--- /dev/null
+/*
+ * 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) 2003-2006 Thomas Graf <tgraf@suug.ch>
+ */
+
+/**
+ * @ingroup utils
+ * @defgroup cache_mngt Cache Management
+ * @{
+ */
+
+#include <netlink-local.h>
+#include <netlink/netlink.h>
+#include <netlink/cache.h>
+#include <netlink/utils.h>
+
+/**
+ * @name Access Functions
+ * @{
+ */
+
+/**
+ * Return the cache type of the cache operations
+ * @arg ops cache operations
+ */
+char *nl_cache_ops_get_name(struct nl_cache_ops *ops)
+{
+ return ops->co_name;
+}
+
+/** @} */
+
+/**
+ * @name Message Type Association
+ * @{
+ */
+
+static struct nl_cache_ops *cache_ops;
+
+/**
+ * Associate a message type to a set of cache operations
+ * @arg protocol netlink protocol
+ * @arg message_type 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_mngt_associate(int protocol, int message_type)
+{
+ int i;
+ struct nl_cache_ops *ops;
+
+ for (ops = cache_ops; ops; ops = ops->co_next)
+ for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++)
+ if (ops->co_msgtypes[i].mt_id == message_type &&
+ ops->co_protocol == protocol)
+ return ops;
+
+ return NULL;
+}
+
+/**
+ * Convert message type to character string.
+ * @arg ops Cache operations.
+ * @arg msgtype Message type.
+ * @arg buf Destination buffer.
+ * @arg len Size of destination buffer.
+ *
+ * Converts a message type to a character string and stores it in the
+ * provided buffer.
+ *
+ * @return The destination buffer or the message type encoded in
+ * hexidecimal form if no match was found.
+ */
+char *nl_cache_mngt_type2name(struct nl_cache_ops *ops, int msgtype,
+ char *buf, size_t len)
+{
+ int i;
+
+ for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++) {
+ if (ops->co_msgtypes[i].mt_id == msgtype) {
+ snprintf(buf, len, "%s::%s",
+ ops->co_name,
+ ops->co_msgtypes[i].mt_name);
+ return buf;
+ }
+ }
+
+ snprintf(buf, len, "%s->0x%x()", ops->co_name, msgtype);
+ return buf;
+}
+
+/** @} */
+
+/**
+ * @name Cache Type Management
+ * @{
+ */
+
+/**
+ * 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_mngt_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;
+}
+
+/**
+ * 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)
+ return nl_error(EINVAL, "No cache name specified");
+
+ if (nl_cache_mngt_lookup(ops->co_name))
+ return nl_error(EEXIST, "Cache operations already 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 nl_error(ENOENT, "No such cache operations");
+
+ 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 = nl_cache_mngt_lookup(cache->c_ops->co_name);
+ 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 = nl_cache_mngt_lookup(cache->c_ops->co_name);
+ 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 cache 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_mngt_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;
+}
+
+/** @} */
+
+/** @} */
git://git.onelab.eu / libnl.git / blobdiff