path: root/src/psyc/psyc_api.c

/*
 * This file is part of GNUnet
 * (C) 2013 Christian Grothoff (and other contributing authors)
 *
 * GNUnet is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 3, or (at your
 * option) any later version.
 *
 * GNUnet is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNUnet; see the file COPYING.  If not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * @file psyc/psyc_api.c
 * @brief PSYC service; high-level access to the PSYC protocol
 *        note that clients of this API are NOT expected to
 *        understand the PSYC message format, only the semantics!
 *        Parsing (and serializing) the PSYC stream format is done
 *        within the implementation of the libgnunetpsyc library,
 *        and this API deliberately exposes as little as possible
 *        of the actual data stream format to the application!
 * @author Gabor X Toth
 */

#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_env_lib.h"
#include "gnunet_psyc_service.h"
#include "psyc.h"

#define LOG(kind,...) GNUNET_log_from (kind, "psyc-api",__VA_ARGS__)


struct OperationHandle
{
  struct OperationHandle *prev;
  struct OperationHandle *next;
  const struct GNUNET_MessageHeader *msg;
};

/**
 * Handle to access PSYC channel operations for both the master and slaves.
 */
struct GNUNET_PSYC_Channel
{
  /**
   * Configuration to use.
   */
  const struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Socket (if available).
   */
  struct GNUNET_CLIENT_Connection *client;

  /**
   * Currently pending transmission request, or NULL for none.
   */
  struct GNUNET_CLIENT_TransmitHandle *th;

  /**
   * Head of operations to transmit.
   */
  struct OperationHandle *transmit_head;

  /**
   * Tail of operations to transmit.
   */
  struct OperationHandle *transmit_tail;

  /**
   * Message to send on reconnect.
   */
  struct GNUNET_MessageHeader *reconnect_msg;

  /**
   * Task doing exponential back-off trying to reconnect.
   */
  GNUNET_SCHEDULER_TaskIdentifier reconnect_task;

  /**
   * Time for next connect retry.
   */
  struct GNUNET_TIME_Relative reconnect_delay;

  GNUNET_PSYC_Method method_cb;

  GNUNET_PSYC_JoinCallback join_cb;

  void *cb_cls;

  /**
   * Are we polling for incoming messages right now?
   */
  int in_receive;

  /**
   * Are we currently transmitting a message?
   */
  int in_transmit;

  /**
   * Is this a master or slave channel?
   */
  int is_master;

  /**
   * Buffer space available for transmitting the next data fragment.
   */
  uint16_t tmit_buf_avail;
};


/**
 * Handle for a pending PSYC transmission operation.
 */
struct GNUNET_PSYC_MasterTransmitHandle
{
  struct GNUNET_PSYC_Master *master;
  GNUNET_PSYC_MasterTransmitNotify notify;
  void *notify_cls;
  enum GNUNET_PSYC_DataStatus status;
};


/**
 * Handle for the master of a PSYC channel.
 */
struct GNUNET_PSYC_Master
{
  struct GNUNET_PSYC_Channel ch;

  struct GNUNET_PSYC_MasterTransmitHandle *tmit;

  GNUNET_PSYC_MasterStartCallback start_cb;

  uint64_t max_message_id;
};


/**
 * Handle for a PSYC channel slave.
 */
struct GNUNET_PSYC_Slave
{
  struct GNUNET_PSYC_Channel ch;
};


/**
 * Handle that identifies a join request.
 *
 * Used to match calls to #GNUNET_PSYC_JoinCallback to the
 * corresponding calls to GNUNET_PSYC_join_decision().
 */
struct GNUNET_PSYC_JoinHandle
{

};


/**
 * Handle for a pending PSYC transmission operation.
 */
struct GNUNET_PSYC_SlaveTransmitHandle
{

};


/**
 * Handle to a story telling operation.
 */
struct GNUNET_PSYC_Story
{

};


/**
 * Handle for a state query operation.
 */
struct GNUNET_PSYC_StateQuery
{

};


/**
 * Try again to connect to the PSYC service.
 *
 * @param cls Handle to the PSYC service.
 * @param tc Scheduler context
 */
static void
reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);


/**
 * Reschedule a connect attempt to the service.
 *
 * @param h transport service to reconnect
 */
static void
reschedule_connect (struct GNUNET_PSYC_Channel *c)
{
  GNUNET_assert (c->reconnect_task == GNUNET_SCHEDULER_NO_TASK);

  if (NULL != c->th)
  {
    GNUNET_CLIENT_notify_transmit_ready_cancel (c->th);
    c->th = NULL;
  }
  if (NULL != c->client)
  {
    GNUNET_CLIENT_disconnect (c->client);
    c->client = NULL;
  }
  c->in_receive = GNUNET_NO;
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Scheduling task to reconnect to PSYC service in %s.\n",
       GNUNET_STRINGS_relative_time_to_string (c->reconnect_delay, GNUNET_YES));
  c->reconnect_task =
      GNUNET_SCHEDULER_add_delayed (c->reconnect_delay, &reconnect, c);
  c->reconnect_delay = GNUNET_TIME_STD_BACKOFF (c->reconnect_delay);
}


/**
 * Schedule transmission of the next message from our queue.
 *
 * @param h PSYC handle
 */
static void
transmit_next (struct GNUNET_PSYC_Channel *c);


void
master_transmit_data (struct GNUNET_PSYC_Master *mst)
{
  struct GNUNET_PSYC_Channel *ch = &mst->ch;
  size_t data_size = ch->tmit_buf_avail;
  struct GNUNET_PSYC_MessageData *pdata;
  </