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Diffstat (limited to 'package/libnl-tiny/src/cache_mngt.c')
-rw-r--r-- | package/libnl-tiny/src/cache_mngt.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/package/libnl-tiny/src/cache_mngt.c b/package/libnl-tiny/src/cache_mngt.c new file mode 100644 index 0000000..d57d836 --- /dev/null +++ b/package/libnl-tiny/src/cache_mngt.c @@ -0,0 +1,249 @@ +/* + * lib/cache_mngt.c Cache Management + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation version 2.1 + * of the License. + * + * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch> + */ + +/** + * @ingroup core + * @defgroup cache_mngt Caching + * @{ + */ + +#include <netlink-local.h> +#include <netlink/netlink.h> +#include <netlink/cache.h> +#include <netlink/utils.h> + +static struct nl_cache_ops *cache_ops; + +/** + * @name Cache Operations Sets + * @{ + */ + +/** + * Lookup the set cache operations of a certain cache type + * @arg name name of the cache type + * + * @return The cache operations or NULL if no operations + * have been registered under the specified name. + */ +struct nl_cache_ops *nl_cache_ops_lookup(const char *name) +{ + struct nl_cache_ops *ops; + + for (ops = cache_ops; ops; ops = ops->co_next) + if (!strcmp(ops->co_name, name)) + return ops; + + return NULL; +} + +/** + * Associate a message type to a set of cache operations + * @arg protocol netlink protocol + * @arg msgtype netlink message type + * + * Associates the specified netlink message type with + * a registered set of cache operations. + * + * @return The cache operations or NULL if no association + * could be made. + */ +struct nl_cache_ops *nl_cache_ops_associate(int protocol, int msgtype) +{ + int i; + struct nl_cache_ops *ops; + + for (ops = cache_ops; ops; ops = ops->co_next) { + if (ops->co_protocol != protocol) + continue; + + for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++) + if (ops->co_msgtypes[i].mt_id == msgtype) + return ops; + } + + return NULL; +} + +/** + * Lookup message type cache association + * @arg ops cache operations + * @arg msgtype netlink message type + * + * Searches for a matching message type association ing the specified + * cache operations. + * + * @return A message type association or NULL. + */ +struct nl_msgtype *nl_msgtype_lookup(struct nl_cache_ops *ops, int msgtype) +{ + int i; + + for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++) + if (ops->co_msgtypes[i].mt_id == msgtype) + return &ops->co_msgtypes[i]; + + return NULL; +} + +static struct nl_cache_ops *cache_ops_lookup_for_obj(struct nl_object_ops *obj_ops) +{ + struct nl_cache_ops *ops; + + for (ops = cache_ops; ops; ops = ops->co_next) + if (ops->co_obj_ops == obj_ops) + return ops; + + return NULL; + +} + +/** + * Call a function for each registered cache operation + * @arg cb Callback function to be called + * @arg arg User specific argument. + */ +void nl_cache_ops_foreach(void (*cb)(struct nl_cache_ops *, void *), void *arg) +{ + struct nl_cache_ops *ops; + + for (ops = cache_ops; ops; ops = ops->co_next) + cb(ops, arg); +} + +/** + * Register a set of cache operations + * @arg ops cache operations + * + * Called by users of caches to announce the avaibility of + * a certain cache type. + * + * @return 0 on success or a negative error code. + */ +int nl_cache_mngt_register(struct nl_cache_ops *ops) +{ + if (!ops->co_name || !ops->co_obj_ops) + return -NLE_INVAL; + + if (nl_cache_ops_lookup(ops->co_name)) + return -NLE_EXIST; + + ops->co_next = cache_ops; + cache_ops = ops; + + NL_DBG(1, "Registered cache operations %s\n", ops->co_name); + + return 0; +} + +/** + * Unregister a set of cache operations + * @arg ops cache operations + * + * Called by users of caches to announce a set of + * cache operations is no longer available. The + * specified cache operations must have been registered + * previously using nl_cache_mngt_register() + * + * @return 0 on success or a negative error code + */ +int nl_cache_mngt_unregister(struct nl_cache_ops *ops) +{ + struct nl_cache_ops *t, **tp; + + for (tp = &cache_ops; (t=*tp) != NULL; tp = &t->co_next) + if (t == ops) + break; + + if (!t) + return -NLE_NOCACHE; + + NL_DBG(1, "Unregistered cache operations %s\n", ops->co_name); + + *tp = t->co_next; + return 0; +} + +/** @} */ + +/** + * @name Global Cache Provisioning/Requiring + * @{ + */ + +/** + * Provide a cache for global use + * @arg cache cache to provide + * + * Offers the specified cache to be used by other modules. + * Only one cache per type may be shared at a time, + * a previsouly provided caches will be overwritten. + */ +void nl_cache_mngt_provide(struct nl_cache *cache) +{ + struct nl_cache_ops *ops; + + ops = cache_ops_lookup_for_obj(cache->c_ops->co_obj_ops); + if (!ops) + BUG(); + else + ops->co_major_cache = cache; +} + +/** + * Unprovide a cache for global use + * @arg cache cache to unprovide + * + * Cancels the offer to use a cache globally. The + * cache will no longer be returned via lookups but + * may still be in use. + */ +void nl_cache_mngt_unprovide(struct nl_cache *cache) +{ + struct nl_cache_ops *ops; + + ops = cache_ops_lookup_for_obj(cache->c_ops->co_obj_ops); + if (!ops) + BUG(); + else if (ops->co_major_cache == cache) + ops->co_major_cache = NULL; +} + +/** + * Demand the use of a global cache + * @arg name name of the required object type + * + * Trys to find a cache of the specified type for global + * use. + * + * @return A cache provided by another subsystem of the + * specified type marked to be available. + */ +struct nl_cache *nl_cache_mngt_require(const char *name) +{ + struct nl_cache_ops *ops; + + ops = nl_cache_ops_lookup(name); + if (!ops || !ops->co_major_cache) { + fprintf(stderr, "Application BUG: Your application must " + "call nl_cache_mngt_provide() and\nprovide a valid " + "%s cache to be used for internal lookups.\nSee the " + " API documentation for more details.\n", name); + + return NULL; + } + + return ops->co_major_cache; +} + +/** @} */ + +/** @} */ |