InheritBranchConfiguration(bool onlyEvaluateTrackedBranches,
                 }
                 var branchesToEvaluate = repository.Branches.Except(excludedInheritBranches).ToList();
 
-                var branchPoint = currentBranch.FindCommitBranchWasBranchedFrom(repository, excludedInheritBranches.ToArray());
+                var branchPoint = context.RepostioryMetadataProvider
+                    .FindCommitBranchWasBranchedFrom(targetBranch, repository, excludedInheritBranches.ToArray());
                 List<Branch> possibleParents;
                 if (branchPoint == BranchCommit.Empty)
                 {
-                    possibleParents = currentCommit.GetBranchesContainingCommit(repository, branchesToEvaluate, true)
+                    possibleParents = context.RepostioryMetadataProvider.GetBranchesContainingCommit(context.CurrentCommit, repository, branchesToEvaluate, true)
                         // It fails to inherit Increment branch configuration if more than 1 parent;
                         // therefore no point to get more than 2 parents
                         .Take(2)
                         .ToList();
                 }
                 else
                 {
-                    var branches = branchPoint.Commit.GetBranchesContainingCommit(repository, branchesToEvaluate, true).ToList();
+                    var branches = context.RepostioryMetadataProvider
+                        .GetBranchesContainingCommit(branchPoint.Commit, repository, branchesToEvaluate, true).ToList();
                     if (branches.Count > 1)
                     {
-                        var currentTipBranches = currentCommit.GetBranchesContainingCommit(repository, branchesToEvaluate, true).ToList();
+                        var currentTipBranches = context.RepostioryMetadataProvider
+                            .GetBranchesContainingCommit(context.CurrentCommit, repository, branchesToEvaluate, true).ToList();
                         possibleParents = branches.Except(currentTipBranches).ToList();
                     }
                     else
@@ -118,7 +123,7 @@ static BranchConfig InheritBranchConfiguration(bool onlyEvaluateTrackedBranches,
 
                 if (possibleParents.Count == 1)
                 {
-                    var branchConfig = GetBranchConfiguration(currentCommit, repository, onlyEvaluateTrackedBranches, config, possibleParents[0], excludedInheritBranches);
+                    var branchConfig = GetBranchConfiguration(context, possibleParents[0], excludedInheritBranches);
                     return new BranchConfig(branchConfiguration)
                     {
                         Increment = branchConfig.Increment,
@@ -149,7 +154,7 @@ static BranchConfig InheritBranchConfiguration(bool onlyEvaluateTrackedBranches,
                 Logger.WriteWarning(errorMessage + Environment.NewLine + Environment.NewLine + "Falling back to " + branchName + " branch config");
 
                 // To prevent infinite loops, make sure that a new branch was chosen.
-                if (LibGitExtensions.IsSameBranch(currentBranch, chosenBranch))
+                if (LibGitExtensions.IsSameBranch(targetBranch, chosenBranch))
                 {
                     Logger.WriteWarning("Fallback branch wants to inherit Increment branch configuration from itself. Using patch increment instead.");
                     return new BranchConfig(branchConfiguration)
@@ -158,7 +163,7 @@ static BranchConfig InheritBranchConfiguration(bool onlyEvaluateTrackedBranches,
                     };
                 }
 
-                var inheritingBranchConfig = GetBranchConfiguration(currentCommit, repository, onlyEvaluateTrackedBranches, config, chosenBranch, excludedInheritBranches);
+                var inheritingBranchConfig = GetBranchConfiguration(context, chosenBranch, excludedInheritBranches);
                 return new BranchConfig(branchConfiguration)
                 {
                     Increment = inheritingBranchConfig.Increment,

src/GitVersionCore/GitRepoMetadataProvider.cs

@@ -0,0 +1,233 @@
+using JetBrains.Annotations;
+using LibGit2Sharp;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace GitVersion
+{
+    public class GitRepoMetadataProvider
+    {
+        private Dictionary<Branch, List<BranchCommit>> mergeBaseCommitsCache;
+        private Dictionary<Tuple<Branch, Branch>, MergeBaseData> mergeBaseCache;
+        private Dictionary<Branch, List<SemanticVersion>> semanticVersionTagsOnBranchCache;
+        private IRepository repository;
+        const string missingTipFormat = "{0} has no tip. Please see http://example.com/docs for information on how to fix this.";
+
+
+        public GitRepoMetadataProvider(IRepository repository)
+        {
+            mergeBaseCache = new Dictionary<Tuple<Branch, Branch>, MergeBaseData>();
+            mergeBaseCommitsCache = new Dictionary<Branch, List<BranchCommit>>();
+            semanticVersionTagsOnBranchCache = new Dictionary<Branch, List<SemanticVersion>>();
+            this.repository = repository;
+        }
+
+        public IEnumerable<SemanticVersion> GetVersionTagsOnBranch(Branch branch, IRepository repository, string tagPrefixRegex)
+        {
+            if (semanticVersionTagsOnBranchCache.ContainsKey(branch))
+            {
+                Logger.WriteDebug(string.Format("Cache hit for version tags on branch '{0}", branch.CanonicalName));
+                return semanticVersionTagsOnBranchCache[branch];
+            }
+
+            using (Logger.IndentLog(string.Format("Getting version tags from branch '{0}'.", branch.CanonicalName)))
+            {
+                var tags = repository.Tags.Select(t => t).ToList();
+
+                var versionTags = repository.Commits.QueryBy(new CommitFilter
+                {
+                    IncludeReachableFrom = branch.Tip
+                })
+                .SelectMany(c => tags.Where(t => c.Sha == t.Target.Sha).SelectMany(t =>
+                {
+                    SemanticVersion semver;
+                    if (SemanticVersion.TryParse(t.FriendlyName, tagPrefixRegex, out semver))
+                        return new[] { semver };
+                    return new SemanticVersion[0];
+                })).ToList();
+
+                semanticVersionTagsOnBranchCache.Add(branch, versionTags);
+                return versionTags;
+            }
+        }
+
+        // TODO Should we cache this?
+        public IEnumerable<Branch> GetBranchesContainingCommit([NotNull] Commit commit, IRepository repository, IList<Branch> branches, bool onlyTrackedBranches)
+        {
+            if (commit == null)
+            {
+                throw new ArgumentNullException("commit");
+            }
+            Logger.WriteDebug("Heh");
+            using (Logger.IndentLog(string.Format("Getting branches containing the commit '{0}'.", commit.Id)))
+            {
+                var directBranchHasBeenFound = false;
+                Logger.WriteInfo("Trying to find direct branches.");
+                // TODO: It looks wasteful looping through the branches twice. Can't these loops be merged somehow? @asbjornu
+                foreach (var branch in branches)
+                {
+                    if (branch.Tip != null && branch.Tip.Sha != commit.Sha || (onlyTrackedBranches && !branch.IsTracking))
+                    {
+                        continue;
+                    }
+
+                    directBranchHasBeenFound = true;
+                    Logger.WriteInfo(string.Format("Direct branch found: '{0}'.", branch.FriendlyName));
+                    yield return branch;
+                }
+
+                if (directBranchHasBeenFound)
+                {
+                    yield break;
+                }
+
+                Logger.WriteInfo(string.Format("No direct branches found, searching through {0} branches.", onlyTrackedBranches ? "tracked" : "all"));
+                foreach (var branch in branches.Where(b => onlyTrackedBranches && !b.IsTracking))
+                {
+                    Logger.WriteInfo(string.Format("Searching for commits reachable from '{0}'.", branch.FriendlyName));
+
+                    var commits = repository.Commits.QueryBy(new CommitFilter
+                    {
+                        IncludeReachableFrom = branch
+                    }).Where(c => c.Sha == commit.Sha);
+
+                    if (!commits.Any())
+                    {
+                        Logger.WriteInfo(string.Format("The branch '{0}' has no matching commits.", branch.FriendlyName));
+                        continue;
+                    }
+
+                    Logger.WriteInfo(string.Format("The branch '{0}' has a matching commit.", branch.FriendlyName));
+                    yield return branch;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Find the merge base of the two branches, i.e. the best common ancestor of the two branches' tips.
+        /// </summary>
+        public Commit FindMergeBase(Branch branch, Branch otherBranch, IRepository repository)
+        {
+            var key = Tuple.Create(branch, otherBranch);
+
+            if (mergeBaseCache.ContainsKey(key))
+            {
+                Logger.WriteDebug(string.Format(
+                    "Cache hit for merge base between '{0}' and '{1}'.",
+                    branch.FriendlyName, otherBranch.FriendlyName));
+                return mergeBaseCache[key].MergeBase;
+            }
+
+            using (Logger.IndentLog(string.Format("Finding merge base between '{0}' and '{1}'.", branch.FriendlyName, otherBranch.FriendlyName)))
+            {
+                // Otherbranch tip is a forward merge
+                var commitToFindCommonBase = otherBranch.Tip;
+                var commit = branch.Tip;
+                if (otherBranch.Tip.Parents.Contains(commit))
+                {
+                    commitToFindCommonBase = otherBranch.Tip.Parents.First();
+                }
+
+                var findMergeBase = repository.ObjectDatabase.FindMergeBase(commit, commitToFindCommonBase);
+                if (findMergeBase != null)
+                {
+                    Logger.WriteInfo(string.Format("Found merge base of {0}", findMergeBase.Sha));
+                    // We do not want to include merge base commits which got forward merged into the other branch
+                    bool mergeBaseWasForwardMerge;
+                    do
+                    {
+                        // Now make sure that the merge base is not a forward merge
+                        mergeBaseWasForwardMerge = otherBranch.Commits
+                            .SkipWhile(c => c != commitToFindCommonBase)
+                            .TakeWhile(c => c != findMergeBase)
+                            .Any(c => c.Parents.Contains(findMergeBase));
+                        if (mergeBaseWasForwardMerge)
+                        {
+                            var second = commitToFindCommonBase.Parents.First();
+                            var mergeBase = repository.ObjectDatabase.FindMergeBase(commit, second);
+                            if (mergeBase == findMergeBase)
+                            {
+                                break;
+                            }
+                            findMergeBase = mergeBase;
+                            Logger.WriteInfo(string.Format("Merge base was due to a forward merge, next merge base is {0}", findMergeBase));
+                        }
+                    } while (mergeBaseWasForwardMerge);
+                }
+
+                // Store in cache.
+                mergeBaseCache.Add(key, new MergeBaseData(branch, otherBranch, repository, findMergeBase));
+
+                return findMergeBase;
+            }
+        }
+
+        /// <summary>
+        /// Find the commit where the given branch was branched from another branch.
+        /// If there are multiple such commits and branches, returns the newest commit.
+        /// </summary>
+        public BranchCommit FindCommitBranchWasBranchedFrom([NotNull] Branch branch, IRepository repository, params Branch[] excludedBranches)
+        {
+            if (branch == null)
+            {
+                throw new ArgumentNullException("branch");
+            }
+
+            using (Logger.IndentLog(string.Format("Finding branch source of '{0}'", branch.FriendlyName)))
+            {
+                if (branch.Tip == null)
+                {
+                    Logger.WriteWarning(string.Format(missingTipFormat, branch.FriendlyName));
+                    return BranchCommit.Empty;
+                }
+
+                return GetMergeCommitsForBranch(branch).ExcludingBranches(excludedBranches).FirstOrDefault(b => !branch.IsSameBranch(b.Branch));
+            }
+        }
+
+
+        List<BranchCommit> GetMergeCommitsForBranch(Branch branch)
+        {
+            if (mergeBaseCommitsCache.ContainsKey(branch))
+            {
+                Logger.WriteDebug(string.Format(
+                    "Cache hit for getting merge commits for branch {0}.",
+                    branch.CanonicalName));
+                return mergeBaseCommitsCache[branch];
+            }
+
+            var branchMergeBases = repository.Branches.Select(otherBranch =>
+            {
+                if (otherBranch.Tip == null)
+                {
+                    Logger.WriteWarning(string.Format(missingTipFormat, otherBranch.FriendlyName));
+                    return BranchCommit.Empty;
+                }
+
+                var findMergeBase = FindMergeBase(branch, otherBranch, repository);
+                return new BranchCommit(findMergeBase, otherBranch);
+            }).Where(b => b.Commit != null).OrderByDescending(b => b.Commit.Committer.When).ToList();
+            mergeBaseCommitsCache.Add(branch, branchMergeBases);
+
+            return branchMergeBases;
+        }
+
+        private class MergeBaseData
+        {
+            public Branch Branch { get; private set; }
+            public Branch OtherBranch { get; private set; }
+            public IRepository Repository { get; private set; }
+
+            public Commit MergeBase { get; private set; }
+
+            public MergeBaseData(Branch branch, Branch otherBranch, IRepository repository, Commit mergeBase)
+            {
+                Branch = branch;
+                OtherBranch = otherBranch;
+                Repository = repository;
+                MergeBase = mergeBase;
+            }
+        }
+    }
+}

src/GitVersionCore/GitVersionCacheKeyFactory.cs

@@ -123,7 +123,15 @@ static List<string> CalculateDirectoryContents(string root)
 
         private static string GetRepositorySnapshotHash(GitPreparer gitPreparer)
         {
-            var repositorySnapshot = gitPreparer.WithRepository(repo => string.Join(":", repo.Head.CanonicalName, repo.Head.Tip.Sha));
+            var repositorySnapshot = gitPreparer.WithRepository(repo => {
+                var head = repo.Head;
+                if (head.Tip == null)
+                {
+                    return head.CanonicalName;
+                }
+                var hash = string.Join(":", head.CanonicalName, head.Tip.Sha);
+                return hash;
+            });
             return GetHash(repositorySnapshot);
         }