configuration serialization
[oweals/gnunet.git] / src / include / gnunet_datastore_service.h
index 53d04e5171a29ede3ab8b0ee4097bb006543b26e..721963bddf194fe412a298915c035a56b7531236 100644 (file)
@@ -63,9 +63,8 @@ struct GNUNET_DATASTORE_Handle;
  * @param cfg configuration 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_DATASTORE_Handle *
+GNUNET_DATASTORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg);
 
 
 /**
@@ -75,8 +74,8 @@ struct GNUNET_DATASTORE_Handle *GNUNET_DATASTORE_connect (const struct
  * @param h handle to the 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);
 
 
 /**
@@ -87,11 +86,15 @@ void GNUNET_DATASTORE_disconnect (struct GNUNET_DATASTORE_Handle *h,
  * @param success GNUNET_SYSERR on failure (including timeout/queue drop)
  *                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,
-                                                       int32_t success,
-                                                       const char *msg);
+typedef void (*GNUNET_DATASTORE_ContinuationWithStatus) (void *cls,
+                                                         int32_t success,
+                                                        struct GNUNET_TIME_Absolute min_expiration,
+                                                         const char *msg);
 
 
 /**
@@ -114,14 +117,12 @@ typedef void (*GNUNET_DATASTORE_ContinuationWithStatus)(void *cls,
  *         (or rather, will already have been invoked)
  */
 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);
+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);
 
 
 /**
@@ -151,21 +152,16 @@ GNUNET_DATASTORE_reserve (struct GNUNET_DATASTORE_Handle *h,
  *         (or rather, will already have been invoked)
  */
 struct GNUNET_DATASTORE_QueueEntry *
-GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h,
-                     uint32_t rid,
-                      const GNUNET_HashCode * key,
-                      size_t size,
-                      const void *data,
-                      enum GNUNET_BLOCK_Type type,
-                      uint32_t priority,
-                      uint32_t anonymity,
-                     uint32_t replication,
+GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h, 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,
+                      unsigned int queue_priority, unsigned int max_queue_size,
                       struct GNUNET_TIME_Relative timeout,
-                     GNUNET_DATASTORE_ContinuationWithStatus cont,
-                     void *cont_cls);
+                      GNUNET_DATASTORE_ContinuationWithStatus cont,
+                      void *cont_cls);
 
 
 /**
@@ -191,12 +187,11 @@ GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h,
  */
 struct GNUNET_DATASTORE_QueueEntry *
 GNUNET_DATASTORE_release_reserve (struct GNUNET_DATASTORE_Handle *h,
-                                 uint32_t 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,
+                                  struct GNUNET_TIME_Relative timeout,
+                                  GNUNET_DATASTORE_ContinuationWithStatus cont,
+                                  void *cont_cls);
 
 
 /**
@@ -217,15 +212,14 @@ GNUNET_DATASTORE_release_reserve (struct GNUNET_DATASTORE_Handle *h,
  *         (or rather, will already have been invoked)
  */
 struct GNUNET_DATASTORE_QueueEntry *
-GNUNET_DATASTORE_update (struct GNUNET_DATASTORE_Handle *h,
-                        uint64_t 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);
+GNUNET_DATASTORE_update (struct GNUNET_DATASTORE_Handle *h, uint64_t 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);
 
 
 /**
@@ -251,18 +245,16 @@ GNUNET_DATASTORE_update (struct GNUNET_DATASTORE_Handle *h,
  */
 struct GNUNET_DATASTORE_QueueEntry *
 GNUNET_DATASTORE_remove (struct GNUNET_DATASTORE_Handle *h,
-                         const GNUNET_HashCode *key,
-                         size_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,
+                         struct GNUNET_TIME_Relative timeout,
+                         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
@@ -275,87 +267,80 @@ GNUNET_DATASTORE_remove (struct GNUNET_DATASTORE_Handle *h,
  * @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,
-                                          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);
+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_iterate_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 proc
  * @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)
+ *         cancel
  */
 struct GNUNET_DATASTORE_QueueEntry *
-GNUNET_DATASTORE_iterate_key (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);
+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,
+                          struct GNUNET_TIME_Relative timeout,
+                          GNUNET_DATASTORE_DatumProcessor proc, void *proc_cls);
 
 
 /**
- * Get all zero-anonymity values 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 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 timeout how long to wait at most for a response
  * @param type allowed type for the operation (never zero)
- * @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 at the end.
- * @param iter_cls closure for iter
+ *        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; note that even if NULL is returned, the callback will be invoked
- *         (or rather, will already have been invoked)
+ *         cancel
  */
 struct GNUNET_DATASTORE_QueueEntry *
-GNUNET_DATASTORE_iterate_zero_anonymity (struct GNUNET_DATASTORE_Handle *h,
-                                        unsigned int queue_priority,
-                                        unsigned int max_queue_size,
-                                        struct GNUNET_TIME_Relative timeout,
-                                        enum GNUNET_BLOCK_Type type,
-                                        GNUNET_DATASTORE_Iterator iter, 
-                                        void *iter_cls);
-
-
-/**
- * Function called to trigger obtaining the next result
- * from the datastore.  ONLY applies for 'GNUNET_DATASTORE_iterate_*'
- * calls, not for 'get' calls.  FIXME: how much mixing of iterate
- * calls with other operations can we permit!?  Should we pass
- * the 'QueueEntry' instead of the datastore handle here instead?
- * 
- * @param h handle to the datastore
- */
-void
-GNUNET_DATASTORE_iterate_get_next (struct GNUNET_DATASTORE_Handle *h);
+GNUNET_DATASTORE_get_zero_anonymity (struct GNUNET_DATASTORE_Handle *h,
+                                     uint64_t offset,
+                                     unsigned int queue_priority,
+                                     unsigned int max_queue_size,
+                                     struct GNUNET_TIME_Relative timeout,
+                                     enum GNUNET_BLOCK_Type type,
+                                     GNUNET_DATASTORE_DatumProcessor proc,
+                                     void *proc_cls);
 
 
 /**
@@ -370,28 +355,27 @@ GNUNET_DATASTORE_iterate_get_next (struct GNUNET_DATASTORE_Handle *h);
  * @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 proc
  * @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)
+ *         cancel
  */
 struct GNUNET_DATASTORE_QueueEntry *
 GNUNET_DATASTORE_get_for_replication (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);
+                                      unsigned int queue_priority,
+                                      unsigned int max_queue_size,
+                                      struct GNUNET_TIME_Relative timeout,
+                                      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