1 files changed, 128 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/git/TagSetHolder.java b/java/com/google/gerrit/server/git/TagSetHolder.java
new file mode 100644
index 0000000000..4c0c035e02
--- /dev/null
+++ b/java/com/google/gerrit/server/git/TagSetHolder.java
@@ -0,0 +1,128 @@
+// Copyright (C) 2011 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.git;
+
+import static java.util.stream.Collectors.toList;
+
+import com.google.gerrit.common.Nullable;
+import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.server.cache.proto.Cache.TagSetHolderProto;
+import com.google.gerrit.server.cache.serialize.CacheSerializer;
+import com.google.gerrit.server.cache.serialize.ProtoCacheSerializers;
+import java.util.Collection;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+
+public class TagSetHolder {
+  private final Object buildLock = new Object();
+  private final Project.NameKey projectName;
+
+  @Nullable private volatile TagSet tags;
+
+  TagSetHolder(Project.NameKey projectName) {
+    this.projectName = projectName;
+  }
+
+  Project.NameKey getProjectName() {
+    return projectName;
+  }
+
+  TagSet getTagSet() {
+    return tags;
+  }
+
+  void setTagSet(TagSet tags) {
+    this.tags = tags;
+  }
+
+  public TagMatcher matcher(TagCache cache, Repository db, Collection<Ref> include) {
+    include = include.stream().filter(r -> !TagSet.skip(r)).collect(toList());
+
+    TagSet tags = this.tags;
+    if (tags == null) {
+      tags = build(cache, db);
+    }
+
+    TagMatcher m = new TagMatcher(this, cache, db, include, tags, false);
+    tags.prepare(m);
+    if (!m.newRefs.isEmpty() || !m.lostRefs.isEmpty()) {
+      tags = rebuild(cache, db, tags, m);
+
+      m = new TagMatcher(this, cache, db, include, tags, true);
+      tags.prepare(m);
+    }
+    return m;
+  }
+
+  void rebuildForNewTags(TagCache cache, TagMatcher m) {
+    m.tags = rebuild(cache, m.db, m.tags, null);
+    m.mask.clear();
+    m.newRefs.clear();
+    m.lostRefs.clear();
+    m.tags.prepare(m);
+  }
+
+  private TagSet build(TagCache cache, Repository db) {
+    synchronized (buildLock) {
+      TagSet tags = this.tags;
+      if (tags == null) {
+        tags = new TagSet(projectName);
+        tags.build(db, null, null);
+        this.tags = tags;
+        cache.put(projectName, this);
+      }
+      return tags;
+    }
+  }
+
+  private TagSet rebuild(TagCache cache, Repository db, TagSet old, TagMatcher m) {
+    synchronized (buildLock) {
+      TagSet cur = this.tags;
+      if (cur == old) {
+        cur = new TagSet(projectName);
+        cur.build(db, old, m);
+        this.tags = cur;
+        cache.put(projectName, this);
+      }
+      return cur;
+    }
+  }
+
+  enum Serializer implements CacheSerializer<TagSetHolder> {
+    INSTANCE;
+
+    @Override
+    public byte[] serialize(TagSetHolder object) {
+      TagSetHolderProto.Builder b =
+          TagSetHolderProto.newBuilder().setProjectName(object.projectName.get());
+      TagSet tags = object.tags;
+      if (tags != null) {
+        b.setTags(tags.toProto());
+      }
+      return ProtoCacheSerializers.toByteArray(b.build());
+    }
+
+    @Override
+    public TagSetHolder deserialize(byte[] in) {
+      TagSetHolderProto proto =
+          ProtoCacheSerializers.parseUnchecked(TagSetHolderProto.parser(), in);
+      TagSetHolder holder = new TagSetHolder(new Project.NameKey(proto.getProjectName()));
+      if (proto.hasTags()) {
+        holder.tags = TagSet.fromProto(proto.getTags());
+      }
+      return holder;
+    }
+  }
+}