60 lines
1.5 KiB
C
60 lines
1.5 KiB
C
/*-------------------------------------------------------------------------
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*
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* lispsort.c
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*
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* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/lib/Attic/lispsort.c,v 1.13 2000/01/26 05:56:26 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include <sys/types.h>
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#include "postgres.h"
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#ifdef NOT_USED
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/*
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** lisp_qsort: Takes a lisp list as input, copies it into an array of lisp
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** nodes which it sorts via qsort() with the comparison function
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** as passed into lisp_qsort(), and returns a new list with
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** the nodes sorted. The old list is *not* freed or modified (?)
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*/
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List *
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lisp_qsort(List *the_list, /* the list to be sorted */
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int (*compare) ()) /* function to compare two nodes */
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{
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int i;
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size_t num;
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List **nodearray;
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List *tmp,
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*output;
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/* find size of list */
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num = length(the_list);
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if (num < 2)
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return copyObject(the_list);
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/* copy elements of the list into an array */
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nodearray = (List **) palloc(num * sizeof(List *));
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for (tmp = the_list, i = 0; tmp != NIL; tmp = lnext(tmp), i++)
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nodearray[i] = copyObject(lfirst(tmp));
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/* sort the array */
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pg_qsort(nodearray, num, sizeof(List *), compare);
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/* lcons together the array elements */
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output = NIL;
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for (i = num - 1; i >= 0; i--)
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output = lcons(nodearray[i], output);
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return output;
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}
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#endif
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