mirror of git://git.gnupg.org/gnupg.git
82 lines
2.7 KiB
C
82 lines
2.7 KiB
C
/* Binary tree data structure.
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Copyright (C) 2006 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#ifndef _TSEARCH_H
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#define _TSEARCH_H
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#if HAVE_TSEARCH
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/* Get tseach(), tfind(), tdelete(), twalk() declarations. */
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#include <search.h>
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#else
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* See <http://www.opengroup.org/susv3xbd/search.h.html>,
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<http://www.opengroup.org/susv3xsh/tsearch.html>
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for details. */
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typedef enum
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{
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preorder,
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postorder,
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endorder,
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leaf
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}
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VISIT;
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/* Searches an element in the tree *VROOTP that compares equal to KEY.
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If one is found, it is returned. Otherwise, a new element equal to KEY
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is inserted in the tree and is returned. */
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extern void * tsearch (const void *key, void **vrootp,
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int (*compar) (const void *, const void *));
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/* Searches an element in the tree *VROOTP that compares equal to KEY.
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If one is found, it is returned. Otherwise, NULL is returned. */
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extern void * tfind (const void *key, void *const *vrootp,
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int (*compar) (const void *, const void *));
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/* Searches an element in the tree *VROOTP that compares equal to KEY.
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If one is found, it is removed from the tree, and its parent node is
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returned. Otherwise, NULL is returned. */
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extern void * tdelete (const void *key, void **vrootp,
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int (*compar) (const void *, const void *));
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/* Perform a depth-first, left-to-right traversal of the tree VROOT.
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The ACTION function is called:
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- for non-leaf nodes: 3 times, before the left subtree traversal,
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after the left subtree traversal but before the right subtree traversal,
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and after the right subtree traversal,
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- for leaf nodes: once.
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The arguments passed to ACTION are:
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1. the node; it can be casted to a 'const void * const *', i.e. into a
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pointer to the key,
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2. an indicator which visit of the node this is,
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3. the level of the node in the tree (0 for the root). */
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extern void twalk (const void *vroot,
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void (*action) (const void *, VISIT, int));
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#ifdef __cplusplus
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}
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#endif
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#endif
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#endif /* _TSEARCH_H */
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