libzmq/src/norm_engine.hpp

#ifndef __ZMQ_NORM_ENGINE_HPP_INCLUDED__
#define __ZMQ_NORM_ENGINE_HPP_INCLUDED__

#if defined ZMQ_HAVE_NORM

#include "io_object.hpp"
#include "i_engine.hpp"
#include "options.hpp"
#include "v2_decoder.hpp"
#include "v2_encoder.hpp"

#include <normApi.h>

namespace zmq
{
class io_thread_t;
class msg_t;
class session_base_t;

class norm_engine_t : public io_object_t, public i_engine
{
  public:
    norm_engine_t (zmq::io_thread_t *parent_, const options_t &options_);
    ~norm_engine_t ();

    // create NORM instance, session, etc
    int init (const char *network_, bool send, bool recv);
    void shutdown ();

    //  i_engine interface implementation.
    //  Plug the engine to the session.
    virtual void plug (zmq::io_thread_t *io_thread_,
                       class session_base_t *session_);

    //  Terminate and deallocate the engine. Note that 'detached'
    //  events are not fired on termination.
    virtual void terminate ();

    //  This method is called by the session to signalise that more
    //  messages can be written to the pipe.
    virtual bool restart_input ();

    //  This method is called by the session to signalise that there
    //  are messages to send available.
    virtual void restart_output ();

    virtual void zap_msg_available (){};

    virtual const endpoint_uri_pair_t &get_endpoint () const;

    // i_poll_events interface implementation.
    // (we only need in_event() for NormEvent notification)
    // (i.e., don't have any output events or timers (yet))
    void in_event ();

  private:
    void unplug ();
    void send_data ();
    void recv_data (NormObjectHandle stream);


    enum
    {
        BUFFER_SIZE = 2048
    };

    // Used to keep track of streams from multiple senders
    class NormRxStreamState
    {
      public:
        NormRxStreamState (NormObjectHandle normStream,
                           int64_t maxMsgSize,
                           bool zeroCopy);
        ~NormRxStreamState ();

        NormObjectHandle GetStreamHandle () const { return norm_stream; }

        bool Init ();

        void SetRxReady (bool state) { rx_ready = state; }
        bool IsRxReady () const { return rx_ready; }

        void SetSync (bool state) { in_sync = state; }
        bool InSync () const { return in_sync; }

        // These are used to feed data to decoder
        // and its underlying "msg" buffer
        char *AccessBuffer () { return (char *) (buffer_ptr + buffer_count); }
        size_t GetBytesNeeded () const { return buffer_size - buffer_count; }
        void IncrementBufferCount (size_t count) { buffer_count += count; }
        msg_t *AccessMsg () { return zmq_decoder->msg (); }
        // This invokes the decoder "decode" method
        // returning 0 if more data is needed,
        // 1 if the message is complete, If an error
        // occurs the 'sync' is dropped and the
        // decoder re-initialized
        int Decode ();

        class List
        {
          public:
            List ();
            ~List ();

            void Append (NormRxStreamState &item);
            void Remove (NormRxStreamState &item);

            bool IsEmpty () const { return NULL == head; }

            void Destroy ();

            class Iterator
            {
              public:
                Iterator (const List &list);
                NormRxStreamState *GetNextItem ();

              private:
                NormRxStreamState *next_item;
            };
            friend class Iterator;

          private:
            NormRxStreamState *head;
            NormRxStreamState *tail;

        }; // end class zmq::norm_engine_t::NormRxStreamState::List

        friend class List;

        List *AccessList () { return list; }


      private:
        NormObjectHandle norm_stream;
        int64_t max_msg_size;
        bool zero_copy;
        bool in_sync;
        bool rx_ready;
        v2_decoder_t *zmq_decoder;
        bool skip_norm_sync;
        unsigned char *buffer_ptr;
        size_t buffer_size;
        size_t buffer_count;

        NormRxStreamState *prev;
        NormRxStreamState *next;
        NormRxStreamState::List *list;

    }; // end class zmq::norm_engine_t::NormRxStreamState

    const endpoint_uri_pair_t _empty_endpoint;

    session_base_t *zmq_session;
    options_t options;
    NormInstanceHandle norm_instance;
    handle_t norm_descriptor_handle;
    NormSessionHandle norm_session;
    bool is_sender;
    bool is_receiver;
    // Sender state
    msg_t tx_msg;
    v2_encoder_t zmq_encoder; // for tx messages (we use v2 for now)
    NormObjectHandle norm_tx_stream;
    bool tx_first_msg;
    bool tx_more_bit;
    bool zmq_output_ready; // zmq has msg(s) to send
    bool norm_tx_ready;    // norm has tx queue vacancy
    // TBD - maybe don't need buffer if can access zmq message buffer directly?
    char tx_buffer[BUFFER_SIZE];
    unsigned int tx_index;
    unsigned int tx_len;

    // Receiver state
    // Lists of norm rx streams from remote senders
    bool zmq_input_ready; // zmq ready to receive msg(s)
    NormRxStreamState::List
      rx_pending_list; // rx streams waiting for data reception
    NormRxStreamState::List
      rx_ready_list; // rx streams ready for NormStreamRead()
    NormRxStreamState::List
      msg_ready_list; // rx streams w/ msg ready for push to zmq


}; // end class norm_engine_t
}

#endif // ZMQ_HAVE_NORM

#endif // !__ZMQ_NORM_ENGINE_HPP_INCLUDED__