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 #include "common.h"
  11
  12 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
  13 #define bitsizeof(x) (CHAR_BIT * sizeof(x))
  14 #define MSB(x, bits) ((x) & (~0ULL << (bitsizeof(x) - (bits))))
  15 #ifndef min
  16 # define min(a,b) ((a) < (b) ? (a) : (b))
  17 #endif
  18 #ifndef max
  19 # define max(a,b) ((a) > (b) ? (a) : (b))
  20 #endif
  21
  22 /*
  23  * Custom memory allocation wrappers
  24  * that set error code and error message
  25  * on allocation failure
  26  */
  27 GIT_INLINE(void *) git__malloc(size_t len)
  28 {
  29         void *ptr = malloc(len);
  30         if (!ptr) giterr_set_oom();
  31         return ptr;
  32 }
  33
  34 GIT_INLINE(void *) git__calloc(size_t nelem, size_t elsize)
  35 {
  36         void *ptr = calloc(nelem, elsize);
  37         if (!ptr) giterr_set_oom();
  38         return ptr;
  39 }
  40
  41 GIT_INLINE(char *) git__strdup(const char *str)
  42 {
  43         char *ptr = strdup(str);
  44         if (!ptr) giterr_set_oom();
  45         return ptr;
  46 }
  47
  48 GIT_INLINE(char *) git__strndup(const char *str, size_t n)
  49 {
  50         size_t length = 0;
  51         char *ptr;
  52
  53         while (length < n && str[length])
  54                 ++length;
  55
  56         ptr = (char*)git__malloc(length + 1);
  57
  58         if (!ptr)
  59                 return NULL;
  60
  61         if (length)
  62                 memcpy(ptr, str, length);
  63
  64         ptr[length] = '\0';
  65
  66         return ptr;
  67 }
  68
  69 /* NOTE: This doesn't do null or '\0' checking.  Watch those boundaries! */
  70 GIT_INLINE(char *) git__substrdup(const char *start, size_t n)
  71 {
  72         char *ptr = (char*)git__malloc(n+1);
  73         memcpy(ptr, start, n);
  74         ptr[n] = '\0';
  75         return ptr;
  76 }
  77
  78 GIT_INLINE(void *) git__realloc(void *ptr, size_t size)
  79 {
  80         void *new_ptr = realloc(ptr, size);
  81         if (!new_ptr) giterr_set_oom();
  82         return new_ptr;
  83 }
  84
  85 GIT_INLINE(void) git__free(void *ptr)
  86 {
  87         free(ptr);
  88 }
  89
  90 #define STRCMP_CASESELECT(IGNORE_CASE, STR1, STR2) \
  91         ((IGNORE_CASE) ? strcasecmp((STR1), (STR2)) : strcmp((STR1), (STR2)))
  92
  93 #define CASESELECT(IGNORE_CASE, ICASE, CASE) \
  94         ((IGNORE_CASE) ? (ICASE) : (CASE))
  95
  96 extern int git__prefixcmp(const char *str, const char *prefix);
  97 extern int git__prefixcmp_icase(const char *str, const char *prefix);
  98 extern int git__suffixcmp(const char *str, const char *suffix);
  99
 100 GIT_INLINE(int) git__signum(int val)
 101 {
 102         return ((val > 0) - (val < 0));
 103 }
 104
 105 extern int git__strtol32(int32_t *n, const char *buff, const char **end_buf, int base);
 106 extern int git__strtol64(int64_t *n, const char *buff, const char **end_buf, int base);
 107
 108 extern void git__hexdump(const char *buffer, size_t n);
 109 extern uint32_t git__hash(const void *key, int len, uint32_t seed);
 110
 111 /** @return true if p fits into the range of a size_t */
 112 GIT_INLINE(int) git__is_sizet(git_off_t p)
 113 {
 114         size_t r = (size_t)p;
 115         return p == (git_off_t)r;
 116 }
 117
 118 /** @return true if p fits into the range of a uint32_t */
 119 GIT_INLINE(int) git__is_uint32(size_t p)
 120 {
 121         uint32_t r = (uint32_t)p;
 122         return p == (size_t)r;
 123 }
 124
 125 /* 32-bit cross-platform rotl */
 126 #ifdef _MSC_VER /* use built-in method in MSVC */
 127 #       define git__rotl(v, s) (uint32_t)_rotl(v, s)
 128 #else /* use bitops in GCC; with o2 this gets optimized to a rotl instruction */
 129 #       define git__rotl(v, s) (uint32_t)(((uint32_t)(v) << (s)) | ((uint32_t)(v) >> (32 - (s))))
 130 #endif
 131
 132 extern char *git__strtok(char **end, const char *sep);
 133 extern char *git__strsep(char **end, const char *sep);
 134
 135 extern void git__strntolower(char *str, size_t len);
 136 extern void git__strtolower(char *str);
 137
 138 GIT_INLINE(const char *) git__next_line(const char *s)
 139 {
 140         while (*s && *s != '\n') s++;
 141         while (*s == '\n' || *s == '\r') s++;
 142         return s;
 143 }
 144
 145 GIT_INLINE(const void *) git__memrchr(const void *s, int c, size_t n)
 146 {
 147         const unsigned char *cp;
 148
 149         if (n != 0) {
 150                 cp = (unsigned char *)s + n;
 151                 do {
 152                         if (*(--cp) == (unsigned char)c)
 153                                 return cp;
 154                 } while (--n != 0);
 155         }
 156
 157         return NULL;
 158 }
 159
 160 typedef int (*git__tsort_cmp)(const void *a, const void *b);
 161
 162 extern void git__tsort(void **dst, size_t size, git__tsort_cmp cmp);
 163
 164 typedef int (*git__sort_r_cmp)(const void *a, const void *b, void *payload);
 165
 166 extern void git__tsort_r(
 167         void **dst, size_t size, git__sort_r_cmp cmp, void *payload);
 168
 169 extern void git__qsort_r(
 170         void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload);
 171
 172 extern void git__insertsort_r(
 173         void *els, size_t nel, size_t elsize, void *swapel,
 174         git__sort_r_cmp cmp, void *payload);
 175
 176 /**
 177  * @param position If non-NULL, this will be set to the position where the
 178  *              element is or would be inserted if not found.
 179  * @return 0 if found; GIT_ENOTFOUND if not found
 180  */
 181 extern int git__bsearch(
 182         void **array,
 183         size_t array_len,
 184         const void *key,
 185         int (*compare)(const void *key, const void *element),
 186         size_t *position);
 187
 188 extern int git__bsearch_r(
 189         void **array,
 190         size_t array_len,
 191         const void *key,
 192         int (*compare_r)(const void *key, const void *element, void *payload),
 193         void *payload,
 194         size_t *position);
 195
 196 extern int git__strcmp_cb(const void *a, const void *b);
 197
 198 extern int git__strcmp(const char *a, const char *b);
 199 extern int git__strcasecmp(const char *a, const char *b);
 200 extern int git__strncmp(const char *a, const char *b, size_t sz);
 201 extern int git__strncasecmp(const char *a, const char *b, size_t sz);
 202
 203 extern int git__strcasesort_cmp(const char *a, const char *b);
 204
 205 #include "thread-utils.h"
 206
 207 typedef struct {
 208         git_atomic refcount;
 209         void *owner;
 210 } git_refcount;
 211
 212 typedef void (*git_refcount_freeptr)(void *r);
 213
 214 #define GIT_REFCOUNT_INC(r) { \
 215         git_atomic_inc(&((git_refcount *)(r))->refcount);       \
 216 }
 217
 218 #define GIT_REFCOUNT_DEC(_r, do_free) { \
 219         git_refcount *r = (git_refcount *)(_r); \
 220         int val = git_atomic_dec(&r->refcount); \
 221         if (val <= 0 && r->owner == NULL) { do_free(_r); } \
 222 }
 223
 224 #define GIT_REFCOUNT_OWN(r, o) { \
 225         ((git_refcount *)(r))->owner = o; \
 226 }
 227
 228 #define GIT_REFCOUNT_OWNER(r) (((git_refcount *)(r))->owner)
 229
 230 #define GIT_REFCOUNT_VAL(r) git_atomic_get(&((git_refcount *)(r))->refcount)
 231
 232
 233 static signed char from_hex[] = {
 234 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 00 */
 235 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 10 */
 236 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 20 */
 237  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /* 30 */
 238 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 40 */
 239 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 50 */
 240 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 60 */
 241 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 70 */
 242 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 80 */
 243 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 90 */
 244 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* a0 */
 245 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* b0 */
 246 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* c0 */
 247 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* d0 */
 248 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* e0 */
 249 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* f0 */
 250 };
 251
 252 GIT_INLINE(int) git__fromhex(char h)
 253 {
 254         return from_hex[(unsigned char) h];
 255 }
 256
 257 GIT_INLINE(int) git__ishex(const char *str)
 258 {
 259         unsigned i;
 260         for (i=0; i<strlen(str); i++)
 261                 if (git__fromhex(str[i]) < 0)
 262                         return 0;
 263         return 1;
 264 }
 265
 266 GIT_INLINE(size_t) git__size_t_bitmask(size_t v)
 267 {
 268         v--;
 269         v |= v >> 1;
 270         v |= v >> 2;
 271         v |= v >> 4;
 272         v |= v >> 8;
 273         v |= v >> 16;
 274
 275         return v;
 276 }
 277
 278 GIT_INLINE(size_t) git__size_t_powerof2(size_t v)
 279 {
 280         return git__size_t_bitmask(v) + 1;
 281 }
 282
 283 GIT_INLINE(bool) git__isupper(int c)
 284 {
 285         return (c >= 'A' && c <= 'Z');
 286 }
 287
 288 GIT_INLINE(bool) git__isalpha(int c)
 289 {
 290         return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
 291 }
 292
 293 GIT_INLINE(bool) git__isdigit(int c)
 294 {
 295         return (c >= '0' && c <= '9');
 296 }
 297
 298 GIT_INLINE(bool) git__isspace(int c)
 299 {
 300         return (c == ' ' || c == '\t' || c == '\n' || c == '\f' || c == '\r' || c == '\v' || c == 0x85 /* Unicode CR+LF */);
 301 }
 302
 303 GIT_INLINE(bool) git__isspace_nonlf(int c)
 304 {
 305         return (c == ' ' || c == '\t' || c == '\f' || c == '\r' || c == '\v' || c == 0x85 /* Unicode CR+LF */);
 306 }
 307
 308 GIT_INLINE(bool) git__iswildcard(int c)
 309 {
 310         return (c == '*' || c == '?' || c == '[');
 311 }
 312
 313 /*
 314  * Parse a string value as a boolean, just like Core Git does.
 315  *
 316  * Valid values for true are: 'true', 'yes', 'on'
 317  * Valid values for false are: 'false', 'no', 'off'
 318  */
 319 extern int git__parse_bool(int *out, const char *value);
 320
 321 /*
 322  * Parse a string into a value as a git_time_t.
 323  *
 324  * Sample valid input:
 325  * - "yesterday"
 326  * - "July 17, 2003"
 327  * - "2003-7-17 08:23"
 328  */
 329 extern int git__date_parse(git_time_t *out, const char *date);
 330
 331 /*
 332  * Unescapes a string in-place.
 333  *
 334  * Edge cases behavior:
 335  * - "jackie\" -> "jacky\"
 336  * - "chan\\" -> "chan\"
 337  */
 338 extern size_t git__unescape(char *str);
 339
 340 /*
 341  * Safely zero-out memory, making sure that the compiler
 342  * doesn't optimize away the operation.
 343  */
 344 GIT_INLINE(void) git__memzero(void *data, size_t size)
 345 {
 346 #ifdef _MSC_VER
 347         SecureZeroMemory((PVOID)data, size);
 348 #else
 349         volatile uint8_t *scan = (volatile uint8_t *)data;
 350
 351         while (size--)
 352                 *scan++ = 0x0;
 353 #endif
 354 }
 355
 356 #ifdef GIT_WIN32
 357
 358 GIT_INLINE(double) git__timer(void)
 359 {
 360         /* We need the initial tick count to detect if the tick
 361          * count has rolled over. */
 362         static DWORD initial_tick_count = 0;
 363
 364         /* GetTickCount returns the number of milliseconds that have
 365          * elapsed since the system was started. */
 366         DWORD count = GetTickCount();
 367
 368         if(initial_tick_count == 0) {
 369                 initial_tick_count = count;
 370         } else if (count < initial_tick_count) {
 371                 /* The tick count has rolled over - adjust for it. */
 372                 count = (0xFFFFFFFF - initial_tick_count) + count;
 373         }
 374
 375         return (double) count / (double) 1000;
 376 }
 377
 378 #elif __APPLE__
 379
 380 #include <mach/mach_time.h>
 381
 382 double git__timer(void)
 383 {
 384    uint64_t time = mach_absolute_time();
 385    static double scaling_factor = 0;
 386
 387    if (scaling_factor == 0) {
 388        mach_timebase_info_data_t info;
 389        (void)mach_timebase_info(&info);
 390        scaling_factor = (double)info.numer / (double)info.denom;
 391    }
 392
 393    return (double)time * scaling_factor / 1.0E-9;
 394 }
 395
 396 #else
 397
 398 #include <sys/time.h>
 399
 400 GIT_INLINE(double) git__timer(void)
 401 {
 402         struct timespec tp;
 403
 404         if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
 405                 return (double) tp.tv_sec + (double) tp.tv_nsec / 1E-9;
 406         } else {
 407                 /* Fall back to using gettimeofday */
 408                 struct timeval tv;
 409                 struct timezone tz;
 410                 gettimeofday(&tv, &tz);
 411                 return (double)tv.tv_sec + (double)tv.tv_usec / 1E-6;
 412         }
 413 }
 414
 415 #endif
 416
 417 #endif /* INCLUDE_util_h__ */