/*
This file is part of GNUnet
- (C) 2004, 2005, 2006, 2008, 2009, 2011 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2004-2013, 2016 GNUnet e.V.
- GNUnet is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published
- by the Free Software Foundation; either version 3, or (at your
- option) any later version.
+ GNUnet is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Affero General Public License as published
+ by the Free Software Foundation, either version 3 of the License,
+ or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
+ Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
- You should have received a copy of the GNU General Public License
- along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
- * @file include/gnunet_dht_service.h
- * @brief API to the DHT service
* @author Christian Grothoff
+ *
+ * @file
+ * API to the DHT service
+ *
+ * @defgroup dht DHT service
+ * Distributed Hash Table
+ *
+ * @see [Documentation](https://gnunet.org/developer-handbook-dht)
+ *
+ * @{
*/
#ifndef GNUNET_DHT_SERVICE_H
#endif
+/**
+ * Default republication frequency for stored data in the DHT.
+ */
+#define GNUNET_DHT_DEFAULT_REPUBLISH_FREQUENCY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 60)
+
+
+
/**
* Connection to the DHT service.
*/
*/
enum GNUNET_DHT_RouteOption
{
- /**
- * Default. Do nothing special.
- */
+ /**
+ * Default. Do nothing special.
+ */
GNUNET_DHT_RO_NONE = 0,
- /**
- * Each peer along the way should look at 'enc' (otherwise
- * only the k-peers closest to the key should look at it).
- */
+ /**
+ * Each peer along the way should look at 'enc' (otherwise
+ * only the k-peers closest to the key should look at it).
+ */
GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE = 1,
- /**
- * We should keep track of the route that the message
- * took in the P2P network.
- */
+ /**
+ * We should keep track of the route that the message
+ * took in the P2P network.
+ */
GNUNET_DHT_RO_RECORD_ROUTE = 2,
/**
*/
GNUNET_DHT_RO_FIND_PEER = 4,
- /**
- * Possible message option for query key randomization.
- */
- GNUNET_DHT_RO_BART = 8
+ /**
+ * Possible message option for query key randomization.
+ */
+ GNUNET_DHT_RO_BART = 8,
+
+ /**
+ * Flag given to monitors if this was the last hop for a GET/PUT.
+ */
+ GNUNET_DHT_RO_LAST_HOP = 16
};
/* *************** Standard API: get and put ******************* */
+
+/**
+ * Opaque handle to cancel a PUT operation.
+ */
+struct GNUNET_DHT_PutHandle;
+
+
/**
* Perform a PUT operation storing data in the DHT.
*
* nearest peers this request should reach
* @param options routing options for this message
* @param type type of the value
- * @param size number of bytes in data; must be less than 64k
+ * @param size number of bytes in @a data; must be less than 64k
* @param data the data to store
* @param exp desired expiration time for the value
- * @param timeout how long to wait for transmission of this request
* @param cont continuation to call when done (transmitting request to service)
- * @param cont_cls closure for cont
+ * You must not call #GNUNET_DHT_disconnect in this continuation
+ * @param cont_cls closure for @a cont
+ * @return handle to cancel the "PUT" operation, NULL on error
+ * (size too big)
*/
-void
-GNUNET_DHT_put (struct GNUNET_DHT_Handle *handle, const GNUNET_HashCode * key,
+struct GNUNET_DHT_PutHandle *
+GNUNET_DHT_put (struct GNUNET_DHT_Handle *handle,
+ const struct GNUNET_HashCode *key,
uint32_t desired_replication_level,
enum GNUNET_DHT_RouteOption options,
- enum GNUNET_BLOCK_Type type, size_t size, const char *data,
+ enum GNUNET_BLOCK_Type type,
+ size_t size,
+ const void *data,
struct GNUNET_TIME_Absolute exp,
- struct GNUNET_TIME_Relative timeout, GNUNET_SCHEDULER_Task cont,
+ GNUNET_SCHEDULER_TaskCallback cont,
void *cont_cls);
+/**
+ * Cancels a DHT PUT operation. Note that the PUT request may still
+ * go out over the network (we can't stop that); However, if the PUT
+ * has not yet been sent to the service, cancelling the PUT will stop
+ * this from happening (but there is no way for the user of this API
+ * to tell if that is the case). The only use for this API is to
+ * prevent a later call to 'cont' from #GNUNET_DHT_put (i.e. because
+ * the system is shutting down).
+ *
+ * @param ph put operation to cancel ('cont' will no longer be called)
+ */
+void
+GNUNET_DHT_put_cancel (struct GNUNET_DHT_PutHandle *ph);
+
+
/**
* Iterator called on each result obtained for a DHT
* operation that expects a reply
* @param exp when will this value expire
* @param key key of the result
* @param get_path peers on reply path (or NULL if not recorded)
- * @param get_path_length number of entries in get_path
+ * [0] = datastore's first neighbor, [length - 1] = local peer
+ * @param get_path_length number of entries in @a get_path
* @param put_path peers on the PUT path (or NULL if not recorded)
- * @param put_path_length number of entries in get_path
+ * [0] = origin, [length - 1] = datastore
+ * @param put_path_length number of entries in @a put_path
* @param type type of the result
- * @param size number of bytes in data
+ * @param size number of bytes in @a data
* @param data pointer to the result data
*/
-typedef void (*GNUNET_DHT_GetIterator) (void *cls,
- struct GNUNET_TIME_Absolute exp,
- const GNUNET_HashCode * key,
- const struct GNUNET_PeerIdentity *get_path,
- unsigned int get_path_length,
- const struct GNUNET_PeerIdentity *put_path,
- unsigned int put_path_length,
- enum GNUNET_BLOCK_Type type,
- size_t size, const void *data);
-
+typedef void
+(*GNUNET_DHT_GetIterator) (void *cls,
+ struct GNUNET_TIME_Absolute exp,
+ const struct GNUNET_HashCode *key,
+ const struct GNUNET_PeerIdentity *get_path,
+ unsigned int get_path_length,
+ const struct GNUNET_PeerIdentity *put_path,
+ unsigned int put_path_length,
+ enum GNUNET_BLOCK_Type type,
+ size_t size,
+ const void *data);
/**
* Perform an asynchronous GET operation on the DHT identified. See
- * also "GNUNET_BLOCK_evaluate".
+ * also #GNUNET_BLOCK_evaluate.
*
* @param handle handle to the DHT service
- * @param timeout how long to wait for transmission of this request to the service
* @param type expected type of the response object
* @param key the key to look up
* @param desired_replication_level estimate of how many
nearest peers this request should reach
* @param options routing options for this message
* @param xquery extended query data (can be NULL, depending on type)
- * @param xquery_size number of bytes in xquery
+ * @param xquery_size number of bytes in @a xquery
* @param iter function to call on each result
- * @param iter_cls closure for iter
- *
+ * @param iter_cls closure for @a iter
* @return handle to stop the async get
*/
struct GNUNET_DHT_GetHandle *
GNUNET_DHT_get_start (struct GNUNET_DHT_Handle *handle,
- struct GNUNET_TIME_Relative timeout,
- enum GNUNET_BLOCK_Type type, const GNUNET_HashCode * key,
+ enum GNUNET_BLOCK_Type type,
+ const struct GNUNET_HashCode *key,
uint32_t desired_replication_level,
enum GNUNET_DHT_RouteOption options,
const void *xquery,
- size_t xquery_size, GNUNET_DHT_GetIterator iter,
+ size_t xquery_size,
+ GNUNET_DHT_GetIterator iter,
void *iter_cls);
+/**
+ * Tell the DHT not to return any of the following known results
+ * to this client.
+ *
+ * @param get_handle get operation for which results should be filtered
+ * @param num_results number of results to be blocked that are
+ * provided in this call (size of the @a results array)
+ * @param results array of hash codes over the `data` of the results
+ * to be blocked
+ */
+void
+GNUNET_DHT_get_filter_known_results (struct GNUNET_DHT_GetHandle *get_handle,
+ unsigned int num_results,
+ const struct GNUNET_HashCode *results);
+
/**
* Stop async DHT-get. Frees associated resources.
*
* @param get_handle GET operation to stop.
- *
- * On return get_handle will no longer be valid, caller
- * must not use again!!!
*/
void
GNUNET_DHT_get_stop (struct GNUNET_DHT_GetHandle *get_handle);
+/* *************** Extended API: monitor ******************* */
+
+/**
+ * Handle to monitor requests
+ */
+struct GNUNET_DHT_MonitorHandle;
+
+/**
+ * Callback called on each GET request going through the DHT.
+ *
+ * @param cls Closure.
+ * @param options Options, for instance RecordRoute, DemultiplexEverywhere.
+ * @param type The type of data in the request.
+ * @param hop_count Hop count so far.
+ * @param path_length number of entries in @a path (or 0 if not recorded).
+ * @param path peers on the GET path (or NULL if not recorded).
+ * @param desired_replication_level Desired replication level.
+ * @param key Key of the requested data.
+ */
+typedef void
+(*GNUNET_DHT_MonitorGetCB) (void *cls,
+ enum GNUNET_DHT_RouteOption options,
+ enum GNUNET_BLOCK_Type type,
+ uint32_t hop_count,
+ uint32_t desired_replication_level,
+ unsigned int path_length,
+ const struct GNUNET_PeerIdentity *path,
+ const struct GNUNET_HashCode *key);
+
+
+/**
+ * Callback called on each GET reply going through the DHT.
+ *
+ * @param cls Closure.
+ * @param type The type of data in the result.
+ * @param get_path Peers on GET path (or NULL if not recorded).
+ * @param get_path_length number of entries in @a get_path.
+ * @param put_path peers on the PUT path (or NULL if not recorded).
+ * @param put_path_length number of entries in @a get_path.
+ * @param exp Expiration time of the data.
+ * @param key Key of the data.
+ * @param data Pointer to the result data.
+ * @param size Number of bytes in @a data.
+ */
+typedef void
+(*GNUNET_DHT_MonitorGetRespCB) (void *cls,
+ enum GNUNET_BLOCK_Type type,
+ const struct GNUNET_PeerIdentity *get_path,
+ unsigned int get_path_length,
+ const struct GNUNET_PeerIdentity *put_path,
+ unsigned int put_path_length,
+ struct GNUNET_TIME_Absolute exp,
+ const struct GNUNET_HashCode *key,
+ const void *data,
+ size_t size);
+
+
+/**
+ * Callback called on each PUT request going through the DHT.
+ *
+ * @param cls Closure.
+ * @param options Options, for instance RecordRoute, DemultiplexEverywhere.
+ * @param type The type of data in the request.
+ * @param hop_count Hop count so far.
+ * @param path_length number of entries in @a path (or 0 if not recorded).
+ * @param path peers on the PUT path (or NULL if not recorded).
+ * @param desired_replication_level Desired replication level.
+ * @param exp Expiration time of the data.
+ * @param key Key under which data is to be stored.
+ * @param data Pointer to the data carried.
+ * @param size Number of bytes in @a data.
+ */
+typedef void
+(*GNUNET_DHT_MonitorPutCB) (void *cls,
+ enum GNUNET_DHT_RouteOption options,
+ enum GNUNET_BLOCK_Type type,
+ uint32_t hop_count,
+ uint32_t desired_replication_level,
+ unsigned int path_length,
+ const struct GNUNET_PeerIdentity *path,
+ struct GNUNET_TIME_Absolute exp,
+ const struct GNUNET_HashCode *key,
+ const void *data,
+ size_t size);
+
+
+
+/**
+ * Start monitoring the local DHT service.
+ *
+ * @param handle Handle to the DHT service.
+ * @param type Type of blocks that are of interest.
+ * @param key Key of data of interest, NULL for all.
+ * @param get_cb Callback to process monitored get messages.
+ * @param get_resp_cb Callback to process monitored get response messages.
+ * @param put_cb Callback to process monitored put messages.
+ * @param cb_cls Closure for callbacks
+ * @return Handle to stop monitoring.
+ */
+struct GNUNET_DHT_MonitorHandle *
+GNUNET_DHT_monitor_start (struct GNUNET_DHT_Handle *handle,
+ enum GNUNET_BLOCK_Type type,
+ const struct GNUNET_HashCode *key,
+ GNUNET_DHT_MonitorGetCB get_cb,
+ GNUNET_DHT_MonitorGetRespCB get_resp_cb,
+ GNUNET_DHT_MonitorPutCB put_cb,
+ void *cb_cls);
+
+
+/**
+ * Stop monitoring.
+ * On return handle will no longer be valid, caller must not use it anymore.
+ *
+ * @param handle The handle to the monitor request returned by
+ * #GNUNET_DHT_monitor_start().
+ */
+void
+GNUNET_DHT_monitor_stop (struct GNUNET_DHT_MonitorHandle *handle);
+
+
#if 0 /* keep Emacsens' auto-indent happy */
{
#endif
}
#endif
-
#endif
-/* gnunet_dht_service.h */
+
+/** @} */ /* end of group dht */
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