2 This file is part of GNUnet
3 (C) 2009 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 3, or (at your
8 option) any later version.
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 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 datastore/plugin_datastore_template.c
23 * @brief template-based datastore backend
24 * @author Christian Grothoff
28 #include "plugin_datastore.h"
32 * Context for all functions in this plugin.
37 * Our execution environment.
39 struct GNUNET_DATASTORE_PluginEnvironment *env;
44 * Get an estimate of how much space the database is
47 * @param cls our "struct Plugin*"
48 * @return number of bytes used on disk
50 static unsigned long long template_plugin_get_size (void *cls)
58 * Store an item in the datastore.
61 * @param key key for the item
62 * @param size number of bytes in data
63 * @param data content stored
64 * @param type type of the content
65 * @param priority priority of the content
66 * @param anonymity anonymity-level for the content
67 * @param expiration expiration time for the content
68 * @param msg set to error message
69 * @return GNUNET_OK on success
72 template_plugin_put (void *cls,
73 const GNUNET_HashCode * key,
76 enum GNUNET_BLOCK_Type type,
79 struct GNUNET_TIME_Absolute expiration,
83 *msg = GNUNET_strdup ("not implemented");
89 * Function invoked on behalf of a "PluginIterator"
90 * asking the database plugin to call the iterator
93 * @param next_cls whatever argument was given
94 * to the PluginIterator as "next_cls".
95 * @param end_it set to GNUNET_YES if we
96 * should terminate the iteration early
97 * (iterator should be still called once more
98 * to signal the end of the iteration).
101 template_plugin_next_request (void *next_cls,
109 * Iterate over the results for a particular key
113 * @param key maybe NULL (to match all entries)
114 * @param vhash hash of the value, maybe NULL (to
115 * match all values that have the right key).
116 * Note that for DBlocks there is no difference
117 * betwen key and vhash, but for other blocks
119 * @param type entries of which type are relevant?
120 * Use 0 for any type.
121 * @param iter function to call on each matching value;
122 * will be called once with a NULL value at the end
123 * @param iter_cls closure for iter
126 template_plugin_get (void *cls,
127 const GNUNET_HashCode * key,
128 const GNUNET_HashCode * vhash,
129 enum GNUNET_BLOCK_Type type,
130 PluginIterator iter, void *iter_cls)
137 * Update the priority for a particular key in the datastore. If
138 * the expiration time in value is different than the time found in
139 * the datastore, the higher value should be kept. For the
140 * anonymity level, the lower value is to be used. The specified
141 * priority should be added to the existing priority, ignoring the
144 * Note that it is possible for multiple values to match this put.
145 * In that case, all of the respective values are updated.
147 * @param cls our "struct Plugin*"
148 * @param uid unique identifier of the datum
149 * @param delta by how much should the priority
150 * change? If priority + delta < 0 the
151 * priority should be set to 0 (never go
153 * @param expire new expiration time should be the
154 * MAX of any existing expiration time and
156 * @param msg set to error message
157 * @return GNUNET_OK on success
160 template_plugin_update (void *cls,
162 int delta, struct GNUNET_TIME_Absolute expire,
166 *msg = GNUNET_strdup ("not implemented");
167 return GNUNET_SYSERR;
172 * Select a subset of the items in the datastore and call
173 * the given iterator for each of them.
175 * @param cls our "struct Plugin*"
176 * @param type entries of which type should be considered?
177 * Use 0 for any type.
178 * @param iter function to call on each matching value;
179 * will be called once with a NULL value at the end
180 * @param iter_cls closure for iter
183 template_plugin_iter_low_priority (void *cls,
184 enum GNUNET_BLOCK_Type type,
194 * Select a subset of the items in the datastore and call
195 * the given iterator for each of them.
197 * @param cls our "struct Plugin*"
198 * @param type entries of which type should be considered?
199 * Use 0 for any type.
200 * @param iter function to call on each matching value;
201 * will be called once with a NULL value at the end
202 * @param iter_cls closure for iter
205 template_plugin_iter_zero_anonymity (void *cls,
206 enum GNUNET_BLOCK_Type type,
216 * Select a subset of the items in the datastore and call
217 * the given iterator for each of them.
219 * @param cls our "struct Plugin*"
220 * @param type entries of which type should be considered?
221 * Use 0 for any type.
222 * @param iter function to call on each matching value;
223 * will be called once with a NULL value at the end
224 * @param iter_cls closure for iter
227 template_plugin_iter_ascending_expiration (void *cls,
228 enum GNUNET_BLOCK_Type type,
238 * Select a subset of the items in the datastore and call
239 * the given iterator for each of them.
241 * @param cls our "struct Plugin*"
242 * @param type entries of which type should be considered?
243 * Use 0 for any type.
244 * @param iter function to call on each matching value;
245 * will be called once with a NULL value at the end
246 * @param iter_cls closure for iter
249 template_plugin_iter_migration_order (void *cls,
250 enum GNUNET_BLOCK_Type type,
260 * Select a subset of the items in the datastore and call
261 * the given iterator for each of them.
263 * @param cls our "struct Plugin*"
264 * @param type entries of which type should be considered?
265 * Use 0 for any type.
266 * @param iter function to call on each matching value;
267 * will be called once with a NULL value at the end
268 * @param iter_cls closure for iter
271 template_plugin_iter_all_now (void *cls,
272 enum GNUNET_BLOCK_Type type,
284 template_plugin_drop (void *cls)
291 * Entry point for the plugin.
293 * @param cls the "struct GNUNET_DATASTORE_PluginEnvironment*"
294 * @return our "struct Plugin*"
297 libgnunet_plugin_datastore_template_init (void *cls)
299 struct GNUNET_DATASTORE_PluginEnvironment *env = cls;
300 struct GNUNET_DATASTORE_PluginFunctions *api;
301 struct Plugin *plugin;
303 plugin = GNUNET_malloc (sizeof (struct Plugin));
305 api = GNUNET_malloc (sizeof (struct GNUNET_DATASTORE_PluginFunctions));
307 api->get_size = &template_plugin_get_size;
308 api->put = &template_plugin_put;
309 api->next_request = &template_plugin_next_request;
310 api->get = &template_plugin_get;
311 api->update = &template_plugin_update;
312 api->iter_low_priority = &template_plugin_iter_low_priority;
313 api->iter_zero_anonymity = &template_plugin_iter_zero_anonymity;
314 api->iter_ascending_expiration = &template_plugin_iter_ascending_expiration;
315 api->iter_migration_order = &template_plugin_iter_migration_order;
316 api->iter_all_now = &template_plugin_iter_all_now;
317 api->drop = &template_plugin_drop;
318 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
319 "template", _("Template database running\n"));
325 * Exit point from the plugin.
326 * @param cls our "struct Plugin*"
327 * @return always NULL
330 libgnunet_plugin_datastore_template_done (void *cls)
332 struct GNUNET_DATASTORE_PluginFunctions *api = cls;
333 struct Plugin *plugin = api->cls;
335 GNUNET_free (plugin);
340 /* end of plugin_datastore_template.c */