/*
* Looks up or creates a cache entry for the specified key.
*/
static struct fsentry *fscache_get(struct fsentry *key)
{
struct fsentry *fse, *future, *waiter;
int dir_not_found;
EnterCriticalSection(&mutex);
/* check if entry is in cache */
fse = fscache_get_wait(key);
if (fse) {
if (fse->st_mode)
fsentry_addref(fse);
else
fse = NULL; /* non-existing directory */
LeaveCriticalSection(&mutex);
return fse;
}
/* if looking for a file, check if directory listing is in cache */
if (!fse && key->list) {
fse = fscache_get_wait(key->list);
if (fse) {
LeaveCriticalSection(&mutex);
/*
* dir entry without file entry, or dir does not
* exist -> file doesn't exist
*/
errno = ENOENT;
return NULL;
}
}
/* add future entry to indicate that we're loading it */
future = key->list ? key->list : key;
future->next = NULL;
future->refcnt = 0;
hashmap_add(&map, future);
/* create the directory listing (outside mutex!) */
LeaveCriticalSection(&mutex);
fse = fsentry_create_list(future, &dir_not_found);
EnterCriticalSection(&mutex);
/* remove future entry and signal waiting threads */
hashmap_remove(&map, future, NULL);
waiter = future->next;
while (waiter) {
HANDLE h = waiter->hwait;
waiter = waiter->next;
SetEvent(h);
}
/* leave on error (errno set by fsentry_create_list) */
if (!fse) {
if (dir_not_found && key->list) {
/*
* Record that the directory does not exist (or is
* empty, which for all practical matters is the same
* thing as far as fscache is concerned).
*/
fse = fsentry_alloc(key->list->list,
key->list->name, key->list->len);
fse->st_mode = 0;
hashmap_add(&map, fse);
}
LeaveCriticalSection(&mutex);
return NULL;
}
/* add directory listing to the cache */
fscache_add(fse);
/* lookup file entry if requested (fse already points to directory) */
if (key->list)
fse = hashmap_get(&map, key, NULL);
if (fse && !fse->st_mode)
fse = NULL; /* non-existing directory */
/* return entry or ENOENT */
if (fse)
fsentry_addref(fse);
else
errno = ENOENT;
LeaveCriticalSection(&mutex);
return fse;
}
/*
* Looks up or creates a cache entry for the specified key.
*/
static struct fsentry *fscache_get(struct fsentry *key)
{
struct fsentry *fse, *future, *waiter;
EnterCriticalSection(&mutex);
/* check if entry is in cache */
fse = fscache_get_wait(key);
if (fse) {
fsentry_addref(fse);
LeaveCriticalSection(&mutex);
return fse;
}
/* if looking for a file, check if directory listing is in cache */
if (!fse && key->list) {
fse = fscache_get_wait(key->list);
if (fse) {
LeaveCriticalSection(&mutex);
/* dir entry without file entry -> file doesn't exist */
errno = ENOENT;
return NULL;
}
}
/* add future entry to indicate that we're loading it */
future = key->list ? key->list : key;
future->next = NULL;
future->refcnt = 0;
hashmap_add(&map, future);
/* create the directory listing (outside mutex!) */
LeaveCriticalSection(&mutex);
fse = fsentry_create_list(future);
EnterCriticalSection(&mutex);
/* remove future entry and signal waiting threads */
hashmap_remove(&map, future, NULL);
waiter = future->next;
while (waiter) {
HANDLE h = waiter->hwait;
waiter = waiter->next;
SetEvent(h);
}
/* leave on error (errno set by fsentry_create_list) */
if (!fse) {
LeaveCriticalSection(&mutex);
return NULL;
}
/* add directory listing to the cache */
fscache_add(fse);
/* lookup file entry if requested (fse already points to directory) */
if (key->list)
fse = hashmap_get(&map, key, NULL);
/* return entry or ENOENT */
if (fse)
fsentry_addref(fse);
else
errno = ENOENT;
LeaveCriticalSection(&mutex);
return fse;
}
