| // Copyright 2024 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.util.io; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import com.google.protobuf.ExtensionRegistry; |
| import com.google.protobuf.Message; |
| import com.google.protobuf.Parser; |
| import com.google.protobuf.util.JsonFormat; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.util.Scanner; |
| import java.util.function.Supplier; |
| import java.util.regex.Pattern; |
| import javax.annotation.Nullable; |
| |
| /** Creates a MessageInputStream from an OutputStream. */ |
| public class MessageInputStreamWrapper { |
| |
| private MessageInputStreamWrapper() {} |
| |
| /** Reads the messages in length-delimited protobuf wire format. */ |
| public static class BinaryInputStreamWrapper<T extends Message> implements MessageInputStream<T> { |
| private final InputStream stream; |
| private final Parser<T> parser; |
| |
| @SuppressWarnings("unchecked") |
| public BinaryInputStreamWrapper(InputStream stream, T defaultInstance) { |
| this.stream = checkNotNull(stream); |
| this.parser = (Parser<T>) defaultInstance.getParserForType(); |
| } |
| |
| @Override |
| @Nullable |
| public T read() throws IOException { |
| return parser.parseDelimitedFrom(stream, ExtensionRegistry.getEmptyRegistry()); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| stream.close(); |
| } |
| } |
| |
| /** Reads the messages in concatenated JSON text format. */ |
| public static class JsonInputStreamWrapper<T extends Message> implements MessageInputStream<T> { |
| private static final JsonFormat.Parser PARSER = JsonFormat.parser().ignoringUnknownFields(); |
| |
| // The string `\n}{\n` is a reliable delimiter, but we must use lookbehind/lookahead to avoid |
| // consuming the braces when tokenizing. |
| private static final Pattern DELIMITER = Pattern.compile("(?<=\\n\\})(?=\\{\\n)"); |
| |
| private final Scanner scanner; |
| private final Supplier<Message.Builder> builderSupplier; |
| |
| public JsonInputStreamWrapper(InputStream stream, T defaultInstance) { |
| this.scanner = new Scanner(checkNotNull(stream), UTF_8).useDelimiter(DELIMITER); |
| this.builderSupplier = defaultInstance::newBuilderForType; |
| } |
| |
| @Override |
| @Nullable |
| @SuppressWarnings("unchecked") |
| public T read() throws IOException { |
| if (!scanner.hasNext()) { |
| return null; |
| } |
| Message.Builder builder = builderSupplier.get(); |
| PARSER.merge(scanner.next(), builder); |
| return (T) builder.build(); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| scanner.close(); |
| } |
| } |
| } |