path: root/src/set/set_api.c

/*
     This file is part of GNUnet.
     Copyright (C) 2012-2014 GNUnet e.V.

     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., 51 Franklin Street, Fifth Floor,
     Boston, MA 02110-1301, USA.
*/
/**
 * @file set/set_api.c
 * @brief api for the set service
 * @author Florian Dold
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_client_lib.h"
#include "gnunet_set_service.h"
#include "set.h"


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

struct SetCopyRequest
{
  struct SetCopyRequest *next;

  struct SetCopyRequest *prev;

  void *cls;

  GNUNET_SET_CopyReadyCallback cb;
};

/**
 * Opaque handle to a set.
 */
struct GNUNET_SET_Handle
{
  /**
   * Client connected to the set service.
   */
  struct GNUNET_CLIENT_Connection *client;

  /**
   * Message queue for @e client.
   */
  struct GNUNET_MQ_Handle *mq;

  /**
   * Linked list of operations on the set.
   */
  struct GNUNET_SET_OperationHandle *ops_head;

  /**
   * Linked list of operations on the set.
   */
  struct GNUNET_SET_OperationHandle *ops_tail;

  /**
   * Callback for the current iteration over the set,
   * NULL if no iterator is active.
   */
  GNUNET_SET_ElementIterator iterator;

  /**
   * Closure for @e iterator
   */
  void *iterator_cls;

  /**
   * Should the set be destroyed once all operations are gone?
   */
  int destroy_requested;

  /**
   * Has the set become invalid (e.g. service died)?
   */
  int invalid;

  /**
   * Both client and service count the number of iterators
   * created so far to match replies with iterators.
   */
  uint16_t iteration_id;

  /**
   * Configuration, needed when creating (lazy) copies.
   */
  const struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Doubly linked list of copy requests.
   */
  struct SetCopyRequest *copy_req_head;

  /**
   * Doubly linked list of copy requests.
   */
  struct SetCopyRequest *copy_req_tail;
};


/**
 * Handle for a set operation request from another peer.
 */
struct GNUNET_SET_Request
{
  /**
   * Id of the request, used to identify the request when
   * accepting/rejecting it.
   */
  uint32_t accept_id;

  /**
   * Has the request been accepted already?
   * #GNUNET_YES/#GNUNET_NO
   */
  int accepted;
};


/**
 * Handle to an operation.  Only known to the service after committing
 * the handle with a set.
 */
struct GNUNET_SET_OperationHandle
{
  /**
   * Function to be called when we have a result,
   * or an error.
   */
  GNUNET_SET_ResultIterator result_cb;

  /**
   * Closure for @e result_cb.
   */
  void *result_cls;

  /**
   * Local set used for the operation,
   * NULL if no set has been provided by conclude yet.
   */
  struct GNUNET_SET_Handle *set;

  /**
   * Message sent to the server on calling conclude,
   * NULL if conclude has been called.
   */
  struct GNUNET_MQ_Envelope *conclude_mqm;

  /**
   * Address of the request if in the conclude message,
   * used to patch the request id into the message when the set is known.
   */
  uint32_t *request_id_addr;

  /**
   * Handles are kept in a linked list.
   */
  struct GNUNET_SET_OperationHandle *prev;

  /**
   * Handles are kept in a linked list.
   */
  struct GNUNET_SET_OperationHandle *next;

  /**
   * Request ID to identify the operation within the set.
   */
  uint32_t request_id;
};


/**
 * Opaque handle to a listen operation.
 */
struct GNUNET_SET_ListenHandle
{
  /**
   * Connection to the service.
   */
  struct GNUNET_CLIENT_Connection *client;

  /**
   * Message queue for the client.
   */
  struct GNUNET_MQ_Handle* mq;

  /**
   * Configuration handle for the listener, stored
   * here to be able to reconnect transparently on
   * connection failure.
   */
  const struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Function to call on a new incoming request,
   * or on error.
   */
  GNUNET_SET_ListenCallback listen_cb;

  /**
   * Closure for @e listen_cb.
   */
  void *listen_cls;

  /**
   * Application ID we listen for.
   */
  struct GNUNET_HashCode app_id;

  /**
   * Time to wait until we try to reconnect on failure.
   */
  struct GNUNET_TIME_Relative reconnect_backoff;

  /**
   * Task for reconnecting when the listener fails.
   */
  struct GNUNET_SCHEDULER_Task * reconnect_task;

  /**
   * Operation we listen for.
   */
  enum GNUNET_SET_OperationType operation;
};


/* mutual recursion with handle_copy_lazy */
static struct GNUNET_SET_Handle *
create_internal (const struct GNUNET_CONFIGURATION_Handle *cfg,
                 enum GNUNET_SET_OperationType op,
                 uint32_t *cookie);


/**
 * Handle element for iteration over the set.  Notifies the
 * iterator and sends an acknowledgement to the service.
 *
 * @param cls the `struct GNUNET_SET_Handle *`
 * @param mh the message
 */
static void
handle_copy_lazy (void *cls,
                  const struct GNUNET_MessageHeader *mh<