lws-lwsac.h

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/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010 - 2020 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 lwsac;
typedef unsigned char * lwsac_cached_file_t;
 
 
#define lws_list_ptr_container(P,T,M) ((T *)((char *)(P) - offsetof(T, M)))
 
/*
 * linked-list helper that's commonly useful to manage lists of things
 * allocated using lwsac.
 *
 * These lists point to their corresponding "next" member in the target, NOT
 * the original containing struct.  To get the containing struct, you must use
 * lws_list_ptr_container() to convert.
 *
 * It's like that because it means we no longer have to have the next pointer
 * at the start of the struct, and we can have the same struct on multiple
 * linked-lists with everything held in the struct itself.
 */
typedef void * lws_list_ptr;
 
/*
 * optional sorting callback called by lws_list_ptr_insert() to sort the right
 * things inside the opqaue struct being sorted / inserted on the list.
 */
typedef int (*lws_list_ptr_sort_func_t)(lws_list_ptr a, lws_list_ptr b);
 
#define lws_list_ptr_advance(_lp) _lp = *((void **)_lp)
 
/* sort may be NULL if you don't care about order */
LWS_VISIBLE LWS_EXTERN void
lws_list_ptr_insert(lws_list_ptr *phead, lws_list_ptr *add,
                    lws_list_ptr_sort_func_t sort);
 
 
LWS_VISIBLE LWS_EXTERN void *
lwsac_use(struct lwsac **head, size_t ensure, size_t chunk_size);
 
LWS_VISIBLE LWS_EXTERN void *
lwsac_use_backfill(struct lwsac **head, size_t ensure, size_t chunk_size);
 
LWS_VISIBLE LWS_EXTERN void *
lwsac_use_zero(struct lwsac **head, size_t ensure, size_t chunk_size);
 
#define lwsac_use_zeroed lwsac_use_zero
 
LWS_VISIBLE LWS_EXTERN void
lwsac_free(struct lwsac **head);
 
/*
 * Optional helpers useful for where consumers may need to defer destruction
 * until all consumers are finished with the lwsac
 */
 
LWS_VISIBLE LWS_EXTERN void
lwsac_detach(struct lwsac **head);
 
LWS_VISIBLE LWS_EXTERN void
lwsac_reference(struct lwsac *head);
 
LWS_VISIBLE LWS_EXTERN void
lwsac_unreference(struct lwsac **head);
 
LWS_VISIBLE LWS_EXTERN int
lwsac_extend(struct lwsac *head, size_t amount);
 
/* helpers to keep a file cached in memory */
 
LWS_VISIBLE LWS_EXTERN void
lwsac_use_cached_file_start(lwsac_cached_file_t cache);
 
LWS_VISIBLE LWS_EXTERN void
lwsac_use_cached_file_end(lwsac_cached_file_t *cache);
 
LWS_VISIBLE LWS_EXTERN void
lwsac_use_cached_file_detach(lwsac_cached_file_t *cache);
 
LWS_VISIBLE LWS_EXTERN int
lwsac_cached_file(const char *filepath, lwsac_cached_file_t *cache,
                  size_t *len);
 
/* more advanced helpers */
 
/* offset from lac to start of payload, first = 1 = first lac in chain */
LWS_VISIBLE LWS_EXTERN size_t
lwsac_sizeof(int first);
 
LWS_VISIBLE LWS_EXTERN size_t
lwsac_get_tail_pos(struct lwsac *lac);
 
LWS_VISIBLE LWS_EXTERN struct lwsac *
lwsac_get_next(struct lwsac *lac);
 
LWS_VISIBLE LWS_EXTERN size_t
lwsac_align(size_t length);
 
LWS_VISIBLE LWS_EXTERN void
lwsac_info(struct lwsac *head);
 
LWS_VISIBLE LWS_EXTERN uint64_t
lwsac_total_alloc(struct lwsac *head);
 
LWS_VISIBLE LWS_EXTERN uint64_t
lwsac_total_overhead(struct lwsac *head);
 
LWS_VISIBLE LWS_EXTERN uint8_t *
lwsac_scan_extant(struct lwsac *head, uint8_t *find, size_t len, int nul);