tsearch.c revision da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2007 AT&T Knowledge Ventures *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Knowledge Ventures *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
/*
* tsearch() for systems that have <search.h> but no tsearch()
* why would such a system provide the interface but not the
* implementation? that's what happens when one slimes their
* way through standards compliance
*
* NOTE: please excuse the crude feature test
*/
#if !_UWIN
void _STUB_tsearch(){}
#else
#if _PACKAGE_ast
#include <ast.h>
#endif
#define tdelete ______tdelete
#define tfind ______tfind
#define tsearch ______tsearch
#define twalk ______twalk
#include <search.h>
#undef tdelete
#undef tfind
#undef tsearch
#undef twalk
#include "dthdr.h"
/* POSIX tsearch library based on libcdt
** Written by Kiem-Phong Vo (AT&T Research, 07/19/95)
*/
typedef struct _tree_s
{ Dtlink_t link;
Void_t* key;
} Tree_t;
typedef struct _treedisc_s
{ Dtdisc_t disc;
int(* comparf)_ARG_((const Void_t*, const Void_t*));
} Treedisc_t;
#if defined(__EXPORT__)
#define extern __EXPORT__
#endif
/* compare function */
#if __STD_C
static int treecompare(Dt_t* dt, char* one, char* two, Dtdisc_t* disc)
#else
static int treecompare(dt, one, two, disc)
Dt_t* dt;
char* one;
char* two;
Dtdisc_t* disc;
#endif
{
return (*((Treedisc_t*)disc)->comparf)((Void_t*)one,(Void_t*)two);
}
static Treedisc_t Treedisc =
{ { sizeof(Dtlink_t), -1, /* object is key */
0,
NIL(Dtmake_f), NIL(Dtfree_f),
treecompare,
NIL(Dthash_f),
NIL(Dtmemory_f),
NIL(Dtevent_f)
},
0
};
extern
#if __STD_C
Void_t* tsearch(const Void_t* key, Void_t** rootp,
int(*comparf)(const Void_t*,const Void_t*) )
#else
Void_t* tsearch(key, rootp, comparf)
Void_t* key;
Void_t** rootp;
int(* comparf)();
#endif
{
reg Dt_t* dt;
reg Tree_t* o;
if(!rootp ||
(!(dt = *((Dt_t**)rootp)) && !(dt = dtopen((Dtdisc_t*)(&Treedisc),Dtorder))) )
return NIL(Void_t*);
/* dangerous to set comparf on each call but that's tsearch */
Treedisc.comparf = comparf;
if(!(o = (Tree_t*)dtmatch(dt,key)) )
{ if(!(o = (Tree_t*)malloc(sizeof(Tree_t))) )
return NIL(Void_t*);
o->key = (Void_t*)key;
dtinsert(dt,o);
}
if(o)
*rootp = (Void_t*)dt;
else if(*rootp == NIL(Void_t*) )
dtclose(dt);
return (Void_t*)(&o->key);
}
extern
#if __STD_C
Void_t* tfind(const Void_t* key, Void_t*const* rootp,
int(*comparf)(const Void_t*, const Void_t*) )
#else
Void_t* tfind(key, rootp, comparf)
Void_t* key;
Void_t** rootp;
int(* comparf)();
#endif
{
reg Dt_t* dt;
reg Tree_t* o;
if(!rootp || !(dt = *((Dt_t**)rootp)) )
return NIL(Void_t*);
Treedisc.comparf = comparf;
return (o = (Tree_t*)dtmatch(dt,key)) ? (Void_t*)(&o->key) : NIL(Void_t*);
}
/* the original tdelete() specifies that it will return the parent pointer
** in the tree if there is one. Since we are using a splay tree, a deleted
** node is always rotated to the root first. So this implementation always
** returns the key of the new root.
*/
extern
#if __STD_C
Void_t* tdelete(const Void_t* key, Void_t** rootp,
int(*comparf)(const Void_t*, const Void_t*) )
#else
Void_t* tdelete(key, rootp, comparf)
Void_t* key;
Void_t** rootp;
int(* comparf)();
#endif
{
reg Dt_t* dt;
reg Tree_t* o;
Tree_t obj;
if(!rootp || !(dt = *((Dt_t**)rootp)) )
return NIL(Void_t*);
Treedisc.comparf = comparf;
obj.key = (Void_t*)key;
dtdelete(dt,&obj);
if(!(o = dtfinger(dt)) )
{ dtclose(dt);
*rootp = NIL(Void_t*);
}
return o ? (Void_t*)(&o->key) : NIL(Void_t*);
}
/* the below routine assumes a particular layout of Dtlink_t.
** If this ever gets changed, this routine should be redone.
*/
#define lchild link.hl._left
#define rchild link.right
#if __STD_C
static void _twalk(Tree_t* obj, void(*action)(const Void_t*,VISIT,int), int level)
#else
static void _twalk(obj,action,level)
Tree_t* obj;
void(* action)();
int level;
#endif
{ if(!obj->lchild && !obj->rchild)
(*action)((Void_t*)obj,leaf,level);
else
{ (*action)((Void_t*)obj,preorder,level);
if(obj->lchild)
_twalk((Tree_t*)obj->lchild,action,level+1);
(*action)((Void_t*)obj,postorder,level);
if(obj->rchild)
_twalk((Tree_t*)obj->rchild,action,level+1);
(*action)((Void_t*)obj,endorder,level);
}
}
/* the original twalk allows specifying arbitrary node to start traversal.
** Since our root is a dictionary structure, the search here will start
** at whichever node happens to be current root.
*/
extern
#if __STD_C
void twalk(const Void_t* root, void(*action)(const Void_t*,VISIT,int) )
#else
void twalk(root, action)
Void_t* root;
void(* action)();
#endif
{
reg Tree_t* o;
if(root && (o = (Tree_t*)dtfinger((Dt_t*)root)) )
_twalk(o,action,0);
}
#endif