io.grpc.protobuf.ProtoUtils Maven / Gradle / Ivy
/*
* Copyright 2014, gRPC 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 io.grpc.protobuf;
import com.google.proto4pingcap.InvalidProtocolBufferException;
import com.google.proto4pingcap.Message;
import com.google.proto4pingcap.Message.Builder;
import com.google.proto4pingcap.util.JsonFormat;
import com.google.proto4pingcap.util.JsonFormat.Parser;
import com.google.proto4pingcap.util.JsonFormat.Printer;
import io.grpc.ExperimentalApi;
import io.grpc.Metadata;
import io.grpc.MethodDescriptor.Marshaller;
import io.grpc.Status;
import io.grpc.protobuf.lite.ProtoLiteUtils;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.charset.Charset;
/**
* Utility methods for using protobuf with grpc.
*/
public class ProtoUtils {
/** Create a {@code Marshaller} for protos of the same type as {@code defaultInstance}. */
public static Marshaller marshaller(final T defaultInstance) {
return ProtoLiteUtils.marshaller(defaultInstance);
}
/**
* Create a {@code Marshaller} for json protos of the same type as {@code defaultInstance}.
*
* This is an unstable API and has not been optimized yet for performance.
*/
@ExperimentalApi("https://github.com/grpc/grpc-java/issues/1786")
public static Marshaller jsonMarshaller(final T defaultInstance) {
final Parser parser = JsonFormat.parser();
final Printer printer = JsonFormat.printer();
return jsonMarshaller(defaultInstance, parser, printer);
}
/**
* Create a {@code Marshaller} for json protos of the same type as {@code defaultInstance}.
*
* This is an unstable API and has not been optimized yet for performance.
*/
@ExperimentalApi("https://github.com/grpc/grpc-java/issues/1786")
public static Marshaller jsonMarshaller(
final T defaultInstance, final Parser parser, final Printer printer) {
final Charset charset = Charset.forName("UTF-8");
return new Marshaller() {
@Override
public InputStream stream(T value) {
try {
return new ByteArrayInputStream(printer.print(value).getBytes(charset));
} catch (InvalidProtocolBufferException e) {
throw Status.INTERNAL
.withCause(e)
.withDescription("Unable to print json proto")
.asRuntimeException();
}
}
@SuppressWarnings("unchecked")
@Override
public T parse(InputStream stream) {
Builder builder = defaultInstance.newBuilderForType();
Reader reader = new InputStreamReader(stream, charset);
T proto;
try {
parser.merge(reader, builder);
proto = (T) builder.build();
reader.close();
} catch (InvalidProtocolBufferException e) {
throw Status.INTERNAL.withDescription("Invalid protobuf byte sequence")
.withCause(e).asRuntimeException();
} catch (IOException e) {
// Same for now, might be unavailable
throw Status.INTERNAL.withDescription("Invalid protobuf byte sequence")
.withCause(e).asRuntimeException();
}
return proto;
}
};
}
/**
* Produce a metadata key for a generated protobuf type.
*/
public static Metadata.Key keyForProto(T instance) {
return Metadata.Key.of(
instance.getDescriptorForType().getFullName() + Metadata.BINARY_HEADER_SUFFIX,
ProtoLiteUtils.metadataMarshaller(instance));
}
private ProtoUtils() {
}
}