xref: /titanic_41/usr/src/lib/libast/common/comp/tsearch.c (revision 0f1702c5201310f0529cd5abb77652e5e9b241b6)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                      by AT&T Knowledge Ventures                      *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 /*
23  * tsearch() for systems that have <search.h> but no tsearch()
24  * why would such a system provide the interface but not the
25  * implementation? that's what happens when one slimes their
26  * way through standards compliance
27  *
28  * NOTE: please excuse the crude feature test
29  */
30 
31 #if !_UWIN
32 
33 void _STUB_tsearch(){}
34 
35 #else
36 
37 #if _PACKAGE_ast
38 #include	<ast.h>
39 #endif
40 
41 #define tdelete		______tdelete
42 #define tfind		______tfind
43 #define tsearch		______tsearch
44 #define twalk		______twalk
45 
46 #include	<search.h>
47 
48 #undef	tdelete
49 #undef	tfind
50 #undef	tsearch
51 #undef	twalk
52 
53 #include	"dthdr.h"
54 
55 /*	POSIX tsearch library based on libcdt
56 **	Written by Kiem-Phong Vo (AT&T Research, 07/19/95)
57 */
58 
59 typedef struct _tree_s
60 {	Dtlink_t	link;
61 	Void_t*		key;
62 } Tree_t;
63 
64 typedef struct _treedisc_s
65 {	Dtdisc_t	disc;
66 	int(*		comparf)_ARG_((const Void_t*, const Void_t*));
67 } Treedisc_t;
68 
69 #if defined(__EXPORT__)
70 #define extern	__EXPORT__
71 #endif
72 
73 /* compare function */
74 #if __STD_C
75 static int treecompare(Dt_t* dt, char* one, char* two, Dtdisc_t* disc)
76 #else
77 static int treecompare(dt, one, two, disc)
78 Dt_t*		dt;
79 char*		one;
80 char*		two;
81 Dtdisc_t*	disc;
82 #endif
83 {
84 	return (*((Treedisc_t*)disc)->comparf)((Void_t*)one,(Void_t*)two);
85 }
86 
87 static Treedisc_t	Treedisc =
88 {	{ sizeof(Dtlink_t), -1,	/* object is key		*/
89 	  0,
90 	  NIL(Dtmake_f), NIL(Dtfree_f),
91 	  treecompare,
92 	  NIL(Dthash_f),
93 	  NIL(Dtmemory_f),
94 	  NIL(Dtevent_f)
95 	},
96 	0
97 };
98 
99 extern
100 #if __STD_C
101 Void_t* tsearch(const Void_t* key, Void_t** rootp,
102 		int(*comparf)(const Void_t*,const Void_t*) )
103 #else
104 Void_t* tsearch(key, rootp, comparf)
105 Void_t*		key;
106 Void_t**	rootp;
107 int(*		comparf)();
108 #endif
109 {
110 	reg Dt_t*	dt;
111 	reg Tree_t*	o;
112 
113 	if(!rootp ||
114 	   (!(dt = *((Dt_t**)rootp)) && !(dt = dtopen((Dtdisc_t*)(&Treedisc),Dtorder))) )
115 		return NIL(Void_t*);
116 
117 	/* dangerous to set comparf on each call but that's tsearch */
118 	Treedisc.comparf = comparf;
119 
120 	if(!(o = (Tree_t*)dtmatch(dt,key)) )
121 	{	if(!(o = (Tree_t*)malloc(sizeof(Tree_t))) )
122 			return NIL(Void_t*);
123 		o->key = (Void_t*)key;
124 		dtinsert(dt,o);
125 	}
126 
127 	if(o)
128 		*rootp = (Void_t*)dt;
129 	else if(*rootp == NIL(Void_t*) )
130 		dtclose(dt);
131 
132 	return (Void_t*)(&o->key);
133 }
134 
135 extern
136 #if __STD_C
137 Void_t* tfind(const Void_t* key, Void_t*const* rootp,
138 		int(*comparf)(const Void_t*, const Void_t*) )
139 #else
140 Void_t* tfind(key, rootp, comparf)
141 Void_t*		key;
142 Void_t**	rootp;
143 int(*		comparf)();
144 #endif
145 {
146 	reg Dt_t*	dt;
147 	reg Tree_t*	o;
148 
149 	if(!rootp || !(dt = *((Dt_t**)rootp)) )
150 		return NIL(Void_t*);
151 	Treedisc.comparf = comparf;
152 
153 	return (o = (Tree_t*)dtmatch(dt,key)) ? (Void_t*)(&o->key) : NIL(Void_t*);
154 }
155 
156 /* the original tdelete() specifies that it will return the parent pointer
157 ** in the tree if there is one. Since we are using a splay tree, a deleted
158 ** node is always rotated to the root first. So this implementation always
159 ** returns the key of the new root.
160 */
161 extern
162 #if __STD_C
163 Void_t* tdelete(const Void_t* key, Void_t** rootp,
164 		int(*comparf)(const Void_t*, const Void_t*) )
165 #else
166 Void_t* tdelete(key, rootp, comparf)
167 Void_t*		key;
168 Void_t**	rootp;
169 int(*		comparf)();
170 #endif
171 {
172 	reg Dt_t*	dt;
173 	reg Tree_t*	o;
174 	Tree_t		obj;
175 
176 	if(!rootp || !(dt = *((Dt_t**)rootp)) )
177 		return NIL(Void_t*);
178 
179 	Treedisc.comparf = comparf;
180 
181 	obj.key = (Void_t*)key;
182 	dtdelete(dt,&obj);
183 
184 	if(!(o = dtfinger(dt)) )
185 	{	dtclose(dt);
186 		*rootp = NIL(Void_t*);
187 	}
188 
189 	return o ? (Void_t*)(&o->key) : NIL(Void_t*);
190 }
191 
192 /* the below routine assumes a particular layout of Dtlink_t.
193 ** If this ever gets changed, this routine should be redone.
194 */
195 #define lchild	link.hl._left
196 #define rchild	link.right
197 
198 #if __STD_C
199 static void _twalk(Tree_t* obj, void(*action)(const Void_t*,VISIT,int), int level)
200 #else
201 static void _twalk(obj,action,level)
202 Tree_t*	obj;
203 void(*		action)();
204 int		level;
205 #endif
206 {	if(!obj->lchild && !obj->rchild)
207 		(*action)((Void_t*)obj,leaf,level);
208 	else
209 	{	(*action)((Void_t*)obj,preorder,level);
210 		if(obj->lchild)
211 			_twalk((Tree_t*)obj->lchild,action,level+1);
212 		(*action)((Void_t*)obj,postorder,level);
213 		if(obj->rchild)
214 			_twalk((Tree_t*)obj->rchild,action,level+1);
215 		(*action)((Void_t*)obj,endorder,level);
216 	}
217 }
218 
219 /* the original twalk allows specifying arbitrary node to start traversal.
220 ** Since our root is a dictionary structure, the search here will start
221 ** at whichever node happens to be current root.
222 */
223 extern
224 #if __STD_C
225 void twalk(const Void_t* root, void(*action)(const Void_t*,VISIT,int) )
226 #else
227 void twalk(root, action)
228 Void_t*	root;
229 void(*	action)();
230 #endif
231 {
232 	reg Tree_t*	o;
233 
234 	if(root && (o = (Tree_t*)dtfinger((Dt_t*)root)) )
235 		_twalk(o,action,0);
236 }
237 
238 #endif
239