src/util.h

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7 #ifndef INCLUDE_util_h__
   8 #define INCLUDE_util_h__
   9
  10 #ifndef GIT_WIN32
  11 # include <ctype.h>
  12 #endif
  13
  14 #include "str.h"
  15 #include "common.h"
  16 #include "strnlen.h"
  17 #include "thread.h"
  18
  19 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
  20 #define bitsizeof(x) (CHAR_BIT * sizeof(x))
  21 #define MSB(x, bits) ((x) & (~UINT64_C(0) << (bitsizeof(x) - (bits))))
  22 #ifndef min
  23 # define min(a,b) ((a) < (b) ? (a) : (b))
  24 #endif
  25 #ifndef max
  26 # define max(a,b) ((a) > (b) ? (a) : (b))
  27 #endif
  28
  29 #if defined(__GNUC__)
  30 # define GIT_CONTAINER_OF(ptr, type, member) \
  31         __builtin_choose_expr( \
  32             __builtin_offsetof(type, member) == 0 && \
  33             __builtin_types_compatible_p(__typeof__(&((type *) 0)->member), __typeof__(ptr)), \
  34                 ((type *) (ptr)), \
  35                 (void)0)
  36 #else
  37 # define GIT_CONTAINER_OF(ptr, type, member) (type *)(ptr)
  38 #endif
  39
  40 /**
  41  * Return the length of a constant string.
  42  * We are aware that `strlen` performs the same task and is usually
  43  * optimized away by the compiler, whilst being safer because it returns
  44  * valid values when passed a pointer instead of a constant string; however
  45  * this macro will transparently work with wide-char and single-char strings.
  46  */
  47 #define CONST_STRLEN(x) ((sizeof(x)/sizeof(x[0])) - 1)
  48
  49 #define STRCMP_CASESELECT(IGNORE_CASE, STR1, STR2) \
  50         ((IGNORE_CASE) ? strcasecmp((STR1), (STR2)) : strcmp((STR1), (STR2)))
  51
  52 #define CASESELECT(IGNORE_CASE, ICASE, CASE) \
  53         ((IGNORE_CASE) ? (ICASE) : (CASE))
  54
  55 extern int git__prefixcmp(const char *str, const char *prefix);
  56 extern int git__prefixcmp_icase(const char *str, const char *prefix);
  57 extern int git__prefixncmp(const char *str, size_t str_n, const char *prefix);
  58 extern int git__prefixncmp_icase(const char *str, size_t str_n, const char *prefix);
  59 extern int git__suffixcmp(const char *str, const char *suffix);
  60
  61 GIT_INLINE(int) git__signum(int val)
  62 {
  63         return ((val > 0) - (val < 0));
  64 }
  65
  66 extern int git__strntol32(int32_t *n, const char *buff, size_t buff_len, const char **end_buf, int base);
  67 extern int git__strntol64(int64_t *n, const char *buff, size_t buff_len, const char **end_buf, int base);
  68
  69
  70 extern void git__hexdump(const char *buffer, size_t n);
  71 extern uint32_t git__hash(const void *key, int len, uint32_t seed);
  72
  73 /* 32-bit cross-platform rotl */
  74 #ifdef _MSC_VER /* use built-in method in MSVC */
  75 #       define git__rotl(v, s) (uint32_t)_rotl(v, s)
  76 #else /* use bitops in GCC; with o2 this gets optimized to a rotl instruction */
  77 #       define git__rotl(v, s) (uint32_t)(((uint32_t)(v) << (s)) | ((uint32_t)(v) >> (32 - (s))))
  78 #endif
  79
  80 extern char *git__strtok(char **end, const char *sep);
  81 extern char *git__strsep(char **end, const char *sep);
  82
  83 extern void git__strntolower(char *str, size_t len);
  84 extern void git__strtolower(char *str);
  85
  86 #ifdef GIT_WIN32
  87 GIT_INLINE(int) git__tolower(int c)
  88 {
  89         return (c >= 'A' && c <= 'Z') ? (c + 32) : c;
  90 }
  91 #else
  92 # define git__tolower(a) tolower(a)
  93 #endif
  94
  95 extern size_t git__linenlen(const char *buffer, size_t buffer_len);
  96
  97 GIT_INLINE(const char *) git__next_line(const char *s)
  98 {
  99         while (*s && *s != '\n') s++;
 100         while (*s == '\n' || *s == '\r') s++;
 101         return s;
 102 }
 103
 104 GIT_INLINE(const void *) git__memrchr(const void *s, int c, size_t n)
 105 {
 106         const unsigned char *cp;
 107
 108         if (n != 0) {
 109                 cp = (unsigned char *)s + n;
 110                 do {
 111                         if (*(--cp) == (unsigned char)c)
 112                                 return cp;
 113                 } while (--n != 0);
 114         }
 115
 116         return NULL;
 117 }
 118
 119 extern const void * git__memmem(const void *haystack, size_t haystacklen,
 120                                 const void *needle, size_t needlelen);
 121
 122 typedef int (*git__tsort_cmp)(const void *a, const void *b);
 123
 124 extern void git__tsort(void **dst, size_t size, git__tsort_cmp cmp);
 125
 126 typedef int (*git__sort_r_cmp)(const void *a, const void *b, void *payload);
 127
 128 extern void git__tsort_r(
 129         void **dst, size_t size, git__sort_r_cmp cmp, void *payload);
 130
 131 extern void git__qsort_r(
 132         void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload);
 133
 134 /**
 135  * @param position If non-NULL, this will be set to the position where the
 136  *              element is or would be inserted if not found.
 137  * @return 0 if found; GIT_ENOTFOUND if not found
 138  */
 139 extern int git__bsearch(
 140         void **array,
 141         size_t array_len,
 142         const void *key,
 143         int (*compare)(const void *key, const void *element),
 144         size_t *position);
 145
 146 extern int git__bsearch_r(
 147         void **array,
 148         size_t array_len,
 149         const void *key,
 150         int (*compare_r)(const void *key, const void *element, void *payload),
 151         void *payload,
 152         size_t *position);
 153
 154 #define git__strcmp strcmp
 155 #define git__strncmp strncmp
 156
 157 extern int git__strcmp_cb(const void *a, const void *b);
 158 extern int git__strcasecmp_cb(const void *a, const void *b);
 159
 160 extern int git__strcasecmp(const char *a, const char *b);
 161 extern int git__strncasecmp(const char *a, const char *b, size_t sz);
 162
 163 extern int git__strcasesort_cmp(const char *a, const char *b);
 164
 165 /*
 166  * Compare some NUL-terminated `a` to a possibly non-NUL terminated
 167  * `b` of length `b_len`; like `strncmp` but ensuring that
 168  * `strlen(a) == b_len` as well.
 169  */
 170 GIT_INLINE(int) git__strlcmp(const char *a, const char *b, size_t b_len)
 171 {
 172         int cmp = strncmp(a, b, b_len);
 173         return cmp ? cmp : (int)a[b_len];
 174 }
 175
 176 typedef struct {
 177         git_atomic32 refcount;
 178         void *owner;
 179 } git_refcount;
 180
 181 typedef void (*git_refcount_freeptr)(void *r);
 182
 183 #define GIT_REFCOUNT_INC(r) { \
 184         git_atomic32_inc(&(r)->rc.refcount);    \
 185 }
 186
 187 #define GIT_REFCOUNT_DEC(_r, do_free) { \
 188         git_refcount *r = &(_r)->rc; \
 189         int val = git_atomic32_dec(&r->refcount); \
 190         if (val <= 0 && r->owner == NULL) { do_free(_r); } \
 191 }
 192
 193 #define GIT_REFCOUNT_OWN(r, o) { \
 194         (void)git_atomic_swap((r)->rc.owner, o); \
 195 }
 196
 197 #define GIT_REFCOUNT_OWNER(r) git_atomic_load((r)->rc.owner)
 198
 199 #define GIT_REFCOUNT_VAL(r) git_atomic32_get((r)->rc.refcount)
 200
 201
 202 static signed char from_hex[] = {
 203 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 00 */
 204 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 10 */
 205 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 20 */
 206  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /* 30 */
 207 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 40 */
 208 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 50 */
 209 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 60 */
 210 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 70 */
 211 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 80 */
 212 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 90 */
 213 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* a0 */
 214 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* b0 */
 215 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* c0 */
 216 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* d0 */
 217 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* e0 */
 218 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* f0 */
 219 };
 220
 221 GIT_INLINE(int) git__fromhex(char h)
 222 {
 223         return from_hex[(unsigned char) h];
 224 }
 225
 226 GIT_INLINE(int) git__ishex(const char *str)
 227 {
 228         unsigned i;
 229         for (i=0; str[i] != '\0'; i++)
 230                 if (git__fromhex(str[i]) < 0)
 231                         return 0;
 232         return 1;
 233 }
 234
 235 GIT_INLINE(size_t) git__size_t_bitmask(size_t v)
 236 {
 237         v--;
 238         v |= v >> 1;
 239         v |= v >> 2;
 240         v |= v >> 4;
 241         v |= v >> 8;
 242         v |= v >> 16;
 243
 244         return v;
 245 }
 246
 247 GIT_INLINE(size_t) git__size_t_powerof2(size_t v)
 248 {
 249         return git__size_t_bitmask(v) + 1;
 250 }
 251
 252 GIT_INLINE(bool) git__isupper(int c)
 253 {
 254         return (c >= 'A' && c <= 'Z');
 255 }
 256
 257 GIT_INLINE(bool) git__isalpha(int c)
 258 {
 259         return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
 260 }
 261
 262 GIT_INLINE(bool) git__isdigit(int c)
 263 {
 264         return (c >= '0' && c <= '9');
 265 }
 266
 267 GIT_INLINE(bool) git__isspace(int c)
 268 {
 269         return (c == ' ' || c == '\t' || c == '\n' || c == '\f' || c == '\r' || c == '\v');
 270 }
 271
 272 GIT_INLINE(bool) git__isspace_nonlf(int c)
 273 {
 274         return (c == ' ' || c == '\t' || c == '\f' || c == '\r' || c == '\v');
 275 }
 276
 277 GIT_INLINE(bool) git__iswildcard(int c)
 278 {
 279         return (c == '*' || c == '?' || c == '[');
 280 }
 281
 282 GIT_INLINE(bool) git__isxdigit(int c)
 283 {
 284         return ((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'));
 285 }
 286
 287 /*
 288  * Parse a string value as a boolean, just like Core Git does.
 289  *
 290  * Valid values for true are: 'true', 'yes', 'on'
 291  * Valid values for false are: 'false', 'no', 'off'
 292  */
 293 extern int git__parse_bool(int *out, const char *value);
 294
 295 /*
 296  * Unescapes a string in-place.
 297  *
 298  * Edge cases behavior:
 299  * - "jackie\" -> "jacky\"
 300  * - "chan\\" -> "chan\"
 301  */
 302 extern size_t git__unescape(char *str);
 303
 304 /*
 305  * Safely zero-out memory, making sure that the compiler
 306  * doesn't optimize away the operation.
 307  */
 308 GIT_INLINE(void) git__memzero(void *data, size_t size)
 309 {
 310 #ifdef _MSC_VER
 311         SecureZeroMemory((PVOID)data, size);
 312 #else
 313         volatile uint8_t *scan = (volatile uint8_t *)data;
 314
 315         while (size--)
 316                 *scan++ = 0x0;
 317 #endif
 318 }
 319
 320 #ifdef GIT_WIN32
 321
 322 GIT_INLINE(double) git__timer(void)
 323 {
 324         /* GetTickCount64 returns the number of milliseconds that have
 325          * elapsed since the system was started. */
 326         return (double) GetTickCount64() / (double) 1000;
 327 }
 328
 329 #elif __APPLE__
 330
 331 #include <mach/mach_time.h>
 332
 333 GIT_INLINE(double) git__timer(void)
 334 {
 335    uint64_t time = mach_absolute_time();
 336    static double scaling_factor = 0;
 337
 338    if (scaling_factor == 0) {
 339        mach_timebase_info_data_t info;
 340        (void)mach_timebase_info(&info);
 341        scaling_factor = (double)info.numer / (double)info.denom;
 342    }
 343
 344    return (double)time * scaling_factor / 1.0E9;
 345 }
 346
 347 #elif defined(__amigaos4__)
 348
 349 #include <proto/timer.h>
 350
 351 GIT_INLINE(double) git__timer(void)
 352 {
 353         struct TimeVal tv;
 354         ITimer->GetUpTime(&tv);
 355         return (double)tv.Seconds + (double)tv.Microseconds / 1.0E6;
 356 }
 357
 358 #else
 359
 360 #include <sys/time.h>
 361
 362 GIT_INLINE(double) git__timer(void)
 363 {
 364         struct timeval tv;
 365
 366 #ifdef CLOCK_MONOTONIC
 367         struct timespec tp;
 368         if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0)
 369                 return (double) tp.tv_sec + (double) tp.tv_nsec / 1.0E9;
 370 #endif
 371
 372         /* Fall back to using gettimeofday */
 373         gettimeofday(&tv, NULL);
 374         return (double)tv.tv_sec + (double)tv.tv_usec / 1.0E6;
 375 }
 376
 377 #endif
 378
 379 extern int git__getenv(git_str *out, const char *name);
 380
 381 extern int git__online_cpus(void);
 382
 383 GIT_INLINE(int) git__noop(void) { return 0; }
 384
 385 #include "alloc.h"
 386
 387 #endif