/*
This file is part of GNUnet
- (C) 2009, 2011 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2009, 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_plugin.h
- * @brief API for the database backend plugins.
* @author Christian Grothoff
+ *
+ * @file
+ * API for the database backend plugins.
+ *
+ * @defgroup datastore-plugin Data Store service plugin API
+ * API for the database backend plugins.
+ * @{
*/
#ifndef PLUGIN_DATASTORE_H
#define PLUGIN_DATASTORE_H
* changes.
*
* @param cls closure
- * @param delta change in disk utilization,
+ * @param delta change in disk utilization,
* 0 for "reset to empty"
*/
-typedef void (*DiskUtilizationChange)(void *cls,
- int delta);
+typedef void
+(*GNUNET_DATASTORE_DiskUtilizationChange) (void *cls,
+ int delta);
/**
/**
* Function to call on disk utilization change.
*/
- DiskUtilizationChange duc;
+ GNUNET_DATASTORE_DiskUtilizationChange duc;
/**
* Closure.
/**
- * Function invoked on behalf of a "PluginIterator"
- * asking the database plugin to call the iterator
- * with the next item.
- *
- * @param next_cls whatever argument was given
- * to the PluginIterator as "next_cls".
- * @param end_it set to GNUNET_YES if we
- * should terminate the iteration early
- * (iterator should be still called once more
- * to signal the end of the iteration).
- */
-typedef void (*PluginNextRequest)(void *next_cls,
- int end_it);
-
-
-/**
- * An iterator over a set of items stored in the datastore.
+ * An processor over a set of items stored in the datastore.
*
* @param cls closure
- * @param next_cls closure to pass to the "next" function.
* @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 replication replication-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
- * (continue on call to "next", of course),
- * GNUNET_NO to delete the item and continue (if supported)
+ * @param uid unique identifier for the datum
+ * @return #GNUNET_OK to keep the item
+ * #GNUNET_NO to delete the item
*/
-typedef int (*PluginIterator) (void *cls,
- void *next_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 int
+(*PluginDatumProcessor) (void *cls,
+ const struct GNUNET_HashCode *key,
+ uint32_t size,
+ const void *data,
+ enum GNUNET_BLOCK_Type type,
+ uint32_t priority,
+ uint32_t anonymity,
+ uint32_t replication,
+ struct GNUNET_TIME_Absolute expiration,
+ uint64_t uid);
+
/**
* Get an estimate of how much space the database is
* currently using.
*
+ * NB: estimate is an output parameter because emscripten cannot handle
+ * returning 64-bit integers from dynamically loaded modules.
+ *
* @param cls closure
+ * @param estimate location to store estimate
* @return number of bytes used on disk
*/
-typedef unsigned long long (*PluginGetSize) (void *cls);
+typedef void
+(*PluginEstimateSize) (void *cls,
+ unsigned long long *estimate);
+
+
+/**
+ * Put continuation.
+ *
+ * @param cls closure
+ * @param key key for the item stored
+ * @param size size of the item stored
+ * @param status #GNUNET_OK if inserted, #GNUNET_NO if updated,
+ * or #GNUNET_SYSERROR if error
+ * @param msg error message on error
+ */
+typedef void
+(*PluginPutCont) (void *cls,
+ const struct GNUNET_HashCode *key,
+ uint32_t size,
+ int status,
+ const char *msg);
/**
*
* @param cls closure
* @param key key for the item
- * @param size number of bytes in data
+ * @param absent true if the key was not found in the bloom filter
+ * @param size number of bytes in @a 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 replication-level for the content
* @param expiration expiration time for the content
- * @param msg set to an error message (on failure)
- * @return GNUNET_OK on success,
- * GNUNET_SYSERR on failure
+ * @param cont continuation called with success or failure status
+ * @param cont_cls continuation closure for @a cont
+ */
+typedef void
+(*PluginPut) (void *cls,
+ const struct GNUNET_HashCode *key,
+ bool absent,
+ uint32_t size,
+ const void *data,
+ enum GNUNET_BLOCK_Type type,
+ uint32_t priority,
+ uint32_t anonymity,
+ uint32_t replication,
+ struct GNUNET_TIME_Absolute expiration,
+ PluginPutCont cont,
+ void *cont_cls);
+
+
+/**
+ * An processor over a set of keys stored in the datastore.
+ *
+ * @param cls closure
+ * @param key key in the data store, if NULL iteration is finished
+ * @param count how many values are stored under this key in the datastore
*/
-typedef int (*PluginPut) (void *cls,
- const GNUNET_HashCode * key,
- uint32_t size,
- const void *data,
- enum GNUNET_BLOCK_Type type,
- uint32_t priority,
- uint32_t anonymity,
- uint32_t replication,
- struct GNUNET_TIME_Absolute expiration,
- char **msg);
+typedef void
+(*PluginKeyProcessor) (void *cls,
+ const struct GNUNET_HashCode *key,
+ unsigned int count);
/**
- * Iterate over the results for a particular key
- * in the datastore.
+ * Get all of the keys in the datastore.
*
* @param cls closure
- * @param key key to match, never NULL
- * @param vhash hash of the value, maybe NULL (to
- * match all values that have the right key).
- * Note that for DBlocks there is no difference
- * betwen key and vhash, but for other blocks
- * there may be!
+ * @param proc function to call on each key
+ * @param proc_cls closure for @a proc
+ */
+typedef void
+(*PluginGetKeys) (void *cls,
+ PluginKeyProcessor proc,
+ void *proc_cls);
+
+
+/**
+ * Get one of the results for a particular key in the datastore.
+ *
+ * @param cls closure
+ * @param next_uid return the result with lowest uid >= next_uid
+ * @param random if true, return a random result instead of using next_uid
+ * @param key maybe NULL (to match all entries)
* @param type entries of which type are relevant?
* Use 0 for any type.
- * @param iter function to call on each matching value; however,
- * after the first call to "iter", the plugin must wait
- * until "NextRequest" was called before giving the iterator
- * the next item; finally, the "iter" should be called once
- * once with a NULL value at the end ("next_cls" should be NULL
- * for that last call)
- * @param iter_cls closure for iter
+ * @param proc function to call on the matching value;
+ * will be called with NULL if nothing matches
+ * @param proc_cls closure for @a proc
*/
-typedef void (*PluginGet) (void *cls,
- const GNUNET_HashCode *key,
- const GNUNET_HashCode *vhash,
- enum GNUNET_BLOCK_Type type,
- PluginIterator iter, void *iter_cls);
-
+typedef void
+(*PluginGetKey) (void *cls,
+ uint64_t next_uid,
+ bool random,
+ const struct GNUNET_HashCode *key,
+ enum GNUNET_BLOCK_Type type,
+ PluginDatumProcessor proc,
+ void *proc_cls);
/**
- * Get a random item (additional constraints may apply depending on
- * the specific implementation). Calls 'iter' with all values ZERO or
- * NULL if no item applies, otherwise 'iter' is called once and only
- * once with an item, with the 'next_cls' argument being NULL.
+ * Remove continuation.
*
* @param cls closure
- * @param iter function to call the value (once only).
- * @param iter_cls closure for iter
+ * @param key key for the content removed
+ * @param size number of bytes removed
+ * @param status #GNUNET_OK if removed, #GNUNET_NO if not found,
+ * or #GNUNET_SYSERROR if error
+ * @param msg error message on error
*/
-typedef void (*PluginRandomGet) (void *cls,
- PluginIterator iter, void *iter_cls);
+typedef void
+(*PluginRemoveCont) (void *cls,
+ const struct GNUNET_HashCode *key,
+ uint32_t size,
+ int status,
+ const char *msg);
/**
- * Update the priority for a particular key in the datastore. If
- * the expiration time in value is different than the time found in
- * the datastore, the higher value should be kept. For the
- * anonymity level, the lower value is to be used. The specified
- * priority should be added to the existing priority, ignoring the
- * priority in value.
+ * Remove a particular key in the datastore.
*
- * Note that it is possible for multiple values to match this put.
- * In that case, all of the respective values are updated.
+ * @param cls closure
+ * @param key key for the content
+ * @param size number of bytes in data
+ * @param data content stored
+ * @param cont continuation called with success or failure status
+ * @param cont_cls continuation closure for @a cont
+ */
+typedef void
+(*PluginRemoveKey) (void *cls,
+ const struct GNUNET_HashCode *key,
+ uint32_t size,
+ const void *data,
+ PluginRemoveCont cont,
+ void *cont_cls);
+
+
+/**
+ * Get a random item (additional constraints may apply depending on
+ * the specific implementation). Calls @a proc with all values ZERO or
+ * NULL if no item applies, otherwise @a proc is called once and only
+ * once with an item.
*
* @param cls closure
- * @param uid unique identifier of the datum
- * @param delta by how much should the priority
- * change? If priority + delta < 0 the
- * priority should be set to 0 (never go
- * negative).
- * @param expire new expiration time should be the
- * MAX of any existing expiration time and
- * this value
- * @param msg set to an error message (on error)
- * @return GNUNET_OK on success
+ * @param proc function to call the value (once only).
+ * @param proc_cls closure for @a proc
*/
-typedef int (*PluginUpdate) (void *cls,
- uint64_t uid,
- int delta,
- struct GNUNET_TIME_Absolute expire,
- char **msg);
+typedef void
+(*PluginGetRandom) (void *cls,
+ PluginDatumProcessor proc,
+ void *proc_cls);
/**
- * Select a subset of the items in the datastore and call the given
- * iterator for the first item; then allow getting more items by
- * calling the 'next_request' callback with the given 'next_cls'
- * argument passed to 'iter'.
+ * Select a single item from the datastore (among those applicable).
*
* @param cls closure
+ * @param next_uid return the result with lowest uid >= next_uid
* @param type entries of which type should be considered?
- * Myst not be zero (ANY).
- * @param iter function to call on each matching value; however,
- * after the first call to "iter", the plugin must wait
- * until "NextRequest" was called before giving the iterator
- * the next item; finally, the "iter" should be called once
- * once with a NULL value at the end ("next_cls" should be NULL
- * for that last call)
- * @param iter_cls closure for iter
+ * Must not be zero (ANY).
+ * @param proc function to call on the matching value;
+ * will be called with NULL if no value matches
+ * @param proc_cls closure for @a proc
*/
-typedef void (*PluginSelector) (void *cls,
- enum GNUNET_BLOCK_Type type,
- PluginIterator iter,
- void *iter_cls);
+typedef void
+(*PluginGetType) (void *cls,
+ uint64_t next_uid,
+ enum GNUNET_BLOCK_Type type,
+ PluginDatumProcessor proc,
+ void *proc_cls);
/**
*
* @param cls closure
*/
-typedef void (*PluginDrop) (void *cls);
-
+typedef void
+(*PluginDrop) (void *cls);
/**
void *cls;
/**
- * Get the current on-disk size of the SQ store. Estimates are
- * fine, if that's the only thing available.
+ * Calculate the current on-disk size of the SQ store. Estimates
+ * are fine, if that's the only thing available.
*/
- PluginGetSize get_size;
+ PluginEstimateSize estimate_size;
/**
* Function to store an item in the datastore.
PluginPut put;
/**
- * Update the priority for a particular key in the datastore. If
- * the expiration time in value is different than the time found in
- * the datastore, the higher value should be kept. For the
- * anonymity level, the lower value is to be used. The specified
- * priority should be added to the existing priority, ignoring the
- * priority in value.
+ * Get a particular datum matching a given hash from the datastore.
*/
- PluginUpdate update;
+ PluginGetKey get_key;
/**
- * Function called by iterators whenever they want the next value;
- * note that unlike all of the other callbacks, this one does get a
- * the "next_cls" closure which is usually different from the "cls"
- * member of this struct!
+ * Get datum (of the specified type) with anonymity level zero.
*/
- PluginNextRequest next_request;
-
- /**
- * Function to iterate over the results for a particular key
- * in the datastore.
- */
- PluginGet get;
-
- /**
- * Iterate over content with anonymity level zero.
- */
- PluginSelector iter_zero_anonymity;
+ PluginGetType get_zero_anonymity;
/**
* Function to get a random item with high replication score from
* the database, lowering the item's replication score. Returns a
- * single, not expired, random item from those with the highest
- * replication counters. The item's replication counter is
- * decremented by one IF it was positive before.
+ * single random item from those with the highest replication
+ * counters. The item's replication counter is decremented by one
+ * IF it was positive before.
*/
- PluginRandomGet replication_get;
+ PluginGetRandom get_replication;
/**
- * Function to get a random expired item or, if none are expired, one
- * with a low priority.
+ * Function to get a random expired item or, if none are expired,
+ * either the oldest entry or one with a low priority (depending
+ * on what was efficiently implementable).
*/
- PluginRandomGet expiration_get;
+ PluginGetRandom get_expiration;
/**
* Delete the database. The next operation is
*/
PluginDrop drop;
-};
+ /**
+ * Iterate over all keys in the database.
+ */
+ PluginGetKeys get_keys;
+ /**
+ * Function to remove an item from the database.
+ */
+ PluginRemoveKey remove_key;
+};
#endif
+
+/** @} */ /* end of group */
projects / oweals / gnunet.git / blobdiff