bb_blackboard.cpp

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#include "bb_blackboard.h"

#include "er_errors.h"

typedef struct {
  enum bb_DataType dt;
  bb_Closure cb;
} Registrant;

struct _bb_Blackboard
{
  bb_Board board; // any board data
  GSList* reg; // of Registrant
};

extern "C"
bb_Board* bb_Blackboard_board(bb_Blackboard* self)
{
  return &(self->board);
}

extern "C"
bb_Blackboard* bb_Blackboard_new(GError** error)
{
  bb_Blackboard* self = g_try_new0(bb_Blackboard, 1);
  if (G_UNLIKELY(!self)) {
    if (error) *error = gx_error_no_memory;
    return NULL;
  }
  // self->reg is left as NULL, meaning an empty list.
  return self;
}

static void Registrant_free(gpointer self, gpointer dummy)
{
  (void)dummy;
  g_slice_free(Registrant, self);
}

extern "C"
void bb_Blackboard_destroy(bb_Blackboard* self)
{
  if (self) {
    if (self->reg) {
      g_slist_foreach(self->reg, Registrant_free, NULL);
      g_slist_free(self->reg);
    }
    g_free(self);
  }
}

static void Registrant_free(Registrant* self)
{
  if (self)
    g_slice_free(Registrant, self);
}

extern "C"
gboolean bb_Blackboard_register(bb_Blackboard* self,
        enum bb_DataType dt,
        bb_Closure cb,
        GError** error)
{
  Registrant* elem = NULL;

  SET_TRAP_OOM(goto fail);
  elem = g_slice_new(Registrant);
  elem->dt = dt;
  elem->cb = cb;
  self->reg = g_slist_prepend(self->reg, elem);
  UNSET_TRAP_OOM();

  return TRUE;

#if HAVE_TRAP_OOM
 fail:
  Registrant_free(elem);
  if (error) *error = gx_error_no_memory;
  return FALSE;
#else
  (void)error;
#endif
}

extern "C"
void bb_Blackboard_unregister(bb_Blackboard* self,
            bb_Closure cb)
{
  GSList* plink = NULL; // previous in chain (if any)
  GSList* link = self->reg;
  while (link != NULL) {
    Registrant* elem = (Registrant*)link->data;
    if ((elem->cb.changed == cb.changed) &&
  (elem->cb.arg == cb.arg)) {
      Registrant_free(elem);
      link = g_slist_delete_link(link, link);
      if (plink)
  plink->next = link;
      else
  self->reg = link;
    } else {
      plink = link;
      link = link->next;
    }
  }
}

extern "C"
void bb_Blackboard_notify(bb_Blackboard* self,
        enum bb_DataType dt,
        gpointer data, int len)
{
  for (GSList* link = self->reg; link != NULL; link = link->next) {
    Registrant* elem = (Registrant*)link->data;
    if (elem->dt == dt) {
      (*(elem->cb.changed))(self, dt, data, len, elem->cb.arg);
    }
  }
}

#if defined(__cplusplus) && defined(__SYMBIAN32__)

static void RHandleFunc(bb_Blackboard* self, enum bb_DataType dt,
      gpointer data, int len, gpointer arg)
{
  bb::RHandle* handle = (bb::RHandle*)arg;
  bb::MObserver* observer = handle->Observer();
  TRAPD(errCode, observer->BbChangedL(handle, dt, data, len));
  if (errCode)
    observer->BbLeave(errCode);
}

void bb::MObserver::BbLeave(TInt errCode)
{
  er_log_symbian(er_FATAL, errCode, "leave in bb::MObserver::BbChangedL");
}

bb::RHandle::RHandle() : iBoard(NULL), iObserver(NULL)
{
  iClosure.changed = RHandleFunc;
  iClosure.arg = this;
}

bb::RHandle::~RHandle()
{
  //logh();
  Unregister();
}

void bb::RHandle::Register(bb_Blackboard* aBoard,
         enum bb_DataType dt, 
         bb::MObserver* aObserver)
{
  iBoard = aBoard;
  iObserver = aObserver;

  GError* localError = NULL;
  if (!bb_Blackboard_register(iBoard, dt, iClosure, &localError)) {
    er_log_gerror(er_FATAL|er_FREE, localError, 
      "bb_Blackboard_register failed");
  }
}
    
void bb::RHandle::Unregister()
{
  if (iBoard)
    bb_Blackboard_unregister(iBoard, iClosure);
}

#endif

/**

Copyright 2010 Helsinki Institute for Information Technology (HIIT)
and the authors. All rights reserved.

Authors: Tero Hasu <tero.hasu@hut.fi>

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation files
(the "Software"), to deal in the Software without restriction,
including without limitation the rights to use, copy, modify, merge,
publish, distribute, sublicense, and/or sell copies of the Software,
and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

 **/