1 /* ----------------------------------------------------------------------- *
2 *
3 * Copyright 2008 H. Peter Anvin - All Rights Reserved
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
8 * Boston MA 02110-1301, USA; either version 2 of the License, or
9 * (at your option) any later version; incorporated herein by reference.
10 *
11 * ----------------------------------------------------------------------- */
12
13 /*
14 * refstr.c
15 *
16 * Simple reference-counted strings
17 */
18
19 #include <stdlib.h>
20 #include <string.h>
21 #include <stdio.h>
22 #include <sys/module.h>
23 #include "refstr.h"
24
25 /* Allocate space for a refstring of len bytes, plus final null */
26 /* The final null is inserted in the string; the rest is uninitialized. */
refstr_alloc(size_t len)27 char *refstr_alloc(size_t len)
28 {
29 char *r = malloc(sizeof(unsigned int) + len + 1);
30 if (!r)
31 return NULL;
32 *(unsigned int *)r = 1;
33 r += sizeof(unsigned int);
34 r[len] = '\0';
35 return r;
36 }
37
refstrndup(const char * str,size_t len)38 const char *refstrndup(const char *str, size_t len)
39 {
40 char *r;
41
42 if (!str)
43 return NULL;
44
45 len = strnlen(str, len);
46 r = refstr_alloc(len);
47 if (r)
48 memcpy(r, str, len);
49 return r;
50 }
51
refstrdup(const char * str)52 const char *refstrdup(const char *str)
53 {
54 char *r;
55 size_t len;
56
57 if (!str)
58 return NULL;
59
60 len = strlen(str);
61 r = refstr_alloc(len);
62 if (r)
63 memcpy(r, str, len);
64 return r;
65 }
66
vrsprintf(const char ** bufp,const char * fmt,va_list ap)67 int vrsprintf(const char **bufp, const char *fmt, va_list ap)
68 {
69 va_list ap1;
70 int len;
71 char *p;
72
73 va_copy(ap1, ap);
74 len = vsnprintf(NULL, 0, fmt, ap1);
75 va_end(ap1);
76
77 *bufp = p = refstr_alloc(len);
78 if (!p)
79 return -1;
80
81 return vsnprintf(p, len + 1, fmt, ap);
82 }
83
rsprintf(const char ** bufp,const char * fmt,...)84 int rsprintf(const char **bufp, const char *fmt, ...)
85 {
86 int rv;
87 va_list ap;
88
89 va_start(ap, fmt);
90 rv = vrsprintf(bufp, fmt, ap);
91 va_end(ap);
92
93 return rv;
94 }
95
refstr_put(const char * r)96 void refstr_put(const char *r)
97 {
98 unsigned int *ref;
99
100 if (r) {
101 ref = (unsigned int *)r - 1;
102
103 if (!--*ref)
104 free(ref);
105 }
106 }
107