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Diffstat (limited to 'src/include/gnunet_datacache_plugin.h')
-rw-r--r-- | src/include/gnunet_datacache_plugin.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/src/include/gnunet_datacache_plugin.h b/src/include/gnunet_datacache_plugin.h new file mode 100644 index 0000000..fbfcdf1 --- /dev/null +++ b/src/include/gnunet_datacache_plugin.h @@ -0,0 +1,154 @@ +/* + This file is part of GNUnet + (C) 2006, 2009 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 + by the Free Software Foundation; either version 2, or (at your + option) any later version. + + GNUnet is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + 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. +*/ + +/** + * @file include/gnunet_datacache_plugin.h + * @brief API for database backends for the datacache + * @author Christian Grothoff + */ +#ifndef PLUGIN_DATACACHE_H +#define PLUGIN_DATACACHE_H + +#include "gnunet_datacache_lib.h" + +#ifdef __cplusplus +extern "C" +{ +#if 0 /* keep Emacsens' auto-indent happy */ +} +#endif +#endif + + +/** + * Function called by plugins to notify the datacache + * about content deletions. + * + * @param cls closure + * @param key key of the content that was deleted + * @param size number of bytes that were made available + */ +typedef void (*GNUNET_DATACACHE_DeleteNotifyCallback) (void *cls, + const GNUNET_HashCode * + key, size_t size); + + +/** + * The datastore service will pass a pointer to a struct + * of this type as the first and only argument to the + * entry point of each datastore plugin. + */ +struct GNUNET_DATACACHE_PluginEnvironment +{ + + + /** + * Configuration to use. + */ + const struct GNUNET_CONFIGURATION_Handle *cfg; + + /** + * Configuration section to use. + */ + const char *section; + + /** + * Closure to use for callbacks. + */ + void *cls; + + /** + * Function to call whenever the plugin needs to + * discard content that it was asked to store. + */ + GNUNET_DATACACHE_DeleteNotifyCallback delete_notify; + + /** + * How much space are we allowed to use? + */ + unsigned long long quota; + +}; + + +/** + * @brief struct returned by the initialization function of the plugin + */ +struct GNUNET_DATACACHE_PluginFunctions +{ + + /** + * Closure to pass to all plugin functions. + */ + void *cls; + + /** + * Store an item in the datastore. + * + * @param cls closure (internal context for the plugin) + * @param size number of bytes in data + * @param data data to store + * @param type type of the value + * @param discard_time when to discard the value in any case + * @return 0 on error, number of bytes used otherwise + */ + size_t (*put) (void *cls, const GNUNET_HashCode * key, size_t size, + const char *data, enum GNUNET_BLOCK_Type type, + struct GNUNET_TIME_Absolute discard_time); + + + /** + * Iterate over the results for a particular key + * in the datastore. + * + * @param cls closure (internal context for the plugin) + * @param key + * @param type entries of which type are relevant? + * @param iter maybe NULL (to just count) + * @param iter_cls closure for iter + * @return the number of results found + */ + unsigned int (*get) (void *cls, const GNUNET_HashCode * key, + enum GNUNET_BLOCK_Type type, + GNUNET_DATACACHE_Iterator iter, void *iter_cls); + + + /** + * Delete the entry with the lowest expiration value + * from the datacache right now. + * + * @param cls closure (internal context for the plugin) + * @return GNUNET_OK on success, GNUNET_SYSERR on error + */ + int (*del) (void *cls); + + +}; + + +#if 0 /* keep Emacsens' auto-indent happy */ +{ +#endif +#ifdef __cplusplus +} +#endif + +/* end of gnunet_datacache_plugin.h */ +#endif |