mirror of https://github.com/grpc/grpc-java.git
126 lines
3.3 KiB
Java
126 lines
3.3 KiB
Java
/*
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* Copyright 2014, gRPC Authors All rights reserved.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package io.grpc.protobuf.lite;
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import com.google.protobuf.CodedOutputStream;
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import com.google.protobuf.MessageLite;
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import com.google.protobuf.Parser;
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import io.grpc.Drainable;
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import io.grpc.KnownLength;
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import java.io.ByteArrayInputStream;
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import java.io.IOException;
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import java.io.InputStream;
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import java.io.OutputStream;
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import javax.annotation.Nullable;
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/**
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* An {@link InputStream} backed by a protobuf.
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*/
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class ProtoInputStream extends InputStream implements Drainable, KnownLength {
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// ProtoInputStream is first initialized with a *message*. *partial* is initially null.
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// Once there has been a read operation on this stream, *message* is serialized to *partial* and
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// set to null.
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@Nullable private MessageLite message;
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private final Parser<?> parser;
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@Nullable private ByteArrayInputStream partial;
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public ProtoInputStream(MessageLite message, Parser<?> parser) {
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this.message = message;
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this.parser = parser;
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}
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@Override
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public int drainTo(OutputStream target) throws IOException {
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int written;
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if (message != null) {
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written = message.getSerializedSize();
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message.writeTo(target);
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message = null;
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} else if (partial != null) {
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written = (int) ProtoLiteUtils.copy(partial, target);
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partial = null;
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} else {
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written = 0;
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}
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return written;
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}
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@Override
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public int read() throws IOException {
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if (message != null) {
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partial = new ByteArrayInputStream(message.toByteArray());
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message = null;
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}
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if (partial != null) {
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return partial.read();
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}
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return -1;
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}
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@Override
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public int read(byte[] b, int off, int len) throws IOException {
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if (message != null) {
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int size = message.getSerializedSize();
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if (size == 0) {
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message = null;
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partial = null;
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return -1;
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}
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if (len >= size) {
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// This is the only case that is zero-copy.
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CodedOutputStream stream = CodedOutputStream.newInstance(b, off, size);
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message.writeTo(stream);
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stream.flush();
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stream.checkNoSpaceLeft();
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message = null;
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partial = null;
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return size;
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}
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partial = new ByteArrayInputStream(message.toByteArray());
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message = null;
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}
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if (partial != null) {
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return partial.read(b, off, len);
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}
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return -1;
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}
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@Override
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public int available() throws IOException {
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if (message != null) {
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return message.getSerializedSize();
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} else if (partial != null) {
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return partial.available();
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}
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return 0;
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}
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MessageLite message() {
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if (message == null) {
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throw new IllegalStateException("message not available");
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}
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return message;
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}
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Parser<?> parser() {
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return parser;
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}
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}
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