From edb898c450d9ea2b902c11e0becbf1ee3f1f9605 Mon Sep 17 00:00:00 2001
From: Joseph Kingry <jkingry@shoplogix.com>
Date: Fri, 16 Feb 2018 10:13:17 -0500
Subject: [PATCH] Filter list of all tags first by those parsable to a semantic
 version

- reduces `Getting version tags from branch` time for our repository
  from a 100 seconds to 2.5 seconds
---
 src/GitVersionCore/GitRepoMetadataProvider.cs | 18 +++++------
 .../TaggedCommitVersionStrategy.cs            | 32 ++++++++++++-------
 2 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/src/GitVersionCore/GitRepoMetadataProvider.cs b/src/GitVersionCore/GitRepoMetadataProvider.cs
index fcf4441e89..b60829ab67 100644
--- a/src/GitVersionCore/GitRepoMetadataProvider.cs
+++ b/src/GitVersionCore/GitRepoMetadataProvider.cs
@@ -34,19 +34,17 @@ public IEnumerable<SemanticVersion> GetVersionTagsOnBranch(Branch branch, string
 
             using (Logger.IndentLog(string.Format("Getting version tags from branch '{0}'.", branch.CanonicalName)))
             {
-                var tags = this.Repository.Tags.Select(t => t).ToList();
-
-                var versionTags = this.Repository.Commits.QueryBy(new CommitFilter
-                {
-                    IncludeReachableFrom = branch.Tip
-                })
-                .SelectMany(c => tags.Where(t => c.Sha == t.Target.Sha).SelectMany(t =>
+                var tags = new List<Tuple<Tag, SemanticVersion>>();
+                foreach(var t in this.Repository.Tags)
                 {
                     SemanticVersion semver;
                     if (SemanticVersion.TryParse(t.FriendlyName, tagPrefixRegex, out semver))
-                        return new[] { semver };
-                    return new SemanticVersion[0];
-                })).ToList();
+                    {
+                        tags.Add(Tuple.Create(t, semver));
+                    }
+                }
+
+                var versionTags = branch.Commits.SelectMany(c => tags.Where(t => c.Sha == t.Item1.Target.Sha).Select(t => t.Item2)).ToList();
 
                 semanticVersionTagsOnBranchCache.Add(branch, versionTags);
                 return versionTags;
diff --git a/src/GitVersionCore/VersionCalculation/BaseVersionCalculators/TaggedCommitVersionStrategy.cs b/src/GitVersionCore/VersionCalculation/BaseVersionCalculators/TaggedCommitVersionStrategy.cs
index 4955be0203..332862923e 100644
--- a/src/GitVersionCore/VersionCalculation/BaseVersionCalculators/TaggedCommitVersionStrategy.cs
+++ b/src/GitVersionCore/VersionCalculation/BaseVersionCalculators/TaggedCommitVersionStrategy.cs
@@ -19,21 +19,31 @@ public override IEnumerable<BaseVersion> GetVersions(GitVersionContext context)
 
         public IEnumerable<BaseVersion> GetTaggedVersions(GitVersionContext context, Branch currentBranch, DateTimeOffset? olderThan)
         {
-            var allTags = context.Repository.Tags
-                .Where(tag => !olderThan.HasValue || ((Commit) tag.PeeledTarget()).When() <= olderThan.Value)
-                .ToList();
+            var allTags = new List<Tuple<Tag, SemanticVersion>>();
+            foreach(var tag in context.Repository.Tags)
+            {
+                if (olderThan.HasValue && ((Commit)tag.PeeledTarget()).When() > olderThan.Value)
+                    continue;
+
+                SemanticVersion version;
+
+                if (!SemanticVersion.TryParse(tag.FriendlyName, context.Configuration.GitTagPrefix, out version))
+                {
+                    continue;
+                }
+
+                allTags.Add(Tuple.Create(tag, version));
+            }
+
             var tagsOnBranch = currentBranch
                 .Commits
-                .SelectMany(commit => { return allTags.Where(t => IsValidTag(t, commit)); })
+                .SelectMany(commit => { return allTags.Where(t => IsValidTag(t.Item1, commit)); })
                 .Select(t =>
                 {
-                    SemanticVersion version;
-                    if (SemanticVersion.TryParse(t.FriendlyName, context.Configuration.GitTagPrefix, out version))
-                    {
-                        var commit = t.PeeledTarget() as Commit;
-                        if (commit != null)
-                            return new VersionTaggedCommit(commit, version, t.FriendlyName);
-                    }
+                    var commit = t.Item1.PeeledTarget() as Commit;
+                    if (commit != null)
+                        return new VersionTaggedCommit(commit, t.Item2, t.Item1.FriendlyName);
+
                     return null;
                 })
                 .Where(a => a != null)