Add serializer for PermissionRule

This commit adds a serializer for the PermissionRule entitiy. The
eventual goal is that we serialize CachedProjectConfig. The entity
is too large to be serialized directly, though, so we divide an
conquer.

Change-Id: Ifc691c58486c57c3a1f3ed80b731ef698011526f

java/com/google/gerrit/server/cache/serialize/entities/PermissionRuleSerializer.java

@@ -0,0 +1,47 @@
+// Copyright (C) 2020 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.cache.serialize.entities;
+
+import com.google.common.base.Converter;
+import com.google.common.base.Enums;
+import com.google.gerrit.common.data.PermissionRule;
+import com.google.gerrit.server.cache.proto.Cache;
+
+/** Helper to (de)serialize values for caches. */
+public class PermissionRuleSerializer {
+  private static final Converter<String, PermissionRule.Action> ACTION_CONVERTER =
+      Enums.stringConverter(PermissionRule.Action.class);
+
+  public static PermissionRule deserialize(Cache.PermissionRuleProto proto) {
+    return PermissionRule.builder(GroupReferenceSerializer.deserialize(proto.getGroup()))
+        .setAction(ACTION_CONVERTER.convert(proto.getAction()))
+        .setForce(proto.getForce())
+        .setMin(proto.getMin())
+        .setMax(proto.getMax())
+        .build();
+  }
+
+  public static Cache.PermissionRuleProto serialize(PermissionRule autoValue) {
+    return Cache.PermissionRuleProto.newBuilder()
+        .setAction(ACTION_CONVERTER.reverse().convert(autoValue.getAction()))
+        .setForce(autoValue.getForce())
+        .setMin(autoValue.getMin())
+        .setMax(autoValue.getMax())
+        .setGroup(GroupReferenceSerializer.serialize(autoValue.getGroup()))
+        .build();
+  }
+
+  private PermissionRuleSerializer() {}
+}

javatests/com/google/gerrit/server/cache/serialize/entities/PermissionRuleSerializerTest.java

@@ -0,0 +1,43 @@
+// Copyright (C) 2020 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.cache.serialize.entities;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.gerrit.server.cache.serialize.entities.PermissionRuleSerializer.deserialize;
+import static com.google.gerrit.server.cache.serialize.entities.PermissionRuleSerializer.serialize;
+
+import com.google.gerrit.common.data.GroupReference;
+import com.google.gerrit.common.data.PermissionRule;
+import org.junit.Test;
+
+public class PermissionRuleSerializerTest {
+  @Test
+  public void roundTrip() {
+    PermissionRule permissionRuleAutoValue =
+        PermissionRule.builder(GroupReference.create("name"))
+            .setAction(PermissionRule.Action.BATCH)
+            .setForce(true)
+            .setMax(321)
+            .setMin(123)
+            .build();
+    assertThat(deserialize(serialize(permissionRuleAutoValue))).isEqualTo(permissionRuleAutoValue);
+  }
+
+  @Test
+  public void roundTripWithMinimalValues() {
+    PermissionRule permissionRuleAutoValue = PermissionRule.create(GroupReference.create("name"));
+    assertThat(deserialize(serialize(permissionRuleAutoValue))).isEqualTo(permissionRuleAutoValue);
+  }
+}

proto/cache.proto

@@ -345,3 +345,13 @@ message GroupReferenceProto {
   string uuid = 1;
   string name = 2;
 }
+
+// Serialized form of com.google.gerrit.common.data.PermissionRule.
+// Next ID: 6
+message PermissionRuleProto {
+  string action = 1; // ENUM as String
+  bool force = 2;
+  int32 min = 3;
+  int32 max = 4;
+  GroupReferenceProto group = 5;
+}