Class NettyClientHandler

netty/src/main/java/io/grpc/netty/NettyClientHandler.java:102–1186

Client-side Netty handler for GRPC processing. All event handlers are executed entirely within the context of the Netty Channel thread.

 * the context of the Netty Channel thread.
 */
class NettyClientHandler extends AbstractNettyHandler {
  private static final Logger logger = Logger.getLogger(NettyClientHandler.class.getName());
  static boolean enablePerRpcAuthorityCheck =
      GrpcUtil.getFlag("GRPC_ENABLE_PER_RPC_AUTHORITY_CHECK", false);

  /**
   * A message that simply passes through the channel without any real processing. It is useful to
   * check if buffers have been drained and test the health of the channel in a single operation.
   */
  static final Object NOOP_MESSAGE = new Object();

  /**
   * Status used when the transport has exhausted the number of streams.
   */
  private static final Status EXHAUSTED_STREAMS_STATUS =
          Status.UNAVAILABLE.withDescription("Stream IDs have been exhausted");
  private static final long USER_PING_PAYLOAD = 1111;

  private final Http2Connection.PropertyKey streamKey;
  private final ClientTransportLifecycleManager lifecycleManager;
  private final KeepAliveManager keepAliveManager;
  // Returns new unstarted stopwatches
  private final Supplier<Stopwatch> stopwatchFactory;
  private final TransportTracer transportTracer;
  private final Attributes eagAttributes;
  private final TcpMetrics tcpMetrics;
  private final String authority;
  private final InUseStateAggregator<Http2Stream> inUseState =
      new InUseStateAggregator<Http2Stream>() {
        @Override
        protected void handleInUse() {
          lifecycleManager.notifyInUse(true);
        }

        @Override
        protected void handleNotInUse() {
          lifecycleManager.notifyInUse(false);
        }
      };
  private final Map<String, Status> peerVerificationResults =
      new LinkedHashMap<String, Status>() {
        @Override
        protected boolean removeEldestEntry(Map.Entry<String, Status> eldest) {
          return size() > 100;
        }
      };

  private WriteQueue clientWriteQueue;
  private Http2Ping ping;
  private Attributes attributes;
  private InternalChannelz.Security securityInfo;
  private Status abruptGoAwayStatus;
  private Status channelInactiveReason;

  static NettyClientHandler newHandler(
      ClientTransportLifecycleManager lifecycleManager,
      @Nullable KeepAliveManager keepAliveManager,
      boolean autoFlowControl,