GNUnet  0.10.x
rps-sampler_client.c
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1 /*
2  This file is part of GNUnet.
3  Copyright (C)
4 
5  GNUnet is free software: you can redistribute it and/or modify it
6  under the terms of the GNU Affero General Public License as published
7  by the Free Software Foundation, either version 3 of the License,
8  or (at your option) any later version.
9 
10  GNUnet is distributed in the hope that it will be useful, but
11  WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  Affero General Public License for more details.
14 
15  You should have received a copy of the GNU Affero General Public License
16  along with this program. If not, see <http://www.gnu.org/licenses/>.
17 
18  SPDX-License-Identifier: AGPL3.0-or-later
19  */
20 
26 #include "platform.h"
27 #include "gnunet_util_lib.h"
29 #include "rps.h"
30 
31 #include "rps-sampler_common.h"
34 
35 #include <math.h>
36 #include <inttypes.h>
37 
38 #include "rps-test_util.h"
39 
40 #define LOG(kind, ...) GNUNET_log_from(kind, "rps-sampler", __VA_ARGS__)
41 
42 
43 // multiple 'clients'?
44 
45 // TODO check for overflows
46 
47 // TODO align message structs
48 
49 // hist_size_init, hist_size_max
50 
51 /***********************************************************************
52 * WARNING: This section needs to be reviewed regarding the use of
53 * functions providing (pseudo)randomness!
54 ***********************************************************************/
55 
56 // TODO care about invalid input of the caller (size 0 or less...)
57 
63 typedef void
64 (*SamplerNotifyUpdateCB) (void *cls);
65 
76 
80  void *cls;
81 
86 
91 };
92 
93 
98 typedef void
100 
101 
108 static void
110 
111 
121 
125  uint32_t num_peers;
126 
130  uint32_t cur_num_peers;
131 
135  struct GNUNET_PeerIdentity *ids;
136 
140  struct GetPeerCls *gpc_head;
141  struct GetPeerCls *gpc_tail;
142 
146  struct RPS_Sampler *sampler;
147 
152 
156  void *cls;
157 };
158 
159 
169 
174 
180 
185 
190 
194  void *cls;
195 };
196 
197 
199 // * Global sampler variable.
200 // */
201 //struct RPS_Sampler *sampler;
202 
203 
207 static size_t min_size;
208 
212 static size_t max_size;
213 
217 //static size_t extra_size;
218 
222 static uint32_t client_get_index;
223 
224 
232 struct RPS_Sampler *
233 RPS_sampler_mod_init(size_t init_size,
235 {
236  struct RPS_Sampler *sampler;
237 
238  /* Initialise context around extended sampler */
239  min_size = 10; // TODO make input to _samplers_init()
240  max_size = 1000; // TODO make input to _samplers_init()
241 
242  sampler = GNUNET_new(struct RPS_Sampler);
245  //sampler->sampler_elements = GNUNET_new_array(init_size, struct GNUNET_PeerIdentity);
246  //GNUNET_array_grow (sampler->sampler_elements, sampler->sampler_size, min_size);
247 
248  client_get_index = 0;
249 
250  //GNUNET_assert (init_size == sampler->sampler_size);
251 
252  RPS_sampler_resize(sampler, init_size);
253 
254  return sampler;
255 }
256 
257 
273 static double
275  uint32_t num_peers_observed,
276  double deficiency_factor)
277 {
278  uint32_t num_peers = num_peers_estim * (1 / deficiency_factor);
279  uint64_t sum = 0;
280 
281  for (uint32_t i = 0; i < num_peers; i++)
282  {
283  uint64_t a = pow(-1, num_peers - i);
284  uint64_t b = binom(num_peers, i);
285  uint64_t c = pow(i, num_peers_observed);
286  sum += a * b * c;
287  }
288 
289  return sum / (double)pow(num_peers, num_peers_observed);
290 }
291 
292 
298 static void
300 {
301  struct GetPeerCls *gpc = cls;
302  struct RPS_SamplerElement *s_elem;
303  struct GNUNET_TIME_Relative last_request_diff;
304  struct RPS_Sampler *sampler;
305  double prob_observed_n;
306  uint32_t num_observed;
307 
308  gpc->get_peer_task = NULL;
309  gpc->notify_ctx = NULL;
310  GNUNET_assert((NULL != gpc->req_handle) ||
311  (NULL != gpc->req_single_info_handle));
312  if (NULL != gpc->req_handle)
313  sampler = gpc->req_handle->sampler;
314  else
315  sampler = gpc->req_single_info_handle->sampler;
316 
317  LOG(GNUNET_ERROR_TYPE_DEBUG, "Single peer was requested\n");
318 
319  /* Cycle the #client_get_index one step further */
320  client_get_index = (client_get_index + 1) % sampler->sampler_size;
321 
322  s_elem = sampler->sampler_elements[client_get_index];
323  *gpc->id = s_elem->peer_id;
324  GNUNET_assert(NULL != s_elem);
325 
326  if (EMPTY == s_elem->is_empty)
327  {
329  "Sampler_mod element empty, rescheduling.\n");
330  GNUNET_assert(NULL == gpc->notify_ctx);
331  gpc->notify_ctx =
332  sampler_notify_on_update(sampler,
334  gpc);
335  return;
336  }
337 
338  /* Check whether we may use this sampler to give it back to the client */
340  {
341  // TODO remove this condition at least for the client sampler
342  last_request_diff =
345  /* We're not going to give it back now if it was
346  * already requested by a client this round */
347  if (last_request_diff.rel_value_us < sampler->max_round_interval.rel_value_us)
348  {
350  "Last client request on this sampler was less than max round interval ago -- scheduling for later\n");
352  //inv_last_request_diff =
353  // GNUNET_TIME_absolute_get_difference (last_request_diff,
354  // sampler->max_round_interval);
355  // add a little delay
356  /* Schedule it one round later */
357  GNUNET_assert(NULL == gpc->notify_ctx);
358  gpc->notify_ctx =
359  sampler_notify_on_update(sampler,
361  gpc);
362  return;
363  }
364  }
365  if (2 > s_elem->num_peers)
366  {
368  "This s_elem saw less than two peers -- scheduling for later\n");
369  GNUNET_assert(NULL == gpc->notify_ctx);
370  gpc->notify_ctx =
371  sampler_notify_on_update(sampler,
373  gpc);
374  return;
375  }
376  /* compute probability */
377  /* Currently disabled due to numerical limitations */
378  //prob_observed_n = prob_observed_n_peers (sampler->num_peers_estim,
379  // s_elem->num_peers,
380  // sampler->deficiency_factor);
381  //LOG (GNUNET_ERROR_TYPE_DEBUG,
382  // "Computed sample - prob %f, %" PRIu32 " peers, n: %" PRIu32 ", roh: %f\n",
383  // prob_observed_n,
384  // s_elem->num_peers,
385  // sampler->num_peers_estim,
386  // sampler->deficiency_factor);
388  //if (prob_observed_n < sampler->desired_probability)
389  //{
390  // LOG (GNUNET_ERROR_TYPE_DEBUG,
391  // "Probability of having observed all peers (%f) too small ( < %f).\n",
392  // prob_observed_n,
393  // sampler->desired_probability);
394  // GNUNET_assert (NULL == gpc->notify_ctx);
395  // gpc->notify_ctx =
396  // sampler_notify_on_update (sampler,
397  // &sampler_mod_get_rand_peer,
398  // gpc);
399  // return;
400  //}
401  /* More reasons to wait could be added here */
402 
403 // GNUNET_STATISTICS_set (stats,
404 // "# client sampler element input",
405 // s_elem->num_peers,
406 // GNUNET_NO);
407 // GNUNET_STATISTICS_set (stats,
408 // "# client sampler element change",
409 // s_elem->num_change,
410 // GNUNET_NO);
411 
412  num_observed = s_elem->num_peers;
413  RPS_sampler_elem_reinit(s_elem);
415 
416  if (NULL != gpc->req_handle)
417  {
419  gpc->req_handle->gpc_tail,
420  gpc);
421  }
422  else
423  {
426  gpc);
427  }
428  gpc->cont(gpc->cont_cls, gpc->id, prob_observed_n, num_observed);
429  GNUNET_free(gpc);
430 }
431 
432 
433 /* end of gnunet-service-rps.c */
434 
#define GNUNET_CONTAINER_DLL_remove(head, tail, element)
Remove an element from a DLL.
uint32_t num_peers
How many times a PeerID was put in this sampler.
void(* RPS_get_peers_type)(void *cls)
Type of function used to differentiate between modified and not modified Sampler. ...
uint64_t rel_value_us
The actual value.
uint32_t num_peers_estim
The estimated total number of peers in the network.
RPS_sampler_rand_peer_ready_cont cont
The callback.
struct SamplerNotifyUpdateCTX * prev
Previous element in DLL.
A sampler element sampling one PeerID at a time.
static size_t min_size
Global sampler variable.
Some utils faciliating the view into the internals for the sampler needed for evaluation.
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
struct RPS_SamplerRequestHandleSingleInfo * prev
sampler element implementation
Code common to client and service sampler.
Context for a callback.
struct GNUNET_TIME_Absolute last_client_request
Time of last request.
#define GNUNET_new(type)
Allocate a struct or union of the given type.
example IPC messages between RPS API and GNS service
#define LOG(kind,...)
struct RPS_SamplerRequestHandleSingleInfo * next
DLL.
void(* SamplerNotifyUpdateCB)(void *cls)
Callback called each time a new peer was put into the sampler.
void RPS_sampler_elem_reinit(struct RPS_SamplerElement *sampler_elem)
Reinitialise a previously initialised sampler element.
struct RPS_SamplerRequestHandle * req_handle
The RPS_SamplerRequestHandle this single request belongs to.
struct GNUNET_TIME_Relative max_round_interval
Maximum time a round takes.
uint64_t abs_value_us
The actual value.
static size_t max_size
The maximal size the extended sampler elements should grow to.
static double prob_observed_n_peers(uint32_t num_peers_estim, uint32_t num_peers_observed, double deficiency_factor)
Compute the probability that we already observed all peers from a biased stream of peer ids...
#define GNUNET_TIME_UNIT_FOREVER_ABS
Constant used to specify "forever".
Closure to _get_n_rand_peers_ready_cb()
struct SamplerNotifyUpdateCTX * notify_ctx
Context to the given callback.
struct SamplerNotifyUpdateCTX * next
Next element in DLL.
static uint32_t client_get_index
The size the extended sampler elements currently have.
struct RPS_Sampler * RPS_sampler_mod_init(size_t init_size, struct GNUNET_TIME_Relative max_round_interval)
Initialise a modified tuple of sampler elements.
struct RPS_Sampler * sampler
Sampler.
static struct GNUNET_CONTAINER_MultiPeerMap * ids
GNUNET_PeerIdentity -> CadetPeer.
enum RPS_SamplerEmpty is_empty
Flag that indicates that we are not holding a valid PeerID right now.
struct GNUNET_PeerIdentity peer_id
The PeerID this sampler currently samples.
SamplerNotifyUpdateCB notify_cb
The Callback to call on updates.
void * cls
The according closure.
Closure to _get_rand_peer_info()
uint32_t binom(uint32_t n, uint32_t k)
Binomial coefficient (n choose k)
static void sampler_mod_get_rand_peer(void *cls)
Get one random peer out of the sampled peers.
struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_get(void)
Get the current time.
Definition: time.c:118
void * cls
Closure given to the callback.
void RPS_sampler_resize(struct RPS_Sampler *sampler, unsigned int new_size)
Grow or shrink the size of the sampler.
struct GetPeerCls * gpc_head
Head and tail for the DLL to store the tasks for single requests.
sampler implementation
static unsigned int num_peers
struct GNUNET_PeerIdentity * id
Pointer to the id.
uint32_t cur_num_peers
Number of peers we currently have.
struct RPS_SamplerRequestHandleSingleInfo * req_single_info_handle
The RPS_SamplerRequestHandleSingleInfo this single request belongs to.
void * cont_cls
The closure to the callback cont.
The identity of the host (wraps the signing key of the peer).
void(* RPS_sampler_n_rand_peers_ready_cb)(const struct GNUNET_PeerIdentity *ids, uint32_t num_peers, void *cls)
Callback that is called from _get_n_rand_peers() when the PeerIDs are ready.
struct SamplerNotifyUpdateCTX * sampler_notify_on_update(struct RPS_Sampler *sampler, SamplerNotifyUpdateCB notify_cb, void *cls)
Add a callback that will be called when the next peer is inserted into the sampler.
Closure for sampler_mod_get_rand_peer() and sampler_get_rand_peer.
unsigned int sampler_size
Number of sampler elements we hold.
double deficiency_factor
A factor that catches the &#39;bias&#39; of a random stream of peer ids.
struct GNUNET_TIME_Relative GNUNET_TIME_absolute_get_difference(struct GNUNET_TIME_Absolute start, struct GNUNET_TIME_Absolute end)
Compute the time difference between the given start and end times.
Definition: time.c:353
void(* RPS_sampler_sinlge_info_ready_cb)(const struct GNUNET_PeerIdentity *ids, void *cls, double probability, uint32_t num_observed)
Callback that is called from _get_n_rand_peers() when the PeerIDs are ready.
RPS_get_peers_type get_peers
Stores the function to return peers.
struct RPS_SamplerElement ** sampler_elements
All sampler elements in one array.
Sampler with its own array of SamplerElements.
struct GNUNET_PeerIdentity * id
The address of the id to be stored at.
struct GNUNET_SCHEDULER_Task * get_peer_task
The task for this function.
RPS_sampler_sinlge_info_ready_cb callback
Callback to be called when all ids are available.
struct GetPeerCls * gpc_head
Head and tail for the DLL to store the tasks for single requests.
#define GNUNET_free(ptr)
Wrapper around free.
Time for relative time used by GNUnet, in microseconds.
struct RPS_Sampler * sampler
Sampler.