| // Copyright 2018 The Bazel Authors. All rights reserved. |
| // |
| // 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.devtools.build.lib.skyframe.serialization; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableListMultimap; |
| import com.google.common.collect.ImmutableMultimap; |
| import com.google.common.collect.ImmutableSetMultimap; |
| import com.google.common.collect.LinkedHashMultimap; |
| import com.google.common.collect.ListMultimap; |
| import com.google.common.collect.Multimap; |
| import com.google.common.collect.SetMultimap; |
| import com.google.protobuf.CodedInputStream; |
| import com.google.protobuf.CodedOutputStream; |
| import java.io.IOException; |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Map; |
| |
| /** |
| * A codec for {@link Multimap}. Handles {@link ImmutableListMultimap}, {@link ImmutableSetMultimap} |
| * and {@link LinkedHashMultimap}. Makes all multimaps immutable, since serialized state shouldn't |
| * be mutable. |
| */ |
| public class MultimapCodec<K, V> implements ObjectCodec<Multimap<K, V>> { |
| @SuppressWarnings("unchecked") |
| @Override |
| public Class<? extends ImmutableMultimap<K, V>> getEncodedClass() { |
| return (Class<ImmutableMultimap<K, V>>) ((Class<?>) ImmutableMultimap.class); |
| } |
| |
| @SuppressWarnings("unchecked") |
| @Override |
| public List<Class<? extends Multimap<K, V>>> additionalEncodedClasses() { |
| return ImmutableList.of((Class<? extends Multimap<K, V>>) (Class<?>) LinkedHashMultimap.class); |
| } |
| |
| @Override |
| public void serialize( |
| SerializationContext context, Multimap<K, V> obj, CodedOutputStream codedOut) |
| throws SerializationException, IOException { |
| if (obj instanceof ListMultimap) { |
| codedOut.writeBoolNoTag(true); |
| } else if (obj instanceof SetMultimap) { |
| codedOut.writeBoolNoTag(false); |
| } else { |
| throw new SerializationException("Unexpected multimap type: " + obj.getClass()); |
| } |
| codedOut.writeInt32NoTag(obj.asMap().size()); |
| for (Map.Entry<K, Collection<V>> entry : obj.asMap().entrySet()) { |
| context.serialize(entry.getKey(), codedOut); |
| context.serialize(entry.getValue(), codedOut); |
| } |
| } |
| |
| @Override |
| public ImmutableMultimap<K, V> deserialize( |
| DeserializationContext context, CodedInputStream codedIn) |
| throws SerializationException, IOException { |
| ImmutableMultimap.Builder<K, V> result; |
| if (codedIn.readBool()) { |
| result = ImmutableListMultimap.builder(); |
| } else { |
| result = ImmutableSetMultimap.builder(); |
| } |
| int length = codedIn.readInt32(); |
| for (int i = 0; i < length; i++) { |
| K key = context.deserialize(codedIn); |
| Collection<V> values = context.deserialize(codedIn); |
| result.putAll(key, values); |
| } |
| return result.build(); |
| } |
| } |