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/* $OpenBSD: lstRequeue.c,v 1.1 2008/01/12 13:05:57 espie Exp $ */ |
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/* |
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* Copyright (c) 2008 Marc Espie. |
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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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* |
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* THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS |
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBSD |
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* PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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*/ |
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#include "lstInt.h" |
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#include <stdlib.h> |
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/* Lst_Requeue(l, ln): takes node ln from the list and requeue it at front. |
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*/ |
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void |
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Lst_Requeue(Lst l, LstNode ln) |
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{ |
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/* already at front */ |
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if (l->firstPtr == ln) |
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return; |
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/* unlink element */ |
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if (ln->nextPtr != NULL) |
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ln->nextPtr->prevPtr = ln->prevPtr; |
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if (ln->prevPtr != NULL) |
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ln->prevPtr->nextPtr = ln->nextPtr; |
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if (l->lastPtr == ln) |
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l->lastPtr = ln->prevPtr; |
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/* relink at front */ |
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ln->nextPtr = l->firstPtr; |
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ln->prevPtr = NULL; |
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l->firstPtr->prevPtr = ln; |
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l->firstPtr = ln; |
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} |
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