Package org.apache.activemq.artemis.core.protocol.core

Interface Channel

All Known Implementing Classes:
ChannelImpl
public interface Channel
A channel is a way of interleaving data meant for different endpoints over the same CoreRemotingConnection.

Any packet sent will have its channel id set to the specific channel sending so it can be routed to its correct channel when received by the CoreRemotingConnection. see Packet.setChannelID(long).

Each Channel should will forward any packets received to its ChannelHandler.

A Channel *does not* support concurrent access by more than one thread!

  • Method Details

    • getID

      long getID()
      Returns the id of this channel.
      Returns:
      the id of this channel

    • getReconnectID

      int getReconnectID()
      This number increases every time the channel reconnects successfully. This is used to guarantee the integrity of the channel on sequential commands such as large messages.

    • supports

      boolean supports(byte packetID)
      For protocol check

    • supports

      boolean supports(byte packetID, int version)
      For protocol check

    • requireSpecialVotingHandling

      default boolean requireSpecialVotingHandling()

    • send

      boolean send(Packet packet)
      Sends a packet on this channel.
      Parameters:
      packet - the packet to send
      Returns:
      false if the packet was rejected by an outgoing interceptor; true if the send was successful

    • send

      boolean send(Packet packet, int reconnectID)
      Sends a packet on this channel.
      Parameters:
      packet - the packet to send
      Returns:
      false if the packet was rejected by an outgoing interceptor; true if the send was successful

    • sendBatched

      boolean sendBatched(Packet packet)
      Sends a packet on this channel using batching algorithm if appropriate
      Parameters:
      packet - the packet to send
      Returns:
      false if the packet was rejected by an outgoing interceptor; true if the send was successful

    • flushConnection

      void flushConnection()
      Similarly to flushConnection on send(Packet, boolean), it requests any un-flushed previous sent packets to be flushed to the underlying connection.

      It can be a no-op in case of InVM transports, because they would likely to flush already on each send.

    • send

      boolean send(Packet packet, boolean flushConnection)
      Sends a packet on this channel, but request it to be flushed (along with the un-flushed previous ones) only iff flushConnection is true.
      Parameters:
      packet - the packet to send
      flushConnection - if true requests this packet and any un-flushed previous sent one to be flushed to the underlying connection
      Returns:
      false if the packet was rejected by an outgoing interceptor; true if the send was successful

    • sendAndFlush

      boolean sendAndFlush(Packet packet)
      Sends a packet on this channel and then blocks until it has been written to the connection.
      Parameters:
      packet - the packet to send
      Returns:
      false if the packet was rejected by an outgoing interceptor; true if the send was successful

    • sendBlocking

      Packet sendBlocking(Packet packet, byte expectedPacket) throws ActiveMQException
      Sends a packet on this channel and then blocks until a response is received or a timeout occurs.
      Parameters:
      packet - the packet to send
      expectedPacket - the packet being expected.
      Returns:
      the response
      Throws:
      ActiveMQException - if an error occurs during the send

    • sendBlocking

      Packet sendBlocking(Packet packet, int reconnectID, byte expectedPacket) throws ActiveMQException
      Sends a packet on this channel and then blocks until a response is received or a timeout occurs.
      Parameters:
      packet - the packet to send
      expectedPacket - the packet being expected.
      Returns:
      the response
      Throws:
      ActiveMQException - if an error occurs during the send

    • sendBlocking

      Packet sendBlocking(Packet packet, int reconnectID, byte expectedPacket, long timeout, boolean failOnTimeout) throws ActiveMQException
      Throws:
      ActiveMQException

    • setHandler

      void setHandler(ChannelHandler handler)
      Sets the ChannelHandler that this channel should forward received packets to.
      Parameters:
      handler - the handler

    • getHandler

      ChannelHandler getHandler()
      Gets the ChannelHandler that this channel should forward received packets to.
      Returns:
      the current channel handler

    • endOfBatch

      void endOfBatch()

    • close

      void close()
      Closes this channel.

      once closed no packets can be sent.

    • transferConnection

      void transferConnection(CoreRemotingConnection newConnection)
      Transfers the connection used by this channel to the one specified.

      All new packets will be sent via this connection.

      Parameters:
      newConnection - the new connection

    • replayCommands

      void replayCommands(int lastConfirmedCommandID)
      resends any packets that have not received confirmations yet.

      Typically called after a connection has been transferred.

      Parameters:
      lastConfirmedCommandID - the last confirmed packet

    • getLastConfirmedCommandID

      int getLastConfirmedCommandID()
      Returns the last confirmed packet command id.
      Returns:
      the last confirmed packet command id

    • isLocked

      boolean isLocked()
      queries if this channel is locked. This method is designed for use in monitoring of the system state, not for synchronization control.
      Returns:
      true it the channel is locked and false otherwise

    • lock

      void lock()
      locks the channel.

      While locked no packets can be sent or received

    • unlock

      void unlock()
      unlocks the channel.

    • returnBlocking

      void returnBlocking()
      forces any sendBlocking(Packet, byte) request to return with an exception.

    • returnBlocking

      void returnBlocking(Throwable cause)
      forces any sendBlocking(Packet, byte) request to return with an exception.

    • getLock

      Lock getLock()
      Returns the channel lock.
      Returns:
      the channel lock

    • getConnection

      CoreRemotingConnection getConnection()
      Returns the CoreRemotingConnection being used by the channel.
      Returns:
      the CoreRemotingConnection being used by the channel

    • confirm

      void confirm(Packet packet)
      sends a confirmation of a packet being received.
      Parameters:
      packet - the packet to confirm

    • setCommandConfirmationHandler

      void setCommandConfirmationHandler(CommandConfirmationHandler handler)
      sets the handler to use when a confirmation is received.
      Parameters:
      handler - the handler to call

    • setResponseHandler

      void setResponseHandler(ResponseHandler handler)

    • flushConfirmations

      void flushConfirmations()
      flushes any confirmations on to the connection.

    • handlePacket

      void handlePacket(Packet packet)
      Called by CoreRemotingConnection when a packet is received.

      This method should then call its ChannelHandler after appropriate processing of the packet

      Parameters:
      packet - the packet to process.

    • clearCommands

      void clearCommands()
      clears any commands from the cache that are yet to be confirmed.

    • getConfirmationWindowSize

      int getConfirmationWindowSize()
      Returns the confirmation window size this channel is using.
      Returns:
      the confirmation window size this channel is using

    • setTransferring

      void setTransferring(boolean transferring)
      notifies the channel if it is transferring its connection. When true it is illegal to send messages.
      Parameters:
      transferring - whether the channel is transferring