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 "refstr.h"
23
24 /* Allocate space for a refstring of len bytes, plus final null */
25 /* The final null is inserted in the string; the rest is uninitialized. */
refstr_alloc(size_t len)26 char *refstr_alloc(size_t len)
27 {
28 char *r = malloc(sizeof(unsigned int) + len + 1);
29 if (!r)
30 return NULL;
31 *(unsigned int *)r = 1;
32 r += sizeof(unsigned int);
33 r[len] = '\0';
34 return r;
35 }
36
refstrndup(const char * str,size_t len)37 const char *refstrndup(const char *str, size_t len)
38 {
39 char *r;
40
41 if (!str)
42 return NULL;
43
44 len = strnlen(str, len);
45 r = refstr_alloc(len);
46 if (r)
47 memcpy(r, str, len);
48 return r;
49 }
50
refstrdup(const char * str)51 const char *refstrdup(const char *str)
52 {
53 char *r;
54 size_t len;
55
56 if (!str)
57 return NULL;
58
59 len = strlen(str);
60 r = refstr_alloc(len);
61 if (r)
62 memcpy(r, str, len);
63 return r;
64 }
65
vrsprintf(const char ** bufp,const char * fmt,va_list ap)66 int vrsprintf(const char **bufp, const char *fmt, va_list ap)
67 {
68 va_list ap1;
69 int len;
70 char *p;
71
72 va_copy(ap1, ap);
73 len = vsnprintf(NULL, 0, fmt, ap1);
74 va_end(ap1);
75
76 *bufp = p = refstr_alloc(len);
77 if (!p)
78 return -1;
79
80 return vsnprintf(p, len + 1, fmt, ap);
81 }
82
rsprintf(const char ** bufp,const char * fmt,...)83 int rsprintf(const char **bufp, const char *fmt, ...)
84 {
85 int rv;
86 va_list ap;
87
88 va_start(ap, fmt);
89 rv = vrsprintf(bufp, fmt, ap);
90 va_end(ap);
91
92 return rv;
93 }
94
refstr_put(const char * r)95 void refstr_put(const char *r)
96 {
97 unsigned int *ref;
98
99 if (r) {
100 ref = (unsigned int *)r - 1;
101
102 if (!--*ref)
103 free(ref);
104 }
105 }
106