2 This file is part of GNUnet
3 (C) 2004, 2005, 2006, 2007, 2009, 2010 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
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11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file datacache/datacache.c
23 * @brief datacache API implementation
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "gnunet_datacache_lib.h"
29 #include "gnunet_statistics_service.h"
30 #include "plugin_datacache.h"
33 * Internal state of the datacache library.
35 struct GNUNET_DATACACHE_Handle
39 * Bloomfilter to quickly tell if we don't have the content.
41 struct GNUNET_CONTAINER_BloomFilter *filter;
46 const struct GNUNET_CONFIGURATION_Handle *cfg;
49 * Opaque handle for the statistics service.
51 struct GNUNET_STATISTICS_Handle *stats;
54 * Configuration section to use.
59 * API of the transport as returned by the plugin's
60 * initialization function.
62 struct GNUNET_DATACACHE_PluginFunctions *api;
65 * Short name for the plugin (i.e. "sqlite").
70 * Name of the library (i.e. "gnunet_plugin_datacache_sqlite").
75 * Name for the bloom filter file.
80 * Environment provided to our plugin.
82 struct GNUNET_DATACACHE_PluginEnvironment env;
85 * How much space is in use right now?
87 unsigned long long utilization;
93 * Function called by plugins to notify the datacache
94 * about content deletions.
97 * @param key key of the content that was deleted
98 * @param size number of bytes that were made available
101 env_delete_notify (void *cls,
102 const GNUNET_HashCode *key,
105 struct GNUNET_DATACACHE_Handle * h = cls;
106 GNUNET_assert (h->utilization >= size);
107 h->utilization -= size;
108 GNUNET_CONTAINER_bloomfilter_remove (h->filter, key);
109 GNUNET_STATISTICS_update (h->stats,
110 gettext_noop ("# bytes stored"),
117 * Create a data cache.
119 * @param sched scheduler to use
120 * @param cfg configuration to use
121 * @param section section in the configuration that contains our options
122 * @return handle to use to access the service
124 struct GNUNET_DATACACHE_Handle *
125 GNUNET_DATACACHE_create (struct GNUNET_SCHEDULER_Handle *sched,
126 const struct GNUNET_CONFIGURATION_Handle *cfg,
129 unsigned int bf_size;
130 unsigned long long quota;
131 struct GNUNET_DATACACHE_Handle *ret;
136 GNUNET_CONFIGURATION_get_value_number (cfg,
137 section, "QUOTA", "a))
139 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
140 _("No `%s' specified for `%s' in configuration!\n"),
146 GNUNET_CONFIGURATION_get_value_string (cfg,
150 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
151 _("No `%s' specified for `%s' in configuration!\n"),
156 bf_size = quota / 32; /* 8 bit per entry, 1 bit per 32 kb in DB */
158 ret = GNUNET_malloc (sizeof(struct GNUNET_DATACACHE_Handle));
159 ret->bloom_name = GNUNET_DISK_mktemp ("gnunet-datacachebloom");
160 if (NULL != ret->bloom_name)
162 ret->filter = GNUNET_CONTAINER_bloomfilter_load (ret->bloom_name,
163 quota / 1024, /* 8 bit per entry in DB, expect 1k entries */
168 ret->filter = GNUNET_CONTAINER_bloomfilter_load (NULL, bf_size, 5); /* approx. 3% false positives at max use */
170 ret->stats = GNUNET_STATISTICS_create (sched,
173 ret->section = GNUNET_strdup (section);
174 ret->env.sched = sched;
176 ret->env.delete_notify = &env_delete_notify;
177 ret->env.section = ret->section;
179 ret->env.delete_notify = &env_delete_notify;
180 ret->env.quota = quota;
181 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
182 _("Loading `%s' datacache plugin\n"), name);
183 GNUNET_asprintf (&libname, "libgnunet_plugin_datacache_%s", name);
184 ret->short_name = name;
185 ret->lib_name = libname;
186 ret->api = GNUNET_PLUGIN_load (libname, &ret->env);
187 if (ret->api == NULL)
189 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
190 _("Failed to load datacache plugin for `%s'\n"), name);
191 GNUNET_DATACACHE_destroy (ret);
199 * Destroy a data cache (and free associated resources).
201 * @param h handle to the datastore
203 void GNUNET_DATACACHE_destroy (struct GNUNET_DATACACHE_Handle *h)
205 if (h->filter != NULL)
206 GNUNET_CONTAINER_bloomfilter_free (h->filter);
208 GNUNET_break (NULL == GNUNET_PLUGIN_unload (h->lib_name, h->api));
209 GNUNET_free (h->lib_name);
210 GNUNET_free (h->short_name);
211 GNUNET_free (h->section);
212 if (h->bloom_name != NULL)
214 if (0 != UNLINK (h->bloom_name))
215 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
218 GNUNET_free (h->bloom_name);
220 GNUNET_STATISTICS_destroy (h->stats,
227 * Store an item in the datastore.
229 * @param h handle to the datacache
230 * @param key key to store data under
231 * @param size number of bytes in data
232 * @param data data to store
233 * @param type type of the value
234 * @param discard_time when to discard the value in any case
235 * @return GNUNET_OK on success, GNUNET_SYSERR on error (full, etc.)
238 GNUNET_DATACACHE_put (struct GNUNET_DATACACHE_Handle *h,
239 const GNUNET_HashCode * key,
242 enum GNUNET_BLOCK_Type type,
243 struct GNUNET_TIME_Absolute discard_time)
247 used = h->api->put (h->api->cls,
256 return GNUNET_SYSERR;
258 GNUNET_STATISTICS_update (h->stats,
259 gettext_noop ("# bytes stored"),
262 GNUNET_CONTAINER_bloomfilter_add (h->filter, key);
263 while (h->utilization + used > h->env.quota)
264 GNUNET_assert (GNUNET_OK == h->api->del (h->api->cls));
265 h->utilization += used;
271 * Iterate over the results for a particular key
274 * @param h handle to the datacache
275 * @param key what to look up
276 * @param type entries of which type are relevant?
277 * @param iter maybe NULL (to just count)
278 * @param iter_cls closure for iter
279 * @return the number of results found
282 GNUNET_DATACACHE_get (struct GNUNET_DATACACHE_Handle *h,
283 const GNUNET_HashCode * key,
284 enum GNUNET_BLOCK_Type type,
285 GNUNET_DATACACHE_Iterator iter,
288 GNUNET_STATISTICS_update (h->stats,
289 gettext_noop ("# requests received"),
292 if (GNUNET_OK != GNUNET_CONTAINER_bloomfilter_test (h->filter,
295 GNUNET_STATISTICS_update (h->stats,
296 gettext_noop ("# requests filtered by bloom filter"),
299 return 0; /* can not be present */
301 return h->api->get (h->api->cls,
310 /* end of datacache_api.c */