1 files changed, 742 insertions, 0 deletions

diff --git a/src/contrib/service/rps/rps-sampler_common.c b/src/contrib/service/rps/rps-sampler_common.c
new file mode 100644
index 000000000..e3fb79501
--- /dev/null
+++ b/src/contrib/service/rps/rps-sampler_common.c
@@ -0,0 +1,742 @@
+/*
+     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/rps-sampler_common.c
+ * @brief Code common to client and service sampler
+ * @author Julius Bünger
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_statistics_service.h"
+
+#include "rps-sampler_common.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_common", __VA_ARGS__)
+
+/**
+ * @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;
+};
+
+
+/**
+ * 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;
+};
+
+
+/**
+ * Closure to _get_rand_peer_info()
+ */
+struct RPS_SamplerRequestHandleSingleInfo
+{
+  /**
+   * DLL
+   */
+  struct RPS_SamplerRequestHandleSingleInfo *next;
+  struct RPS_SamplerRequestHandleSingleInfo *prev;
+
+  /**
+   * Pointer to the id
+   */
+  struct GNUNET_PeerIdentity *id;
+
+  /**
+   * 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_sinlge_info_ready_cb callback;
+
+  /**
+   * Closure given to the callback
+   */
+  void *cls;
+};
+
+
+/**
+ * @brief Update the current estimate of the network size stored at the sampler
+ *
+ * Used for computing the condition when to return elements to the client
+ *
+ * Only used/useful with the client sampler
+ * (Maybe move to rps-sampler_client.{h|c} ?)
+ *
+ * @param sampler The sampler to update
+ * @param num_peers The estimated value
+ */
+void
+RPS_sampler_update_with_nw_size (struct RPS_Sampler *sampler,
+                                 uint32_t num_peers)
+{
+  sampler->num_peers_estim = num_peers;
+}
+
+
+/**
+ * @brief Set the probability that is needed at least with what a sampler
+ * element has to have observed all elements from the network.
+ *
+ * Only used/useful with the client sampler
+ * (Maybe move to rps-sampler_client.{h|c} ?)
+ *
+ * @param sampler
+ * @param desired_probability
+ */
+void
+RPS_sampler_set_desired_probability (struct RPS_Sampler *sampler,
+                                     double desired_probability)
+{
+  sampler->desired_probability = desired_probability;
+}
+
+
+void
+RPS_sampler_set_deficiency_factor (struct RPS_Sampler *sampler,
+                                   double deficiency_factor)
+{
+  sampler->deficiency_factor = deficiency_factor;
+}
+
+
+/**
+ * @brief Add a callback that will be called when the next peer is inserted
+ * into the sampler
+ *
+ * @param sampler The sampler on which update it will be called
+ * @param notify_cb The callback
+ * @param cls Closure given to the callback
+ *
+ * @return The context containing callback and closure
+ */
+struct SamplerNotifyUpdateCTX *
+sampler_notify_on_update (struct RPS_Sampler *sampler,
+                          SamplerNotifyUpdateCB notify_cb,
+                          void *cls)
+{
+  struct SamplerNotifyUpdateCTX *notify_ctx;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Inserting new context for notification\n");
+  notify_ctx = GNUNET_new (struct SamplerNotifyUpdateCTX);
+  notify_ctx->notify_cb = notify_cb;
+  notify_ctx->cls = cls;
+  GNUNET_CONTAINER_DLL_insert (sampler->notify_ctx_head,
+                               sampler->notify_ctx_tail,
+                               notify_ctx);
+  return notify_ctx;
+}
+
+
+/**
+ * Get the size of the sampler.
+ *
+ * @param sampler the sampler to return the size of.
+ * @return the size of the sampler
+ */
+unsigned int
+RPS_sampler_get_size (struct RPS_Sampler *sampler)
+{
+  return sampler->sampler_size;
+}
+
+
+/**
+ * @brief Notify about update of the sampler.
+ *
+ * Call the callbacks that are waiting for notification on updates to the
+ * sampler.
+ *
+ * @param sampler The sampler the updates are waiting for
+ */
+static void
+notify_update (struct RPS_Sampler *sampler)
+{
+  struct SamplerNotifyUpdateCTX *tmp_notify_head;
+  struct SamplerNotifyUpdateCTX *tmp_notify_tail;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Calling callbacks waiting for update notification.\n");
+  tmp_notify_head = sampler->notify_ctx_head;
+  tmp_notify_tail = sampler->notify_ctx_tail;
+  sampler->notify_ctx_head = NULL;
+  sampler->notify_ctx_tail = NULL;
+  for (struct SamplerNotifyUpdateCTX *notify_iter = tmp_notify_head;
+       NULL != tmp_notify_head;
+       notify_iter = tmp_notify_head)
+  {
+    GNUNET_assert (NULL != notify_iter->notify_cb);
+    GNUNET_CONTAINER_DLL_remove (tmp_notify_head,
+                                 tmp_notify_tail,
+                                 notify_iter);
+    notify_iter->notify_cb (notify_iter->cls);
+    GNUNET_free (notify_iter);
+  }
+}
+
+
+/**
+ * Update every sampler element of this sampler with given peer
+ *
+ * @param sampler the sampler to update.
+ * @param id the PeerID that is put in the sampler
+ */
+void
+RPS_sampler_update (struct RPS_Sampler *sampler,
+                    const struct GNUNET_PeerIdentity *id)
+{
+  for (uint32_t i = 0; i < sampler->sampler_size; i++)
+  {
+    RPS_sampler_elem_next (sampler->sampler_elements[i],
+                           id);
+  }
+  notify_update (sampler);
+}
+
+
+/**
+ * Reinitialise all previously initialised sampler elements with the given value.
+ *
+ * Used to get rid of a PeerID.
+ *
+ * FIXME: This should also consider currently pending requests
+ *        (Pending requests already collect peerids. As long as not all
+ *        requested IDs have been collected, they are kept.
+ *        Ideally, the @p id should be removed from all pending requests. This
+ *        seems quite complicated.)
+ *
+ * @param sampler the sampler to reinitialise a sampler element in.
+ * @param id the id of the sampler elements to update.
+ */
+void
+RPS_sampler_reinitialise_by_value (struct RPS_Sampler *sampler,
+                                   const struct GNUNET_PeerIdentity *id)
+{
+  uint32_t i;
+
+  for (i = 0; i < sampler->sampler_size; i++)
+  {
+    if (0 == GNUNET_memcmp (id,
+                            &(sampler->sampler_elements[i]->peer_id)))
+    {
+      LOG (GNUNET_ERROR_TYPE_DEBUG, "Reinitialising sampler\n");
+      RPS_sampler_elem_reinit (sampler->sampler_elements[i]);
+    }
+  }
+}
+
+
+/**
+ * Counts how many Samplers currently hold a given PeerID.
+ *
+ * @param sampler the sampler to count ids in.
+ * @param id the PeerID to count.
+ *
+ * @return the number of occurrences of id.
+ */
+uint32_t
+RPS_sampler_count_id (struct RPS_Sampler *sampler,
+                      const struct GNUNET_PeerIdentity *id)
+{
+  uint32_t count;
+  uint32_t i;
+
+  count = 0;
+  for (i = 0; i < sampler->sampler_size; i++)
+  {
+    if ((0 == GNUNET_memcmp (&sampler->sampler_elements[i]->peer_id, id))
+        && (EMPTY != sampler->sampler_elements[i]->is_empty) )
+      count++;
+  }
+  return count;
+}
+
+
+/**
+ * Grow or shrink the size of the sampler.
+ *
+ * @param sampler the sampler to resize.
+ * @param new_size the new size of the sampler
+ */
+static void
+sampler_resize (struct RPS_Sampler *sampler, unsigned int new_size)
+{
+  unsigned int old_size;
+  uint32_t i;
+
+  // TODO check min and max size
+
+  old_size = sampler->sampler_size;
+
+  if (old_size > new_size)
+  {   /* Shrinking */
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Shrinking sampler %d -> %d\n",
+         old_size,
+         new_size);
+
+    for (i = new_size; i < old_size; i++)
+    {
+      RPS_sampler_elem_destroy (sampler->sampler_elements[i]);
+    }
+
+    GNUNET_array_grow (sampler->sampler_elements,
+                       sampler->sampler_size,
+                       new_size);
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "sampler->sampler_elements now points to %p\n",
+         sampler->sampler_elements);
+  }
+  else if (old_size < new_size)
+  {   /* Growing */
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Growing sampler %d -> %d\n",
+         old_size,
+         new_size);
+
+    GNUNET_array_grow (sampler->sampler_elements,
+                       sampler->sampler_size,
+                       new_size);
+
+    for (i = old_size; i < new_size; i++)
+    {     /* Add new sampler elements */
+      sampler->sampler_elements[i] = RPS_sampler_elem_create ();
+    }
+  }
+  else
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG, "Size remains the same -- nothing to do\n");
+    return;
+  }
+
+  GNUNET_assert (sampler->sampler_size == new_size);
+}
+
+
+/**
+ * Grow or shrink the size of the sampler.
+ *
+ * @param sampler the sampler to resize.
+ * @param new_size the new size of the sampler
+ */
+void
+RPS_sampler_resize (struct RPS_Sampler *sampler, unsigned int new_size)
+{
+  GNUNET_assert (0 < new_size);
+  sampler_resize (sampler, new_size);
+}
+
+
+/**
+ * Empty the sampler.
+ *
+ * @param sampler the sampler to empty.
+ */
+static void
+sampler_empty (struct RPS_Sampler *sampler)
+{
+  sampler_resize (sampler, 0);
+}
+
+
+/**
+ * Callback to _get_rand_peer() used by _get_n_rand_peers().
+ *
+ * Implements #RPS_sampler_rand_peer_ready_cont
+ *
+ * Checks whether all n peers are available. If they are,
+ * give those back.
+ * @param cls Closure
+ * @param id Peer ID
+ * @param probability The probability with which this sampler has seen all ids
+ * @param num_observed How many ids this sampler has observed
+ */
+static void
+check_n_peers_ready (void *cls,
+                     const struct GNUNET_PeerIdentity *id,
+                     double probability,
+                     uint32_t num_observed)
+{
+  struct RPS_SamplerRequestHandle *req_handle = cls;
+
+  (void) id;
+  RPS_sampler_n_rand_peers_ready_cb tmp_cb;
+  struct GNUNET_PeerIdentity *peers;
+  uint32_t num_peers;
+  void *cb_cls;
+  (void) probability;
+  (void) num_observed;
+
+  req_handle->cur_num_peers++;
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Got %" PRIX32 ". of %" PRIX32 " peers\n",
+       req_handle->cur_num_peers, req_handle->num_peers);
+
+  if (req_handle->num_peers == req_handle->cur_num_peers)
+  {   /* All peers are ready -- return those to the client */
+    GNUNET_assert (NULL != req_handle->callback);
+
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "returning %" PRIX32 " peers to the client\n",
+         req_handle->num_peers);
+
+    /* Copy pointers and peers temporarily as they
+    * might be deleted from within the callback */
+    tmp_cb = req_handle->callback;
+    num_peers = req_handle->num_peers;
+    peers = GNUNET_new_array (num_peers, struct GNUNET_PeerIdentity);
+    GNUNET_memcpy (peers,
+                   req_handle->ids,
+                   num_peers * sizeof(struct GNUNET_PeerIdentity));
+    cb_cls = req_handle->cls;
+    RPS_sampler_request_cancel (req_handle);
+    req_handle = NULL;
+    tmp_cb (peers, num_peers, cb_cls);
+    GNUNET_free (peers);
+  }
+}
+
+
+/**
+ * Callback to _get_rand_peer() used by _get_rand_peer_info().
+ *
+ * Implements #RPS_sampler_rand_peer_ready_cont
+ *
+ * @param cls Closure
+ * @param id Peer ID
+ * @param probability The probability with which this sampler has seen all ids
+ * @param num_observed How many ids this sampler has observed
+ */
+static void
+check_peer_info_ready (void *cls,
+                       const struct GNUNET_PeerIdentity *id,
+                       double probability,
+                       uint32_t num_observed)
+{
+  struct RPS_SamplerRequestHandleSingleInfo *req_handle = cls;
+
+  (void) id;
+  RPS_sampler_sinlge_info_ready_cb tmp_cb;
+  struct GNUNET_PeerIdentity *peer;
+  void *cb_cls;
+  (void) probability;
+  (void) num_observed;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Got single peer with additional info\n");
+
+  GNUNET_assert (NULL != req_handle->callback);
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "returning single peer with info to the client\n");
+
+  /* Copy pointers and peers temporarily as they
+  * might be deleted from within the callback */
+  tmp_cb = req_handle->callback;
+  peer = GNUNET_new (struct GNUNET_PeerIdentity);
+  GNUNET_memcpy (peer,
+                 req_handle->id,
+                 sizeof(struct GNUNET_PeerIdentity));
+  cb_cls = req_handle->cls;
+  RPS_sampler_request_single_info_cancel (req_handle);
+  req_handle = NULL;
+  tmp_cb (peer, cb_cls, probability, num_observed);
+  GNUNET_free (peer);
+}
+
+
+struct RPS_SamplerRequestHandle *
+RPS_sampler_get_n_rand_peers (struct RPS_Sampler *sampler,
+                              uint32_t num_peers,
+                              RPS_sampler_n_rand_peers_ready_cb cb,
+                              void *cls)
+{
+  uint32_t i;
+  struct RPS_SamplerRequestHandle *req_handle;
+  struct GetPeerCls *gpc;
+
+  GNUNET_assert (0 != sampler->sampler_size);
+  if (0 == num_peers)
+    return NULL;
+
+  // TODO check if we have too much (distinct) sampled peers
+  req_handle = GNUNET_new (struct RPS_SamplerRequestHandle);
+  req_handle->num_peers = num_peers;
+  req_handle->cur_num_peers = 0;
+  req_handle->ids = GNUNET_new_array (num_peers, struct GNUNET_PeerIdentity);
+  req_handle->sampler = sampler;
+  req_handle->callback = cb;
+  req_handle->cls = cls;
+  GNUNET_CONTAINER_DLL_insert (sampler->req_handle_head,
+                               sampler->req_handle_tail,
+                               req_handle);
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Scheduling requests for %" PRIu32 " peers\n", num_peers);
+
+  for (i = 0; i < num_peers; i++)
+  {
+    gpc = GNUNET_new (struct GetPeerCls);
+    gpc->req_handle = req_handle;
+    gpc->req_single_info_handle = NULL;
+    gpc->cont = check_n_peers_ready;
+    gpc->cont_cls = req_handle;
+    gpc->id = &req_handle->ids[i];
+
+    GNUNET_CONTAINER_DLL_insert (req_handle->gpc_head,
+                                 req_handle->gpc_tail,
+                                 gpc);
+    // maybe add a little delay
+    gpc->get_peer_task = GNUNET_SCHEDULER_add_now (sampler->get_peers,
+                                                   gpc);
+  }
+  return req_handle;
+}
+
+
+/**
+ * Get one random peer with additional information.
+ *
+ * @param sampler the sampler to get peers from.
+ * @param cb callback that will be called once the ids are ready.
+ * @param cls closure given to @a cb
+ */
+struct RPS_SamplerRequestHandleSingleInfo *
+RPS_sampler_get_rand_peer_info (struct RPS_Sampler *sampler,
+                                RPS_sampler_sinlge_info_ready_cb cb,
+                                void *cls)
+{
+  struct RPS_SamplerRequestHandleSingleInfo *req_handle;
+  struct GetPeerCls *gpc;
+
+  GNUNET_assert (0 != sampler->sampler_size);
+
+  // TODO check if we have too much (distinct) sampled peers
+  req_handle = GNUNET_new (struct RPS_SamplerRequestHandleSingleInfo);
+  req_handle->id = GNUNET_malloc (sizeof(struct GNUNET_PeerIdentity));
+  req_handle->sampler = sampler;
+  req_handle->callback = cb;
+  req_handle->cls = cls;
+  GNUNET_CONTAINER_DLL_insert (sampler->req_handle_single_head,
+                               sampler->req_handle_single_tail,
+                               req_handle);
+
+  gpc = GNUNET_new (struct GetPeerCls);
+  gpc->req_handle = NULL;
+  gpc->req_single_info_handle = req_handle;
+  gpc->cont = check_peer_info_ready;
+  gpc->cont_cls = req_handle;
+  gpc->id = req_handle->id;
+
+  GNUNET_CONTAINER_DLL_insert (req_handle->gpc_head,
+                               req_handle->gpc_tail,
+                               gpc);
+  // maybe add a little delay
+  gpc->get_peer_task = GNUNET_SCHEDULER_add_now (sampler->get_peers,
+                                                 gpc);
+  return req_handle;
+}
+
+
+/**
+ * Cancel a request issued through #RPS_sampler_n_rand_peers_ready_cb.
+ *
+ * @param req_handle the handle to the request
+ */
+void
+RPS_sampler_request_cancel (struct RPS_SamplerRequestHandle *req_handle)
+{
+  struct GetPeerCls *i;
+
+  while (NULL != (i = req_handle->gpc_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (req_handle->gpc_head,
+                                 req_handle->gpc_tail,
+                                 i);
+    if (NULL != i->get_peer_task)
+    {
+      GNUNET_SCHEDULER_cancel (i->get_peer_task);
+    }
+    if (NULL != i->notify_ctx)
+    {
+      GNUNET_CONTAINER_DLL_remove (req_handle->sampler->notify_ctx_head,
+                                   req_handle->sampler->notify_ctx_tail,
+                                   i->notify_ctx);
+      GNUNET_free (i->notify_ctx);
+      i->notify_ctx = NULL;
+    }
+    GNUNET_free (i);
+  }
+  GNUNET_free (req_handle->ids);
+  req_handle->ids = NULL;
+  GNUNET_CONTAINER_DLL_remove (req_handle->sampler->req_handle_head,
+                               req_handle->sampler->req_handle_tail,
+                               req_handle);
+  GNUNET_free (req_handle);
+}
+
+
+/**
+ * Cancel a request issued through #RPS_sampler_sinlge_info_ready_cb.
+ *
+ * @param req_handle the handle to the request
+ */
+void
+RPS_sampler_request_single_info_cancel (
+  struct RPS_SamplerRequestHandleSingleInfo *req_single_info_handle)
+{
+  struct GetPeerCls *i;
+
+  while (NULL != (i = req_single_info_handle->gpc_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (req_single_info_handle->gpc_head,
+                                 req_single_info_handle->gpc_tail,
+                                 i);
+    if (NULL != i->get_peer_task)
+    {
+      GNUNET_SCHEDULER_cancel (i->get_peer_task);
+    }
+    if (NULL != i->notify_ctx)
+    {
+      GNUNET_CONTAINER_DLL_remove (
+        req_single_info_handle->sampler->notify_ctx_head,
+        req_single_info_handle->sampler->
+        notify_ctx_tail,
+        i->notify_ctx);
+      GNUNET_free (i->notify_ctx);
+      i->notify_ctx = NULL;
+    }
+    GNUNET_free (i);
+  }
+  GNUNET_free (req_single_info_handle->id);
+  req_single_info_handle->id = NULL;
+  GNUNET_CONTAINER_DLL_remove (
+    req_single_info_handle->sampler->req_handle_single_head,
+    req_single_info_handle->sampler->
+    req_handle_single_tail,
+    req_single_info_handle);
+  GNUNET_free (req_single_info_handle);
+}
+
+
+/**
+ * Cleans the sampler.
+ */
+void
+RPS_sampler_destroy (struct RPS_Sampler *sampler)
+{
+  if (NULL != sampler->req_handle_head)
+  {
+    LOG (GNUNET_ERROR_TYPE_WARNING,
+         "There are still pending requests. Going to remove them.\n");
+    while (NULL != sampler->req_handle_head)
+    {
+      RPS_sampler_request_cancel (sampler->req_handle_head);
+    }
+  }
+  sampler_empty (sampler);
+  GNUNET_free (sampler);
+}
+
+
+/* end of rps-sampler_common.c */