search.c

GNUnet是一个安全的点对点网络框架

  event.data.SearchStarted.sc.pos = pos;
  event.data.SearchStarted.sc.cctx = NULL;
  event.data.SearchStarted.searchURI = pos->uri;
  event.data.SearchStarted.anonymityLevel = pos->anonymityLevel;
  pos->cctx = pos->ctx->ecb (pos->ctx->ecbClosure, &event);
  if (GNUNET_ECRS_uri_test_ksk (uri))
    {
      /* (possibly boolean) keyword search */
      GNUNET_ECRS_uri_get_keywords_from_ksk (uri, &count_mandatory_keywords,
                                             pos);
      GNUNET_ECRS_uri_get_keywords_from_ksk (uri, &create_ecrs_search, pos);
      if (pos->start_time == 0)
        {
          /* failed to start ECRS searches */
          while (pos->searches != NULL)
            {
              srl = pos->searches;
              pos->searches = srl->next;
              GNUNET_ECRS_search_stop (srl->search);
              GNUNET_ECRS_uri_destroy (srl->uri);
              GNUNET_free (srl);
            }
        }
    }
  else
    {
      /* Namespace search, only one ECRS search */
      srl = GNUNET_malloc (sizeof (struct SearchRecordList));
      memset (srl, 0, sizeof (struct SearchRecordList));
      srl->uri = GNUNET_ECRS_uri_duplicate (uri);
      srl->search = GNUNET_ECRS_search_start (pos->ctx->ectx,
                                              pos->ctx->cfg,
                                              pos->probe_context,
                                              pos->uri,
                                              pos->anonymityLevel,
                                              &GNUNET_FSUI_search_progress_callback,
                                              pos);
      if (srl->search == NULL)
        {
          GNUNET_ECRS_uri_destroy (srl->uri);
          GNUNET_free (srl);
        }
      else
        {
          pos->searches = srl;
        }
    }
  if (pos->searches == NULL)
    {
      /* failed to initiate searches */
      event.type = GNUNET_FSUI_search_stopped;
      event.data.SearchStopped.sc.pos = pos;
      event.data.SearchStopped.sc.cctx = NULL;
      pos->cctx = pos->ctx->ecb (pos->ctx->ecbClosure, &event);
      GNUNET_ECRS_uri_destroy (pos->uri);
      GNUNET_free (pos);
      return NULL;
    }
  /* success, add to FSUI state */
  GNUNET_mutex_lock (ctx->lock);
  pos->next = ctx->activeSearches;
  ctx->activeSearches = pos;
  GNUNET_mutex_unlock (ctx->lock);
  return pos;
}

/**
 * Abort a search.
 */
int
GNUNET_FSUI_search_abort (struct GNUNET_FSUI_SearchList *sl)
{
  GNUNET_FSUI_Event event;
  struct SearchRecordList *rec;
  struct SearchResultList *srl;
  struct GNUNET_FSUI_Context *ctx;

  ctx = sl->ctx;
  GNUNET_mutex_lock (ctx->lock);
  if (sl->state == GNUNET_FSUI_PENDING)
    {
      sl->state = GNUNET_FSUI_ABORTED_JOINED;
      GNUNET_mutex_unlock (ctx->lock);
      return GNUNET_OK;
    }
  if (sl->state != GNUNET_FSUI_ACTIVE)
    {
      GNUNET_mutex_unlock (ctx->lock);
      return GNUNET_SYSERR;
    }
  sl->state = GNUNET_FSUI_ABORTED_JOINED;
  GNUNET_mutex_unlock (ctx->lock);
  /* must not hold lock while stopping ECRS searches! */
  while (sl->searches != NULL)
    {
      rec = sl->searches;
      GNUNET_ECRS_search_stop (rec->search);
      sl->searches = rec->next;
      GNUNET_ECRS_uri_destroy (rec->uri);
      GNUNET_free (rec);
    }
  /* clean up a bit more: we don't need matchingSearches
     anymore, and the pointers are now invalid! */
  GNUNET_mutex_lock (ctx->lock);
  srl = sl->resultsReceived;
  while (srl != NULL)
    {
      GNUNET_array_grow (srl->matchingSearches, srl->matchingSearchCount, 0);
      if (srl->test_download != NULL)
        {
          GNUNET_ECRS_file_download_partial_stop (srl->test_download);
          srl->test_download = NULL;
          ctx->active_probes--;
        }
      srl = srl->next;
    }
  event.type = GNUNET_FSUI_search_aborted;
  event.data.SearchAborted.sc.pos = sl;
  event.data.SearchAborted.sc.cctx = sl->cctx;
  sl->ctx->ecb (sl->ctx->ecbClosure, &event);
  GNUNET_mutex_unlock (ctx->lock);
  return GNUNET_OK;
}

/**
 * Pause a search.
 */
int
GNUNET_FSUI_search_pause (struct GNUNET_FSUI_SearchList *sl)
{
  GNUNET_FSUI_Event event;
  struct SearchRecordList *rec;
  struct SearchResultList *srl;
  struct GNUNET_FSUI_Context *ctx;

  ctx = sl->ctx;
  GNUNET_mutex_lock (ctx->lock);
  if (sl->state != GNUNET_FSUI_ACTIVE)
    {
      GNUNET_mutex_unlock (ctx->lock);
      return GNUNET_SYSERR;
    }
  sl->state = GNUNET_FSUI_PAUSED;
  GNUNET_mutex_unlock (ctx->lock);
  /* must not hold lock while stopping ECRS searches */
  rec = sl->searches;
  while (rec != NULL)
    {
      if (rec->search != NULL)
        GNUNET_ECRS_search_stop (rec->search);
      rec->search = NULL;
      rec = rec->next;
    }
  GNUNET_mutex_lock (ctx->lock);
  srl = sl->resultsReceived;
  while (srl != NULL)
    {
      if (srl->test_download != NULL)
        {
          GNUNET_ECRS_file_download_partial_stop (srl->test_download);
          srl->test_download = NULL;
          ctx->active_probes--;
        }
      srl = srl->next;
    }
  event.type = GNUNET_FSUI_search_paused;
  event.data.SearchPaused.sc.pos = sl;
  event.data.SearchPaused.sc.cctx = sl->cctx;
  sl->ctx->ecb (sl->ctx->ecbClosure, &event);
  GNUNET_mutex_unlock (ctx->lock);
  return GNUNET_OK;
}

/**
 * Restart a paused search.
 */
int
GNUNET_FSUI_search_restart (struct GNUNET_FSUI_SearchList *pos)
{
  GNUNET_FSUI_Event event;
  struct SearchRecordList *rec;
  struct GNUNET_FSUI_Context *ctx;

  ctx = pos->ctx;
  GNUNET_mutex_lock (ctx->lock);
  pos->state = GNUNET_FSUI_ACTIVE;
  event.type = GNUNET_FSUI_search_restarted;
  event.data.SearchStarted.sc.pos = pos;
  event.data.SearchStarted.sc.cctx = pos->cctx;
  pos->ctx->ecb (pos->ctx->ecbClosure, &event);
  rec = pos->searches;
  while (rec != NULL)
    {
      rec->search = GNUNET_ECRS_search_start (pos->ctx->ectx,
                                              pos->ctx->cfg,
                                              pos->probe_context,
                                              rec->uri,
                                              pos->anonymityLevel,
                                              &GNUNET_FSUI_search_progress_callback,
                                              pos);
      if (rec->search == NULL)
        break;
      rec = rec->next;
    }
  if (rec != NULL)
    {
      /* failed to restart, auto-pause again */
      GNUNET_FSUI_search_pause (pos);
      GNUNET_mutex_unlock (ctx->lock);
      return GNUNET_SYSERR;
    }
  GNUNET_mutex_unlock (ctx->lock);
  return GNUNET_OK;
}

/**
 * Stop a search.
 */
int
GNUNET_FSUI_search_stop (struct GNUNET_FSUI_SearchList *sl)
{
  GNUNET_FSUI_Event event;
  GNUNET_FSUI_SearchList *pos;
  GNUNET_FSUI_SearchList *prev;
  int i;
  struct SearchRecordList *rec;
  struct SearchResultList *srl;
  struct GNUNET_FSUI_Context *ctx;

  ctx = sl->ctx;
  GNUNET_mutex_lock (ctx->lock);
  if (sl->state == GNUNET_FSUI_ACTIVE)
    GNUNET_FSUI_search_abort (sl);
  prev = NULL;
  pos = ctx->activeSearches;
  while ((pos != sl) && (pos != NULL))
    {
      prev = pos;
      pos = pos->next;
    }
  if (pos == NULL)
    {
      GNUNET_mutex_unlock (ctx->lock);
      return GNUNET_SYSERR;
    }
  if (prev == NULL)
    ctx->activeSearches = pos->next;
  else
    prev->next = pos->next;
  for (i = 0; i < sl->my_downloads_size; i++)
    sl->my_downloads[i]->search = NULL;
  GNUNET_array_grow (sl->my_downloads, sl->my_downloads_size, 0);
  GNUNET_mutex_unlock (ctx->lock);
  pos->next = NULL;
  while (sl->searches != NULL)
    {
      rec = sl->searches;
      sl->searches = rec->next;
      if (rec->search != NULL)
        {
          GNUNET_GE_BREAK (ctx->ectx, 0);
          GNUNET_ECRS_search_stop (rec->search);
          rec->search = NULL;
        }
      GNUNET_ECRS_uri_destroy (rec->uri);
      GNUNET_free (rec);
    }
  event.type = GNUNET_FSUI_search_stopped;
  event.data.SearchStopped.sc.pos = pos;
  event.data.SearchStopped.sc.cctx = pos->cctx;
  pos->ctx->ecb (pos->ctx->ecbClosure, &event);
  GNUNET_ECRS_uri_destroy (pos->uri);
  while (sl->resultsReceived != NULL)
    {
      srl = sl->resultsReceived;
      sl->resultsReceived = srl->next;
      GNUNET_array_grow (srl->matchingSearches, srl->matchingSearchCount, 0);
      GNUNET_ECRS_uri_destroy (srl->fi.uri);
      GNUNET_meta_data_destroy (srl->fi.meta);
      if (srl->test_download != NULL)
        {
          GNUNET_ECRS_file_download_partial_stop (srl->test_download);
          ctx->active_probes--;
        }
      GNUNET_free (srl);
    }
  if (pos->probe_context != NULL)
    GNUNET_FS_destroy_search_context (pos->probe_context);
  GNUNET_free (pos);
  return GNUNET_OK;
}

/* end of search.c */