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3 (C) 2004, 2005, 2006, 2008, 2009, 2011 Christian Grothoff (and other contributing authors)
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22 * @file include/gnunet_dht_service.h
23 * @brief API to the DHT service
24 * @author Christian Grothoff
27 #ifndef GNUNET_DHT_SERVICE_H
28 #define GNUNET_DHT_SERVICE_H
30 #include "gnunet_util_lib.h"
31 #include "gnunet_block_lib.h"
32 #include "gnunet_hello_lib.h"
37 #if 0 /* keep Emacsens' auto-indent happy */
44 * Default republication frequency for stored data in the DHT.
46 #define GNUNET_DHT_DEFAULT_REPUBLISH_FREQUENCY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 60)
51 * Connection to the DHT service.
53 struct GNUNET_DHT_Handle;
56 * Handle to control a get operation.
58 struct GNUNET_DHT_GetHandle;
61 * Handle to control a find peer operation.
63 struct GNUNET_DHT_FindPeerHandle;
67 * Options for routing.
69 enum GNUNET_DHT_RouteOption
72 * Default. Do nothing special.
74 GNUNET_DHT_RO_NONE = 0,
77 * Each peer along the way should look at 'enc' (otherwise
78 * only the k-peers closest to the key should look at it).
80 GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE = 1,
83 * We should keep track of the route that the message
84 * took in the P2P network.
86 GNUNET_DHT_RO_RECORD_ROUTE = 2,
89 * This is a 'FIND-PEER' request, so approximate results are fine.
91 GNUNET_DHT_RO_FIND_PEER = 4,
94 * Possible message option for query key randomization.
96 GNUNET_DHT_RO_BART = 8
101 * Initialize the connection with the DHT service.
103 * @param cfg configuration to use
104 * @param ht_len size of the internal hash table to use for
105 * processing multiple GET/FIND requests in parallel
106 * @return NULL on error
108 struct GNUNET_DHT_Handle *
109 GNUNET_DHT_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
110 unsigned int ht_len);
114 * Shutdown connection with the DHT service.
116 * @param handle connection to shut down
119 GNUNET_DHT_disconnect (struct GNUNET_DHT_Handle *handle);
122 /* *************** Standard API: get and put ******************* */
125 * Perform a PUT operation storing data in the DHT.
127 * @param handle handle to DHT service
128 * @param key the key to store under
129 * @param desired_replication_level estimate of how many
130 * nearest peers this request should reach
131 * @param options routing options for this message
132 * @param type type of the value
133 * @param size number of bytes in data; must be less than 64k
134 * @param data the data to store
135 * @param exp desired expiration time for the value
136 * @param timeout how long to wait for transmission of this request
137 * @param cont continuation to call when done (transmitting request to service)
138 * You must not call GNUNET_DHT_DISCONNECT in this continuation
139 * @param cont_cls closure for cont
142 GNUNET_DHT_put (struct GNUNET_DHT_Handle *handle, const GNUNET_HashCode * key,
143 uint32_t desired_replication_level,
144 enum GNUNET_DHT_RouteOption options,
145 enum GNUNET_BLOCK_Type type, size_t size, const char *data,
146 struct GNUNET_TIME_Absolute exp,
147 struct GNUNET_TIME_Relative timeout, GNUNET_SCHEDULER_Task cont,
152 * Iterator called on each result obtained for a DHT
153 * operation that expects a reply
156 * @param exp when will this value expire
157 * @param key key of the result
158 * @param get_path peers on reply path (or NULL if not recorded)
159 * @param get_path_length number of entries in get_path
160 * @param put_path peers on the PUT path (or NULL if not recorded)
161 * @param put_path_length number of entries in get_path
162 * @param type type of the result
163 * @param size number of bytes in data
164 * @param data pointer to the result data
166 typedef void (*GNUNET_DHT_GetIterator) (void *cls,
167 struct GNUNET_TIME_Absolute exp,
168 const GNUNET_HashCode * key,
169 const struct GNUNET_PeerIdentity *
170 get_path, unsigned int get_path_length,
171 const struct GNUNET_PeerIdentity *
172 put_path, unsigned int put_path_length,
173 enum GNUNET_BLOCK_Type type,
174 size_t size, const void *data);
179 * Perform an asynchronous GET operation on the DHT identified. See
180 * also "GNUNET_BLOCK_evaluate".
182 * @param handle handle to the DHT service
183 * @param timeout how long to wait for transmission of this request to the service
184 * @param type expected type of the response object
185 * @param key the key to look up
186 * @param desired_replication_level estimate of how many
187 nearest peers this request should reach
188 * @param options routing options for this message
189 * @param xquery extended query data (can be NULL, depending on type)
190 * @param xquery_size number of bytes in xquery
191 * @param iter function to call on each result
192 * @param iter_cls closure for iter
194 * @return handle to stop the async get
196 struct GNUNET_DHT_GetHandle *
197 GNUNET_DHT_get_start (struct GNUNET_DHT_Handle *handle,
198 struct GNUNET_TIME_Relative timeout,
199 enum GNUNET_BLOCK_Type type, const GNUNET_HashCode * key,
200 uint32_t desired_replication_level,
201 enum GNUNET_DHT_RouteOption options, const void *xquery,
202 size_t xquery_size, GNUNET_DHT_GetIterator iter,
207 * Stop async DHT-get. Frees associated resources.
209 * @param get_handle GET operation to stop.
211 * On return get_handle will no longer be valid, caller
212 * must not use again!!!
215 GNUNET_DHT_get_stop (struct GNUNET_DHT_GetHandle *get_handle);
218 /* *************** Extended API: monitor ******************* */
221 * Handle to monitor requests
223 struct GNUNET_DHT_MonitorHandle;
226 * Callback called on each GET request going through the DHT.
228 * @param cls Closure.
229 * @param options Options, for instance RecordRoute, DemultiplexEverywhere.
230 * @param type The type of data in the request.
231 * @param hop_count Hop count so far.
232 * @param path_length number of entries in path (or 0 if not recorded).
233 * @param path peers on the GET path (or NULL if not recorded).
234 * @param desired_replication_level Desired replication level.
235 * @param key Key of the requested data.
237 typedef void (*GNUNET_DHT_MonitorGetCB) (void *cls,
238 enum GNUNET_DHT_RouteOption options,
239 enum GNUNET_BLOCK_Type type,
241 uint32_t desired_replication_level,
242 unsigned int path_length,
243 const struct GNUNET_PeerIdentity *path,
244 const GNUNET_HashCode * key);
247 * Callback called on each GET reply going through the DHT.
249 * @param cls Closure.
250 * @param type The type of data in the result.
251 * @param get_path Peers on GET path (or NULL if not recorded).
252 * @param get_path_length number of entries in get_path.
253 * @param put_path peers on the PUT path (or NULL if not recorded).
254 * @param put_path_length number of entries in get_path.
255 * @param exp Expiration time of the data.
256 * @param key Key of the data.
257 * @param data Pointer to the result data.
258 * @param size Number of bytes in data.
260 typedef void (*GNUNET_DHT_MonitorGetRespCB) (void *cls,
261 enum GNUNET_BLOCK_Type type,
262 const struct GNUNET_PeerIdentity
264 unsigned int get_path_length,
265 const struct GNUNET_PeerIdentity
267 unsigned int put_path_length,
268 struct GNUNET_TIME_Absolute exp,
269 const GNUNET_HashCode * key,
274 * Callback called on each PUT request going through the DHT.
276 * @param cls Closure.
277 * @param options Options, for instance RecordRoute, DemultiplexEverywhere.
278 * @param type The type of data in the request.
279 * @param hop_count Hop count so far.
280 * @param path_length number of entries in path (or 0 if not recorded).
281 * @param path peers on the PUT path (or NULL if not recorded).
282 * @param desired_replication_level Desired replication level.
283 * @param exp Expiration time of the data.
284 * @param key Key under which data is to be stored.
285 * @param data Pointer to the data carried.
286 * @param size Number of bytes in data.
288 typedef void (*GNUNET_DHT_MonitorPutCB) (void *cls,
289 enum GNUNET_DHT_RouteOption options,
290 enum GNUNET_BLOCK_Type type,
292 uint32_t desired_replication_level,
293 unsigned int path_length,
294 const struct GNUNET_PeerIdentity *path,
295 struct GNUNET_TIME_Absolute exp,
296 const GNUNET_HashCode * key,
301 * Start monitoring the local DHT service.
303 * @param handle Handle to the DHT service.
304 * @param type Type of blocks that are of interest.
305 * @param key Key of data of interest, NULL for all.
306 * @param get_cb Callback to process monitored get messages.
307 * @param get_resp_cb Callback to process monitored get response messages.
308 * @param put_cb Callback to process monitored put messages.
309 * @param cb_cls Closure for cb.
311 * @return Handle to stop monitoring.
313 struct GNUNET_DHT_MonitorHandle *
314 GNUNET_DHT_monitor_start (struct GNUNET_DHT_Handle *handle,
315 enum GNUNET_BLOCK_Type type,
316 const GNUNET_HashCode *key,
317 GNUNET_DHT_MonitorGetCB get_cb,
318 GNUNET_DHT_MonitorGetRespCB get_resp_cb,
319 GNUNET_DHT_MonitorPutCB put_cb,
326 * @param handle The handle to the monitor request returned by monitor_start.
328 * On return handle will no longer be valid, caller must not use again!!!
331 GNUNET_DHT_monitor_stop (struct GNUNET_DHT_MonitorHandle *handle);
334 #if 0 /* keep Emacsens' auto-indent happy */
343 /* gnunet_dht_service.h */