1 files changed, 93 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/query/change/ConflictKey.java b/java/com/google/gerrit/server/query/change/ConflictKey.java
new file mode 100644
index 0000000000..42f5b13314
--- /dev/null
+++ b/java/com/google/gerrit/server/query/change/ConflictKey.java
@@ -0,0 +1,93 @@
+// Copyright (C) 2013 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.query.change;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Converter;
+import com.google.common.base.Enums;
+import com.google.common.collect.Ordering;
+import com.google.gerrit.extensions.client.SubmitType;
+import com.google.gerrit.server.cache.proto.Cache.ConflictKeyProto;
+import com.google.gerrit.server.cache.serialize.CacheSerializer;
+import com.google.gerrit.server.cache.serialize.ProtoCacheSerializers;
+import com.google.gerrit.server.cache.serialize.ProtoCacheSerializers.ObjectIdConverter;
+import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.ObjectId;
+
+@AutoValue
+public abstract class ConflictKey {
+  public static ConflictKey create(
+      AnyObjectId commit, AnyObjectId otherCommit, SubmitType submitType, boolean contentMerge) {
+    ObjectId commitCopy = commit.copy();
+    ObjectId otherCommitCopy = otherCommit.copy();
+    if (submitType == SubmitType.FAST_FORWARD_ONLY) {
+      // The conflict check for FF-only is non-symmetrical, and we need to treat (X, Y) differently
+      // from (Y, X). Store the commits in the input order.
+      return new AutoValue_ConflictKey(commitCopy, otherCommitCopy, submitType, contentMerge);
+    }
+    // Otherwise, the check is symmetrical; sort commit/otherCommit before storing, so the actual
+    // key is independent of the order in which they are passed to this method.
+    return new AutoValue_ConflictKey(
+        Ordering.natural().min(commitCopy, otherCommitCopy),
+        Ordering.natural().max(commitCopy, otherCommitCopy),
+        submitType,
+        contentMerge);
+  }
+
+  @VisibleForTesting
+  static ConflictKey createWithoutNormalization(
+      AnyObjectId commit, AnyObjectId otherCommit, SubmitType submitType, boolean contentMerge) {
+    return new AutoValue_ConflictKey(commit.copy(), otherCommit.copy(), submitType, contentMerge);
+  }
+
+  public abstract ObjectId commit();
+
+  public abstract ObjectId otherCommit();
+
+  public abstract SubmitType submitType();
+
+  public abstract boolean contentMerge();
+
+  public enum Serializer implements CacheSerializer<ConflictKey> {
+    INSTANCE;
+
+    private static final Converter<String, SubmitType> SUBMIT_TYPE_CONVERTER =
+        Enums.stringConverter(SubmitType.class);
+
+    @Override
+    public byte[] serialize(ConflictKey object) {
+      ObjectIdConverter idConverter = ObjectIdConverter.create();
+      return ProtoCacheSerializers.toByteArray(
+          ConflictKeyProto.newBuilder()
+              .setCommit(idConverter.toByteString(object.commit()))
+              .setOtherCommit(idConverter.toByteString(object.otherCommit()))
+              .setSubmitType(SUBMIT_TYPE_CONVERTER.reverse().convert(object.submitType()))
+              .setContentMerge(object.contentMerge())
+              .build());
+    }
+
+    @Override
+    public ConflictKey deserialize(byte[] in) {
+      ConflictKeyProto proto = ProtoCacheSerializers.parseUnchecked(ConflictKeyProto.parser(), in);
+      ObjectIdConverter idConverter = ObjectIdConverter.create();
+      return create(
+          idConverter.fromByteString(proto.getCommit()),
+          idConverter.fromByteString(proto.getOtherCommit()),
+          SUBMIT_TYPE_CONVERTER.convert(proto.getSubmitType()),
+          proto.getContentMerge());
+    }
+  }
+}