| // 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.strings; |
| |
| import com.google.devtools.build.lib.skyframe.serialization.LeafDeserializationContext; |
| import com.google.devtools.build.lib.skyframe.serialization.LeafObjectCodec; |
| import com.google.devtools.build.lib.skyframe.serialization.LeafSerializationContext; |
| import com.google.devtools.build.lib.skyframe.serialization.ObjectCodec; |
| import com.google.devtools.build.lib.skyframe.serialization.SerializationException; |
| import com.google.devtools.build.lib.unsafe.StringUnsafe; |
| import com.google.protobuf.CodedInputStream; |
| import com.google.protobuf.CodedOutputStream; |
| import java.io.IOException; |
| import java.util.Arrays; |
| |
| /** |
| * A high-performance {@link ObjectCodec} for {@link String} objects specialized for Strings in |
| * JDK9+, where a String can be represented as a byte array together with a single byte (0 or 1) for |
| * Latin-1 or UTF16 encoding. |
| */ |
| public final class UnsafeStringCodec extends LeafObjectCodec<String> { |
| /** |
| * An instance to use for delegation by other codecs. |
| * |
| * <p>The default constructor is left intact to allow the usual codec registration mechanisms to |
| * work. |
| */ |
| private static final UnsafeStringCodec INSTANCE = new UnsafeStringCodec(); |
| |
| private final StringUnsafe stringUnsafe = StringUnsafe.getInstance(); |
| |
| public static UnsafeStringCodec stringCodec() { |
| return INSTANCE; |
| } |
| |
| @Override |
| public Class<String> getEncodedClass() { |
| return String.class; |
| } |
| |
| @Override |
| public void serialize(LeafSerializationContext context, String obj, CodedOutputStream codedOut) |
| throws SerializationException, IOException { |
| byte coder = stringUnsafe.getCoder(obj); |
| byte[] value = stringUnsafe.getByteArray(obj); |
| // Optimize for the case that coder == 0, in which case we can just write the length here, |
| // potentially using just one byte. If coder != 0, we'll use 4 bytes, but that's vanishingly |
| // rare. |
| if (coder == 0) { |
| codedOut.writeInt32NoTag(value.length); |
| } else if (coder == 1) { |
| codedOut.writeInt32NoTag(-value.length); |
| } else { |
| throw new SerializationException("Unexpected coder value: " + coder + " for " + obj); |
| } |
| codedOut.writeRawBytes(value); |
| } |
| |
| @Override |
| public String deserialize(LeafDeserializationContext context, CodedInputStream codedIn) |
| throws SerializationException, IOException { |
| int length = codedIn.readInt32(); |
| byte coder; |
| if (length >= 0) { |
| coder = 0; |
| } else { |
| coder = 1; |
| length = -length; |
| } |
| byte[] value = codedIn.readRawBytes(length); |
| try { |
| return stringUnsafe.newInstance(value, coder); |
| } catch (ReflectiveOperationException e) { |
| throw new SerializationException( |
| "Could not instantiate string: " + Arrays.toString(value) + ", " + coder, e); |
| } |
| } |
| } |