lws-dll2.h

/*
 * 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.
 */
 
 
#define lws_start_foreach_ll(type, it, start)\
{ \
        type it = start; \
        while (it) {
 
#define lws_end_foreach_ll(it, nxt) \
                it = it->nxt; \
        } \
}
 
#define lws_start_foreach_ll_safe(type, it, start, nxt)\
{ \
        type it = start; \
        while (it) { \
                type next_##it = it->nxt;
 
#define lws_end_foreach_ll_safe(it) \
                it = next_##it; \
        } \
}
 
#define lws_start_foreach_llp(type, it, start)\
{ \
        type it = &(start); \
        while (*(it)) {
 
#define lws_start_foreach_llp_safe(type, it, start, nxt)\
{ \
        type it = &(start); \
        type next; \
        while (*(it)) { \
                next = &((*(it))->nxt); \
 
#define lws_end_foreach_llp(it, nxt) \
                it = &(*(it))->nxt; \
        } \
}
 
#define lws_end_foreach_llp_safe(it) \
                it = next; \
        } \
}
 
#define lws_ll_fwd_insert(\
        ___new_object,  /* pointer to new object */ \
        ___m_list,      /* member for next list object ptr */ \
        ___list_head    /* list head */ \
                ) {\
                ___new_object->___m_list = ___list_head; \
                ___list_head = ___new_object; \
        }
 
#define lws_ll_fwd_remove(\
        ___type,        /* type of listed object */ \
        ___m_list,      /* member for next list object ptr */ \
        ___target,      /* object to remove from list */ \
        ___list_head    /* list head */ \
        ) { \
                lws_start_foreach_llp(___type **, ___ppss, ___list_head) { \
                        if (*___ppss == ___target) { \
                                *___ppss = ___target->___m_list; \
                                break; \
                        } \
                } lws_end_foreach_llp(___ppss, ___m_list); \
        }
 
 
/*
 * doubly linked-list
 */
 
/*
 * lws_dll2_owner / lws_dll2 : more capable version of lws_dll.  Differences:
 *
 *  - there's an explicit lws_dll2_owner struct which holds head, tail and
 *    count of members.
 *
 *  - list members all hold a pointer to their owner.  So user code does not
 *    have to track anything about exactly what lws_dll2_owner list the object
 *    is a member of.
 *
 *  - you can use lws_dll unless you want the member count or the ability to
 *    not track exactly which list it's on.
 *
 *  - layout is compatible with lws_dll (but lws_dll apis will not update the
 *    new stuff)
 */
 
 
struct lws_dll2;
struct lws_dll2_owner;
 
typedef struct lws_dll2 {
        struct lws_dll2         *prev;
        struct lws_dll2         *next;
        struct lws_dll2_owner   *owner;
} lws_dll2_t;
 
typedef struct lws_dll2_owner {
        struct lws_dll2         *tail;
        struct lws_dll2         *head;
 
        uint32_t                count;
} lws_dll2_owner_t;
 
LWS_VISIBLE LWS_EXTERN int
lws_dll2_is_detached(const struct lws_dll2 *d);
 
static LWS_INLINE const struct lws_dll2_owner *
lws_dll2_owner(const struct lws_dll2 *d) { return d->owner; }
 
static LWS_INLINE struct lws_dll2 *
lws_dll2_get_head(struct lws_dll2_owner *owner) { return owner->head; }
 
static LWS_INLINE struct lws_dll2 *
lws_dll2_get_tail(struct lws_dll2_owner *owner) { return owner->tail; }
 
LWS_VISIBLE LWS_EXTERN void
lws_dll2_add_head(struct lws_dll2 *d, struct lws_dll2_owner *owner);
 
LWS_VISIBLE LWS_EXTERN void
lws_dll2_add_tail(struct lws_dll2 *d, struct lws_dll2_owner *owner);
 
LWS_VISIBLE LWS_EXTERN void
lws_dll2_remove(struct lws_dll2 *d);
 
typedef int (*lws_dll2_foreach_cb_t)(struct lws_dll2 *d, void *user);
 
LWS_VISIBLE LWS_EXTERN int
lws_dll2_foreach_safe(struct lws_dll2_owner *owner, void *user,
                      lws_dll2_foreach_cb_t cb);
 
LWS_VISIBLE LWS_EXTERN void
lws_dll2_clear(struct lws_dll2 *d);
 
LWS_VISIBLE LWS_EXTERN void
lws_dll2_owner_clear(struct lws_dll2_owner *d);
 
LWS_VISIBLE LWS_EXTERN void
lws_dll2_add_before(struct lws_dll2 *d, struct lws_dll2 *after);
 
LWS_VISIBLE LWS_EXTERN void
lws_dll2_add_sorted(lws_dll2_t *d, lws_dll2_owner_t *own,
                    int (*compare)(const lws_dll2_t *d, const lws_dll2_t *i));
 
LWS_VISIBLE LWS_EXTERN void
lws_dll2_add_sorted_priv(lws_dll2_t *d, lws_dll2_owner_t *own, void *priv,
                         int (*compare3)(void *priv, const lws_dll2_t *d,
                                         const lws_dll2_t *i));
 
LWS_VISIBLE LWS_EXTERN void *
_lws_dll2_search_sz_pl(lws_dll2_owner_t *own, const char *name, size_t namelen,
                      size_t dll2_ofs, size_t ptr_ofs);
 
/*
 * Searches objects in an owner list linearly and returns one with a given
 * member C-string matching a supplied length-provided string if it exists, else
 * NULL.
 */
 
#define lws_dll2_search_sz_pl(own, name, namelen, type, membd2list, membptr) \
                ((type *)_lws_dll2_search_sz_pl(own, name, namelen, \
                                       offsetof(type, membd2list), \
                                       offsetof(type, membptr)))
 
#if defined(_DEBUG)
void
lws_dll2_describe(struct lws_dll2_owner *owner, const char *desc);
#else
#define lws_dll2_describe(x, y)
#endif
 
/*
 * these are safe against the current container object getting deleted,
 * since the hold his next in a temp and go to that next.  ___tmp is
 * the temp.
 */
 
#define lws_start_foreach_dll_safe(___type, ___it, ___tmp, ___start) \
{ \
        ___type ___it = ___start; \
        while (___it) { \
                ___type ___tmp = (___it)->next;
 
#define lws_end_foreach_dll_safe(___it, ___tmp) \
                ___it = ___tmp; \
        } \
}
 
#define lws_start_foreach_dll(___type, ___it, ___start) \
{ \
        ___type ___it = ___start; \
        while (___it) {
 
#define lws_end_foreach_dll(___it) \
                ___it = (___it)->next; \
        } \
}