summaryrefslogtreecommitdiff
path: root/src/datacache/datacache.c
blob: 1ae228b866c573e11d89dde1f585a5f2899219e3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
/*
     This file is part of GNUnet
     Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2015 GNUnet e.V.

     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 datacache/datacache.c
 * @brief datacache API implementation
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_datacache_lib.h"
#include "gnunet_statistics_service.h"
#include "gnunet_datacache_plugin.h"


#define LOG(kind, ...) GNUNET_log_from (kind, "datacache", __VA_ARGS__)

#define LOG_STRERROR_FILE(kind, op, fn) \
  GNUNET_log_from_strerror_file (kind, "datacache", op, fn)

/**
 * Internal state of the datacache library.
 */
struct GNUNET_DATACACHE_Handle
{
  /**
   * Bloomfilter to quickly tell if we don't have the content.
   */
  struct GNUNET_CONTAINER_BloomFilter *filter;

  /**
   * Our configuration.
   */
  const struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Opaque handle for the statistics service.
   */
  struct GNUNET_STATISTICS_Handle *stats;

  /**
   * Configuration section to use.
   */
  char *section;

  /**
   * API of the transport as returned by the plugin's
   * initialization function.
   */
  struct GNUNET_DATACACHE_PluginFunctions *api;

  /**
   * Short name for the plugin (i.e. "sqlite").
   */
  char *short_name;

  /**
   * Name of the library (i.e. "gnunet_plugin_datacache_sqlite").
   */
  char *lib_name;

  /**
   * Name for the bloom filter file.
   */
  char *bloom_name;

  /**
   * Environment provided to our plugin.
   */
  struct GNUNET_DATACACHE_PluginEnvironment env;

  /**
   * How much space is in use right now?
   */
  unsigned long long utilization;
};


/**
 * Function called by plugins to notify the datacache
 * about content deletions.
 *
 * @param cls closure
 * @param key key of the content that was deleted
 * @param size number of bytes that were made available
 */
static void
env_delete_notify (void *cls, const struct GNUNET_HashCode *key, size_t size)
{
  struct GNUNET_DATACACHE_Handle *h = cls;

  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Content under key `%s' discarded\n",
       GNUNET_h2s (key));
  GNUNET_assert (h->utilization >= size);
  h->utilization -= size;
  GNUNET_CONTAINER_bloomfilter_remove (h->filter, key);
  GNUNET_STATISTICS_update (h->stats,
                            gettext_noop ("# bytes stored"),
                            -(long long) size,
                            GNUNET_NO);
  GNUNET_STATISTICS_update (h->stats,
                            gettext_noop ("# items stored"),
                            -1,
                            GNUNET_NO);
}


/**
 * Create a data cache.
 *
 * @param cfg configuration to use
 * @param section section in the configuration that contains our options
 * @return handle to use to access the service
 */
struct GNUNET_DATACACHE_Handle *
GNUNET_DATACACHE_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
                         const char *section)
{
  unsigned int bf_size;
  unsigned long long quota;
  struct GNUNET_DATACACHE_Handle *ret;
  char *libname;
  char *name;

  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_size (cfg, section, "QUOTA", &quota))
  {
    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, section, "QUOTA");
    return NULL;
  }
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (cfg, section, "DATABASE", &name))
  {
    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, section, "DATABASE");
    return NULL;
  }
  bf_size = quota / 32; /* 8 bit per entry, 1 bit per 32 kb in DB */

  ret = GNUNET_new (struct GNUNET_DATACACHE_Handle);

  if (GNUNET_YES !=
      GNUNET_CONFIGURATION_get_value_yesno (cfg, section, "DISABLE_BF"))
  {
    if (GNUNET_YES !=
        GNUNET_CONFIGURATION_get_value_yesno (cfg, section, "DISABLE_BF_RC"))
    {
      ret->bloom_name = GNUNET_DISK_mktemp ("gnunet-datacachebloom");
    }
    if (NULL != ret->bloom_name)
    {
      ret->filter = GNUNET_CONTAINER_bloomfilter_load (
        ret->bloom_name,
        quota / 1024,     /* 8 bit per entry in DB, expect 1k entries */
        5);
    }
    if (NULL == ret->filter)
    {
      ret->filter =
        GNUNET_CONTAINER_bloomfilter_init (NULL,
                                           bf_size,
                                           5);    /* approx. 3% false positives at max use */
    }
  }
  ret->stats = GNUNET_STATISTICS_create ("datacache", cfg);
  ret->section = GNUNET_strdup (section);
  ret->env.cfg = cfg;
  ret->env.delete_notify = &env_delete_notify;
  ret->env.section = ret->section;
  ret->env.cls = ret;
  ret->env.delete_notify = &env_delete_notify;
  ret->env.quota = quota;
  LOG (GNUNET_ERROR_TYPE_INFO, _ ("Loading `%s' datacache plugin\n"), name);
  GNUNET_asprintf (&libname, "libgnunet_plugin_datacache_%s", name);
  ret->short_name = name;
  ret->lib_name = libname;
  ret->api = GNUNET_PLUGIN_load (libname, &ret->env);
  if (ret->api == NULL)
  {
    LOG (GNUNET_ERROR_TYPE_ERROR,
         _ ("Failed to load datacache plugin for `%s'\n"),
         name);
    GNUNET_DATACACHE_destroy (ret);
    return NULL;
  }
  return ret;
}


/**
 * Destroy a data cache (and free associated resources).
 *
 * @param h handle to the datastore
 */
void
GNUNET_DATACACHE_destroy (struct GNUNET_DATACACHE_Handle *h)
{
  if (NULL != h->filter)
    GNUNET_CONTAINER_bloomfilter_free (h->filter);
  if (NULL != h->api)
    GNUNET_break (NULL == GNUNET_PLUGIN_unload (h->lib_name, h->api));
  GNUNET_free (h->lib_name);
  GNUNET_free (h->short_name);
  GNUNET_free (h->section);
  if (NULL != h->bloom_name)
  {
    if (0 != unlink (h->bloom_name))
      GNUNET_log_from_strerror_file (GNUNET_ERROR_TYPE_WARNING,
                                     "datacache",
                                     "unlink",
                                     h->bloom_name);
    GNUNET_free (h->bloom_name);
  }
  GNUNET_STATISTICS_destroy (h->stats, GNUNET_NO);
  GNUNET_free (h);
}


/**
 * Store an item in the datastore.
 *
 * @param h handle to the datacache
 * @param key key to store data under
 * @param xor_distance distance of @a key to our PID
 * @param data_size number of bytes in @a data
 * @param data data to store
 * @param type type of the value
 * @param discard_time when to discard the value in any case
 * @param path_info_len number of entries in @a path_info
 * @param path_info a path through the network
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error, #GNUNET_NO if duplicate
 */
int
GNUNET_DATACACHE_put (struct GNUNET_DATACACHE_Handle *h,
                      const struct GNUNET_HashCode *key,
                      uint32_t xor_distance,
                      size_t data_size,
                      const char *data,
                      enum GNUNET_BLOCK_Type type,
                      struct GNUNET_TIME_Absolute discard_time,
                      unsigned int path_info_len,
                      const struct GNUNET_PeerIdentity *path_info)
{
  ssize_t used;

  used = h->api->put (h->api->cls,
                      key,
                      xor_distance,
                      data_size,
                      data,
                      type,
                      discard_time,
                      path_info_len,
                      path_info);
  if (-1 == used)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  if (0 == used)
  {
    /* duplicate */
    return GNUNET_NO;
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Stored data under key `%s' in cache\n",
       GNUNET_h2s (key));
  if (NULL != h->filter)
    GNUNET_CONTAINER_bloomfilter_add (h->filter, key);
  GNUNET_STATISTICS_update (h->stats,
                            gettext_noop ("# bytes stored"),
                            used,
                            GNUNET_NO);
  GNUNET_STATISTICS_update (h->stats,
                            gettext_noop ("# items stored"),
                            1,
                            GNUNET_NO);
  while (h->utilization + used > h->env.quota)
    GNUNET_assert (GNUNET_OK == h->api->del (h->api->cls));
  h->utilization += used;
  return GNUNET_OK;
}


/**
 * Iterate over the results for a particular key
 * in the datacache.
 *
 * @param h handle to the datacache
 * @param key what to look up
 * @param type entries of which type are relevant?
 * @param iter maybe NULL (to just count)
 * @param iter_cls closure for @a iter
 * @return the number of results found
 */
unsigned int
GNUNET_DATACACHE_get (struct GNUNET_DATACACHE_Handle *h,
                      const struct GNUNET_HashCode *key,
                      enum GNUNET_BLOCK_Type type,
                      GNUNET_DATACACHE_Iterator iter,
                      void *iter_cls)
{
  GNUNET_STATISTICS_update (h->stats,
                            gettext_noop ("# requests received"),
                            1,
                            GNUNET_NO);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Processing request for key `%s'\n",
       GNUNET_h2s (key));
  if ((NULL != h->filter) &&
      (GNUNET_OK != GNUNET_CONTAINER_bloomfilter_test (h->filter, key)))
  {
    GNUNET_STATISTICS_update (h->stats,
                              gettext_noop (
                                "# requests filtered by bloom filter"),
                              1,
                              GNUNET_NO);
    LOG (GNUNET_ERROR_TYPE_DEBUG,
         "Bloomfilter filters request for key `%s'\n",
         GNUNET_h2s (key));
    return 0;   /* can not be present */
  }
  return h->api->get (h->api->cls, key, type, iter, iter_cls);
}


/**
 * Obtain a random element from the datacache.
 *
 * @param h handle to the datacache
 * @param iter maybe NULL (to just count)
 * @param iter_cls closure for @a iter
 * @return the number of results found (zero or 1)
 */
unsigned int
GNUNET_DATACACHE_get_random (struct GNUNET_DATACACHE_Handle *h,
                             GNUNET_DATACACHE_Iterator iter,
                             void *iter_cls)
{
  GNUNET_STATISTICS_update (h->stats,
                            gettext_noop (
                              "# requests for random value received"),
                            1,
                            GNUNET_NO);
  LOG (GNUNET_ERROR_TYPE_DEBUG, "Processing request for random value\n");
  return h->api->get_random (h->api->cls, iter, iter_cls);
}


/**
 * Iterate over the results that are "close" to a particular key in
 * the datacache.  "close" is defined as numerically larger than @a
 * key (when interpreted as a circular address space), with small
 * distance.
 *
 * @param h handle to the datacache
 * @param key area of the keyspace to look into
 * @param num_results number of results that should be returned to @a iter
 * @param iter maybe NULL (to just count)
 * @param iter_cls closure for @a iter
 * @return the number of results found
 */
unsigned int
GNUNET_DATACACHE_get_closest (struct GNUNET_DATACACHE_Handle *h,
                              const struct GNUNET_HashCode *key,
                              unsigned int num_results,
                              GNUNET_DATACACHE_Iterator iter,
                              void *iter_cls)
{
  GNUNET_STATISTICS_update (h->stats,
                            gettext_noop (
                              "# proximity search requests received"),
                            1,
                            GNUNET_NO);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Processing proximity search at `%s'\n",
       GNUNET_h2s (key));
  return h->api->get_closest (h->api->cls, key, num_results, iter, iter_cls);
}


/* end of datacache.c */