2 This file is part of GNUnet
3 (C) 2006, 2009 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file datacache/plugin_datacache.h
23 * @brief API for database backends for the datacache
24 * @author Christian Grothoff
26 #ifndef PLUGIN_DATACACHE_H
27 #define PLUGIN_DATACACHE_H
29 #include "gnunet_datacache_lib.h"
34 #if 0 /* keep Emacsens' auto-indent happy */
41 * Function called by plugins to notify the datacache
42 * about content deletions.
45 * @param key key of the content that was deleted
46 * @param size number of bytes that were made available
48 typedef void (*GNUNET_DATACACHE_DeleteNotifyCallback)(void *cls,
49 const GNUNET_HashCode *key,
54 * The datastore service will pass a pointer to a struct
55 * of this type as the first and only argument to the
56 * entry point of each datastore plugin.
58 struct GNUNET_DATACACHE_PluginEnvironment
64 struct GNUNET_SCHEDULER_Handle *sched;
67 * Configuration to use.
69 const struct GNUNET_CONFIGURATION_Handle *cfg;
72 * Configuration section to use.
77 * Closure to use for callbacks.
82 * Function to call whenever the plugin needs to
83 * discard content that it was asked to store.
85 GNUNET_DATACACHE_DeleteNotifyCallback delete_notify;
88 * How much space are we allowed to use?
90 unsigned long long quota;
96 * @brief struct returned by the initialization function of the plugin
98 struct GNUNET_DATACACHE_PluginFunctions {
101 * Closure to pass to all plugin functions.
106 * Store an item in the datastore.
108 * @param cls closure (internal context for the plugin)
109 * @param size number of bytes in data
110 * @param data data to store
111 * @param type type of the value
112 * @param discard_time when to discard the value in any case
113 * @return 0 on error, number of bytes used otherwise
115 uint32_t (*put) (void *cls,
116 const GNUNET_HashCode * key,
119 enum GNUNET_BLOCK_Type type,
120 struct GNUNET_TIME_Absolute discard_time);
124 * Iterate over the results for a particular key
127 * @param cls closure (internal context for the plugin)
129 * @param type entries of which type are relevant?
130 * @param iter maybe NULL (to just count)
131 * @param iter_cls closure for iter
132 * @return the number of results found
134 unsigned int (*get) (void *cls,
135 const GNUNET_HashCode * key,
136 enum GNUNET_BLOCK_Type type,
137 GNUNET_DATACACHE_Iterator iter,
142 * Delete the entry with the lowest expiration value
143 * from the datacache right now.
145 * @param cls closure (internal context for the plugin)
146 * @return GNUNET_OK on success, GNUNET_SYSERR on error
148 int (*del) (void *cls);
154 #if 0 /* keep Emacsens' auto-indent happy */
161 /* end of plugin_datacache.h */