list.h

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/* -*- C -*- */
/*
 * Copyright (c) 2012-2020 Seagate Technology LLC and/or its Affiliates
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * For any questions about this software or licensing,
 * please email opensource@seagate.com or cortx-questions@seagate.com.
 *
 */


#pragma once

#ifndef __MOTR_LIB_LIST_H__
#define __MOTR_LIB_LIST_H__

#include "lib/misc.h"  /* offsetof */

struct m0_list_link {
        struct m0_list_link *ll_next;
        struct m0_list_link *ll_prev;
} M0_XCA_RECORD M0_XCA_DOMAIN(be);

M0_INTERNAL void m0_list_link_init(struct m0_list_link *link);

M0_INTERNAL void m0_list_link_fini(struct m0_list_link *link);

M0_INTERNAL bool m0_list_link_invariant(const struct m0_list_link *link);

struct m0_list {
        struct m0_list_link *l_head;
        struct m0_list_link *l_tail;
} M0_XCA_RECORD M0_XCA_DOMAIN(be);

/*
   It is necessary that m0_list and m0_list_link structures have exactly the
   same layout as.
 */

M0_BASSERT(offsetof(struct m0_list, l_head) ==
           offsetof(struct m0_list_link, ll_next));
M0_BASSERT(offsetof(struct m0_list, l_tail) ==
           offsetof(struct m0_list_link, ll_prev));

M0_INTERNAL void m0_list_init(struct m0_list *head);

M0_INTERNAL void m0_list_fini(struct m0_list *head);

M0_INTERNAL bool m0_list_is_empty(const struct m0_list *head);

M0_INTERNAL bool m0_list_contains(const struct m0_list *list,
                                  const struct m0_list_link *link);

M0_INTERNAL bool m0_list_invariant(const struct m0_list *list);

M0_INTERNAL size_t m0_list_length(const struct m0_list *list);

M0_INTERNAL void m0_list_add(struct m0_list *head, struct m0_list_link *next);

M0_INTERNAL void m0_list_add_tail(struct m0_list *head,
                                  struct m0_list_link *next);

M0_INTERNAL void m0_list_add_after(struct m0_list_link *anchor,
                                   struct m0_list_link *next);

M0_INTERNAL void m0_list_add_before(struct m0_list_link *anchor,
                                    struct m0_list_link *next);

M0_INTERNAL void m0_list_del(struct m0_list_link *old);

M0_INTERNAL void m0_list_move(struct m0_list *head, struct m0_list_link *next);

M0_INTERNAL void m0_list_move_tail(struct m0_list *head,
                                   struct m0_list_link *next);

static inline struct m0_list_link *m0_list_first(const struct m0_list *head)
{
        return head->l_head !=
                (struct m0_list_link *)head ?
                head->l_head : (struct m0_list_link *)NULL;
}


M0_INTERNAL bool m0_list_link_is_in(const struct m0_list_link *link);

M0_INTERNAL bool m0_list_link_is_last(const struct m0_list_link *link,
                                      const struct m0_list *head);

M0_INTERNAL size_t m0_list_length(const struct m0_list *list);

#define m0_list_entry(link, type, member) \
        container_of(link, type, member)

#define m0_list_for_each(head, pos) \
        for (pos = (head)->l_head; pos != (void *)(head); \
             pos = (pos)->ll_next)

#define m0_list_for_each_entry(head, pos, type, member) \
        for (pos = m0_list_entry((head)->l_head, type, member); \
             &(pos->member) != (void *)head; \
             pos = m0_list_entry((pos)->member.ll_next, type, member))

#define m0_list_for_each_entry_safe(head, pos, next, type, member)      \
        for (pos = m0_list_entry((head)->l_head, type, member),         \
             next = m0_list_entry((pos)->member.ll_next, type, member); \
             &(pos)->member != (void *)head;                            \
             pos = next,                                                \
             next = m0_list_entry((next)->member.ll_next, type, member))

#define m0_list_forall(var, head, ...)          \
({                                              \
        struct m0_list_link *var;               \
                                                \
        m0_list_for_each(head, var) {           \
                if (!({ __VA_ARGS__ ; }))       \
                    break;                      \
        }                                       \
        var == (void *)head;                    \
})

#define m0_list_entry_forall(var, head, type, member, ...)              \
({                                                                      \
        type *var;                                                      \
        type *next;                                                     \
                                                                        \
        m0_list_for_each_entry_safe(head, var, next, type, member) {    \
                if (!({ __VA_ARGS__ ; }))                               \
                    break;                                              \
        }                                                               \
        &var->member == (void *)head;                                   \
})

#define m0_list_teardown(head, pos, type, member) \
  while (!m0_list_is_empty((head)) && \
         ((pos) = m0_list_entry((head)->l_head, type, member)) && \
         (m0_list_del(&(pos)->member), true))

#endif /* __MOTR_LIB_LIST_H__ */

/*
 *  Local variables:
 *  c-indentation-style: "K&R"
 *  c-basic-offset: 8
 *  tab-width: 8
 *  fill-column: 80
 *  scroll-step: 1
 *  End:
 */