content: /*
   * 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.celeborn.common.network.client;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.net.SocketAddress;
  import java.nio.ByteBuffer;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicLong;
  
  import javax.annotation.Nullable;
  
  import com.google.common.annotations.VisibleForTesting;
  import com.google.common.base.Preconditions;
  import com.google.common.util.concurrent.SettableFuture;
  import io.netty.channel.Channel;
  import io.netty.channel.ChannelFuture;
  import io.netty.util.concurrent.Future;
  import io.netty.util.concurrent.GenericFutureListener;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import org.apache.celeborn.common.network.buffer.NioManagedBuffer;
  import org.apache.celeborn.common.network.protocol.OneWayMessage;
  import org.apache.celeborn.common.network.protocol.PushData;
  import org.apache.celeborn.common.network.protocol.PushMergedData;
  import org.apache.celeborn.common.network.protocol.RpcRequest;
  import org.apache.celeborn.common.network.protocol.StreamChunkSlice;
  import org.apache.celeborn.common.network.protocol.TransportMessage;
  import org.apache.celeborn.common.network.util.NettyUtils;
  import org.apache.celeborn.common.protocol.MessageType;
  import org.apache.celeborn.common.protocol.PbChunkFetchRequest;
  import org.apache.celeborn.common.read.FetchRequestInfo;
  import org.apache.celeborn.common.write.PushRequestInfo;
  
  /**
   * Client for fetching consecutive chunks of a pre-negotiated stream. This API is intended to allow
   * efficient transfer of a large amount of data, broken up into chunks with size ranging from
   * hundreds of KB to a few MB.
   *
   * <p>Note that while this client deals with the fetching of chunks from a stream (i.e., data
   * plane), the actual setup of the streams is done outside the scope of the transport layer. The
   * convenience method "sendRPC" is provided to enable control plane communication between the client
   * and server to perform this setup.
   *
   * <p>For example, a typical workflow might be: client.sendRPC(new OpenFile("/foo")) --&gt; returns
   * StreamId = 100 client.fetchChunk(streamId = 100, chunkIndex = 0, callback)
   * client.fetchChunk(streamId = 100, chunkIndex = 1, callback) ... client.sendRPC(new
   * CloseStream(100))
   *
   * <p>Construct an instance of TransportClient using {@link TransportClientFactory}. A single
   * TransportClient may be used for multiple streams, but any given stream must be restricted to a
   * single client, in order to avoid out-of-order responses.
   *
   * <p>NB: This class is used to make requests to the server, while {@link TransportResponseHandler}
   * is responsible for handling responses from the server.
   *
   * <p>Concurrency: thread safe and can be called from multiple threads.
   */
  public class TransportClient implements Closeable {
    private static final Logger logger = LoggerFactory.getLogger(TransportClient.class);
  
    private final Channel channel;
    private final TransportResponseHandler handler;
    private volatile boolean timedOut;
    @Nullable private String clientId;
  
    public TransportClient(Channel channel, TransportResponseHandler handler) {
      this.channel = Preconditions.checkNotNull(channel);
      this.handler = Preconditions.checkNotNull(handler);
      this.timedOut = false;
    }
  
    public Channel getChannel() {
      return channel;
    }
  
    public boolean isActive() {
      return !timedOut && (channel.isOpen() || channel.isActive());
    }
  
    public SocketAddress getSocketAddress() {
      return channel.remoteAddress();
    }
  
    public void fetchChunk(
        long streamId, int chunkIndex, long fetchDataTimeout, ChunkReceivedCallback callback) {
      fetchChunk(streamId, chunkIndex, 0, Integer.MAX_VALUE, fetchDataTimeout, callback);
    }
  
    /**
     * Requests a single chunk from the remote side, from the pre-negotiated streamId.
     *
     * <p>Chunk indices go from 0 onwards. It is valid to request the same chunk multiple times,
     * though some streams may not support this.
     *
     * <p>Multiple fetchChunk requests may be outstanding simultaneously, and the chunks are
     * guaranteed to be returned in the same order that they were requested, assuming only a single
     * TransportClient is used to fetch the chunks.
     *
     * @param streamId Identifier that refers to a stream in the remote StreamManager. This should be
     *     agreed upon by client and server beforehand.
     * @param chunkIndex 0-based index of the chunk to fetch
     * @param offset offset from the beginning of the chunk to fetch
     * @param len size to fetch
     * @param callback Callback invoked upon successful receipt of chunk, or upon any failure.
     */
    public void fetchChunk(
        long streamId,
        int chunkIndex,
        int offset,
        int len,
        long fetchDataTimeout,
        ChunkReceivedCallback callback) {
  
      StreamChunkSlice streamChunkSlice = new StreamChunkSlice(streamId, chunkIndex, offset, len);
      if (logger.isDebugEnabled()) {
        logger.debug(
            "Sending fetch chunk request {} to {}.",
            streamChunkSlice,
            NettyUtils.getRemoteAddress(channel));
      }
      StdChannelListener listener =
          new StdChannelListener(streamChunkSlice) {
            @Override
            protected void handleFailure(String errorMsg, Throwable cause) {
              handler.handleFetchFailure(streamChunkSlice, errorMsg, cause);
            }
          };
  
      long dueTime = System.currentTimeMillis() + fetchDataTimeout;
      FetchRequestInfo info = new FetchRequestInfo(dueTime, callback);
      handler.addFetchRequest(streamChunkSlice, info);
  
      ChannelFuture channelFuture =
          channel
              .writeAndFlush(
                  new RpcRequest(
                      TransportClient.requestId(),
                      new NioManagedBuffer(
                          new TransportMessage(
                                  MessageType.CHUNK_FETCH_REQUEST,
                                  PbChunkFetchRequest.newBuilder()
                                      .setStreamChunkSlice(streamChunkSlice.toProto())
                                      .build()
                                      .toByteArray())
                              .toByteBuffer())))
              .addListener(listener);
      info.setChannelFuture(channelFuture);
    }
  
    /**
     * Sends an opaque message to the RpcHandler on the server-side. The callback will be invoked with
     * the server's response or upon any failure.
     *
     * @param message The message to send.
     * @param callback Callback to handle the RPC's reply.
     * @return The RPC's id.
     */
    public long sendRpc(ByteBuffer message, RpcResponseCallback callback) {
      if (logger.isTraceEnabled()) {
        logger.trace("Sending RPC to {}", NettyUtils.getRemoteAddress(channel));
      }
  
      long requestId = requestId();
      handler.addRpcRequest(requestId, callback);
  
      RpcChannelListener listener = new RpcChannelListener(requestId);
      channel
          .writeAndFlush(new RpcRequest(requestId, new NioManagedBuffer(message)))
          .addListener(listener);
  
      return requestId;
    }
  
    /**
     * Sends an opaque message to the RpcHandler on the server-side. No reply is expected for the
     * message, and no delivery guarantees are made.
     *
     * @param message The message to send.
     */
    public void sendRpc(ByteBuffer message) {
      if (logger.isTraceEnabled()) {
        logger.trace("Sending RPC to {}", NettyUtils.getRemoteAddress(channel));
      }
  
      long requestId = requestId();
      channel.writeAndFlush(new RpcRequest(requestId, new NioManagedBuffer(message)));
    }
  
    public ChannelFuture pushData(
        PushData pushData, long pushDataTimeout, RpcResponseCallback callback) {
      return pushData(pushData, pushDataTimeout, callback, null);
    }
  
    public ChannelFuture pushData(
        PushData pushData,
        long pushDataTimeout,
        RpcResponseCallback callback,
        Runnable rpcSendoutCallback) {
      if (logger.isTraceEnabled()) {
        logger.trace("Pushing data to {}", NettyUtils.getRemoteAddress(channel));
      }
  
      long requestId = requestId();
      long dueTime = System.currentTimeMillis() + pushDataTimeout;
      PushRequestInfo info = new PushRequestInfo(dueTime, callback);
      handler.addPushRequest(requestId, info);
      pushData.requestId = requestId;
      PushChannelListener listener = new PushChannelListener(requestId, rpcSendoutCallback);
      ChannelFuture channelFuture = channel.writeAndFlush(pushData).addListener(listener);
      info.setChannelFuture(channelFuture);
      return channelFuture;
    }
  
    public ChannelFuture pushMergedData(
        PushMergedData pushMergedData, long pushDataTimeout, RpcResponseCallback callback) {
      if (logger.isTraceEnabled()) {
        logger.trace("Pushing merged data to {}", NettyUtils.getRemoteAddress(channel));
      }
  
      long requestId = requestId();
      long dueTime = System.currentTimeMillis() + pushDataTimeout;
      PushRequestInfo info = new PushRequestInfo(dueTime, callback);
      handler.addPushRequest(requestId, info);
      pushMergedData.requestId = requestId;
  
      PushChannelListener listener = new PushChannelListener(requestId);
      ChannelFuture channelFuture = channel.writeAndFlush(pushMergedData).addListener(listener);
      info.setChannelFuture(channelFuture);
      return channelFuture;
    }
  
    /**
     * Synchronously sends an opaque message to the RpcHandler on the server-side, waiting for up to a
     * specified timeout for a response.
     */
    public ByteBuffer sendRpcSync(ByteBuffer message, long timeoutMs) throws IOException {
      final SettableFuture<ByteBuffer> result = SettableFuture.create();
  
      sendRpc(
          message,
          new RpcResponseCallback() {
            @Override
            public void onSuccess(ByteBuffer response) {
              try {
                ByteBuffer copy = ByteBuffer.allocate(response.remaining());
                copy.put(response);
                // flip "copy" to make it readable
                copy.flip();
                result.set(copy);
              } catch (Throwable t) {
                logger.warn("Error in responding RPC callback", t);
                result.setException(t);
              }
            }
  
            @Override
            public void onFailure(Throwable e) {
              result.setException(e);
            }
          });
  
      try {
        return result.get(timeoutMs, TimeUnit.MILLISECONDS);
      } catch (Exception e) {
        throw new IOException("Exception in sendRpcSync to: " + this.getSocketAddress(), e);
      }
    }
  
    /**
     * Synchronously sends an opaque message to the RpcHandler on the server-side, waiting for up to a
     * specified timeout for a response. The callback will be invoked with the server's response or
     * upon any failure.
     */
    public void sendRpcSync(ByteBuffer message, RpcResponseCallback callback, long timeoutMs)
        throws IOException {
      final SettableFuture<Void> result = SettableFuture.create();
  
      sendRpc(
          message,
          new RpcResponseCallback() {
            @Override
            public void onSuccess(ByteBuffer response) {
              try {
                ByteBuffer copy = ByteBuffer.allocate(response.remaining());
                copy.put(response);
                // flip "copy" to make it readable
                copy.flip();
                callback.onSuccess(copy);
                result.set(null);
              } catch (Throwable t) {
                logger.warn("Error in responding RPC callback", t);
                callback.onFailure(t);
                result.set(null);
              }
            }
  
            @Override
            public void onFailure(Throwable e) {
              callback.onFailure(e);
              result.set(null);
            }
          });
  
      try {
        result.get(timeoutMs, TimeUnit.MILLISECONDS);
      } catch (Exception e) {
        throw new IOException("Exception in sendRpcSync to: " + this.getSocketAddress(), e);
      }
    }
  
    /**
     * Sends an opaque message to the RpcHandler on the server-side. No reply is expected for the
     * message, and no delivery guarantees are made.
     *
     * @param message The message to send.
     */
    public void send(ByteBuffer message) {
      channel.writeAndFlush(new OneWayMessage(new NioManagedBuffer(message)));
    }
  
    /**
     * Removes any state associated with the given RPC.
     *
     * @param requestId The RPC id returned by {@link #sendRpc(ByteBuffer, RpcResponseCallback)}.
     */
    public void removeRpcRequest(long requestId) {
      handler.removeRpcRequest(requestId);
    }
  
    /** Mark this channel as having timed out. */
    public void timeOut() {
      this.timedOut = true;
    }
  
    @VisibleForTesting
    public TransportResponseHandler getHandler() {
      return handler;
    }
  
    @Override
    public void close() {
      // Mark the connection as timed out, so we do not return a connection that's being closed
      // from the TransportClientFactory if closing takes some time (e.g. with SSL)
      this.timedOut = true;
      // close is a local operation and should finish with milliseconds; timeout just to be safe
      channel.close().awaitUninterruptibly(10, TimeUnit.SECONDS);
    }
  
    @Override
    public String toString() {
      return "TransportClient[remoteAddress="
          + channel.remoteAddress()
          + "clientId="
          + clientId
          + ",isActive="
          + isActive()
          + "]";
    }
  
    private static final AtomicLong counter = new AtomicLong();
  
    public static long requestId() {
      return counter.getAndIncrement();
    }
  
    /**
     * Returns the ID used by the client to authenticate itself when authentication is enabled.
     *
     * @return The client ID, or null if authentication is disabled.
     */
    public String getClientId() {
      return clientId;
    }
  
    /**
     * Sets the authenticated client ID. This is meant to be used by the authentication layer.
     *
     * <p>Trying to set a different client ID after it's been set will result in an exception.
     */
    public void setClientId(String id) {
      Preconditions.checkState(
          clientId == null || clientId.equals(id), "Client ID has already been set.");
      this.clientId = id;
    }
  
    public class StdChannelListener implements GenericFutureListener<Future<? super Void>> {
      final long startTime;
      final Object requestId;
  
      public StdChannelListener(Object requestId) {
        this.startTime = System.currentTimeMillis();
        this.requestId = requestId;
      }
  
      @Override
      public void operationComplete(Future<? super Void> future) throws Exception {
        if (future.isSuccess()) {
          if (logger.isDebugEnabled()) {
            long timeTaken = System.currentTimeMillis() - startTime;
            logger.debug(
                "Sending request {} to {} took {} ms",
                requestId,
                NettyUtils.getRemoteAddress(channel),
                timeTaken);
          }
        } else {
          String errorMsg =
              String.format(
                  "Failed to send request %s to %s: %s, channel will be closed",
                  requestId, NettyUtils.getRemoteAddress(channel), future.cause());
          logger.warn(errorMsg);
          channel.close();
          try {
            handleFailure(errorMsg, future.cause());
          } catch (Exception e) {
            logger.error("Uncaught exception in RPC response callback handler!", e);
          }
        }
      }
  
      protected void handleFailure(String errorMsg, Throwable cause) {
        logger.error("Error encountered " + errorMsg, cause);
      }
    }
  
    private class RpcChannelListener extends StdChannelListener {
      final long rpcRequestId;
  
      RpcChannelListener(long rpcRequestId) {
        super("RPC " + rpcRequestId);
        this.rpcRequestId = rpcRequestId;
      }
  
      @Override
      protected void handleFailure(String errorMsg, Throwable cause) {
        handler.handleRpcFailure(rpcRequestId, errorMsg, cause);
      }
    }
  
    private class PushChannelListener extends StdChannelListener {
      final long pushRequestId;
      Runnable rpcSendOutCallback;
  
      PushChannelListener(long pushRequestId) {
        this(pushRequestId, null);
      }
  
      PushChannelListener(long pushRequestId, Runnable rpcSendOutCallback) {
        super("PUSH " + pushRequestId);
        this.pushRequestId = pushRequestId;
        this.rpcSendOutCallback = rpcSendOutCallback;
      }
  
      @Override
      public void operationComplete(Future<? super Void> future) throws Exception {
        super.operationComplete(future);
        if (rpcSendOutCallback != null) {
          rpcSendOutCallback.run();
        }
      }
  
      @Override
      protected void handleFailure(String errorMsg, Throwable cause) {
        handler.handlePushFailure(pushRequestId, errorMsg, cause);
      }
    }
  }
  