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22 * @file datastore/plugin_datastore_template.c
23 * @brief template-based datastore backend
24 * @author Christian Grothoff
28 #include "gnunet_datastore_plugin.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
51 template_plugin_estimate_size (void *cls, unsigned long long *estimate)
61 * Store an item in the datastore.
64 * @param key key for the item
65 * @param size number of bytes in data
66 * @param data content stored
67 * @param type type of the content
68 * @param priority priority of the content
69 * @param anonymity anonymity-level for the content
70 * @param replication replication-level for the content
71 * @param expiration expiration time for the content
72 * @param cont continuation called with success or failure status
73 * @param cont_cls continuation closure
76 template_plugin_put (void *cls, const struct GNUNET_HashCode * key, uint32_t size,
77 const void *data, enum GNUNET_BLOCK_Type type,
78 uint32_t priority, uint32_t anonymity,
80 struct GNUNET_TIME_Absolute expiration, PluginPutCont cont,
84 cont (cont_cls, key, size, GNUNET_SYSERR, "not implemented");
89 * Get one of the results for a particular key in the datastore.
92 * @param next_uid return the result with lowest uid >= next_uid
93 * @param random if true, return a random result instead of using next_uid
94 * @param key maybe NULL (to match all entries)
95 * @param vhash hash of the value, maybe NULL (to
96 * match all values that have the right key).
97 * Note that for DBlocks there is no difference
98 * betwen key and vhash, but for other blocks
100 * @param type entries of which type are relevant?
101 * Use 0 for any type.
102 * @param proc function to call on each matching value;
103 * will be called with NULL if nothing matches
104 * @param proc_cls closure for proc
107 template_plugin_get_key (void *cls, uint64_t next_uid, bool random,
108 const struct GNUNET_HashCode * key,
109 const struct GNUNET_HashCode * vhash,
110 enum GNUNET_BLOCK_Type type, PluginDatumProcessor proc,
119 * Get a random item for replication. Returns a single, not expired,
120 * random item from those with the highest replication counters. The
121 * item's replication counter is decremented by one IF it was positive
122 * before. Call 'proc' with all values ZERO or NULL if the datastore
126 * @param proc function to call the value (once only).
127 * @param proc_cls closure for proc
130 template_plugin_get_replication (void *cls, PluginDatumProcessor proc,
138 * Get a random item for expiration. Call 'proc' with all values ZERO
139 * or NULL if the datastore is empty.
142 * @param proc function to call the value (once only).
143 * @param proc_cls closure for proc
146 template_plugin_get_expiration (void *cls, PluginDatumProcessor proc,
154 * Update the priority for a particular key in the datastore. If
155 * the expiration time in value is different than the time found in
156 * the datastore, the higher value should be kept. For the
157 * anonymity level, the lower value is to be used. The specified
158 * priority should be added to the existing priority, ignoring the
161 * Note that it is possible for multiple values to match this put.
162 * In that case, all of the respective values are updated.
164 * @param cls our "struct Plugin*"
165 * @param uid unique identifier of the datum
166 * @param delta by how much should the priority
168 * @param expire new expiration time should be the
169 * MAX of any existing expiration time and
171 * @param cont continuation called with success or failure status
172 * @param cons_cls continuation closure
175 template_plugin_update (void *cls, uint64_t uid, uint32_t delta,
176 struct GNUNET_TIME_Absolute expire,
177 PluginUpdateCont cont, void *cont_cls)
180 cont (cont_cls, GNUNET_SYSERR, "not implemented");
185 * Call the given processor on an item with zero anonymity.
187 * @param cls our "struct Plugin*"
188 * @param next_uid return the result with lowest uid >= next_uid
189 * @param type entries of which type should be considered?
190 * Must not be zero (ANY).
191 * @param proc function to call on the matching value;
192 * will be called with NULL if no value matches
193 * @param proc_cls closure for proc
196 template_plugin_get_zero_anonymity (void *cls, uint64_t next_uid,
197 enum GNUNET_BLOCK_Type type,
198 PluginDatumProcessor proc, void *proc_cls)
208 template_plugin_drop (void *cls)
215 * Get all of the keys in the datastore.
218 * @param proc function to call on each key
219 * @param proc_cls closure for proc
222 template_get_keys (void *cls,
223 PluginKeyProcessor proc,
226 proc (proc_cls, NULL, 0);
231 * Entry point for the plugin.
233 * @param cls the "struct GNUNET_DATASTORE_PluginEnvironment*"
234 * @return our "struct Plugin*"
237 libgnunet_plugin_datastore_template_init (void *cls)
239 struct GNUNET_DATASTORE_PluginEnvironment *env = cls;
240 struct GNUNET_DATASTORE_PluginFunctions *api;
241 struct Plugin *plugin;
243 plugin = GNUNET_new (struct Plugin);
245 api = GNUNET_new (struct GNUNET_DATASTORE_PluginFunctions);
247 api->estimate_size = &template_plugin_estimate_size;
248 api->put = &template_plugin_put;
249 api->update = &template_plugin_update;
250 api->get_key = &template_plugin_get_key;
251 api->get_replication = &template_plugin_get_replication;
252 api->get_expiration = &template_plugin_get_expiration;
253 api->get_zero_anonymity = &template_plugin_get_zero_anonymity;
254 api->drop = &template_plugin_drop;
255 api->get_keys = &template_get_keys;
256 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "template",
257 _("Template database running\n"));
263 * Exit point from the plugin.
264 * @param cls our "struct Plugin*"
265 * @return always NULL
268 libgnunet_plugin_datastore_template_done (void *cls)
270 struct GNUNET_DATASTORE_PluginFunctions *api = cls;
271 struct Plugin *plugin = api->cls;
273 GNUNET_free (plugin);
278 /* end of plugin_datastore_template.c */