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root/Development/ray/src/common/savestr.c

Comparing ray/src/common/savestr.c (file contents):
Revision 2.1 by greg, Tue Nov 12 16:54:33 1991 UTC vs.
Revision 2.9 by schorsch, Fri Nov 14 17:22:06 2003 UTC

#	Line 1 | Line 1
1	–	/* Copyright 1988 Regents of the University of California */
2	–
1		#ifndef lint
2	<	static char SCCSid[] = "$SunId$ LBL";
2	>	static const char       RCSid[] = "$Id$";
3		#endif
6	–
4		/*
5		*  savestr.c - routines for efficient string storage.
6		*
#	Line 12 | Line 9 | static char SCCSid[] = "$SunId$ LBL";
9		*      All strings must be null-terminated.  There is
10		*  no imposed length limit.
11		*      Strings stored with savestr(s) can be equated
12	<	*  reliably using their pointer values.  A tailored version
16	<	*  of strcmp(s1,s2) is included.
12	>	*  reliably using their pointer values.
13		*      Calls to savestr(s) and freestr(s) should be
14		*  balanced (obviously).  The last call to freestr(s)
15		*  frees memory associated with the string; it should
16		*  never be referenced again.
17		*
18	<	*     5/14/87
18	>	*  External symbols declared in standard.h
19		*/
20
21	+	#include "copyright.h"
22	+
23	+	#include <string.h>
24	+	#include <stdlib.h>
25	+
26	+	#include "rtmisc.h"
27	+	#include "rterror.h"
28	+	#include "rtio.h"
29	+
30		#ifndef  NHASH
31		#define  NHASH          509             /* hash table size (prime!) */
32		#endif
#	Line 33 | Line 38 | typedef struct s_head {
38
39		static S_HEAD  *stab[NHASH];
40
41	<	static int  shash();
41	>	#define  hash(s)        (shash(s)%NHASH)
42
38	–	extern char  *savestr(), *strcpy(), *malloc();
39	–
40	–	#define  NULL           0
41	–
43		#define  string(sp)     ((char *)((sp)+1))
44
45		#define  salloc(str)    (S_HEAD *)malloc(sizeof(S_HEAD)+1+strlen(str))
46
47	<	#define  sfree(sp)      free((char *)(sp))
47	>	#define  sfree(sp)      free((void *)(sp))
48
49
50		char *
51	<	savestr(str)                            /* save a string */
51	<	char  *str;
51	>	savestr(char *str)                              /* save a string */
52		{
53		register int  hval;
54		register S_HEAD  *sp;
55
56		if (str == NULL)
57		return(NULL);
58	<	hval = shash(str);
58	>	hval = hash(str);
59		for (sp = stab[hval]; sp != NULL; sp = sp->next)
60		if (!strcmp(str, string(sp))) {
61		sp->nl++;
#	Line 73 | Line 73 | char  *str;
73		}
74
75
76	<	freestr(s)                              /* free a string */
77	<	char  *s;
76	>	void
77	>	freestr(char *s)                                /* free a string */
78		{
79		int  hval;
80		register S_HEAD  *spl, *sp;
81
82		if (s == NULL)
83		return;
84	<	hval = shash(s);
84	>	hval = hash(s);
85		for (spl = NULL, sp = stab[hval]; sp != NULL; spl = sp, sp = sp->next)
86		if (s == string(sp)) {
87		if (--sp->nl > 0)
#	Line 97 | Line 97 | char  *s;
97
98
99		int
100	<	strcmp(s1, s2)                          /* check for s1==s2 */
101	<	register char  *s1, *s2;
100	>	shash(register char  *s)
101		{
103	–	if (s1 == s2)
104	–	return(0);
105	–
106	–	while (*s1 == *s2++)
107	–	if (!*s1++)
108	–	return(0);
109	–
110	–	return(*s1 - *--s2);
111	–	}
112	–
113	–
114	–	static int
115	–	shash(s)                                /* hash a string */
116	–	register char  *s;
117	–	{
102		register int  h = 0;
103
104		while (*s)
105	<	h += *s++;
106	<
123	<	return(h % NHASH);
105	>	h = (h<<1 & 0x7fff) ^ (*s++ & 0xff);
106	>	return(h);
107		}

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