/*
This file is part of GNUnet
- (C) 2004, 2005, 2006, 2007, 2009, 2010 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 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 2, or (at your
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
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.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
- * @file include/gnunet_datastore_service.h
- * @brief API that can be used manage the
- * datastore for files stored on a GNUnet node;
- * note that the datastore is NOT responsible for
- * on-demand encoding, that is achieved using
- * a special kind of entry.
* @author Christian Grothoff
+ *
+ * @file
+ * datastore service
+ *
+ * @defgroup datastore Data Store service
+ * Data store for files stored on a GNUnet node.
+ *
+ * Provides an API that can be used manage the
+ * datastore for files stored on a GNUnet node.
+ * Note that the datastore is NOT responsible for
+ * on-demand encoding, that is achieved using
+ * a special kind of entry.
+ *
+ * @{
*/
#ifndef GNUNET_DATASTORE_SERVICE_H
#endif
#endif
+/**
+ * Entry in the queue.
+ */
+struct GNUNET_DATASTORE_QueueEntry;
/**
* Handle to the datastore service.
*/
struct GNUNET_DATASTORE_Handle;
+/**
+ * Maximum size of a value that can be stored in the datastore.
+ */
+#define GNUNET_DATASTORE_MAX_VALUE_SIZE 65536
/**
* Connect to the datastore service.
*
* @param cfg configuration to use
- * @param sched scheduler to use
* @return handle to use to access the service
*/
-struct GNUNET_DATASTORE_Handle *GNUNET_DATASTORE_connect (const struct
- GNUNET_CONFIGURATION_Handle
- *cfg,
- struct
- GNUNET_SCHEDULER_Handle
- *sched);
+struct GNUNET_DATASTORE_Handle *
+GNUNET_DATASTORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg);
/**
* associated resources).
*
* @param h handle to the datastore
- * @param drop set to GNUNET_YES to delete all data in datastore (!)
+ * @param drop set to #GNUNET_YES to delete all data in datastore (!)
*/
-void GNUNET_DATASTORE_disconnect (struct GNUNET_DATASTORE_Handle *h,
- int drop);
+void
+GNUNET_DATASTORE_disconnect (struct GNUNET_DATASTORE_Handle *h,
+ int drop);
/**
* operation.
*
* @param cls closure
- * @param success GNUNET_SYSERR on failure,
- * GNUNET_NO on timeout/queue drop
- * GNUNET_YES on success
+ * @param success #GNUNET_SYSERR on failure
+ * #GNUNET_NO if content was already there
+ * #GNUNET_YES (or other positive value) on success
+ * @param min_expiration minimum expiration time required for 0-priority content to be stored
+ * by the datacache at this time, zero for unknown, forever if we have no
+ * space for 0-priority content
* @param msg NULL on success, otherwise an error message
*/
-typedef void (*GNUNET_DATASTORE_ContinuationWithStatus)(void *cls,
- int success,
- const char *msg);
+typedef void
+(*GNUNET_DATASTORE_ContinuationWithStatus) (void *cls,
+ int32_t success,
+ struct GNUNET_TIME_Absolute min_expiration,
+ const char *msg);
/**
* @param h handle to the datastore
* @param amount how much space (in bytes) should be reserved (for content only)
* @param entries how many entries will be created (to calculate per-entry overhead)
- * @param queue_priority ranking of this request in the priority queue
- * @param max_queue_size at what queue size should this request be dropped
- * (if other requests of higher priority are in the queue)
- * @param timeout how long to wait at most for a response (or before dying in queue)
* @param cont continuation to call when done; "success" will be set to
* a positive reservation value if space could be reserved.
- * @param cont_cls closure for cont
+ * @param cont_cls closure for @a cont
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel; note that even if NULL is returned, the callback will be invoked
+ * (or rather, will already have been invoked)
*/
-void
+struct GNUNET_DATASTORE_QueueEntry *
GNUNET_DATASTORE_reserve (struct GNUNET_DATASTORE_Handle *h,
- uint64_t amount,
- uint32_t entries,
- unsigned int queue_priority,
- unsigned int max_queue_size,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_DATASTORE_ContinuationWithStatus cont,
- void *cont_cls);
+ uint64_t amount,
+ uint32_t entries,
+ GNUNET_DATASTORE_ContinuationWithStatus cont,
+ void *cont_cls);
/**
* Store an item in the datastore. If the item is already present,
- * the priorities are summed up and the higher expiration time and
- * lower anonymity level is used.
+ * the priorities and replication values are summed up and the higher
+ * expiration time and lower anonymity level is used.
*
* @param h handle to the datastore
* @param rid reservation ID to use (from "reserve"); use 0 if no
* @param type type of the content
* @param priority priority of the content
* @param anonymity anonymity-level for the content
+ * @param replication how often should the content be replicated to other peers?
* @param expiration expiration time for the content
* @param queue_priority ranking of this request in the priority queue
* @param max_queue_size at what queue size should this request be dropped
* (if other requests of higher priority are in the queue)
- * @param timeout timeout for the operation
* @param cont continuation to call when done
- * @param cont_cls closure for cont
+ * @param cont_cls closure for @a cont
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel; note that even if NULL is returned, the callback will be invoked
+ * (or rather, will already have been invoked)
*/
-void
+struct GNUNET_DATASTORE_QueueEntry *
GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h,
- int rid,
- const GNUNET_HashCode * key,
- uint32_t size,
+ uint32_t rid,
+ const struct GNUNET_HashCode *key,
+ size_t size,
const void *data,
enum GNUNET_BLOCK_Type type,
uint32_t priority,
uint32_t anonymity,
+ uint32_t replication,
struct GNUNET_TIME_Absolute expiration,
- unsigned int queue_priority,
- unsigned int max_queue_size,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_DATASTORE_ContinuationWithStatus cont,
- void *cont_cls);
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_ContinuationWithStatus cont,
+ void *cont_cls);
/**
* @param queue_priority ranking of this request in the priority queue
* @param max_queue_size at what queue size should this request be dropped
* (if other requests of higher priority are in the queue)
- * @param timeout how long to wait at most for a response
* @param cont continuation to call when done
- * @param cont_cls closure for cont
+ * @param cont_cls closure for @a cont
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel; note that even if NULL is returned, the callback will be invoked
+ * (or rather, will already have been invoked)
*/
-void
+struct GNUNET_DATASTORE_QueueEntry *
GNUNET_DATASTORE_release_reserve (struct GNUNET_DATASTORE_Handle *h,
- int rid,
- unsigned int queue_priority,
- unsigned int max_queue_size,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_DATASTORE_ContinuationWithStatus cont,
- void *cont_cls);
+ uint32_t rid, unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_ContinuationWithStatus cont,
+ void *cont_cls);
/**
* @param queue_priority ranking of this request in the priority queue
* @param max_queue_size at what queue size should this request be dropped
* (if other requests of higher priority are in the queue)
- * @param timeout how long to wait at most for a response
* @param cont continuation to call when done
- * @param cont_cls closure for cont
+ * @param cont_cls closure for @a cont
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel; note that even if NULL is returned, the callback will be invoked
+ * (or rather, will already have been invoked)
*/
-void
+struct GNUNET_DATASTORE_QueueEntry *
GNUNET_DATASTORE_update (struct GNUNET_DATASTORE_Handle *h,
- unsigned long long uid,
- uint32_t priority,
- struct GNUNET_TIME_Absolute expiration,
- unsigned int queue_priority,
- unsigned int max_queue_size,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_DATASTORE_ContinuationWithStatus cont,
- void *cont_cls);
+ uint64_t uid,
+ uint32_t priority,
+ struct GNUNET_TIME_Absolute expiration,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_ContinuationWithStatus cont,
+ void *cont_cls);
/**
- * Explicitly remove some content from the database.
- * The "cont"inuation will be called with status
- * "GNUNET_OK" if content was removed, "GNUNET_NO"
- * if no matching entry was found and "GNUNET_SYSERR"
- * on all other types of errors.
+ * Explicitly remove some content from the database. @a cont will be
+ * called with status #GNUNET_OK if content was removed, #GNUNET_NO if
+ * no matching entry was found and #GNUNET_SYSERR on all other types
+ * of errors.
*
* @param h handle to the datastore
* @param key key for the value
- * @param size number of bytes in data
+ * @param size number of bytes in @a data
* @param data content stored
* @param queue_priority ranking of this request in the priority queue
* @param max_queue_size at what queue size should this request be dropped
* (if other requests of higher priority are in the queue)
- * @param timeout how long to wait at most for a response
* @param cont continuation to call when done
- * @param cont_cls closure for cont
+ * @param cont_cls closure for @a cont
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel; note that even if NULL is returned, the callback will be invoked
+ * (or rather, will already have been invoked)
*/
-void
+struct GNUNET_DATASTORE_QueueEntry *
GNUNET_DATASTORE_remove (struct GNUNET_DATASTORE_Handle *h,
- const GNUNET_HashCode *key,
- uint32_t size,
- const void *data,
- unsigned int queue_priority,
- unsigned int max_queue_size,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_DATASTORE_ContinuationWithStatus cont,
- void *cont_cls);
+ const struct GNUNET_HashCode *key,
+ size_t size,
+ const void *data,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_ContinuationWithStatus cont,
+ void *cont_cls);
/**
- * An iterator over a set of items stored in the datastore.
+ * Process a datum that was stored in the datastore.
*
* @param cls closure
* @param key key for the content
* @param uid unique identifier for the datum;
* maybe 0 if no unique identifier is available
*/
-typedef void (*GNUNET_DATASTORE_Iterator) (void *cls,
- const GNUNET_HashCode * key,
- uint32_t size,
- const void *data,
- enum GNUNET_BLOCK_Type type,
- uint32_t priority,
- uint32_t anonymity,
- struct GNUNET_TIME_Absolute
- expiration, uint64_t uid);
+typedef void
+(*GNUNET_DATASTORE_DatumProcessor) (void *cls,
+ const struct GNUNET_HashCode *key,
+ size_t size,
+ const void *data,
+ enum GNUNET_BLOCK_Type type,
+ uint32_t priority,
+ uint32_t anonymity,
+ struct GNUNET_TIME_Absolute expiration,
+ uint64_t uid);
/**
- * Iterate over the results for a particular key
- * in the datastore. The iterator will only be called
- * once initially; if the first call did contain a
- * result, further results can be obtained by calling
- * "GNUNET_DATASTORE_get_next" with the given argument.
+ * Get a result for a particular key from the datastore. The processor
+ * will only be called once.
*
* @param h handle to the datastore
+ * @param offset offset of the result (modulo num-results); set to
+ * a random 64-bit value initially; then increment by
+ * one each time; detect that all results have been found by uid
+ * being again the first uid ever returned.
* @param key maybe NULL (to match all entries)
* @param type desired type, 0 for any
* @param queue_priority ranking of this request in the priority queue
* @param max_queue_size at what queue size should this request be dropped
* (if other requests of higher priority are in the queue)
- * @param timeout how long to wait at most for a response
- * @param iter function to call on each matching value;
- * will be called once with a NULL value at the end
- * @param iter_cls closure for iter
+ * @param proc function to call on a matching value;
+ * or with a NULL value if no datum matches
+ * @param proc_cls closure for @a proc
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel
*/
-void
-GNUNET_DATASTORE_get (struct GNUNET_DATASTORE_Handle *h,
- const GNUNET_HashCode * key,
- enum GNUNET_BLOCK_Type type,
- unsigned int queue_priority,
- unsigned int max_queue_size,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_DATASTORE_Iterator iter,
- void *iter_cls);
+struct GNUNET_DATASTORE_QueueEntry *
+GNUNET_DATASTORE_get_key (struct GNUNET_DATASTORE_Handle *h,
+ uint64_t offset,
+ const struct GNUNET_HashCode *key,
+ enum GNUNET_BLOCK_Type type,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_DatumProcessor proc,
+ void *proc_cls);
/**
- * Function called to trigger obtaining the next result
- * from the datastore.
- *
+ * Get a single zero-anonymity value from the datastore.
+ * Note that some implementations can ignore the 'offset' and
+ * instead return a random zero-anonymity value. In that case,
+ * detecting the wrap-around based on a repeating UID is at best
+ * probabilistic.
+ *
* @param h handle to the datastore
- * @param more GNUNET_YES to get moxre results, GNUNET_NO to abort
- * iteration (with a final call to "iter" with key/data == NULL).
+ * @param offset offset of the result (modulo num-results); set to
+ * a random 64-bit value initially; then increment by
+ * one each time; detect that all results have been found by uid
+ * being again the first uid ever returned.
+ * @param queue_priority ranking of this request in the priority queue
+ * @param max_queue_size at what queue size should this request be dropped
+ * (if other requests of higher priority are in the queue)
+ * @param type allowed type for the operation (never zero)
+ * @param proc function to call on a random value; it
+ * will be called once with a value (if available)
+ * or with NULL if none value exists.
+ * @param proc_cls closure for proc
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel
*/
-void
-GNUNET_DATASTORE_get_next (struct GNUNET_DATASTORE_Handle *h,
- int more);
+struct GNUNET_DATASTORE_QueueEntry *
+GNUNET_DATASTORE_get_zero_anonymity (struct GNUNET_DATASTORE_Handle *h,
+ uint64_t offset,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ enum GNUNET_BLOCK_Type type,
+ GNUNET_DATASTORE_DatumProcessor proc,
+ void *proc_cls);
/**
- * Get a random value from the datastore.
+ * Get a random value from the datastore for content replication.
+ * Returns a single, random value among those with the highest
+ * replication score, lowering positive replication scores by one for
+ * the chosen value (if only content with a replication score exists,
+ * a random value is returned and replication scores are not changed).
*
* @param h handle to the datastore
* @param queue_priority ranking of this request in the priority queue
* @param max_queue_size at what queue size should this request be dropped
* (if other requests of higher priority are in the queue)
- * @param timeout how long to wait at most for a response
- * @param iter function to call on a random value; it
+ * @param proc function to call on a random value; it
* will be called once with a value (if available)
* and always once with a value of NULL.
- * @param iter_cls closure for iter
+ * @param proc_cls closure for @a proc
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel
*/
-void
-GNUNET_DATASTORE_get_random (struct GNUNET_DATASTORE_Handle *h,
- unsigned int queue_priority,
- unsigned int max_queue_size,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_DATASTORE_Iterator iter,
- void *iter_cls);
+struct GNUNET_DATASTORE_QueueEntry *
+GNUNET_DATASTORE_get_for_replication (struct GNUNET_DATASTORE_Handle *h,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_DatumProcessor proc,
+ void *proc_cls);
+
+/**
+ * Cancel a datastore operation. The final callback from the
+ * operation must not have been done yet.
+ *
+ * @param qe operation to cancel
+ */
+void
+GNUNET_DATASTORE_cancel (struct GNUNET_DATASTORE_QueueEntry *qe);
+
#if 0 /* keep Emacsens' auto-indent happy */
{
}
#endif
-/* end of gnunet_datastore_service.h */
#endif
+
+/** @} */ /* end of group */