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3 (C) 2004, 2005, 2006, 2007, 2009, 2010 Christian Grothoff (and other contributing authors)
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6 it under the terms of the GNU General Public License as published
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13 General Public License for more details.
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22 * @file include/gnunet_datastore_service.h
23 * @brief API that can be used manage the
24 * datastore for files stored on a GNUnet node;
25 * note that the datastore is NOT responsible for
26 * on-demand encoding, that is achieved using
27 * a special kind of entry.
28 * @author Christian Grothoff
31 #ifndef GNUNET_DATASTORE_SERVICE_H
32 #define GNUNET_DATASTORE_SERVICE_H
34 #include "gnunet_util_lib.h"
35 #include "gnunet_block_lib.h"
40 #if 0 /* keep Emacsens' auto-indent happy */
47 * Handle to the datastore service.
49 struct GNUNET_DATASTORE_Handle;
53 * Connect to the datastore service.
55 * @param cfg configuration to use
56 * @param sched scheduler to use
57 * @return handle to use to access the service
59 struct GNUNET_DATASTORE_Handle *GNUNET_DATASTORE_connect (const struct
60 GNUNET_CONFIGURATION_Handle
63 GNUNET_SCHEDULER_Handle
68 * Disconnect from the datastore service (and free
69 * associated resources).
71 * @param h handle to the datastore
72 * @param drop set to GNUNET_YES to delete all data in datastore (!)
74 void GNUNET_DATASTORE_disconnect (struct GNUNET_DATASTORE_Handle *h,
79 * Continuation called to notify client about result of the
83 * @param success GNUNET_SYSERR on failure,
84 * GNUNET_NO on timeout/queue drop
85 * GNUNET_YES on success
86 * @param msg NULL on success, otherwise an error message
88 typedef void (*GNUNET_DATASTORE_ContinuationWithStatus)(void *cls,
94 * Reserve space in the datastore. This function should be used
95 * to avoid "out of space" failures during a longer sequence of "put"
96 * operations (for example, when a file is being inserted).
98 * @param h handle to the datastore
99 * @param amount how much space (in bytes) should be reserved (for content only)
100 * @param entries how many entries will be created (to calculate per-entry overhead)
101 * @param queue_priority ranking of this request in the priority queue
102 * @param max_queue_size at what queue size should this request be dropped
103 * (if other requests of higher priority are in the queue)
104 * @param timeout how long to wait at most for a response (or before dying in queue)
105 * @param cont continuation to call when done; "success" will be set to
106 * a positive reservation value if space could be reserved.
107 * @param cont_cls closure for cont
110 GNUNET_DATASTORE_reserve (struct GNUNET_DATASTORE_Handle *h,
113 unsigned int queue_priority,
114 unsigned int max_queue_size,
115 struct GNUNET_TIME_Relative timeout,
116 GNUNET_DATASTORE_ContinuationWithStatus cont,
121 * Store an item in the datastore. If the item is already present,
122 * the priorities are summed up and the higher expiration time and
123 * lower anonymity level is used.
125 * @param h handle to the datastore
126 * @param rid reservation ID to use (from "reserve"); use 0 if no
127 * prior reservation was made
128 * @param key key for the value
129 * @param size number of bytes in data
130 * @param data content stored
131 * @param type type of the content
132 * @param priority priority of the content
133 * @param anonymity anonymity-level for the content
134 * @param expiration expiration time for the content
135 * @param queue_priority ranking of this request in the priority queue
136 * @param max_queue_size at what queue size should this request be dropped
137 * (if other requests of higher priority are in the queue)
138 * @param timeout timeout for the operation
139 * @param cont continuation to call when done
140 * @param cont_cls closure for cont
143 GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h,
145 const GNUNET_HashCode * key,
148 enum GNUNET_BLOCK_Type type,
151 struct GNUNET_TIME_Absolute expiration,
152 unsigned int queue_priority,
153 unsigned int max_queue_size,
154 struct GNUNET_TIME_Relative timeout,
155 GNUNET_DATASTORE_ContinuationWithStatus cont,
160 * Signal that all of the data for which a reservation was made has
161 * been stored and that whatever excess space might have been reserved
162 * can now be released.
164 * @param h handle to the datastore
165 * @param rid reservation ID (value of "success" in original continuation
166 * from the "reserve" function).
167 * @param queue_priority ranking of this request in the priority queue
168 * @param max_queue_size at what queue size should this request be dropped
169 * (if other requests of higher priority are in the queue)
170 * @param queue_priority ranking of this request in the priority queue
171 * @param max_queue_size at what queue size should this request be dropped
172 * (if other requests of higher priority are in the queue)
173 * @param timeout how long to wait at most for a response
174 * @param cont continuation to call when done
175 * @param cont_cls closure for cont
178 GNUNET_DATASTORE_release_reserve (struct GNUNET_DATASTORE_Handle *h,
180 unsigned int queue_priority,
181 unsigned int max_queue_size,
182 struct GNUNET_TIME_Relative timeout,
183 GNUNET_DATASTORE_ContinuationWithStatus cont,
188 * Update a value in the datastore.
190 * @param h handle to the datastore
191 * @param uid identifier for the value
192 * @param priority how much to increase the priority of the value
193 * @param expiration new expiration value should be MAX of existing and this argument
194 * @param queue_priority ranking of this request in the priority queue
195 * @param max_queue_size at what queue size should this request be dropped
196 * (if other requests of higher priority are in the queue)
197 * @param timeout how long to wait at most for a response
198 * @param cont continuation to call when done
199 * @param cont_cls closure for cont
202 GNUNET_DATASTORE_update (struct GNUNET_DATASTORE_Handle *h,
203 unsigned long long uid,
205 struct GNUNET_TIME_Absolute expiration,
206 unsigned int queue_priority,
207 unsigned int max_queue_size,
208 struct GNUNET_TIME_Relative timeout,
209 GNUNET_DATASTORE_ContinuationWithStatus cont,
214 * Explicitly remove some content from the database.
215 * The "cont"inuation will be called with status
216 * "GNUNET_OK" if content was removed, "GNUNET_NO"
217 * if no matching entry was found and "GNUNET_SYSERR"
218 * on all other types of errors.
220 * @param h handle to the datastore
221 * @param key key for the value
222 * @param size number of bytes in data
223 * @param data content stored
224 * @param queue_priority ranking of this request in the priority queue
225 * @param max_queue_size at what queue size should this request be dropped
226 * (if other requests of higher priority are in the queue)
227 * @param timeout how long to wait at most for a response
228 * @param cont continuation to call when done
229 * @param cont_cls closure for cont
232 GNUNET_DATASTORE_remove (struct GNUNET_DATASTORE_Handle *h,
233 const GNUNET_HashCode *key,
236 unsigned int queue_priority,
237 unsigned int max_queue_size,
238 struct GNUNET_TIME_Relative timeout,
239 GNUNET_DATASTORE_ContinuationWithStatus cont,
244 * An iterator over a set of items stored in the datastore.
247 * @param key key for the content
248 * @param size number of bytes in data
249 * @param data content stored
250 * @param type type of the content
251 * @param priority priority of the content
252 * @param anonymity anonymity-level for the content
253 * @param expiration expiration time for the content
254 * @param uid unique identifier for the datum;
255 * maybe 0 if no unique identifier is available
257 typedef void (*GNUNET_DATASTORE_Iterator) (void *cls,
258 const GNUNET_HashCode * key,
261 enum GNUNET_BLOCK_Type type,
264 struct GNUNET_TIME_Absolute
265 expiration, uint64_t uid);
269 * Iterate over the results for a particular key
270 * in the datastore. The iterator will only be called
271 * once initially; if the first call did contain a
272 * result, further results can be obtained by calling
273 * "GNUNET_DATASTORE_get_next" with the given argument.
275 * @param h handle to the datastore
276 * @param key maybe NULL (to match all entries)
277 * @param type desired type, 0 for any
278 * @param queue_priority ranking of this request in the priority queue
279 * @param max_queue_size at what queue size should this request be dropped
280 * (if other requests of higher priority are in the queue)
281 * @param timeout how long to wait at most for a response
282 * @param iter function to call on each matching value;
283 * will be called once with a NULL value at the end
284 * @param iter_cls closure for iter
287 GNUNET_DATASTORE_get (struct GNUNET_DATASTORE_Handle *h,
288 const GNUNET_HashCode * key,
289 enum GNUNET_BLOCK_Type type,
290 unsigned int queue_priority,
291 unsigned int max_queue_size,
292 struct GNUNET_TIME_Relative timeout,
293 GNUNET_DATASTORE_Iterator iter,
298 * Function called to trigger obtaining the next result
299 * from the datastore.
301 * @param h handle to the datastore
302 * @param more GNUNET_YES to get moxre results, GNUNET_NO to abort
303 * iteration (with a final call to "iter" with key/data == NULL).
306 GNUNET_DATASTORE_get_next (struct GNUNET_DATASTORE_Handle *h,
311 * Get a random value from the datastore.
313 * @param h handle to the datastore
314 * @param queue_priority ranking of this request in the priority queue
315 * @param max_queue_size at what queue size should this request be dropped
316 * (if other requests of higher priority are in the queue)
317 * @param timeout how long to wait at most for a response
318 * @param iter function to call on a random value; it
319 * will be called once with a value (if available)
320 * and always once with a value of NULL.
321 * @param iter_cls closure for iter
324 GNUNET_DATASTORE_get_random (struct GNUNET_DATASTORE_Handle *h,
325 unsigned int queue_priority,
326 unsigned int max_queue_size,
327 struct GNUNET_TIME_Relative timeout,
328 GNUNET_DATASTORE_Iterator iter,
333 #if 0 /* keep Emacsens' auto-indent happy */
340 /* end of gnunet_datastore_service.h */