1 files changed, 268 insertions, 0 deletions

diff --git a/src/contrib/service/rps/gnunet-service-rps_sampler.c b/src/contrib/service/rps/gnunet-service-rps_sampler.c
new file mode 100644
index 000000000..598cc887e
--- /dev/null
+++ b/src/contrib/service/rps/gnunet-service-rps_sampler.c
@@ -0,0 +1,268 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C)
+
+     GNUnet is free software: you can redistribute it and/or modify it
+     under the terms of the GNU Affero General Public License as published
+     by the Free Software Foundation, either version 3 of the License,
+     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
+     Affero General Public License for more details.
+
+     You should have received a copy of the GNU Affero General Public License
+     along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+     SPDX-License-Identifier: AGPL3.0-or-later
+ */
+
+/**
+ * @file rps/gnunet-service-rps_sampler.c
+ * @brief sampler implementation
+ * @author Julius Bünger
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_statistics_service.h"
+#include "rps.h"
+
+#include "rps-sampler_common.h"
+#include "gnunet-service-rps_sampler.h"
+#include "gnunet-service-rps_sampler_elem.h"
+
+#include <math.h>
+#include <inttypes.h>
+
+#include "rps-test_util.h"
+
+#define LOG(kind, ...) GNUNET_log_from (kind, "rps-sampler", __VA_ARGS__)
+
+
+// multiple 'clients'?
+
+// TODO check for overflows
+
+// TODO align message structs
+
+// hist_size_init, hist_size_max
+
+/***********************************************************************
+* WARNING: This section needs to be reviewed regarding the use of
+* functions providing (pseudo)randomness!
+***********************************************************************/
+
+// TODO care about invalid input of the caller (size 0 or less...)
+
+/**
+ * @brief Callback called each time a new peer was put into the sampler
+ *
+ * @param cls A possibly given closure
+ */
+typedef void
+(*SamplerNotifyUpdateCB) (void *cls);
+
+/**
+ * @brief Context for a callback. Contains callback and closure.
+ *
+ * Meant to be an entry in an DLL.
+ */
+struct SamplerNotifyUpdateCTX
+{
+  /**
+   * @brief The Callback to call on updates
+   */
+  SamplerNotifyUpdateCB notify_cb;
+
+  /**
+   * @brief The according closure.
+   */
+  void *cls;
+
+  /**
+   * @brief Next element in DLL.
+   */
+  struct SamplerNotifyUpdateCTX *next;
+
+  /**
+   * @brief Previous element in DLL.
+   */
+  struct SamplerNotifyUpdateCTX *prev;
+};
+
+
+/**
+ * Type of function used to differentiate between modified and not modified
+ * Sampler.
+ */
+typedef void
+(*RPS_get_peers_type) (void *cls);
+
+/**
+ * Get one random peer out of the sampled peers.
+ *
+ * We might want to reinitialise this sampler after giving the
+ * corrsponding peer to the client.
+ * Only used internally
+ */
+static void
+sampler_get_rand_peer (void *cls);
+
+
+/**
+ * Closure to _get_n_rand_peers_ready_cb()
+ */
+struct RPS_SamplerRequestHandle
+{
+  /**
+   * DLL
+   */
+  struct RPS_SamplerRequestHandle *next;
+  struct RPS_SamplerRequestHandle *prev;
+
+  /**
+   * Number of peers we are waiting for.
+   */
+  uint32_t num_peers;
+
+  /**
+   * Number of peers we currently have.
+   */
+  uint32_t cur_num_peers;
+
+  /**
+   * Pointer to the array holding the ids.
+   */
+  struct GNUNET_PeerIdentity *ids;
+
+  /**
+   * Head and tail for the DLL to store the tasks for single requests
+   */
+  struct GetPeerCls *gpc_head;
+  struct GetPeerCls *gpc_tail;
+
+  /**
+   * Sampler.
+   */
+  struct RPS_Sampler *sampler;
+
+  /**
+   * Callback to be called when all ids are available.
+   */
+  RPS_sampler_n_rand_peers_ready_cb callback;
+
+  /**
+   * Closure given to the callback
+   */
+  void *cls;
+};
+
+///**
+// * Global sampler variable.
+// */
+// struct RPS_Sampler *sampler;
+
+
+/**
+ * The minimal size for the extended sampler elements.
+ */
+static size_t min_size;
+
+/**
+ * The maximal size the extended sampler elements should grow to.
+ */
+static size_t max_size;
+
+/**
+ * The size the extended sampler elements currently have.
+ */
+// static size_t extra_size;
+
+/**
+ * Inedex to the sampler element that is the next to be returned
+ */
+static uint32_t client_get_index;
+
+
+/**
+ * Initialise a tuple of sampler elements.
+ *
+ * @param init_size the size the sampler is initialised with
+ * @param max_round_interval maximum time a round takes
+ * @return a handle to a sampler that consists of sampler elements.
+ */
+struct RPS_Sampler *
+RPS_sampler_init (size_t init_size,
+                  struct GNUNET_TIME_Relative max_round_interval)
+{
+  struct RPS_Sampler *sampler;
+
+  /* Initialise context around extended sampler */
+  min_size = 10; // TODO make input to _samplers_init()
+  max_size = 1000; // TODO make input to _samplers_init()
+
+  sampler = GNUNET_new (struct RPS_Sampler);
+
+  sampler->max_round_interval = max_round_interval;
+  sampler->get_peers = sampler_get_rand_peer;
+  // sampler->sampler_elements = GNUNET_new_array(init_size, struct GNUNET_PeerIdentity);
+  // GNUNET_array_grow (sampler->sampler_elements, sampler->sampler_size, min_size);
+  RPS_sampler_resize (sampler, init_size);
+
+  client_get_index = 0;
+
+  // GNUNET_assert (init_size == sampler->sampler_size);
+  return sampler;
+}
+
+
+/**
+ * Get one random peer out of the sampled peers.
+ *
+ * We might want to reinitialise this sampler after giving the
+ * corrsponding peer to the client.
+ * Only used internally
+ */
+static void
+sampler_get_rand_peer (void *cls)
+{
+  struct GetPeerCls *gpc = cls;
+  uint32_t r_index;
+  struct RPS_Sampler *sampler;
+
+  gpc->get_peer_task = NULL;
+  gpc->notify_ctx = NULL;
+  sampler = gpc->req_handle->sampler;
+
+  /**;
+   * Choose the r_index of the peer we want to return
+   * at random from the interval of the gossip list
+   */
+  r_index = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_STRONG,
+                                      sampler->sampler_size);
+
+  if (EMPTY == sampler->sampler_elements[r_index]->is_empty)
+  {
+    // LOG (GNUNET_ERROR_TYPE_DEBUG,
+    //     "Not returning randomly selected, empty PeerID. - Rescheduling.\n");
+
+    gpc->notify_ctx =
+      sampler_notify_on_update (sampler,
+                                &sampler_get_rand_peer,
+                                gpc);
+    return;
+  }
+
+  GNUNET_CONTAINER_DLL_remove (gpc->req_handle->gpc_head,
+                               gpc->req_handle->gpc_tail,
+                               gpc);
+  *gpc->id = sampler->sampler_elements[r_index]->peer_id;
+  gpc->cont (gpc->cont_cls, gpc->id, 0,
+             sampler->sampler_elements[r_index]->num_peers);
+
+  GNUNET_free (gpc);
+}
+
+
+/* end of gnunet-service-rps.c */