2 This file is part of GNUnet
3 (C) 2004, 2005, 2006, 2007, 2009 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 * @param msg NULL on success, otherwise an error message
86 typedef void (*GNUNET_DATASTORE_ContinuationWithStatus)(void *cls,
92 * Reserve space in the datastore. This function should be used
93 * to avoid "out of space" failures during a longer sequence of "put"
94 * operations (for example, when a file is being inserted).
96 * @param h handle to the datastore
97 * @param amount how much space (in bytes) should be reserved (for content only)
98 * @param entries how many entries will be created (to calculate per-entry overhead)
99 * @param cont continuation to call when done; "success" will be set to
100 * a positive reservation value if space could be reserved.
101 * @param cont_cls closure for cont
102 * @param timeout how long to wait at most for a response
105 GNUNET_DATASTORE_reserve (struct GNUNET_DATASTORE_Handle *h,
108 GNUNET_DATASTORE_ContinuationWithStatus cont,
110 struct GNUNET_TIME_Relative timeout);
114 * Store an item in the datastore. If the item is already present,
115 * the priorities are summed up and the higher expiration time and
116 * lower anonymity level is used.
118 * @param h handle to the datastore
119 * @param rid reservation ID to use (from "reserve"); use 0 if no
120 * prior reservation was made
121 * @param key key for the value
122 * @param size number of bytes in data
123 * @param data content stored
124 * @param type type of the content
125 * @param priority priority of the content
126 * @param anonymity anonymity-level for the content
127 * @param expiration expiration time for the content
128 * @param timeout timeout for the operation
129 * @param cont continuation to call when done
130 * @param cont_cls closure for cont
133 GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h,
135 const GNUNET_HashCode * key,
138 enum GNUNET_BLOCK_Type type,
141 struct GNUNET_TIME_Absolute expiration,
142 struct GNUNET_TIME_Relative timeout,
143 GNUNET_DATASTORE_ContinuationWithStatus cont,
148 * Signal that all of the data for which a reservation was made has
149 * been stored and that whatever excess space might have been reserved
150 * can now be released.
152 * @param h handle to the datastore
153 * @param rid reservation ID (value of "success" in original continuation
154 * from the "reserve" function).
155 * @param cont continuation to call when done
156 * @param cont_cls closure for cont
157 * @param timeout how long to wait at most for a response
160 GNUNET_DATASTORE_release_reserve (struct GNUNET_DATASTORE_Handle *h,
162 GNUNET_DATASTORE_ContinuationWithStatus cont,
164 struct GNUNET_TIME_Relative timeout);
168 * Update a value in the datastore.
170 * @param h handle to the datastore
171 * @param uid identifier for the value
172 * @param priority how much to increase the priority of the value
173 * @param expiration new expiration value should be MAX of existing and this argument
174 * @param cont continuation to call when done
175 * @param cont_cls closure for cont
176 * @param timeout how long to wait at most for a response
179 GNUNET_DATASTORE_update (struct GNUNET_DATASTORE_Handle *h,
180 unsigned long long uid,
182 struct GNUNET_TIME_Absolute expiration,
183 GNUNET_DATASTORE_ContinuationWithStatus cont,
185 struct GNUNET_TIME_Relative timeout);
189 * An iterator over a set of items stored in the datastore.
192 * @param key key for the content
193 * @param size number of bytes in data
194 * @param data content stored
195 * @param type type of the content
196 * @param priority priority of the content
197 * @param anonymity anonymity-level for the content
198 * @param expiration expiration time for the content
199 * @param uid unique identifier for the datum;
200 * maybe 0 if no unique identifier is available
202 typedef void (*GNUNET_DATASTORE_Iterator) (void *cls,
203 const GNUNET_HashCode * key,
206 enum GNUNET_BLOCK_Type type,
209 struct GNUNET_TIME_Absolute
210 expiration, uint64_t uid);
214 * Iterate over the results for a particular key
215 * in the datastore. The iterator will only be called
216 * once initially; if the first call did contain a
217 * result, further results can be obtained by calling
218 * "GNUNET_DATASTORE_get_next" with the given argument.
220 * @param h handle to the datastore
221 * @param key maybe NULL (to match all entries)
222 * @param type desired type, 0 for any
223 * @param iter function to call on each matching value;
224 * will be called once with a NULL value at the end
225 * @param iter_cls closure for iter
226 * @param timeout how long to wait at most for a response
229 GNUNET_DATASTORE_get (struct GNUNET_DATASTORE_Handle *h,
230 const GNUNET_HashCode * key,
231 enum GNUNET_BLOCK_Type type,
232 GNUNET_DATASTORE_Iterator iter,
234 struct GNUNET_TIME_Relative timeout);
238 * Function called to trigger obtaining the next result
239 * from the datastore.
241 * @param h handle to the datastore
242 * @param more GNUNET_YES to get moxre results, GNUNET_NO to abort
243 * iteration (with a final call to "iter" with key/data == NULL).
246 GNUNET_DATASTORE_get_next (struct GNUNET_DATASTORE_Handle *h,
251 * Get a random value from the datastore.
253 * @param h handle to the datastore
254 * @param iter function to call on a random value; it
255 * will be called once with a value (if available)
256 * and always once with a value of NULL.
257 * @param iter_cls closure for iter
258 * @param timeout how long to wait at most for a response
261 GNUNET_DATASTORE_get_random (struct GNUNET_DATASTORE_Handle *h,
262 GNUNET_DATASTORE_Iterator iter, void *iter_cls,
263 struct GNUNET_TIME_Relative timeout);
267 * Explicitly remove some content from the database.
268 * The "cont"inuation will be called with status
269 * "GNUNET_OK" if content was removed, "GNUNET_NO"
270 * if no matching entry was found and "GNUNET_SYSERR"
271 * on all other types of errors.
273 * @param h handle to the datastore
274 * @param key key for the value
275 * @param size number of bytes in data
276 * @param data content stored
277 * @param cont continuation to call when done
278 * @param cont_cls closure for cont
279 * @param timeout how long to wait at most for a response
282 GNUNET_DATASTORE_remove (struct GNUNET_DATASTORE_Handle *h,
283 const GNUNET_HashCode *key,
284 uint32_t size, const void *data,
285 GNUNET_DATASTORE_ContinuationWithStatus cont,
287 struct GNUNET_TIME_Relative timeout);
290 #if 0 /* keep Emacsens' auto-indent happy */
297 /* end of gnunet_datastore_service.h */