/*
This file is part of GNUnet
- (C) 2004, 2005, 2006, 2007, 2009 Christian Grothoff (and other contributing authors)
+ (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
#define GNUNET_DATASTORE_SERVICE_H
#include "gnunet_util_lib.h"
+#include "gnunet_block_lib.h"
#ifdef __cplusplus
extern "C"
#endif
#endif
+/**
+ * Entry in the queue.
+ */
+struct GNUNET_DATASTORE_QueueEntry;
/**
* Handle to the datastore service.
*/
struct GNUNET_DATASTORE_Handle;
-
/**
- * An iterator over a set of items stored in the datastore.
- *
- * @param cls closure
- * @param key key for the content
- * @param size number of bytes in data
- * @param data content stored
- * @param type type of the content
- * @param priority priority of the content
- * @param anonymity anonymity-level for the content
- * @param expiration expiration time for the content
- * @param uid unique identifier for the datum;
- * maybe 0 if no unique identifier is available
- *
- * @return GNUNET_SYSERR to abort the iteration, GNUNET_OK to continue,
- * GNUNET_NO to delete the item and continue (if supported)
+ * Maximum size of a value that can be stored in the datastore.
*/
-typedef int (*GNUNET_DATASTORE_Iterator) (void *cls,
- const GNUNET_HashCode * key,
- uint32_t size,
- const void *data,
- uint32_t type,
- uint32_t priority,
- uint32_t anonymity,
- struct GNUNET_TIME_Absolute
- expiration, unsigned long long uid);
+#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 (struct
- GNUNET_CONFIGURATION_Handle
- *cfg,
- struct
- GNUNET_SCHEDULER_Handle
- *sched);
+struct GNUNET_DATASTORE_Handle *
+GNUNET_DATASTORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg);
/**
* @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);
+
+
+/**
+ * Continuation called to notify client about result of the
+ * operation.
+ *
+ * @param cls closure
+ * @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 msg NULL on success, otherwise an error message
+ */
+typedef void (*GNUNET_DATASTORE_ContinuationWithStatus) (void *cls,
+ int32_t success,
+ const char *msg);
/**
- * Get the current on-disk size of the datastore.
+ * Reserve space in the datastore. This function should be used
+ * to avoid "out of space" failures during a longer sequence of "put"
+ * operations (for example, when a file is being inserted).
+ *
* @param h handle to the datastore
- * @return size estimate, -1 if datastore is not available (yet)
+ * @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
+ * @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)
*/
-unsigned long long GNUNET_DATASTORE_size (struct GNUNET_DATASTORE_Handle *h);
+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);
/**
* 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
+ * prior reservation was made
* @param key key for the value
* @param size number of bytes in data
* @param data content stored
* @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
+ * @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
-GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h,
- const GNUNET_HashCode * key,
- uint32_t size,
- const void *data,
- uint32_t type,
- uint32_t priority,
- uint32_t anonymity,
- struct GNUNET_TIME_Absolute expiration);
-
-/**
- * Iterate over the results for a particular key
- * in the datastore.
+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,
+ 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);
+
+
+/**
+ * Signal that all of the data for which a reservation was made has
+ * been stored and that whatever excess space might have been reserved
+ * can now be released.
*
* @param h handle to the datastore
- * @param key maybe NULL (to match all entries)
- * @param type desired type, 0 for any
- * @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 rid reservation ID (value of "success" in original continuation
+ * from the "reserve" function).
+ * @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 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
+ * @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
-GNUNET_DATASTORE_get (struct GNUNET_DATASTORE_Handle *h,
- const GNUNET_HashCode * key,
- uint32_t type,
- GNUNET_DATASTORE_Iterator iter, void *iter_cls);
+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);
/**
- * Get a random value from the datastore.
+ * Update a value in the datastore.
*
* @param h handle to the datastore
- * @param iter function to call on each matching value;
- * will be called exactly once; if no values
- * are available, the value will be NULL.
- * @param iter_cls closure for iter
+ * @param uid identifier for the value
+ * @param priority how much to increase the priority of the value
+ * @param expiration new expiration value should be MAX of existing and this argument
+ * @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
+ * @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
-GNUNET_DATASTORE_get_random (struct GNUNET_DATASTORE_Handle *h,
- GNUNET_DATASTORE_Iterator iter, void *iter_cls);
+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);
/**
* 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.
*
* @param h handle to the datastore
* @param key key for the value
* @param size number of bytes in 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
+ * @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);
+ 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);
+
+
+/**
+ * Process a datum that was stored in the datastore.
+ *
+ * @param cls closure
+ * @param key key for the content
+ * @param size number of bytes in data
+ * @param data content stored
+ * @param type type of the content
+ * @param priority priority of the content
+ * @param anonymity anonymity-level for the content
+ * @param expiration expiration time for the content
+ * @param uid unique identifier for the datum;
+ * maybe 0 if no unique identifier is available
+ */
+typedef void (*GNUNET_DATASTORE_DatumProcessor) (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);
+
+
+/**
+ * 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 proc function to call on each matching value;
+ * will be called once with a NULL value at the end
+ * @param proc_cls closure for proc
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel
+ */
+struct GNUNET_DATASTORE_QueueEntry *
+GNUNET_DATASTORE_get_key (struct GNUNET_DATASTORE_Handle *h, uint64_t offset,
+ 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_DatumProcessor proc, void *proc_cls);
+
+
+/**
+ * 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 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
+ */
+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,
+ struct GNUNET_TIME_Relative timeout,
+ enum GNUNET_BLOCK_Type type,
+ GNUNET_DATASTORE_DatumProcessor proc,
+ void *proc_cls);
+
+
+/**
+ * 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 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 proc_cls closure for proc
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * 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_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 */