| // Copyright 2017 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.base.Preconditions; |
| import com.google.common.collect.ImmutableList; |
| import com.google.protobuf.CodedInputStream; |
| import com.google.protobuf.CodedOutputStream; |
| import java.io.IOException; |
| |
| /** Codec for an enum. */ |
| public class EnumCodec<T extends Enum<T>> implements ObjectCodec<T> { |
| |
| private final Class<T> enumClass; |
| |
| /** |
| * A cached copy of T.values(), to avoid allocating an array upon every deserialization operation. |
| */ |
| private final ImmutableList<T> values; |
| |
| public EnumCodec(Class<T> enumClass) { |
| this.enumClass = enumClass; |
| this.values = ImmutableList.copyOf(enumClass.getEnumConstants()); |
| } |
| |
| @Override |
| public Class<T> getEncodedClass() { |
| return enumClass; |
| } |
| |
| @Override |
| public void serialize(SerializationContext context, T value, CodedOutputStream codedOut) |
| throws IOException { |
| Preconditions.checkNotNull(value, "Enum value for %s is null", enumClass); |
| codedOut.writeEnumNoTag(value.ordinal()); |
| } |
| |
| @Override |
| public T deserialize(DeserializationContext context, CodedInputStream codedIn) |
| throws SerializationException, IOException { |
| int ordinal = codedIn.readEnum(); |
| try { |
| return values.get(ordinal); |
| } catch (ArrayIndexOutOfBoundsException e) { |
| throw new SerializationException( |
| "Invalid ordinal for " + enumClass.getName() + " enum: " + ordinal, e); |
| } |
| } |
| } |