113 lines
5.2 KiB
C
113 lines
5.2 KiB
C
/*
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* BSD linked list implementation - extracted for use with liberasurecode
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*
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*/
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#ifndef _LIST_H
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#define _LIST_H
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/*
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* A singly-linked list is headed by a single forward pointer. The elements
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* are singly linked for minimum space and pointer manipulation overhead at
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* the expense of O(n) removal for arbitrary elements. New elements can be
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* added to the list after an existing element or at the head of the list.
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* Elements being removed from the head of the list should use the explicit
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* macro for this purpose for optimum efficiency. A singly-linked list may
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* only be traversed in the forward direction. Singly-linked lists are ideal
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* for applications with large datasets and few or no removals or for
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* implementing a LIFO queue.
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*/
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/*
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* Singly-linked List declarations.
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*/
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#define SLIST_HEAD(name, type) \
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struct name { \
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struct type *slh_first; /* first element */ \
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}
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#define SLIST_HEAD_INITIALIZER(head) \
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{ NULL }
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#define SLIST_ENTRY(type) \
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struct { \
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struct type *sle_next; /* next element */ \
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}
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/*
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* Singly-linked List functions.
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*/
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#define SLIST_EMPTY(head) ((head)->slh_first == NULL)
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#define SLIST_FIRST(head) ((head)->slh_first)
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#define SLIST_FOREACH(var, head, field) \
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for ((var) = SLIST_FIRST((head)); \
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(var); \
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(var) = SLIST_NEXT((var), field))
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#define SLIST_INIT(head) do { \
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SLIST_FIRST((head)) = NULL; \
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} while (0)
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#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
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SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \
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SLIST_NEXT((slistelm), field) = (elm); \
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} while (0)
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#define SLIST_INSERT_HEAD(head, elm, field) do { \
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SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \
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SLIST_FIRST((head)) = (elm); \
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} while (0)
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#define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
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#define SLIST_REMOVE(head, elm, type, field) do { \
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if (SLIST_FIRST((head)) == (elm)) { \
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SLIST_REMOVE_HEAD((head), field); \
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} \
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else { \
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struct type *curelm = SLIST_FIRST((head)); \
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while (SLIST_NEXT(curelm, field) != (elm)) \
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curelm = SLIST_NEXT(curelm, field); \
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SLIST_NEXT(curelm, field) = \
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SLIST_NEXT(SLIST_NEXT(curelm, field), field); \
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} \
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} while (0)
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#define SLIST_REMOVE_HEAD(head, field) do { \
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SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \
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} while (0)
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#endif // _LIST_H
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