ratis-grpc/src/main/java/org/apache/ratis/grpc/client/GrpcOutputStream.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.ratis.grpc.client;

import org.apache.ratis.conf.RaftProperties;
import org.apache.ratis.grpc.GrpcConfigKeys;
import org.apache.ratis.grpc.GrpcTlsConfig;
import org.apache.ratis.protocol.ClientId;
import org.apache.ratis.protocol.RaftGroup;
import org.apache.ratis.protocol.RaftPeerId;
import org.apache.ratis.util.JavaUtils;
import org.apache.ratis.util.ProtoUtils;

import java.io.IOException;
import java.io.OutputStream;
import java.util.concurrent.atomic.AtomicLong;

public class GrpcOutputStream extends OutputStream {
  /** internal buffer */
  private final byte[] buf;
  private int count;
  private final AtomicLong seqNum = new AtomicLong();
  private final ClientId clientId;
  private final String name;
  private final GrpcClientStreamer streamer;

  private boolean closed = false;

  public GrpcOutputStream(RaftProperties prop, ClientId clientId,
      RaftGroup group, RaftPeerId leaderId, GrpcTlsConfig tlsConfig) {
    final int bufferSize = GrpcConfigKeys.OutputStream.bufferSize(prop).getSizeInt();
    buf = new byte[bufferSize];
    count = 0;
    this.clientId = clientId;
    this.name = JavaUtils.getClassSimpleName(getClass()) + "-" + clientId;
    streamer = new GrpcClientStreamer(prop, group, leaderId, clientId, tlsConfig);
  }

  @Override
  public void write(int b) throws IOException {
    checkClosed();
    buf[count++] = (byte)b;
    flushIfNecessary();
  }

  private void flushIfNecessary() throws IOException {
    if(count == buf.length) {
      flushToStreamer();
    }
  }

  @Override
  public void write(byte[] b, int off, int len) throws IOException {
    checkClosed();
    if (off < 0 || len < 0 || off > b.length - len) {
      throw new ArrayIndexOutOfBoundsException();
    }

    int total = 0;
    while (total < len) {
      int toWrite = Math.min(len - total, buf.length - count);
      System.arraycopy(b, off + total, buf, count, toWrite);
      count += toWrite;
      total += toWrite;
      flushIfNecessary();
    }
  }

  private void flushToStreamer() throws IOException {
    if (count > 0) {
      streamer.write(ProtoUtils.toByteString(buf, 0, count),
          seqNum.getAndIncrement());
      count = 0;
    }
  }

  @Override
  public void flush() throws IOException {
    checkClosed();
    flushToStreamer();
    streamer.flush();
  }

  @Override
  public void close() throws IOException {
    flushToStreamer();
    streamer.close(); // streamer will flush
    this.closed = true;
  }

  @Override
  public String toString() {
    return name;
  }

  private void checkClosed() throws IOException {
    if (closed) {
      throw new IOException(this.toString() + " was closed.");
    }
  }
}