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.
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16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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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 "gnunet_datacache_plugin.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, const GNUNET_HashCode * key, size_t size)
103 struct GNUNET_DATACACHE_Handle *h = cls;
105 GNUNET_assert (h->utilization >= size);
106 h->utilization -= size;
107 GNUNET_CONTAINER_bloomfilter_remove (h->filter, key);
108 GNUNET_STATISTICS_update (h->stats, gettext_noop ("# bytes stored"), -size,
114 * Create a data cache.
116 * @param cfg configuration to use
117 * @param section section in the configuration that contains our options
118 * @return handle to use to access the service
120 struct GNUNET_DATACACHE_Handle *
121 GNUNET_DATACACHE_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
124 unsigned int bf_size;
125 unsigned long long quota;
126 struct GNUNET_DATACACHE_Handle *ret;
131 GNUNET_CONFIGURATION_get_value_number (cfg, section, "QUOTA", "a))
133 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
134 _("No `%s' specified for `%s' in configuration!\n"), "QUOTA",
139 GNUNET_CONFIGURATION_get_value_string (cfg, section, "DATABASE", &name))
141 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
142 _("No `%s' specified for `%s' in configuration!\n"), "DATABASE",
146 bf_size = quota / 32; /* 8 bit per entry, 1 bit per 32 kb in DB */
148 ret = GNUNET_malloc (sizeof (struct GNUNET_DATACACHE_Handle));
149 ret->bloom_name = GNUNET_DISK_mktemp ("gnunet-datacachebloom");
150 if (NULL != ret->bloom_name)
152 ret->filter = GNUNET_CONTAINER_bloomfilter_load (ret->bloom_name, quota / 1024, /* 8 bit per entry in DB, expect 1k entries */
157 ret->filter = GNUNET_CONTAINER_bloomfilter_init (NULL, bf_size, 5); /* approx. 3% false positives at max use */
159 ret->stats = GNUNET_STATISTICS_create ("datacache", cfg);
160 ret->section = GNUNET_strdup (section);
162 ret->env.delete_notify = &env_delete_notify;
163 ret->env.section = ret->section;
165 ret->env.delete_notify = &env_delete_notify;
166 ret->env.quota = quota;
167 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Loading `%s' datacache plugin\n"),
169 GNUNET_asprintf (&libname, "libgnunet_plugin_datacache_%s", name);
170 ret->short_name = name;
171 ret->lib_name = libname;
172 ret->api = GNUNET_PLUGIN_load (libname, &ret->env);
173 if (ret->api == NULL)
175 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
176 _("Failed to load datacache plugin for `%s'\n"), name);
177 GNUNET_DATACACHE_destroy (ret);
185 * Destroy a data cache (and free associated resources).
187 * @param h handle to the datastore
190 GNUNET_DATACACHE_destroy (struct GNUNET_DATACACHE_Handle *h)
192 if (h->filter != NULL)
193 GNUNET_CONTAINER_bloomfilter_free (h->filter);
195 GNUNET_break (NULL == GNUNET_PLUGIN_unload (h->lib_name, h->api));
196 GNUNET_free (h->lib_name);
197 GNUNET_free (h->short_name);
198 GNUNET_free (h->section);
199 if (h->bloom_name != NULL)
201 if (0 != UNLINK (h->bloom_name))
202 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "unlink",
204 GNUNET_free (h->bloom_name);
206 GNUNET_STATISTICS_destroy (h->stats, GNUNET_NO);
212 * Store an item in the datastore.
214 * @param h handle to the datacache
215 * @param key key to store data under
216 * @param size number of bytes in data
217 * @param data data to store
218 * @param type type of the value
219 * @param discard_time when to discard the value in any case
220 * @return GNUNET_OK on success, GNUNET_SYSERR on error (full, etc.)
223 GNUNET_DATACACHE_put (struct GNUNET_DATACACHE_Handle *h,
224 const GNUNET_HashCode * key, size_t size,
225 const char *data, enum GNUNET_BLOCK_Type type,
226 struct GNUNET_TIME_Absolute discard_time)
230 used = h->api->put (h->api->cls, key, size, data, type, discard_time);
234 return GNUNET_SYSERR;
236 GNUNET_STATISTICS_update (h->stats, gettext_noop ("# bytes stored"), size,
238 GNUNET_CONTAINER_bloomfilter_add (h->filter, key);
239 while (h->utilization + used > h->env.quota)
240 GNUNET_assert (GNUNET_OK == h->api->del (h->api->cls));
241 h->utilization += used;
247 * Iterate over the results for a particular key
250 * @param h handle to the datacache
251 * @param key what to look up
252 * @param type entries of which type are relevant?
253 * @param iter maybe NULL (to just count)
254 * @param iter_cls closure for iter
255 * @return the number of results found
258 GNUNET_DATACACHE_get (struct GNUNET_DATACACHE_Handle *h,
259 const GNUNET_HashCode * key, enum GNUNET_BLOCK_Type type,
260 GNUNET_DATACACHE_Iterator iter, void *iter_cls)
262 GNUNET_STATISTICS_update (h->stats, gettext_noop ("# requests received"), 1,
264 if (GNUNET_OK != GNUNET_CONTAINER_bloomfilter_test (h->filter, key))
266 GNUNET_STATISTICS_update (h->stats,
268 ("# requests filtered by bloom filter"), 1,
270 return 0; /* can not be present */
272 return h->api->get (h->api->cls, key, type, iter, iter_cls);
277 /* end of datacache_api.c */