src/common/compat/string.h

   1 /*
   2  * Copyright (C) 2015 Michael Jeanson <mjeanson@efficios.com>
   3  *               2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy
   6  * of this software and associated documentation files (the "Software"), to deal
   7  * in the Software without restriction, including without limitation the rights
   8  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9  * copies of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23
  24 #ifndef _COMPAT_STRING_H
  25 #define _COMPAT_STRING_H
  26
  27 #include <string.h>
  28
  29 #ifdef HAVE_STRNLEN
  30 static inline
  31 size_t lttng_strnlen(const char *str, size_t max)
  32 {
  33         return strnlen(str, max);
  34 }
  35 #else
  36 static inline
  37 size_t lttng_strnlen(const char *str, size_t max)
  38 {
  39         size_t ret;
  40         const char *end;
  41
  42         end = memchr(str, 0, max);
  43
  44         if (end) {
  45                 ret = (size_t) (end - str);
  46         } else {
  47                 ret = max;
  48         }
  49
  50         return ret;
  51 }
  52 #endif /* HAVE_STRNLEN */
  53
  54 #ifdef HAVE_STRNDUP
  55 static inline
  56 char *lttng_strndup(const char *s, size_t n)
  57 {
  58         return strndup(s, n);
  59 }
  60 #else
  61 static inline
  62 char *lttng_strndup(const char *s, size_t n)
  63 {
  64         char *ret;
  65         size_t navail;
  66
  67         if (!s) {
  68                 ret = NULL;
  69                 goto end;
  70         }
  71
  72         /* min() */
  73         navail = strlen(s) + 1;
  74         if ((n + 1) < navail) {
  75                 navail = n + 1;
  76         }
  77
  78         ret = malloc(navail);
  79         if (!ret) {
  80                 goto end;
  81         }
  82
  83         memcpy(ret, s, navail);
  84         ret[navail - 1] = '\0';
  85 end:
  86         return ret;
  87 }
  88 #endif /* HAVE_STRNDUP */
  89
  90 #ifdef HAVE_FLS
  91 static inline int lttng_fls(int val)
  92 {
  93         return fls(val);
  94 }
  95 #else
  96 static inline int lttng_fls(int val)
  97 {
  98         int r = 32;
  99         unsigned int x = (unsigned int) val;
 100
 101         if (!x)
 102                 return 0;
 103         if (!(x & 0xFFFF0000U)) {
 104                 x <<= 16;
 105                 r -= 16;
 106         }
 107         if (!(x & 0xFF000000U)) {
 108                 x <<= 8;
 109                 r -= 8;
 110         }
 111         if (!(x & 0xF0000000U)) {
 112                 x <<= 4;
 113                 r -= 4;
 114         }
 115         if (!(x & 0xC0000000U)) {
 116                 x <<= 2;
 117                 r -= 2;
 118         }
 119         if (!(x & 0x80000000U)) {
 120                 r -= 1;
 121         }
 122         return r;
 123 }
 124 #endif /* HAVE_FLS */
 125
 126 #endif /* _COMPAT_STRING_H */