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.
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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 include/gnunet_datacache_plugin.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 *
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
63 * Configuration to use.
65 const struct GNUNET_CONFIGURATION_Handle *cfg;
68 * Configuration section to use.
73 * Closure to use for callbacks.
78 * Function to call whenever the plugin needs to
79 * discard content that it was asked to store.
81 GNUNET_DATACACHE_DeleteNotifyCallback delete_notify;
84 * How much space are we allowed to use?
86 unsigned long long quota;
92 * @brief struct returned by the initialization function of the plugin
94 struct GNUNET_DATACACHE_PluginFunctions
98 * Closure to pass to all plugin functions.
103 * Store an item in the datastore.
105 * @param cls closure (internal context for the plugin)
106 * @param size number of bytes in data
107 * @param data data to store
108 * @param type type of the value
109 * @param discard_time when to discard the value in any case
110 * @return 0 on error, number of bytes used otherwise
112 size_t (*put) (void *cls, const GNUNET_HashCode * key, size_t size,
113 const char *data, enum GNUNET_BLOCK_Type type,
114 struct GNUNET_TIME_Absolute discard_time);
118 * Iterate over the results for a particular key
121 * @param cls closure (internal context for the plugin)
123 * @param type entries of which type are relevant?
124 * @param iter maybe NULL (to just count)
125 * @param iter_cls closure for iter
126 * @return the number of results found
128 unsigned int (*get) (void *cls, const GNUNET_HashCode * key,
129 enum GNUNET_BLOCK_Type type,
130 GNUNET_DATACACHE_Iterator iter, void *iter_cls);
134 * Delete the entry with the lowest expiration value
135 * from the datacache right now.
137 * @param cls closure (internal context for the plugin)
138 * @return GNUNET_OK on success, GNUNET_SYSERR on error
140 int (*del) (void *cls);
146 #if 0 /* keep Emacsens' auto-indent happy */
153 /* end of gnunet_datacache_plugin.h */