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/*
This file is part of GNUnet
Copyright (C) 2006, 2009, 2015 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 3, 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., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
/**
* @file datacache/plugin_datacache_template.c
* @brief template for an implementation of a database backend for the datacache
* @author Christian Grothoff
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_datacache_plugin.h"
/**
* Context for all functions in this plugin.
*/
struct Plugin
{
/**
* Our execution environment.
*/
struct GNUNET_DATACACHE_PluginEnvironment *env;
};
/**
* Store an item in the datastore.
*
* @param cls closure (our `struct Plugin`)
* @param key key to store @a data under
* @param am_closest are we the closest peer?
* @param size number of bytes in @a data
* @param data data to store
* @param type type of the value
* @param discard_time when to discard the value in any case
* @param path_info_len number of entries in @a path_info
* @param path_info a path through the network
* @return 0 if duplicate, -1 on error, number of bytes used otherwise
*/
static ssize_t
template_plugin_put (void *cls,
const struct GNUNET_HashCode *key,
int am_closest,
size_t size,
const char *data,
enum GNUNET_BLOCK_Type type,
struct GNUNET_TIME_Absolute discard_time,
unsigned int path_info_len,
const struct GNUNET_PeerIdentity *path_info)
{
GNUNET_break (0);
return -1;
}
/**
* Iterate over the results for a particular key
* in the datastore.
*
* @param cls closure (our `struct Plugin`)
* @param key
* @param type entries of which type are relevant?
* @param iter maybe NULL (to just count)
* @param iter_cls closure for @a iter
* @return the number of results found
*/
static unsigned int
template_plugin_get (void *cls,
const struct GNUNET_HashCode *key,
enum GNUNET_BLOCK_Type type,
GNUNET_DATACACHE_Iterator iter,
void *iter_cls)
{
GNUNET_break (0);
return 0;
}
/**
* Delete the entry with the lowest expiration value
* from the datacache right now.
*
* @param cls closure (our `struct Plugin`)
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
static int
template_plugin_del (void *cls)
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
/**
* Return a random value from the datastore.
*
* @param cls closure (internal context for the plugin)
* @param iter maybe NULL (to just count)
* @param iter_cls closure for @a iter
* @return the number of results found (zero or one)
*/
static unsigned int
template_plugin_get_random (void *cls,
GNUNET_DATACACHE_Iterator iter,
void *iter_cls)
{
GNUNET_break (0);
return 0;
}
/**
* Iterate over the results that are "close" to a particular key in
* the datacache. "close" is defined as numerically larger than @a
* key (when interpreted as a circular address space), with small
* distance.
*
* @param cls closure (internal context for the plugin)
* @param key area of the keyspace to look into
* @param num_results number of results that should be returned to @a iter
* @param iter maybe NULL (to just count)
* @param iter_cls closure for @a iter
* @return the number of results found
*/
static unsigned int
template_plugin_get_closest (void *cls,
const struct GNUNET_HashCode *key,
unsigned int num_results,
GNUNET_DATACACHE_Iterator iter,
void *iter_cls)
{
GNUNET_break (0);
return 0;
}
/**
* Entry point for the plugin.
*
* @param cls closure (the `struct GNUNET_DATACACHE_PluginEnvironmnet`)
* @return the plugin's closure (our `struct Plugin`)
*/
void *
libgnunet_plugin_datacache_template_init (void *cls)
{
struct GNUNET_DATACACHE_PluginEnvironment *env = cls;
struct GNUNET_DATACACHE_PluginFunctions *api;
struct Plugin *plugin;
plugin = GNUNET_new (struct Plugin);
plugin->env = env;
api = GNUNET_new (struct GNUNET_DATACACHE_PluginFunctions);
api->cls = plugin;
api->get = &template_plugin_get;
api->put = &template_plugin_put;
api->del = &template_plugin_del;
api->get_random = &template_plugin_get_random;
api->get_closest = &template_plugin_get_closest;
GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
"template",
"Template datacache running\n");
return api;
}
/**
* Exit point from the plugin.
*
* @param cls closure (our `struct Plugin`)
* @return NULL
*/
void *
libgnunet_plugin_datacache_template_done (void *cls)
{
struct GNUNET_DATACACHE_PluginFunctions *api = cls;
struct Plugin *plugin = api->cls;
GNUNET_free (plugin);
GNUNET_free (api);
return NULL;
}
/* end of plugin_datacache_template.c */
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