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A driver for Apache Cassandra 1.2+ that works exclusively with the Cassandra Query Language version 3 (CQL3) and Cassandra's binary protocol.

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/*
 * Copyright DataStax, Inc.
 *
 * 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 com.datastax.driver.core;

import static com.datastax.driver.core.Message.Response.Type.ERROR;
import static io.netty.handler.timeout.IdleState.READER_IDLE;

import com.datastax.driver.core.Responses.Result.SetKeyspace;
import com.datastax.driver.core.exceptions.AuthenticationException;
import com.datastax.driver.core.exceptions.BusyConnectionException;
import com.datastax.driver.core.exceptions.ConnectionException;
import com.datastax.driver.core.exceptions.CrcMismatchException;
import com.datastax.driver.core.exceptions.DriverException;
import com.datastax.driver.core.exceptions.DriverInternalError;
import com.datastax.driver.core.exceptions.FrameTooLongException;
import com.datastax.driver.core.exceptions.OperationTimedOutException;
import com.datastax.driver.core.exceptions.TransportException;
import com.datastax.driver.core.exceptions.UnsupportedProtocolVersionException;
import com.datastax.driver.core.utils.MoreFutures;
import com.datastax.driver.core.utils.MoreObjects;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.Lists;
import com.google.common.collect.MapMaker;
import com.google.common.util.concurrent.AbstractFuture;
import com.google.common.util.concurrent.AsyncFunction;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.common.util.concurrent.SettableFuture;
import com.google.common.util.concurrent.Uninterruptibles;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoop;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.DecoderException;
import io.netty.handler.ssl.SslHandler;
import io.netty.handler.timeout.IdleStateEvent;
import io.netty.handler.timeout.IdleStateHandler;
import io.netty.util.Timeout;
import io.netty.util.Timer;
import io.netty.util.TimerTask;
import io.netty.util.concurrent.GlobalEventExecutor;
import java.lang.ref.WeakReference;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

// For LoggingHandler
// import org.jboss.netty.handler.logging.LoggingHandler;
// import org.jboss.netty.logging.InternalLogLevel;

/** A connection to a Cassandra Node. */
class Connection {

  private static final Logger logger = LoggerFactory.getLogger(Connection.class);
  private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];

  private static final boolean DISABLE_COALESCING =
      SystemProperties.getBoolean("com.datastax.driver.DISABLE_COALESCING", false);
  private static final int FLUSHER_SCHEDULE_PERIOD_NS =
      SystemProperties.getInt("com.datastax.driver.FLUSHER_SCHEDULE_PERIOD_NS", 10000);

  enum State {
    OPEN,
    TRASHED,
    RESURRECTING,
    GONE
  }

  final AtomicReference state = new AtomicReference(State.OPEN);

  volatile long maxIdleTime;

  final EndPoint endPoint;
  private final String name;

  @VisibleForTesting volatile Channel channel;
  private final Factory factory;

  @VisibleForTesting final Dispatcher dispatcher;

  // Used by connection pooling to count how many requests are "in flight" on that connection.
  final AtomicInteger inFlight = new AtomicInteger(0);

  private final AtomicInteger writer = new AtomicInteger(0);

  private final AtomicReference targetKeyspace;
  private final SetKeyspaceAttempt defaultKeyspaceAttempt;

  private volatile boolean isInitialized;
  private final AtomicBoolean isDefunct = new AtomicBoolean();
  private final AtomicBoolean signaled = new AtomicBoolean();

  private final AtomicReference closeFuture =
      new AtomicReference();

  private final AtomicReference ownerRef = new AtomicReference();

  /**
   * Create a new connection to a Cassandra node and associate it with the given pool.
   *
   * @param name the connection name
   * @param endPoint the information to connect to the node
   * @param factory the connection factory to use
   * @param owner the component owning this connection (may be null). Note that an existing
   *     connection can also be associated to an owner later with {@link #setOwner(Owner)}.
   */
  protected Connection(String name, EndPoint endPoint, Factory factory, Owner owner) {
    this.endPoint = endPoint;
    this.factory = factory;
    this.dispatcher = new Dispatcher();
    this.name = name;
    this.ownerRef.set(owner);
    ListenableFuture thisFuture = Futures.immediateFuture(this);
    this.defaultKeyspaceAttempt = new SetKeyspaceAttempt(null, thisFuture);
    this.targetKeyspace = new AtomicReference(defaultKeyspaceAttempt);
  }

  /** Create a new connection to a Cassandra node. */
  Connection(String name, EndPoint endPoint, Factory factory) {
    this(name, endPoint, factory, null);
  }

  ListenableFuture initAsync() {
    if (factory.isShutdown)
      return Futures.immediateFailedFuture(
          new ConnectionException(endPoint, "Connection factory is shut down"));

    ProtocolVersion protocolVersion =
        factory.protocolVersion == null
            ? ProtocolVersion.NEWEST_SUPPORTED
            : factory.protocolVersion;
    final SettableFuture channelReadyFuture = SettableFuture.create();

    try {
      Bootstrap bootstrap = factory.newBootstrap();
      ProtocolOptions protocolOptions = factory.configuration.getProtocolOptions();
      bootstrap.handler(
          new Initializer(
              this,
              protocolVersion,
              protocolOptions.getCompression().compressor(),
              protocolOptions.getSSLOptions(),
              factory.configuration.getPoolingOptions().getHeartbeatIntervalSeconds(),
              factory.configuration.getNettyOptions(),
              factory.configuration.getCodecRegistry(),
              factory.configuration.getMetricsOptions().isEnabled()
                  ? factory.manager.metrics
                  : null));

      ChannelFuture future = bootstrap.connect(endPoint.resolve());

      writer.incrementAndGet();
      future.addListener(
          new ChannelFutureListener() {
            @Override
            public void operationComplete(ChannelFuture future) throws Exception {
              writer.decrementAndGet();
              // Note: future.channel() can be null in some error cases, so we need to guard against
              // it in the rest of the code below.
              channel = future.channel();
              if (isClosed() && channel != null) {
                channel
                    .close()
                    .addListener(
                        new ChannelFutureListener() {
                          @Override
                          public void operationComplete(ChannelFuture future) throws Exception {
                            channelReadyFuture.setException(
                                new TransportException(
                                    Connection.this.endPoint,
                                    "Connection closed during initialization."));
                          }
                        });
              } else {
                if (channel != null) {
                  Connection.this.factory.allChannels.add(channel);
                }
                if (!future.isSuccess()) {
                  if (logger.isDebugEnabled())
                    logger.debug(
                        String.format(
                            "%s Error connecting to %s%s",
                            Connection.this,
                            Connection.this.endPoint,
                            extractMessage(future.cause())));
                  channelReadyFuture.setException(
                      new TransportException(
                          Connection.this.endPoint, "Cannot connect", future.cause()));
                } else {
                  assert channel != null;
                  logger.debug(
                      "{} Connection established, initializing transport", Connection.this);
                  channel.closeFuture().addListener(new ChannelCloseListener());
                  channelReadyFuture.set(null);
                }
              }
            }
          });
    } catch (RuntimeException e) {
      closeAsync().force();
      throw e;
    }

    Executor initExecutor =
        factory.manager.configuration.getPoolingOptions().getInitializationExecutor();

    ListenableFuture initializeTransportFuture =
        GuavaCompatibility.INSTANCE.transformAsync(
            channelReadyFuture, onChannelReady(protocolVersion, initExecutor), initExecutor);

    // Fallback on initializeTransportFuture so we can properly propagate specific exceptions.
    ListenableFuture initFuture =
        GuavaCompatibility.INSTANCE.withFallback(
            initializeTransportFuture,
            new AsyncFunction() {
              @Override
              public ListenableFuture apply(Throwable t) throws Exception {
                SettableFuture future = SettableFuture.create();
                // Make sure the connection gets properly closed.
                if (t instanceof ClusterNameMismatchException
                    || t instanceof UnsupportedProtocolVersionException) {
                  // Just propagate
                  closeAsync().force();
                  future.setException(t);
                } else {
                  // Defunct to ensure that the error will be signaled (marking the host down)
                  Throwable e =
                      (t instanceof ConnectionException
                              || t instanceof DriverException
                              || t instanceof InterruptedException
                              || t instanceof Error)
                          ? t
                          : new ConnectionException(
                              Connection.this.endPoint,
                              String.format(
                                  "Unexpected error during transport initialization (%s)", t),
                              t);
                  future.setException(defunct(e));
                }
                return future;
              }
            },
            initExecutor);

    // Ensure the connection gets closed if the caller cancels the returned future.
    GuavaCompatibility.INSTANCE.addCallback(
        initFuture,
        new MoreFutures.FailureCallback() {
          @Override
          public void onFailure(Throwable t) {
            if (!isClosed()) {
              closeAsync().force();
            }
          }
        },
        initExecutor);

    return initFuture;
  }

  private static String extractMessage(Throwable t) {
    if (t == null) return "";
    String msg = t.getMessage() == null || t.getMessage().isEmpty() ? t.toString() : t.getMessage();
    return " (" + msg + ')';
  }

  public ListenableFuture optionsQuery() {
    Future startupOptionsFuture = write(new Requests.Options());

    return GuavaCompatibility.INSTANCE.transformAsync(startupOptionsFuture, onSupportedResponse());
  }

  private AsyncFunction onChannelReady(
      final ProtocolVersion protocolVersion, final Executor initExecutor) {
    return new AsyncFunction() {
      @Override
      public ListenableFuture apply(Void input) throws Exception {
        ProtocolOptions protocolOptions = factory.configuration.getProtocolOptions();
        Future startupResponseFuture =
            write(
                new Requests.Startup(
                    protocolOptions.getCompression(), protocolOptions.isNoCompact()));
        return GuavaCompatibility.INSTANCE.transformAsync(
            startupResponseFuture, onStartupResponse(protocolVersion, initExecutor), initExecutor);
      }
    };
  }

  private AsyncFunction onSupportedResponse() {
    return new AsyncFunction() {
      @Override
      public ListenableFuture apply(Message.Response response) throws Exception {
        switch (response.type) {
          case SUPPORTED:
            return getProductType((Responses.Supported) response);
          case ERROR:
            Responses.Error error = (Responses.Error) response;
            throw new TransportException(
                endPoint, String.format("Error initializing connection: %s", error.message));
          default:
            throw new TransportException(
                endPoint,
                String.format(
                    "Unexpected %s response message from server to a STARTUP message",
                    response.type));
        }
      }
    };
  }

  private AsyncFunction onStartupResponse(
      final ProtocolVersion protocolVersion, final Executor initExecutor) {
    return new AsyncFunction() {
      @Override
      public ListenableFuture apply(Message.Response response) throws Exception {
        switch (response.type) {
          case READY:
            return checkClusterName(protocolVersion, initExecutor);
          case ERROR:
            Responses.Error error = (Responses.Error) response;
            if (isUnsupportedProtocolVersion(error))
              throw unsupportedProtocolVersionException(
                  protocolVersion, error.serverProtocolVersion);
            throw new TransportException(
                endPoint, String.format("Error initializing connection: %s", error.message));
          case AUTHENTICATE:
            Responses.Authenticate authenticate = (Responses.Authenticate) response;
            Authenticator authenticator;
            try {
              if (factory.authProvider instanceof ExtendedAuthProvider) {
                authenticator =
                    ((ExtendedAuthProvider) factory.authProvider)
                        .newAuthenticator(endPoint, authenticate.authenticator);
              } else {
                authenticator =
                    factory.authProvider.newAuthenticator(
                        endPoint.resolve(), authenticate.authenticator);
              }
            } catch (AuthenticationException e) {
              incrementAuthErrorMetric();
              throw e;
            }
            switch (protocolVersion) {
              case V1:
                if (authenticator instanceof ProtocolV1Authenticator)
                  return authenticateV1(authenticator, protocolVersion, initExecutor);
                else
                  // DSE 3.x always uses SASL authentication backported from protocol v2
                  return authenticateV2(authenticator, protocolVersion, initExecutor);
              case V2:
              case V3:
              case V4:
              case V5:
              case V6:
                return authenticateV2(authenticator, protocolVersion, initExecutor);
              default:
                throw defunct(protocolVersion.unsupported());
            }
          default:
            throw new TransportException(
                endPoint,
                String.format(
                    "Unexpected %s response message from server to a STARTUP message",
                    response.type));
        }
      }
    };
  }

  // Due to C* gossip bugs, system.peers may report nodes that are gone from the cluster.
  // If these nodes have been recommissionned to another cluster and are up, nothing prevents the
  // driver from connecting
  // to them. So we check that the cluster the node thinks it belongs to is our cluster (JAVA-397).
  private ListenableFuture checkClusterName(
      ProtocolVersion protocolVersion, final Executor executor) {
    final String expected = factory.manager.metadata.clusterName;

    // At initialization, the cluster is not known yet
    if (expected == null) {
      markInitialized();
      return MoreFutures.VOID_SUCCESS;
    }

    DefaultResultSetFuture clusterNameFuture =
        new DefaultResultSetFuture(
            null,
            protocolVersion,
            new Requests.Query("select cluster_name from system.local where key = 'local'"));
    try {
      write(clusterNameFuture);
      return GuavaCompatibility.INSTANCE.transformAsync(
          clusterNameFuture,
          new AsyncFunction() {
            @Override
            public ListenableFuture apply(ResultSet rs) throws Exception {
              Row row = rs.one();
              String actual = row.getString("cluster_name");
              if (!expected.equals(actual))
                throw new ClusterNameMismatchException(endPoint, actual, expected);
              markInitialized();
              return MoreFutures.VOID_SUCCESS;
            }
          },
          executor);
    } catch (Exception e) {
      return Futures.immediateFailedFuture(e);
    }
  }

  private ListenableFuture getProductType(Responses.Supported response) {
    if (response.supported.containsKey("PRODUCT_TYPE")
        && response.supported.get("PRODUCT_TYPE").size() > 0) {
      return Futures.immediateFuture(response.supported.get("PRODUCT_TYPE").get(0));
    } else {
      return Futures.immediateFuture("");
    }
  }

  private void markInitialized() {
    isInitialized = true;
    Host.statesLogger.debug("[{}] {} Transport initialized, connection ready", endPoint, this);
  }

  private ListenableFuture authenticateV1(
      Authenticator authenticator, final ProtocolVersion protocolVersion, final Executor executor) {
    Requests.Credentials creds =
        new Requests.Credentials(((ProtocolV1Authenticator) authenticator).getCredentials());
    try {
      Future authResponseFuture = write(creds);
      return GuavaCompatibility.INSTANCE.transformAsync(
          authResponseFuture,
          new AsyncFunction() {
            @Override
            public ListenableFuture apply(Message.Response authResponse) throws Exception {
              switch (authResponse.type) {
                case READY:
                  return checkClusterName(protocolVersion, executor);
                case ERROR:
                  incrementAuthErrorMetric();
                  throw new AuthenticationException(
                      endPoint, ((Responses.Error) authResponse).message);
                default:
                  throw new TransportException(
                      endPoint,
                      String.format(
                          "Unexpected %s response message from server to a CREDENTIALS message",
                          authResponse.type));
              }
            }
          },
          executor);
    } catch (Exception e) {
      return Futures.immediateFailedFuture(e);
    }
  }

  private ListenableFuture authenticateV2(
      final Authenticator authenticator,
      final ProtocolVersion protocolVersion,
      final Executor executor) {
    byte[] initialResponse = authenticator.initialResponse();
    if (null == initialResponse) initialResponse = EMPTY_BYTE_ARRAY;

    try {
      Future authResponseFuture = write(new Requests.AuthResponse(initialResponse));
      return GuavaCompatibility.INSTANCE.transformAsync(
          authResponseFuture, onV2AuthResponse(authenticator, protocolVersion, executor), executor);
    } catch (Exception e) {
      return Futures.immediateFailedFuture(e);
    }
  }

  private AsyncFunction onV2AuthResponse(
      final Authenticator authenticator,
      final ProtocolVersion protocolVersion,
      final Executor executor) {
    return new AsyncFunction() {
      @Override
      public ListenableFuture apply(Message.Response authResponse) throws Exception {
        switch (authResponse.type) {
          case AUTH_SUCCESS:
            logger.trace("{} Authentication complete", this);
            authenticator.onAuthenticationSuccess(((Responses.AuthSuccess) authResponse).token);
            return checkClusterName(protocolVersion, executor);
          case AUTH_CHALLENGE:
            byte[] responseToServer =
                authenticator.evaluateChallenge(((Responses.AuthChallenge) authResponse).token);
            if (responseToServer == null) {
              // If we generate a null response, then authentication has completed, proceed without
              // sending a further response back to the server.
              logger.trace("{} Authentication complete (No response to server)", this);
              return checkClusterName(protocolVersion, executor);
            } else {
              // Otherwise, send the challenge response back to the server
              logger.trace("{} Sending Auth response to challenge", this);
              Future nextResponseFuture = write(new Requests.AuthResponse(responseToServer));
              return GuavaCompatibility.INSTANCE.transformAsync(
                  nextResponseFuture,
                  onV2AuthResponse(authenticator, protocolVersion, executor),
                  executor);
            }
          case ERROR:
            // This is not very nice, but we're trying to identify if we
            // attempted v2 auth against a server which only supports v1
            // The AIOOBE indicates that the server didn't recognise the
            // initial AuthResponse message
            String message = ((Responses.Error) authResponse).message;
            if (message.startsWith("java.lang.ArrayIndexOutOfBoundsException: 15"))
              message =
                  String.format(
                      "Cannot use authenticator %s with protocol version 1, "
                          + "only plain text authentication is supported with this protocol version",
                      authenticator);
            incrementAuthErrorMetric();
            throw new AuthenticationException(endPoint, message);
          default:
            throw new TransportException(
                endPoint,
                String.format(
                    "Unexpected %s response message from server to authentication message",
                    authResponse.type));
        }
      }
    };
  }

  private void incrementAuthErrorMetric() {
    if (factory.manager.configuration.getMetricsOptions().isEnabled()) {
      factory.manager.metrics.getErrorMetrics().getAuthenticationErrors().inc();
    }
  }

  private boolean isUnsupportedProtocolVersion(Responses.Error error) {
    // Testing for a specific string is a tad fragile but well, we don't have much choice
    // C* 2.1 reports a server error instead of protocol error, see CASSANDRA-9451
    return (error.code == ExceptionCode.PROTOCOL_ERROR || error.code == ExceptionCode.SERVER_ERROR)
        && (error.message.contains("Invalid or unsupported protocol version")
            // JAVA-2924: server is behind driver and considers the proposed version as beta
            || error.message.contains("Beta version of the protocol used"));
  }

  private UnsupportedProtocolVersionException unsupportedProtocolVersionException(
      ProtocolVersion triedVersion, ProtocolVersion serverProtocolVersion) {
    UnsupportedProtocolVersionException e =
        new UnsupportedProtocolVersionException(endPoint, triedVersion, serverProtocolVersion);
    logger.debug(e.getMessage());
    return e;
  }

  boolean isDefunct() {
    return isDefunct.get();
  }

  int maxAvailableStreams() {
    return dispatcher.streamIdHandler.maxAvailableStreams();
  }

   E defunct(E e) {
    if (isDefunct.compareAndSet(false, true)) {

      if (Host.statesLogger.isTraceEnabled()) Host.statesLogger.trace("Defuncting " + this, e);
      else if (Host.statesLogger.isDebugEnabled())
        Host.statesLogger.debug("Defuncting {} because: {}", this, e.getMessage());

      Host host = getHost();
      if (host != null) {
        // Sometimes close() can be called before defunct(); avoid decrementing the connection count
        // twice, but
        // we still want to signal the error to the conviction policy.
        boolean decrement = signaled.compareAndSet(false, true);

        boolean hostDown = host.convictionPolicy.signalConnectionFailure(this, decrement);
        if (hostDown) {
          factory.manager.signalHostDown(host, host.wasJustAdded());
        } else {
          notifyOwnerWhenDefunct();
        }
      }

      // Force the connection to close to make sure the future completes. Otherwise force() might
      // never get called and
      // threads will wait on the future forever.
      // (this also errors out pending handlers)
      closeAsync().force();
    }
    return e;
  }

  private void notifyOwnerWhenDefunct() {
    // If an error happens during initialization, the owner will detect it and take appropriate
    // action
    if (!isInitialized) return;

    Owner owner = this.ownerRef.get();
    if (owner != null) owner.onConnectionDefunct(this);
  }

  String keyspace() {
    return targetKeyspace.get().keyspace;
  }

  void setKeyspace(String keyspace) throws ConnectionException {
    if (keyspace == null) return;

    if (MoreObjects.equal(keyspace(), keyspace)) return;

    try {
      Uninterruptibles.getUninterruptibly(setKeyspaceAsync(keyspace));
    } catch (ConnectionException e) {
      throw defunct(e);
    } catch (BusyConnectionException e) {
      logger.warn(
          "Tried to set the keyspace on busy {}. "
              + "This should not happen but is not critical (it will be retried)",
          this);
      throw new ConnectionException(endPoint, "Tried to set the keyspace on busy connection");
    } catch (ExecutionException e) {
      Throwable cause = e.getCause();
      if (cause instanceof OperationTimedOutException) {
        // Rethrow so that the caller doesn't try to use the connection, but do not defunct as we
        // don't want to mark down
        logger.warn(
            "Timeout while setting keyspace on {}. "
                + "This should not happen but is not critical (it will be retried)",
            this);
        throw new ConnectionException(endPoint, "Timeout while setting keyspace on connection");
      } else {
        throw defunct(new ConnectionException(endPoint, "Error while setting keyspace", cause));
      }
    }
  }

  ListenableFuture setKeyspaceAsync(final String keyspace)
      throws ConnectionException, BusyConnectionException {
    SetKeyspaceAttempt existingAttempt = targetKeyspace.get();
    if (MoreObjects.equal(existingAttempt.keyspace, keyspace)) return existingAttempt.future;

    final SettableFuture ksFuture = SettableFuture.create();
    final SetKeyspaceAttempt attempt = new SetKeyspaceAttempt(keyspace, ksFuture);

    // Check for an existing keyspace attempt.
    while (true) {
      existingAttempt = targetKeyspace.get();
      // if existing attempts' keyspace matches what we are trying to set, use it.
      if (attempt.equals(existingAttempt)) {
        return existingAttempt.future;
      } else if (!existingAttempt.future.isDone()) {
        // If the existing attempt is still in flight, fail this attempt immediately.
        ksFuture.setException(
            new DriverException(
                "Aborting attempt to set keyspace to '"
                    + keyspace
                    + "' since there is already an in flight attempt to set keyspace to '"
                    + existingAttempt.keyspace
                    + "'.  "
                    + "This can happen if you try to USE different keyspaces from the same session simultaneously."));
        return ksFuture;
      } else if (targetKeyspace.compareAndSet(existingAttempt, attempt)) {
        // Otherwise, if the existing attempt is done, start a new set keyspace attempt for the new
        // keyspace.
        logger.debug("{} Setting keyspace {}", this, keyspace);
        // Note: we quote the keyspace below, because the name is the one coming from Cassandra, so
        // it's in the right case already
        Future future = write(new Requests.Query("USE \"" + keyspace + '"'));
        GuavaCompatibility.INSTANCE.addCallback(
            future,
            new FutureCallback() {

              @Override
              public void onSuccess(Message.Response response) {
                if (response instanceof SetKeyspace) {
                  logger.debug("{} Keyspace set to {}", Connection.this, keyspace);
                  ksFuture.set(Connection.this);
                } else {
                  // Unset this attempt so new attempts may be made for the same keyspace.
                  targetKeyspace.compareAndSet(attempt, defaultKeyspaceAttempt);
                  if (response.type == ERROR) {
                    Responses.Error error = (Responses.Error) response;
                    ksFuture.setException(defunct(error.asException(endPoint)));
                  } else {
                    ksFuture.setException(
                        defunct(
                            new DriverInternalError(
                                "Unexpected response while setting keyspace: " + response)));
                  }
                }
              }

              @Override
              public void onFailure(Throwable t) {
                targetKeyspace.compareAndSet(attempt, defaultKeyspaceAttempt);
                ksFuture.setException(t);
              }
            },
            factory.manager.configuration.getPoolingOptions().getInitializationExecutor());

        return ksFuture;
      }
    }
  }

  /**
   * Write a request on this connection.
   *
   * @param request the request to send
   * @return a future on the server response
   * @throws ConnectionException if the connection is closed
   * @throws TransportException if an I/O error while sending the request
   */
  Future write(Message.Request request) throws ConnectionException, BusyConnectionException {
    Future future = new Future(request);
    write(future);
    return future;
  }

  ResponseHandler write(ResponseCallback callback)
      throws ConnectionException, BusyConnectionException {
    return write(callback, -1, true);
  }

  ResponseHandler write(
      ResponseCallback callback, long statementReadTimeoutMillis, boolean startTimeout)
      throws ConnectionException, BusyConnectionException {

    ResponseHandler handler = new ResponseHandler(this, statementReadTimeoutMillis, callback);
    dispatcher.add(handler);

    Message.Request request = callback.request().setStreamId(handler.streamId);

    /*
     * We check for close/defunct *after* having set the handler because closing/defuncting
     * will set their flag and then error out handler if need. So, by doing the check after
     * having set the handler, we guarantee that even if we race with defunct/close, we may
     * never leave a handler that won't get an answer or be errored out.
     */
    if (isDefunct.get()) {
      dispatcher.removeHandler(handler, true);
      throw new ConnectionException(endPoint, "Write attempt on defunct connection");
    }

    if (isClosed()) {
      dispatcher.removeHandler(handler, true);
      throw new ConnectionException(endPoint, "Connection has been closed");
    }

    logger.trace("{}, stream {}, writing request {}", this, request.getStreamId(), request);
    writer.incrementAndGet();

    if (DISABLE_COALESCING) {
      channel.writeAndFlush(request).addListener(writeHandler(request, handler));
    } else {
      flush(new FlushItem(channel, request, writeHandler(request, handler)));
    }
    if (startTimeout) handler.startTimeout();

    return handler;
  }

  private ChannelFutureListener writeHandler(
      final Message.Request request, final ResponseHandler handler) {
    return new ChannelFutureListener() {
      @Override
      public void operationComplete(ChannelFuture writeFuture) {

        writer.decrementAndGet();

        if (!writeFuture.isSuccess()) {
          logger.debug(
              "{}, stream {}, Error writing request {}",
              Connection.this,
              request.getStreamId(),
              request);
          // Remove this handler from the dispatcher so it don't get notified of the error
          // twice (we will fail that method already)
          dispatcher.removeHandler(handler, true);

          final ConnectionException ce;
          if (writeFuture.cause() instanceof java.nio.channels.ClosedChannelException) {
            ce = new TransportException(endPoint, "Error writing: Closed channel");
          } else {
            ce = new TransportException(endPoint, "Error writing", writeFuture.cause());
          }
          final long latency = System.nanoTime() - handler.startTime;
          // This handler is executed while holding the writeLock of the channel.
          // defunct might close the pool, which will close all of its connections; closing a
          // connection also
          // requires its writeLock.
          // Therefore if multiple connections in the same pool get a write error, they could
          // deadlock;
          // we run defunct on a separate thread to avoid that.
          ListeningExecutorService executor = factory.manager.executor;
          if (!executor.isShutdown())
            executor.execute(
                new Runnable() {
                  @Override
                  public void run() {
                    handler.callback.onException(
                        Connection.this, defunct(ce), latency, handler.retryCount);
                  }
                });
        } else {
          logger.trace(
              "{}, stream {}, request sent successfully", Connection.this, request.getStreamId());
        }
      }
    };
  }

  boolean hasOwner() {
    return this.ownerRef.get() != null;
  }

  /** @return whether the connection was already associated with an owner */
  boolean setOwner(Owner owner) {
    return ownerRef.compareAndSet(null, owner);
  }

  /**
   * If the connection is part of a pool, return it to the pool. The connection should generally not
   * be reused after that.
   */
  void release(boolean busy) {
    Owner owner = ownerRef.get();
    if (owner instanceof HostConnectionPool)
      ((HostConnectionPool) owner).returnConnection(this, busy);
  }

  void release() {
    release(false);
  }

  boolean isClosed() {
    return closeFuture.get() != null;
  }

  /**
   * Closes the connection: no new writes will be accepted after this method has returned.
   *
   * 

However, a closed connection might still have ongoing queries awaiting for their result. * When all these ongoing queries have completed, the underlying channel will be closed; we refer * to this final state as "terminated". * * @return a future that will complete once the connection has terminated. * @see #tryTerminate(boolean) */ CloseFuture closeAsync() { ConnectionCloseFuture future = new ConnectionCloseFuture(); if (!closeFuture.compareAndSet(null, future)) { // close had already been called, return the existing future return closeFuture.get(); } logger.debug("{} closing connection", this); // Only signal if defunct hasn't done it already if (signaled.compareAndSet(false, true)) { Host host = getHost(); if (host != null) { host.convictionPolicy.signalConnectionClosed(this); } } boolean terminated = tryTerminate(false); if (!terminated) { // The time by which all pending requests should have normally completed (use twice the read // timeout for a generous // estimate -- note that this does not cover the eventuality that read timeout is updated // dynamically, but we can live // with that). long terminateTime = System.currentTimeMillis() + 2 * factory.getReadTimeoutMillis(); factory.reaper.register(this, terminateTime); } return future; } private Host getHost() { Metadata metadata = factory.manager.metadata; Host host = metadata.getHost(endPoint); // During init the host might not be in metatada.hosts yet, try the contact points if (host == null) { host = metadata.getContactPoint(endPoint); } return host; } /** * Tries to terminate a closed connection, i.e. release system resources. * *

This is called both by "normal" code and by {@link Cluster.ConnectionReaper}. * * @param force whether to proceed if there are still outstanding requests. * @return whether the connection has actually terminated. * @see #closeAsync() */ boolean tryTerminate(boolean force) { assert isClosed(); ConnectionCloseFuture future = closeFuture.get(); if (future.isDone()) { logger.debug("{} has already terminated", this); return true; } else { if (force || dispatcher.pending.isEmpty()) { if (force) logger.warn( "Forcing termination of {}. This should not happen and is likely a bug, please report.", this); future.force(); return true; } else { logger.debug("Not terminating {}: there are still pending requests", this); return false; } } } @Override public String toString() { return String.format( "Connection[%s, inFlight=%d, closed=%b]", name, inFlight.get(), isClosed()); } static class Factory { final Timer timer; final EventLoopGroup eventLoopGroup; private final Class channelClass; private final ChannelGroup allChannels = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE); private final ConcurrentMap idGenerators = new ConcurrentHashMap(); final DefaultResponseHandler defaultHandler; final Cluster.Manager manager; final Cluster.ConnectionReaper reaper; final Configuration configuration; final AuthProvider authProvider; private volatile boolean isShutdown; volatile ProtocolVersion protocolVersion; private final NettyOptions nettyOptions; Factory(Cluster.Manager manager, Configuration configuration) { this.defaultHandler = manager; this.manager = manager; this.reaper = manager.reaper; this.configuration = configuration; this.authProvider = configuration.getProtocolOptions().getAuthProvider(); this.protocolVersion = configuration.getProtocolOptions().initialProtocolVersion; this.nettyOptions = configuration.getNettyOptions(); this.eventLoopGroup = nettyOptions.eventLoopGroup( manager .configuration .getThreadingOptions() .createThreadFactory(manager.clusterName, "nio-worker")); this.channelClass = nettyOptions.channelClass(); this.timer = nettyOptions.timer( manager .configuration .getThreadingOptions() .createThreadFactory(manager.clusterName, "timeouter")); } int getPort() { return configuration.getProtocolOptions().getPort(); } /** * Opens a new connection to the node this factory points to. * * @return the newly created (and initialized) connection. * @throws ConnectionException if connection attempt fails. */ Connection open(Host host) throws ConnectionException, InterruptedException, UnsupportedProtocolVersionException, ClusterNameMismatchException { EndPoint endPoint = host.getEndPoint(); if (isShutdown) throw new ConnectionException(endPoint, "Connection factory is shut down"); host.convictionPolicy.signalConnectionsOpening(1); Connection connection = new Connection(buildConnectionName(host), endPoint, this); // This method opens the connection synchronously, so wait until it's initialized try { connection.initAsync().get(); return connection; } catch (ExecutionException e) { throw launderAsyncInitException(e); } } /** Same as open, but associate the created connection to the provided connection pool. */ Connection open(HostConnectionPool pool) throws ConnectionException, InterruptedException, UnsupportedProtocolVersionException, ClusterNameMismatchException { pool.host.convictionPolicy.signalConnectionsOpening(1); Connection connection = new Connection(buildConnectionName(pool.host), pool.host.getEndPoint(), this, pool); try { connection.initAsync().get(); return connection; } catch (ExecutionException e) { throw launderAsyncInitException(e); } } /** * Creates new connections and associate them to the provided connection pool, but does not * start them. */ List newConnections(HostConnectionPool pool, int count) { pool.host.convictionPolicy.signalConnectionsOpening(count); List connections = Lists.newArrayListWithCapacity(count); for (int i = 0; i < count; i++) connections.add( new Connection(buildConnectionName(pool.host), pool.host.getEndPoint(), this, pool)); return connections; } private String buildConnectionName(Host host) { return host.getEndPoint().toString() + '-' + getIdGenerator(host).getAndIncrement(); } static RuntimeException launderAsyncInitException(ExecutionException e) throws ConnectionException, InterruptedException, UnsupportedProtocolVersionException, ClusterNameMismatchException { Throwable t = e.getCause(); if (t instanceof ConnectionException) throw (ConnectionException) t; if (t instanceof InterruptedException) throw (InterruptedException) t; if (t instanceof UnsupportedProtocolVersionException) throw (UnsupportedProtocolVersionException) t; if (t instanceof ClusterNameMismatchException) throw (ClusterNameMismatchException) t; if (t instanceof DriverException) throw (DriverException) t; if (t instanceof Error) throw (Error) t; return new RuntimeException("Unexpected exception during connection initialization", t); } private AtomicInteger getIdGenerator(Host host) { AtomicInteger g = idGenerators.get(host); if (g == null) { g = new AtomicInteger(1); AtomicInteger old = idGenerators.putIfAbsent(host, g); if (old != null) g = old; } return g; } long getReadTimeoutMillis() { return configuration.getSocketOptions().getReadTimeoutMillis(); } private Bootstrap newBootstrap() { Bootstrap b = new Bootstrap(); b.group(eventLoopGroup).channel(channelClass); SocketOptions options = configuration.getSocketOptions(); b.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, options.getConnectTimeoutMillis()); Boolean keepAlive = options.getKeepAlive(); if (keepAlive != null) b.option(ChannelOption.SO_KEEPALIVE, keepAlive); Boolean reuseAddress = options.getReuseAddress(); if (reuseAddress != null) b.option(ChannelOption.SO_REUSEADDR, reuseAddress); Integer soLinger = options.getSoLinger(); if (soLinger != null) b.option(ChannelOption.SO_LINGER, soLinger); Boolean tcpNoDelay = options.getTcpNoDelay(); if (tcpNoDelay != null) b.option(ChannelOption.TCP_NODELAY, tcpNoDelay); Integer receiveBufferSize = options.getReceiveBufferSize(); if (receiveBufferSize != null) b.option(ChannelOption.SO_RCVBUF, receiveBufferSize); Integer sendBufferSize = options.getSendBufferSize(); if (sendBufferSize != null) b.option(ChannelOption.SO_SNDBUF, sendBufferSize); nettyOptions.afterBootstrapInitialized(b); return b; } void shutdown() { // Make sure we skip creating connection from now on. isShutdown = true; // All channels should be closed already, we call this just to be sure. And we know // we're not on an I/O thread or anything, so just call await. allChannels.close().awaitUninterruptibly(); nettyOptions.onClusterClose(eventLoopGroup); nettyOptions.onClusterClose(timer); } } private static final class Flusher implements Runnable { final WeakReference eventLoopRef; final Queue queued = new ConcurrentLinkedQueue(); final AtomicBoolean running = new AtomicBoolean(false); final HashSet channels = new HashSet(); private Flusher(EventLoop eventLoop) { this.eventLoopRef = new WeakReference(eventLoop); } void start() { if (!running.get() && running.compareAndSet(false, true)) { EventLoop eventLoop = eventLoopRef.get(); if (eventLoop != null) eventLoop.execute(this); } } @Override public void run() { FlushItem flush; while (null != (flush = queued.poll())) { Channel channel = flush.channel; if (channel.isActive()) { channels.add(channel); channel.write(flush.request).addListener(flush.listener); } } // Always flush what we have (don't artificially delay to try to coalesce more messages) for (Channel channel : channels) channel.flush(); channels.clear(); // either reschedule or cancel running.set(false); if (queued.isEmpty() || !running.compareAndSet(false, true)) return; EventLoop eventLoop = eventLoopRef.get(); if (eventLoop != null && !eventLoop.isShuttingDown()) { if (FLUSHER_SCHEDULE_PERIOD_NS > 0) { eventLoop.schedule(this, FLUSHER_SCHEDULE_PERIOD_NS, TimeUnit.NANOSECONDS); } else { eventLoop.execute(this); } } } } private static final ConcurrentMap flusherLookup = new MapMaker().concurrencyLevel(16).weakKeys().makeMap(); private static class FlushItem { final Channel channel; final Object request; final ChannelFutureListener listener; private FlushItem(Channel channel, Object request, ChannelFutureListener listener) { this.channel = channel; this.request = request; this.listener = listener; } } private void flush(FlushItem item) { EventLoop loop = item.channel.eventLoop(); Flusher flusher = flusherLookup.get(loop); if (flusher == null) { Flusher alt = flusherLookup.putIfAbsent(loop, flusher = new Flusher(loop)); if (alt != null) flusher = alt; } flusher.queued.add(item); flusher.start(); } class Dispatcher extends SimpleChannelInboundHandler { final StreamIdGenerator streamIdHandler; private final ConcurrentMap pending = new ConcurrentHashMap(); Dispatcher() { ProtocolVersion protocolVersion = factory.protocolVersion; if (protocolVersion == null) { // This happens for the first control connection because the protocol version has not been // negotiated yet. protocolVersion = ProtocolVersion.V2; } streamIdHandler = StreamIdGenerator.newInstance(protocolVersion); } void add(ResponseHandler handler) { ResponseHandler old = pending.put(handler.streamId, handler); assert old == null; } void removeHandler(ResponseHandler handler, boolean releaseStreamId) { // If we don't release the ID, mark first so that we can rely later on the fact that if // we receive a response for an ID with no handler, it's that this ID has been marked. if (!releaseStreamId) streamIdHandler.mark(handler.streamId); // If a RequestHandler is cancelled right when the response arrives, this method (called with // releaseStreamId=false) will race with messageReceived. // messageReceived could have already released the streamId, which could have already been // reused by another request. We must not remove the handler // if it's not ours, because that would cause the other request to hang forever. boolean removed = pending.remove(handler.streamId, handler); if (!removed) { // We raced, so if we marked the streamId above, that was wrong. if (!releaseStreamId) streamIdHandler.unmark(handler.streamId); return; } handler.cancelTimeout(); if (releaseStreamId) streamIdHandler.release(handler.streamId); if (isClosed()) tryTerminate(false); } @Override protected void channelRead0(ChannelHandlerContext ctx, Message.Response response) throws Exception { int streamId = response.getStreamId(); if (logger.isTraceEnabled()) logger.trace( "{}, stream {}, received: {}", Connection.this, streamId, asDebugString(response)); if (streamId < 0) { factory.defaultHandler.handle(response); return; } ResponseHandler handler = pending.remove(streamId); streamIdHandler.release(streamId); if (handler == null) { /* * During normal operation, we should not receive responses for which we don't have a handler. There is * two cases however where this can happen: * 1) The connection has been defuncted due to some internal error and we've raced between removing the * handler and actually closing the connection; since the original error has been logged, we're fine * ignoring this completely. * 2) This request has timed out. In that case, we've already switched to another host (or errored out * to the user). So log it for debugging purpose, but it's fine ignoring otherwise. */ streamIdHandler.unmark(streamId); if (logger.isDebugEnabled()) logger.debug( "{} Response received on stream {} but no handler set anymore (either the request has " + "timed out or it was closed due to another error). Received message is {}", Connection.this, streamId, asDebugString(response)); return; } handler.cancelTimeout(); handler.callback.onSet( Connection.this, response, System.nanoTime() - handler.startTime, handler.retryCount); // If we happen to be closed and we're the last outstanding request, we need to terminate the // connection // (note: this is racy as the signaling can be called more than once, but that's not a // problem) if (isClosed()) tryTerminate(false); } @Override public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception { if (isInitialized && !isClosed() && evt instanceof IdleStateEvent && ((IdleStateEvent) evt).state() == READER_IDLE) { logger.debug( "{} was inactive for {} seconds, sending heartbeat", Connection.this, factory.configuration.getPoolingOptions().getHeartbeatIntervalSeconds()); write(HEARTBEAT_CALLBACK); } } // Make sure we don't print huge responses in debug/error logs. private String asDebugString(Object obj) { if (obj == null) return "null"; String msg = obj.toString(); if (msg.length() < 500) return msg; return msg.substring(0, 500) + "... [message of size " + msg.length() + " truncated]"; } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { if (logger.isDebugEnabled()) logger.debug(String.format("%s connection error", Connection.this), cause); // Ignore exception while writing, this will be handled by write() directly if (writer.get() > 0) return; if (cause instanceof DecoderException) { Throwable error = cause.getCause(); // Special case, if we encountered a FrameTooLongException, raise exception on handler and // don't defunct it since // the connection is in an ok state. if (error instanceof FrameTooLongException) { FrameTooLongException ftle = (FrameTooLongException) error; int streamId = ftle.getStreamId(); ResponseHandler handler = pending.remove(streamId); streamIdHandler.release(streamId); if (handler == null) { streamIdHandler.unmark(streamId); if (logger.isDebugEnabled()) logger.debug( "{} FrameTooLongException received on stream {} but no handler set anymore (either the request has " + "timed out or it was closed due to another error).", Connection.this, streamId); return; } handler.cancelTimeout(); handler.callback.onException( Connection.this, ftle, System.nanoTime() - handler.startTime, handler.retryCount); return; } else if (error instanceof CrcMismatchException) { // Fall back to the defunct call below, but we want a clear warning in the logs logger.warn("CRC mismatch while decoding a response, dropping the connection", error); } } defunct( new TransportException( endPoint, String.format("Unexpected exception triggered (%s)", cause), cause)); } void errorOutAllHandler(ConnectionException ce) { Iterator iter = pending.values().iterator(); while (iter.hasNext()) { ResponseHandler handler = iter.next(); handler.cancelTimeout(); handler.callback.onException( Connection.this, ce, System.nanoTime() - handler.startTime, handler.retryCount); iter.remove(); } } } private class ChannelCloseListener implements ChannelFutureListener { @Override public void operationComplete(ChannelFuture future) throws Exception { // If we've closed the channel client side then we don't really want to defunct the // connection, but // if there is remaining thread waiting on us, we still want to wake them up if (!isInitialized || isClosed()) { dispatcher.errorOutAllHandler(new TransportException(endPoint, "Channel has been closed")); // we still want to force so that the future completes Connection.this.closeAsync().force(); } else defunct(new TransportException(endPoint, "Channel has been closed")); } } private static final ResponseCallback HEARTBEAT_CALLBACK = new ResponseCallback() { @Override public Message.Request request() { return new Requests.Options(); } @Override public int retryCount() { return 0; // no retries here } @Override public void onSet( Connection connection, Message.Response response, long latency, int retryCount) { switch (response.type) { case SUPPORTED: logger.debug("{} heartbeat query succeeded", connection); break; default: fail( connection, new ConnectionException( connection.endPoint, "Unexpected heartbeat response: " + response)); } } @Override public void onException( Connection connection, Exception exception, long latency, int retryCount) { // Nothing to do: the connection is already defunct if we arrive here } @Override public boolean onTimeout(Connection connection, long latency, int retryCount) { fail( connection, new ConnectionException(connection.endPoint, "Heartbeat query timed out")); return true; } private void fail(Connection connection, Exception e) { connection.defunct(e); } }; private class ConnectionCloseFuture extends CloseFuture { @Override public ConnectionCloseFuture force() { // Note: we must not call releaseExternalResources on the bootstrap, because this shutdown the // executors, which are shared // This method can be thrown during initialization, at which point channel is not yet set. // This is ok. if (channel == null) { set(null); return this; } // We're going to close this channel. If anyone is waiting on that connection, we should // defunct it otherwise it'll wait // forever. In general this won't happen since we get there only when all ongoing query are // done, but this can happen // if the shutdown is forced. This is a no-op if there is no handler set anymore. dispatcher.errorOutAllHandler(new TransportException(endPoint, "Connection has been closed")); ChannelFuture future = channel.close(); future.addListener( new ChannelFutureListener() { @Override public void operationComplete(ChannelFuture future) { factory.allChannels.remove(channel); if (future.cause() != null) { logger.warn("Error closing channel", future.cause()); ConnectionCloseFuture.this.setException(future.cause()); } else ConnectionCloseFuture.this.set(null); } }); return this; } } private class SetKeyspaceAttempt { private final String keyspace; private final ListenableFuture future; SetKeyspaceAttempt(String keyspace, ListenableFuture future) { this.keyspace = keyspace; this.future = future; } @Override public boolean equals(Object o) { if (this == o) return true; if (!(o instanceof SetKeyspaceAttempt)) return false; SetKeyspaceAttempt that = (SetKeyspaceAttempt) o; return keyspace != null ? keyspace.equals(that.keyspace) : that.keyspace == null; } @Override public int hashCode() { return keyspace != null ? keyspace.hashCode() : 0; } } static class Future extends AbstractFuture implements RequestHandler.Callback { private final Message.Request request; private volatile EndPoint endPoint; Future(Message.Request request) { this.request = request; } @Override public void register(RequestHandler handler) { // noop, we don't care about the handler here so far } @Override public Message.Request request() { return request; } @Override public int retryCount() { // This is ignored, as there is no retry logic in this class return 0; } @Override public void onSet( Connection connection, Message.Response response, ExecutionInfo info, Statement statement, long latency) { onSet(connection, response, latency, 0); } @Override public void onSet( Connection connection, Message.Response response, long latency, int retryCount) { this.endPoint = connection.endPoint; super.set(response); } @Override public void onException( Connection connection, Exception exception, long latency, int retryCount) { // If all nodes are down, we will get a null connection here. This is fine, if we have // an exception, consumers shouldn't assume the address is not null. if (connection != null) this.endPoint = connection.endPoint; super.setException(exception); } @Override public boolean onTimeout(Connection connection, long latency, int retryCount) { assert connection != null; // We always timeout on a specific connection, so this shouldn't be null this.endPoint = connection.endPoint; return super.setException(new OperationTimedOutException(connection.endPoint)); } EndPoint getEndPoint() { return endPoint; } } interface ResponseCallback { Message.Request request(); int retryCount(); void onSet(Connection connection, Message.Response response, long latency, int retryCount); void onException(Connection connection, Exception exception, long latency, int retryCount); boolean onTimeout(Connection connection, long latency, int retryCount); } static class ResponseHandler { final Connection connection; final int streamId; final ResponseCallback callback; final int retryCount; private final long readTimeoutMillis; private final long startTime; private volatile Timeout timeout; private final AtomicBoolean isCancelled = new AtomicBoolean(); ResponseHandler( Connection connection, long statementReadTimeoutMillis, ResponseCallback callback) throws BusyConnectionException { this.connection = connection; this.readTimeoutMillis = (statementReadTimeoutMillis >= 0) ? statementReadTimeoutMillis : connection.factory.getReadTimeoutMillis(); this.streamId = connection.dispatcher.streamIdHandler.next(); if (streamId == -1) throw new BusyConnectionException(connection.endPoint); this.callback = callback; this.retryCount = callback.retryCount(); this.startTime = System.nanoTime(); } void startTimeout() { this.timeout = this.readTimeoutMillis <= 0 ? null : connection.factory.timer.newTimeout( onTimeoutTask(), this.readTimeoutMillis, TimeUnit.MILLISECONDS); } void cancelTimeout() { if (timeout != null) timeout.cancel(); } boolean cancelHandler() { if (!isCancelled.compareAndSet(false, true)) return false; // We haven't really received a response: we want to remove the handle because we gave up on // that // request and there is no point in holding the handler, but we don't release the streamId. If // we // were, a new request could reuse that ID but get the answer to the request we just gave up // on instead // of its own answer, and we would have no way to detect that. connection.dispatcher.removeHandler(this, false); return true; } private TimerTask onTimeoutTask() { return new TimerTask() { @Override public void run(Timeout timeout) { if (callback.onTimeout(connection, System.nanoTime() - startTime, retryCount)) cancelHandler(); } }; } } interface DefaultResponseHandler { void handle(Message.Response response); } private static class Initializer extends ChannelInitializer { // Stateless handlers private static final Message.ProtocolDecoder messageDecoder = new Message.ProtocolDecoder(); private static final Message.ProtocolEncoder messageEncoderV1 = new Message.ProtocolEncoder(ProtocolVersion.V1); private static final Message.ProtocolEncoder messageEncoderV2 = new Message.ProtocolEncoder(ProtocolVersion.V2); private static final Message.ProtocolEncoder messageEncoderV3 = new Message.ProtocolEncoder(ProtocolVersion.V3); private static final Message.ProtocolEncoder messageEncoderV4 = new Message.ProtocolEncoder(ProtocolVersion.V4); private static final Message.ProtocolEncoder messageEncoderV5 = new Message.ProtocolEncoder(ProtocolVersion.V5); private static final Message.ProtocolEncoder messageEncoderV6 = new Message.ProtocolEncoder(ProtocolVersion.V6); private static final Frame.Encoder frameEncoder = new Frame.Encoder(); private final ProtocolVersion protocolVersion; private final Connection connection; private final FrameCompressor compressor; private final SSLOptions sslOptions; private final NettyOptions nettyOptions; private final ChannelHandler idleStateHandler; private final CodecRegistry codecRegistry; private final Metrics metrics; Initializer( Connection connection, ProtocolVersion protocolVersion, FrameCompressor compressor, SSLOptions sslOptions, int heartBeatIntervalSeconds, NettyOptions nettyOptions, CodecRegistry codecRegistry, Metrics metrics) { this.connection = connection; this.protocolVersion = protocolVersion; this.compressor = compressor; this.sslOptions = sslOptions; this.nettyOptions = nettyOptions; this.codecRegistry = codecRegistry; this.idleStateHandler = new IdleStateHandler(heartBeatIntervalSeconds, 0, 0); this.metrics = metrics; } @Override protected void initChannel(SocketChannel channel) throws Exception { // set the codec registry so that it can be accessed by ProtocolDecoder channel.attr(Message.CODEC_REGISTRY_ATTRIBUTE_KEY).set(codecRegistry); ChannelPipeline pipeline = channel.pipeline(); if (sslOptions != null) { SslHandler handler; if (sslOptions instanceof ExtendedRemoteEndpointAwareSslOptions) { handler = ((ExtendedRemoteEndpointAwareSslOptions) sslOptions) .newSSLHandler(channel, connection.endPoint); } else if (sslOptions instanceof RemoteEndpointAwareSSLOptions) { handler = ((RemoteEndpointAwareSSLOptions) sslOptions) .newSSLHandler(channel, connection.endPoint.resolve()); } else { handler = sslOptions.newSSLHandler(channel); } pipeline.addLast("ssl", handler); } // pipeline.addLast("debug", new LoggingHandler(LogLevel.INFO)); if (metrics != null) { pipeline.addLast( "inboundTrafficMeter", new InboundTrafficMeter(metrics.getBytesReceived())); pipeline.addLast("outboundTrafficMeter", new OutboundTrafficMeter(metrics.getBytesSent())); } pipeline.addLast("frameDecoder", new Frame.Decoder()); pipeline.addLast("frameEncoder", frameEncoder); pipeline.addLast("framingFormatHandler", new FramingFormatHandler(connection.factory)); if (compressor != null // Frame-level compression is only done in legacy protocol versions. In V5 and above, it // happens at a higher level ("segment" that groups multiple frames), so never install // those handlers. && protocolVersion.compareTo(ProtocolVersion.V5) < 0) { pipeline.addLast("frameDecompressor", new Frame.Decompressor(compressor)); pipeline.addLast("frameCompressor", new Frame.Compressor(compressor)); } pipeline.addLast("messageDecoder", messageDecoder); pipeline.addLast("messageEncoder", messageEncoderFor(protocolVersion)); pipeline.addLast("idleStateHandler", idleStateHandler); pipeline.addLast("dispatcher", connection.dispatcher); nettyOptions.afterChannelInitialized(channel); } private Message.ProtocolEncoder messageEncoderFor(ProtocolVersion version) { switch (version) { case V1: return messageEncoderV1; case V2: return messageEncoderV2; case V3: return messageEncoderV3; case V4: return messageEncoderV4; case V5: return messageEncoderV5; case V6: return messageEncoderV6; default: throw new DriverInternalError("Unsupported protocol version " + protocolVersion); } } } /** A component that "owns" a connection, and should be notified when it dies. */ interface Owner { void onConnectionDefunct(Connection connection); } }





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