lws-diskcache.h

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/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

 
struct lws_diskcache_scan;
 
/*
 * Cache object names are the caller's hash in hex: up to a SHA-512 hex name
 * (128 chars) plus the NUL.
 */
#define LWS_DISKCACHE_NAME_MAX          129
/*
 * The cache dir base with a subdir after it, "<base>/x/y", has to fit in this:
 * lws_diskcache_create() and lws_diskcache_prepare() refuse a base that does
 * not.
 */
#define LWS_DISKCACHE_DIR_MAX           256
/*
 * The longest object path lws_diskcache_query() composes, including the temp
 * name suffix used while the object is being created.  A cache path buffer of
 * this size works with any base that lws_diskcache_create() accepted.
 */
#define LWS_DISKCACHE_PATH_MAX          (LWS_DISKCACHE_DIR_MAX + \
                                         LWS_DISKCACHE_NAME_MAX + 32)

LWS_VISIBLE LWS_EXTERN struct lws_diskcache_scan *
lws_diskcache_create(const char *cache_dir_base, uint64_t cache_size_limit);

LWS_VISIBLE LWS_EXTERN void
lws_diskcache_destroy(struct lws_diskcache_scan **lds);

LWS_VISIBLE LWS_EXTERN int
lws_diskcache_prepare(const char *cache_base_dir, int mode, uid_t uid);
 
#define LWS_DISKCACHE_QUERY_NO_CACHE    0
#define LWS_DISKCACHE_QUERY_EXISTS      1
#define LWS_DISKCACHE_QUERY_CREATING    2
#define LWS_DISKCACHE_QUERY_ONGOING     3 /* something else is creating it */

LWS_VISIBLE LWS_EXTERN int
lws_diskcache_query(struct lws_diskcache_scan *lds, int is_bot,
                    const char *hash_hex, int *_fd, char *cache, int cache_len,
                    size_t *extant_cache_len);

LWS_VISIBLE LWS_EXTERN int
lws_diskcache_finalize_name(char *cache);

LWS_VISIBLE LWS_EXTERN int
lws_diskcache_trim(struct lws_diskcache_scan *lds);
 

LWS_VISIBLE LWS_EXTERN int
lws_diskcache_secs_to_idle(struct lws_diskcache_scan *lds);