static bool lookup_by_uid(const uid_t uid, struct cache_info **info)
{
struct cache_info prototype = {
.uid = uid
};
void **cache_slot = (void **)
&uid_grplist_cache[prototype.uid % id_cache_size];
struct avltree_node *found_node = atomic_fetch_voidptr(cache_slot);
struct cache_info *found_info;
bool found = false;
/* Verify that the node found in the cache array is in fact what we
* want.
*/
if (likely(found_node)) {
found_info =
avltree_container_of(found_node, struct cache_info,
uid_node);
if (found_info->uid == uid)
found = true;
}
if (unlikely(!found)) {
found_node = avltree_lookup(&prototype.uid_node, &uid_tree);
if (unlikely(!found_node))
return false;
atomic_store_voidptr(cache_slot, found_node);
found_info =
avltree_container_of(found_node, struct cache_info,
uid_node);
}
static bool lookup_by_uname(const struct gsh_buffdesc *name,
struct cache_info **info)
{
struct cache_info prototype = {
.uname = *name
};
struct avltree_node *found_node = avltree_lookup(&prototype.uname_node,
&uname_tree);
struct cache_info *found_info;
void **cache_slot;
if (unlikely(!found_node))
return false;
found_info = avltree_container_of(found_node,
struct cache_info,
uname_node);
/* I assume that if someone likes this user enough to look it
up by name, they'll like it enough to look it up by ID
later. */
cache_slot = (void **)
&uid_grplist_cache[found_info->uid % id_cache_size];
atomic_store_voidptr(cache_slot, &found_info->uid_node);
*info = found_info;
return true;
}
/**
* @brief Locate a key within a partition
*
* This function traverses the red-black tree within a hash table
* partition and returns, if one exists, a pointer to a node matching
* the supplied key.
*
* @param[in] ht The hashtable to be used
* @param[in] key The key to look up
* @param[in] index Index into RBT array
* @param[in] rbthash Hash in red-black tree
* @param[out] node On success, the found node, NULL otherwise
*
* @retval HASHTABLE_SUCCESS if successfull
* @retval HASHTABLE_NO_SUCH_KEY if key was not found
*/
static hash_error_t
key_locate(struct hash_table *ht, const struct gsh_buffdesc *key,
uint32_t index, uint64_t rbthash, struct rbt_node **node)
{
/* The current partition */
struct hash_partition *partition = &(ht->partitions[index]);
/* The root of the red black tree matching this index */
struct rbt_head *root = NULL;
/* A pair of buffer descriptors locating key and value for this
entry */
struct hash_data *data = NULL;
/* The node in the red-black tree currently being traversed */
struct rbt_node *cursor = NULL;
/* true if we have located the key */
int found = false;
*node = NULL;
if (partition->cache) {
void **cache_slot = (void **)
&(partition->cache[cache_offsetof(ht, rbthash)]);
cursor = atomic_fetch_voidptr(cache_slot);
LogFullDebug(COMPONENT_HASHTABLE_CACHE,
"hash %s index %" PRIu32 " slot %d",
(cursor) ? "hit" : "miss", index,
cache_offsetof(ht, rbthash));
if (cursor) {
data = RBT_OPAQ(cursor);
if (ht->parameter.
compare_key((struct gsh_buffdesc *)key,
&(data->key)) == 0) {
goto out;
}
}
}
root = &(ht->partitions[index].rbt);
/* The lefmost occurrence of the value is the one from which we
may start iteration to visit all nodes containing a value. */
RBT_FIND_LEFT(root, cursor, rbthash);
if (cursor == NULL) {
if (isFullDebug(COMPONENT_HASHTABLE)
&& isFullDebug(ht->parameter.ht_log_component))
LogFullDebug(ht->parameter.ht_log_component,
"Key not found: rbthash = %" PRIu64,
rbthash);
return HASHTABLE_ERROR_NO_SUCH_KEY;
}
while ((cursor != NULL) && (RBT_VALUE(cursor) == rbthash)) {
data = RBT_OPAQ(cursor);
if (ht->parameter.
compare_key((struct gsh_buffdesc *)key,
&(data->key)) == 0) {
if (partition->cache) {
void **cache_slot = (void **)
&(partition->
cache[cache_offsetof(ht, rbthash)]);
atomic_store_voidptr(cache_slot, cursor);
}
found = true;
break;
}
RBT_INCREMENT(cursor);
}
if (!found) {
if (isFullDebug(COMPONENT_HASHTABLE)
&& isFullDebug(ht->parameter.ht_log_component))
LogFullDebug(ht->parameter.ht_log_component,
"Matching hash found, but no matching key.");
return HASHTABLE_ERROR_NO_SUCH_KEY;
}
out:
*node = cursor;
return HASHTABLE_SUCCESS;
}
