common/util.h

   1 /*
   2  * util.h - useful functions header
   3  *
   4  * Copyright © 2007-2008 Julien Danjou <julien@danjou.info>
   5  * Copyright © 2006 Pierre Habouzit <madcoder@debian.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  */
  22
  23 #ifndef AWESOME_COMMON_UTIL_H
  24 #define AWESOME_COMMON_UTIL_H
  25
  26 /* asprintf */
  27 #define _GNU_SOURCE
  28
  29 #include <string.h>
  30 #include <stdlib.h>
  31 #include <stdbool.h>
  32 #include <stdarg.h>
  33 #include <assert.h>
  34 #include <stdio.h>
  35
  36 #if !(defined (__FreeBSD__) || defined(__OpenBSD__))
  37 #include <alloca.h>
  38 #endif
  39
  40 typedef enum
  41 {
  42     East,
  43     South,
  44     North,
  45 } orientation_t;
  46
  47 /** A list of possible position, not sex related */
  48 typedef enum
  49 {
  50     Top,
  51     Bottom,
  52     Right,
  53     Left,
  54     Floating
  55 } position_t;
  56
  57 /** Link a name to a function */
  58 typedef struct
  59 {
  60     const char *name;
  61     size_t len;
  62     void *func;
  63 } name_func_link_t;
  64
  65 /** \brief replace \c NULL strings with emtpy strings */
  66 #define NONULL(x)       (x ? x : "")
  67
  68 #define DO_NOTHING(...)
  69
  70 #undef MAX
  71 #undef MIN
  72 #define MAX(a,b) ((a) < (b) ? (b) : (a))
  73 #define MIN(a,b) ((a) < (b) ? (a) : (b))
  74
  75 #define unsigned_subtract(a, b)  \
  76     do {                         \
  77         if (b > a)               \
  78             a = 0;               \
  79         else                     \
  80             a -= b;              \
  81     } while (0)
  82
  83 #define ssizeof(foo)            (ssize_t)sizeof(foo)
  84 #define countof(foo)            (ssizeof(foo) / ssizeof(foo[0]))
  85
  86 #define p_alloca(type, count)                                \
  87         ((type *)memset(alloca(sizeof(type) * (count)),      \
  88                         0, sizeof(type) * (count)))
  89
  90 #define p_alloc_nr(x)           (((x) + 16) * 3 / 2)
  91 #define p_new(type, count)      ((type *)xmalloc(sizeof(type) * (count)))
  92 #define p_clear(p, count)       ((void)memset((p), 0, sizeof(*(p)) * (count)))
  93 #define p_realloc(pp, count)    xrealloc((void*)(pp), sizeof(**(pp)) * (count))
  94 #define p_dup(p, count)         xmemdup((p), sizeof(*(p)) * (count))
  95 #define p_grow(pp, goalnb, allocnb)                  \
  96     do {                                             \
  97         if ((goalnb) > *(allocnb)) {                 \
  98             if (p_alloc_nr(*(allocnb)) < (goalnb)) { \
  99                 *(allocnb) = (goalnb);               \
 100             } else {                                 \
 101                 *(allocnb) = p_alloc_nr(*(allocnb)); \
 102             }                                        \
 103             p_realloc(pp, *(allocnb));               \
 104         }                                            \
 105     } while (0)
 106
 107
 108 #ifdef __GNUC__
 109
 110 #define p_delete(mem_pp)                           \
 111     do {                                           \
 112         typeof(**(mem_pp)) **__ptr = (mem_pp);     \
 113         free(*__ptr);                              \
 114         *__ptr = NULL;                             \
 115     } while(0)
 116
 117 #define likely(expr)    __builtin_expect(!!(expr), 1)
 118 #define unlikely(expr)  __builtin_expect((expr), 0)
 119
 120 #else
 121
 122 #define p_delete(mem_p)                            \
 123     do {                                           \
 124         void *__ptr = (mem_p);                     \
 125         free(*__ptr);                              \
 126         *(void **)__ptr = NULL;                    \
 127     } while (0)
 128
 129 #define likely(expr)    expr
 130 #define unlikely(expr)  expr
 131
 132 #endif
 133
 134 static inline void * __attribute__ ((malloc)) xmalloc(ssize_t size)
 135 {
 136     void *ptr;
 137
 138     if(size <= 0)
 139         return NULL;
 140
 141     ptr = calloc(1, size);
 142
 143     if(!ptr)
 144         abort();
 145
 146     return ptr;
 147 }
 148
 149 static inline void
 150 xrealloc(void **ptr, ssize_t newsize)
 151 {
 152     if(newsize <= 0)
 153         p_delete(ptr);
 154     else
 155     {
 156         *ptr = realloc(*ptr, newsize);
 157         if(!*ptr)
 158             abort();
 159     }
 160 }
 161
 162 /** Duplicate a memory zone.
 163  * \param src The source.
 164  * \param size The source size.
 165  * \return The memory address of the copy.
 166  */
 167 static inline void *xmemdup(const void *src, ssize_t size)
 168 {
 169     return memcpy(xmalloc(size), src, size);
 170 }
 171
 172 /** \brief \c NULL resistant strlen.
 173  *
 174  * Unlike it's libc sibling, a_strlen returns a ssize_t, and supports its
 175  * argument being NULL.
 176  *
 177  * \param[in] s the string.
 178  * \return the string length (or 0 if \c s is \c NULL).
 179  */
 180 static inline ssize_t a_strlen(const char *s)
 181 {
 182     return s ? strlen(s) : 0;
 183 }
 184
 185 /** \brief \c NULL resistant strnlen.
 186  *
 187  * Unlike it's GNU libc sibling, a_strnlen returns a ssize_t, and supports
 188  * its argument being NULL.
 189  *
 190  * The a_strnlen() function returns the number of characters in the string
 191  * pointed to by \c s, not including the terminating \c \\0 character, but at
 192  * most \c n. In doing this, a_strnlen() looks only at the first \c n
 193  * characters at \c s and never beyond \c s+n.
 194  *
 195  * \param[in]  s    the string.
 196  * \param[in]  n    the maximum length to return.
 197  * \return \c a_strlen(s) if less than \c n, else \c n.
 198  */
 199 static inline ssize_t a_strnlen(const char *s, ssize_t n)
 200 {
 201     if (s)
 202     {
 203         const char *p = memchr(s, '\0', n);
 204         return p ? p - s : n;
 205     }
 206     return 0;
 207 }
 208
 209 /** \brief \c NULL resistant strdup.
 210  *
 211  * the a_strdup() function returns a pointer to a new string, which is a
 212  * duplicate of \c s. Memory should be freed using p_delete().
 213  *
 214  * \warning when s is \c "", it returns NULL !
 215  *
 216  * \param[in] s the string to duplicate.
 217  * \return a pointer to the duplicated string.
 218  */
 219 static inline
 220 char *a_strdup(const char *s)
 221 {
 222     ssize_t len = a_strlen(s);
 223     return len ? p_dup(s, len + 1) : NULL;
 224 }
 225
 226 /** \brief safe limited strdup.
 227  *
 228  * Copies at most min(<tt>n-1</tt>, \c l) characters from \c src into a newly
 229  * allocated buffer, always adding a final \c \\0, and returns that buffer.
 230  *
 231  * \warning when s is \c "" or l is 0, it returns NULL !
 232  *
 233  * \param[in]  s        source string.
 234  * \param[in]  l        maximum number of chars to copy.
 235  * \return a newly allocated buffer containing the first \c l chars of \c src.
 236 */
 237 static inline
 238 char * a_strndup(const char *s, ssize_t l)
 239 {
 240     ssize_t len = MIN(a_strlen(s), l);
 241     if(len)
 242     {
 243         char *p = p_dup(s, len + 1);
 244         p[len] = '\0';
 245         return p;
 246     }
 247     return NULL;
 248 }
 249
 250 /** \brief \c NULL resistant strcmp.
 251  * \param[in]  a     the first string.
 252  * \param[in]  b     the second string.
 253  * \return <tt>strcmp(a, b)</tt>, and treats \c NULL strings like \c ""
 254  * ones.
 255  */
 256 static inline int a_strcmp(const char *a, const char *b)
 257 {
 258     return strcmp(NONULL(a), NONULL(b));
 259 }
 260
 261 /** \brief \c NULL resistant strcasecmp.
 262  * \param[in]  a     the first string.
 263  * \param[in]  b     the second string.
 264  * \return <tt>strcasecmp(a, b)</tt>, and treats \c NULL strings like \c ""
 265  * ones.
 266  */
 267 static inline int a_strcasecmp(const char *a, const char *b)
 268 {
 269     return strcasecmp(NONULL(a), NONULL(b));
 270 }
 271
 272 /** \brief \c NULL resistant strncmp.
 273  * \param[in]  a     the first string.
 274  * \param[in]  b     the second string.
 275  * \param[in]  n     the number of maximum chars to compare.
 276  * \return <tt>strncmp(a, b, n)</tt>, and treats \c NULL strings like \c ""
 277  * ones.
 278  */
 279 static inline int a_strncmp(const char *a, const char *b, ssize_t n)
 280 {
 281     return strncmp(NONULL(a), NONULL(b), n);
 282 }
 283
 284 ssize_t a_strncpy(char *dst, ssize_t n, const char *src, ssize_t l) __attribute__((nonnull(1)));
 285 ssize_t a_strcpy(char *dst, ssize_t n, const char *src) __attribute__((nonnull(1)));
 286
 287 /** \brief safe strcat.
 288  *
 289  * The a_strcat() function appends the string \c src at the end of the buffer
 290  * \c dst if space is available.
 291  *
 292  * \param[in]  dst   destination buffer.
 293  * \param[in]  n     size of the buffer, Negative sizes are allowed.
 294  * \param[in]  src   the string to append.
 295  * \return <tt>a_strlen(dst) + a_strlen(src)</tt>
 296  */
 297 static inline ssize_t a_strcat(char *dst, ssize_t n, const char *src)
 298 {
 299     ssize_t dlen = a_strnlen(dst, n - 1);
 300     return dlen + a_strcpy(dst + dlen, n - dlen, src);
 301 }
 302
 303 /** \brief safe strncat.
 304  *
 305  * The a_strncat() function appends at most \c n chars from the string \c src
 306  * at the end of the buffer \c dst if space is available.
 307  *
 308  * \param[in]  dst   destination buffer.
 309  * \param[in]  n     size of the buffer, Negative sizes are allowed.
 310  * \param[in]  src   the string to append.
 311  * \param[in]  l     maximum number of chars of src to consider.
 312  * \return the smallest value between <tt>a_strlen(dst) + a_strlen(src)</tt>
 313  * and <tt>a_strlen(dst) + l</tt>
 314  */
 315 static inline ssize_t
 316 a_strncat(char *dst, ssize_t n, const char *src, ssize_t l)
 317 {
 318     ssize_t dlen = a_strnlen(dst, n - 1);
 319     return dlen + a_strncpy(dst + dlen, n - dlen, src, l);
 320 }
 321
 322 #define fatal(string, ...) _fatal(__LINE__, \
 323                                   __FUNCTION__, \
 324                                   string, ## __VA_ARGS__)
 325 void _fatal(int, const char *, const char *, ...)
 326     __attribute__ ((noreturn)) __attribute__ ((format(printf, 3, 4)));
 327
 328 #define warn(string, ...) _warn(__LINE__, \
 329                                 __FUNCTION__, \
 330                                 string, ## __VA_ARGS__)
 331 void _warn(int, const char *, const char *, ...)
 332     __attribute__ ((format(printf, 3, 4)));
 333
 334 position_t position_fromstr(const char *, ssize_t);
 335 const char * position_tostr(position_t);
 336 orientation_t orientation_fromstr(const char *, ssize_t);
 337 const char * orientation_tostr(orientation_t);
 338 void *name_func_lookup(const char *, size_t, const name_func_link_t *);
 339 const char * name_func_rlookup(void *, const name_func_link_t *);
 340 void a_exec(const char *);
 341 char ** a_strsplit(const char *, ssize_t, char);
 342
 343 #define a_asprintf(strp, fmt, ...) \
 344     do { \
 345         if(asprintf(strp, fmt, ## __VA_ARGS__) < 0) \
 346             abort(); \
 347     } while(0)
 348
 349 #endif
 350 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80