mirror of
https://github.com/shadowsocks/shadowsocks-libev.git
synced 2026-10-31 06:23:52 +00:00
WiP
This commit is contained in:
Max Lv
+207
@@ -0,0 +1,207 @@
|
||||
/*
|
||||
* Original Author: Oliver Lorenz (ol), olli@olorenz.org, https://olorenz.org
|
||||
* License: This is licensed under the same terms as uthash itself
|
||||
*/
|
||||
|
||||
#include <errno.h>
|
||||
#include <pthread.h>
|
||||
#include <stdlib.h>
|
||||
#include "cache.h"
|
||||
#include "uthash.h"
|
||||
|
||||
/**
|
||||
* A cache entry
|
||||
*/
|
||||
struct client_cache_entry {
|
||||
char *key; /**<The key */
|
||||
void *data; /**<Payload */
|
||||
UT_hash_handle hh; /**<Hash Handle for uthash */
|
||||
};
|
||||
#define KEY_MAX_LENGTH 32
|
||||
|
||||
/**
|
||||
* A cache object
|
||||
*/
|
||||
struct client_cache {
|
||||
size_t max_entries; /**<Amount of entries this cache object can hold */
|
||||
pthread_rwlock_t cache_lock; /**<A lock for concurrent access */
|
||||
struct client_cache_entry *entries; /**<Head pointer for uthash */
|
||||
void (*free_cb) (void *element);/**<Callback function to free cache entries */
|
||||
};
|
||||
|
||||
/** Creates a new cache object
|
||||
|
||||
@param dst
|
||||
Where the newly allocated cache object will be stored in
|
||||
|
||||
@param capacity
|
||||
The maximum number of elements this cache object can hold
|
||||
|
||||
@return EINVAL if dst is NULL, ENOMEM if malloc fails, 0 otherwise
|
||||
*/
|
||||
int client_cache_create(struct client_cache **dst, const size_t capacity,
|
||||
void (*free_cb) (void *element))
|
||||
{
|
||||
struct client_cache *new = NULL;
|
||||
int rv;
|
||||
|
||||
if (!dst)
|
||||
return EINVAL;
|
||||
|
||||
if ((new = malloc(sizeof(*new))) == NULL)
|
||||
return ENOMEM;
|
||||
|
||||
if ((rv = pthread_rwlock_init(&(new->cache_lock), NULL)) != 0)
|
||||
goto err_out;
|
||||
|
||||
new->max_entries = capacity;
|
||||
new->entries = NULL;
|
||||
new->free_cb = free_cb;
|
||||
*dst = new;
|
||||
return 0;
|
||||
|
||||
err_out:
|
||||
if (new)
|
||||
free(new);
|
||||
return rv;
|
||||
}
|
||||
|
||||
/** Frees an allocated cache object
|
||||
|
||||
@param cache
|
||||
The cache object to free
|
||||
|
||||
@param keep_data
|
||||
Whether to free contained data or just delete references to it
|
||||
|
||||
@return EINVAL if cache is NULL, 0 otherwise
|
||||
*/
|
||||
int client_cache_delete(struct client_cache *cache, int keep_data)
|
||||
{
|
||||
struct client_cache_entry *entry, *tmp;
|
||||
int rv;
|
||||
|
||||
if (!cache)
|
||||
return EINVAL;
|
||||
|
||||
rv = pthread_rwlock_wrlock(&(cache->cache_lock));
|
||||
if (rv)
|
||||
return rv;
|
||||
|
||||
if (keep_data) {
|
||||
HASH_CLEAR(hh, cache->entries);
|
||||
} else {
|
||||
HASH_ITER(hh, cache->entries, entry, tmp) {
|
||||
HASH_DEL(cache->entries, entry);
|
||||
if (cache->free_cb)
|
||||
cache->free_cb(entry->data);
|
||||
free(entry);
|
||||
}
|
||||
}
|
||||
(void)pthread_rwlock_unlock(&(cache->cache_lock));
|
||||
(void)pthread_rwlock_destroy(&(cache->cache_lock));
|
||||
free(cache);
|
||||
cache = NULL;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/** Checks if a given key is in the cache
|
||||
|
||||
@param cache
|
||||
The cache object
|
||||
|
||||
@param key
|
||||
The key to look-up
|
||||
|
||||
@param result
|
||||
Where to store the result if key is found.
|
||||
|
||||
A warning: Even though result is just a pointer,
|
||||
you have to call this function with a **ptr,
|
||||
otherwise this will blow up in your face.
|
||||
|
||||
@return EINVAL if cache is NULL, 0 otherwise
|
||||
*/
|
||||
int client_cache_lookup(struct client_cache *cache, char *key, void *result)
|
||||
{
|
||||
int rv;
|
||||
struct client_cache_entry *tmp = NULL;
|
||||
char **dirty_hack = result;
|
||||
|
||||
if (!cache || !key || !result)
|
||||
return EINVAL;
|
||||
|
||||
rv = pthread_rwlock_wrlock(&(cache->cache_lock));
|
||||
if (rv)
|
||||
return rv;
|
||||
|
||||
HASH_FIND_STR(cache->entries, key, tmp);
|
||||
if (tmp) {
|
||||
size_t key_len = strnlen(tmp->key, KEY_MAX_LENGTH);
|
||||
HASH_DELETE(hh, cache->entries, tmp);
|
||||
HASH_ADD_KEYPTR(hh, cache->entries, tmp->key, key_len, tmp);
|
||||
*dirty_hack = tmp->data;
|
||||
} else {
|
||||
*dirty_hack = result = NULL;
|
||||
}
|
||||
rv = pthread_rwlock_unlock(&(cache->cache_lock));
|
||||
return rv;
|
||||
}
|
||||
|
||||
/** Inserts a given <key, value> pair into the cache
|
||||
|
||||
@param cache
|
||||
The cache object
|
||||
|
||||
@param key
|
||||
The key that identifies <value>
|
||||
|
||||
@param data
|
||||
Data associated with <key>
|
||||
|
||||
@return EINVAL if cache is NULL, ENOMEM if malloc fails, 0 otherwise
|
||||
*/
|
||||
int client_cache_insert(struct client_cache *cache, char *key, void *data)
|
||||
{
|
||||
struct client_cache_entry *entry = NULL;
|
||||
struct client_cache_entry *tmp_entry = NULL;
|
||||
size_t key_len = 0;
|
||||
int rv;
|
||||
|
||||
if (!cache || !data)
|
||||
return EINVAL;
|
||||
|
||||
if ((entry = malloc(sizeof(*entry))) == NULL)
|
||||
return ENOMEM;
|
||||
|
||||
if ((rv = pthread_rwlock_wrlock(&(cache->cache_lock))) != 0)
|
||||
goto err_out;
|
||||
|
||||
entry->key = key;
|
||||
entry->data = data;
|
||||
key_len = strnlen(entry->key, KEY_MAX_LENGTH);
|
||||
HASH_ADD_KEYPTR(hh, cache->entries, entry->key, key_len, entry);
|
||||
|
||||
if (HASH_COUNT(cache->entries) >= cache->max_entries) {
|
||||
HASH_ITER(hh, cache->entries, entry, tmp_entry) {
|
||||
HASH_DELETE(hh, cache->entries, entry);
|
||||
if (cache->free_cb)
|
||||
cache->free_cb(entry->data);
|
||||
else
|
||||
free(entry->data);
|
||||
/* free(key->key) if data has been copied */
|
||||
free(entry);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
rv = pthread_rwlock_unlock(&(cache->cache_lock));
|
||||
return rv;
|
||||
|
||||
err_out:
|
||||
if (entry)
|
||||
free(entry);
|
||||
(void)pthread_rwlock_unlock(&(cache->cache_lock));
|
||||
return rv;
|
||||
|
||||
}
|
||||
Reference in New Issue
Block a user