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 #include "strnlen.h"
  12
  13 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
  14 #define bitsizeof(x) (CHAR_BIT * sizeof(x))
  15 #define MSB(x, bits) ((x) & (~0ULL << (bitsizeof(x) - (bits))))
  16 #ifndef min
  17 # define min(a,b) ((a) < (b) ? (a) : (b))
  18 #endif
  19 #ifndef max
  20 # define max(a,b) ((a) > (b) ? (a) : (b))
  21 #endif
  22
  23 #define GIT_DATE_RFC2822_SZ  32
  24
  25 /**
  26  * Return the length of a constant string.
  27  * We are aware that `strlen` performs the same task and is usually
  28  * optimized away by the compiler, whilst being safer because it returns
  29  * valid values when passed a pointer instead of a constant string; however
  30  * this macro will transparently work with wide-char and single-char strings.
  31  */
  32 #define CONST_STRLEN(x) ((sizeof(x)/sizeof(x[0])) - 1)
  33
  34 /*
  35  * Custom memory allocation wrappers
  36  * that set error code and error message
  37  * on allocation failure
  38  */
  39 GIT_INLINE(void *) git__malloc(size_t len)
  40 {
  41         void *ptr = malloc(len);
  42         if (!ptr) giterr_set_oom();
  43         return ptr;
  44 }
  45
  46 GIT_INLINE(void *) git__calloc(size_t nelem, size_t elsize)
  47 {
  48         void *ptr = calloc(nelem, elsize);
  49         if (!ptr) giterr_set_oom();
  50         return ptr;
  51 }
  52
  53 GIT_INLINE(char *) git__strdup(const char *str)
  54 {
  55         char *ptr = strdup(str);
  56         if (!ptr) giterr_set_oom();
  57         return ptr;
  58 }
  59
  60 GIT_INLINE(char *) git__strndup(const char *str, size_t n)
  61 {
  62         size_t length = 0;
  63         char *ptr;
  64
  65         length = p_strnlen(str, n);
  66
  67         ptr = (char*)git__malloc(length + 1);
  68
  69         if (!ptr)
  70                 return NULL;
  71
  72         if (length)
  73                 memcpy(ptr, str, length);
  74
  75         ptr[length] = '\0';
  76
  77         return ptr;
  78 }
  79
  80 /* NOTE: This doesn't do null or '\0' checking.  Watch those boundaries! */
  81 GIT_INLINE(char *) git__substrdup(const char *start, size_t n)
  82 {
  83         char *ptr = (char*)git__malloc(n+1);
  84         memcpy(ptr, start, n);
  85         ptr[n] = '\0';
  86         return ptr;
  87 }
  88
  89 GIT_INLINE(void *) git__realloc(void *ptr, size_t size)
  90 {
  91         void *new_ptr = realloc(ptr, size);
  92         if (!new_ptr) giterr_set_oom();
  93         return new_ptr;
  94 }
  95
  96 GIT_INLINE(void) git__free(void *ptr)
  97 {
  98         free(ptr);
  99 }
 100
 101 #define STRCMP_CASESELECT(IGNORE_CASE, STR1, STR2) \
 102         ((IGNORE_CASE) ? strcasecmp((STR1), (STR2)) : strcmp((STR1), (STR2)))
 103
 104 #define CASESELECT(IGNORE_CASE, ICASE, CASE) \
 105         ((IGNORE_CASE) ? (ICASE) : (CASE))
 106
 107 extern int git__prefixcmp(const char *str, const char *prefix);
 108 extern int git__prefixcmp_icase(const char *str, const char *prefix);
 109 extern int git__suffixcmp(const char *str, const char *suffix);
 110
 111 GIT_INLINE(int) git__signum(int val)
 112 {
 113         return ((val > 0) - (val < 0));
 114 }
 115
 116 extern int git__strtol32(int32_t *n, const char *buff, const char **end_buf, int base);
 117 extern int git__strtol64(int64_t *n, const char *buff, const char **end_buf, int base);
 118
 119 extern void git__hexdump(const char *buffer, size_t n);
 120 extern uint32_t git__hash(const void *key, int len, uint32_t seed);
 121
 122 /** @return true if p fits into the range of a size_t */
 123 GIT_INLINE(int) git__is_sizet(git_off_t p)
 124 {
 125         size_t r = (size_t)p;
 126         return p == (git_off_t)r;
 127 }
 128
 129 /** @return true if p fits into the range of a uint32_t */
 130 GIT_INLINE(int) git__is_uint32(size_t p)
 131 {
 132         uint32_t r = (uint32_t)p;
 133         return p == (size_t)r;
 134 }
 135
 136 /** @return true if p fits into the range of an unsigned long */
 137 GIT_INLINE(int) git__is_ulong(git_off_t p)
 138 {
 139         unsigned long r = (unsigned long)p;
 140         return p == (git_off_t)r;
 141 }
 142
 143 /* 32-bit cross-platform rotl */
 144 #ifdef _MSC_VER /* use built-in method in MSVC */
 145 #       define git__rotl(v, s) (uint32_t)_rotl(v, s)
 146 #else /* use bitops in GCC; with o2 this gets optimized to a rotl instruction */
 147 #       define git__rotl(v, s) (uint32_t)(((uint32_t)(v) << (s)) | ((uint32_t)(v) >> (32 - (s))))
 148 #endif
 149
 150 extern char *git__strtok(char **end, const char *sep);
 151 extern char *git__strsep(char **end, const char *sep);
 152
 153 extern void git__strntolower(char *str, size_t len);
 154 extern void git__strtolower(char *str);
 155
 156 GIT_INLINE(const char *) git__next_line(const char *s)
 157 {
 158         while (*s && *s != '\n') s++;
 159         while (*s == '\n' || *s == '\r') s++;
 160         return s;
 161 }
 162
 163 GIT_INLINE(const void *) git__memrchr(const void *s, int c, size_t n)
 164 {
 165         const unsigned char *cp;
 166
 167         if (n != 0) {
 168                 cp = (unsigned char *)s + n;
 169                 do {
 170                         if (*(--cp) == (unsigned char)c)
 171                                 return cp;
 172                 } while (--n != 0);
 173         }
 174
 175         return NULL;
 176 }
 177
 178 typedef int (*git__tsort_cmp)(const void *a, const void *b);
 179
 180 extern void git__tsort(void **dst, size_t size, git__tsort_cmp cmp);
 181
 182 typedef int (*git__sort_r_cmp)(const void *a, const void *b, void *payload);
 183
 184 extern void git__tsort_r(
 185         void **dst, size_t size, git__sort_r_cmp cmp, void *payload);
 186
 187 extern void git__qsort_r(
 188         void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload);
 189
 190 extern void git__insertsort_r(
 191         void *els, size_t nel, size_t elsize, void *swapel,
 192         git__sort_r_cmp cmp, void *payload);
 193
 194 /**
 195  * @param position If non-NULL, this will be set to the position where the
 196  *              element is or would be inserted if not found.
 197  * @return 0 if found; GIT_ENOTFOUND if not found
 198  */
 199 extern int git__bsearch(
 200         void **array,
 201         size_t array_len,
 202         const void *key,
 203         int (*compare)(const void *key, const void *element),
 204         size_t *position);
 205
 206 extern int git__bsearch_r(
 207         void **array,
 208         size_t array_len,
 209         const void *key,
 210         int (*compare_r)(const void *key, const void *element, void *payload),
 211         void *payload,
 212         size_t *position);
 213
 214 extern int git__strcmp_cb(const void *a, const void *b);
 215 extern int git__strcasecmp_cb(const void *a, const void *b);
 216
 217 extern int git__strcmp(const char *a, const char *b);
 218 extern int git__strcasecmp(const char *a, const char *b);
 219 extern int git__strncmp(const char *a, const char *b, size_t sz);
 220 extern int git__strncasecmp(const char *a, const char *b, size_t sz);
 221
 222 extern int git__strcasesort_cmp(const char *a, const char *b);
 223
 224 #include "thread-utils.h"
 225
 226 typedef struct {
 227         git_atomic refcount;
 228         void *owner;
 229 } git_refcount;
 230
 231 typedef void (*git_refcount_freeptr)(void *r);
 232
 233 #define GIT_REFCOUNT_INC(r) { \
 234         git_atomic_inc(&((git_refcount *)(r))->refcount);       \
 235 }
 236
 237 #define GIT_REFCOUNT_DEC(_r, do_free) { \
 238         git_refcount *r = (git_refcount *)(_r); \
 239         int val = git_atomic_dec(&r->refcount); \
 240         if (val <= 0 && r->owner == NULL) { do_free(_r); } \
 241 }
 242
 243 #define GIT_REFCOUNT_OWN(r, o) { \
 244         ((git_refcount *)(r))->owner = o; \
 245 }
 246
 247 #define GIT_REFCOUNT_OWNER(r) (((git_refcount *)(r))->owner)
 248
 249 #define GIT_REFCOUNT_VAL(r) git_atomic_get(&((git_refcount *)(r))->refcount)
 250
 251
 252 static signed char from_hex[] = {
 253 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 00 */
 254 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 10 */
 255 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 20 */
 256  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /* 30 */
 257 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 40 */
 258 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 50 */
 259 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 60 */
 260 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 70 */
 261 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 80 */
 262 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 90 */
 263 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* a0 */
 264 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* b0 */
 265 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* c0 */
 266 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* d0 */
 267 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* e0 */
 268 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* f0 */
 269 };
 270
 271 GIT_INLINE(int) git__fromhex(char h)
 272 {
 273         return from_hex[(unsigned char) h];
 274 }
 275
 276 GIT_INLINE(int) git__ishex(const char *str)
 277 {
 278         unsigned i;
 279         for (i=0; i<strlen(str); i++)
 280                 if (git__fromhex(str[i]) < 0)
 281                         return 0;
 282         return 1;
 283 }
 284
 285 GIT_INLINE(size_t) git__size_t_bitmask(size_t v)
 286 {
 287         v--;
 288         v |= v >> 1;
 289         v |= v >> 2;
 290         v |= v >> 4;
 291         v |= v >> 8;
 292         v |= v >> 16;
 293
 294         return v;
 295 }
 296
 297 GIT_INLINE(size_t) git__size_t_powerof2(size_t v)
 298 {
 299         return git__size_t_bitmask(v) + 1;
 300 }
 301
 302 GIT_INLINE(bool) git__isupper(int c)
 303 {
 304         return (c >= 'A' && c <= 'Z');
 305 }
 306
 307 GIT_INLINE(bool) git__isalpha(int c)
 308 {
 309         return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
 310 }
 311
 312 GIT_INLINE(bool) git__isdigit(int c)
 313 {
 314         return (c >= '0' && c <= '9');
 315 }
 316
 317 GIT_INLINE(bool) git__isspace(int c)
 318 {
 319         return (c == ' ' || c == '\t' || c == '\n' || c == '\f' || c == '\r' || c == '\v' || c == 0x85 /* Unicode CR+LF */);
 320 }
 321
 322 GIT_INLINE(bool) git__isspace_nonlf(int c)
 323 {
 324         return (c == ' ' || c == '\t' || c == '\f' || c == '\r' || c == '\v' || c == 0x85 /* Unicode CR+LF */);
 325 }
 326
 327 GIT_INLINE(bool) git__iswildcard(int c)
 328 {
 329         return (c == '*' || c == '?' || c == '[');
 330 }
 331
 332 /*
 333  * Parse a string value as a boolean, just like Core Git does.
 334  *
 335  * Valid values for true are: 'true', 'yes', 'on'
 336  * Valid values for false are: 'false', 'no', 'off'
 337  */
 338 extern int git__parse_bool(int *out, const char *value);
 339
 340 /*
 341  * Parse a string into a value as a git_time_t.
 342  *
 343  * Sample valid input:
 344  * - "yesterday"
 345  * - "July 17, 2003"
 346  * - "2003-7-17 08:23"
 347  */
 348 extern int git__date_parse(git_time_t *out, const char *date);
 349
 350 /*
 351  * Format a git_time as a RFC2822 string
 352  *
 353  * @param out buffer to store formatted date; a '\\0' terminator will automatically be added.
 354  * @param len size of the buffer; should be atleast `GIT_DATE_RFC2822_SZ` in size;
 355  * @param date the date to be formatted
 356  * @return 0 if successful; -1 on error
 357  */
 358 extern int git__date_rfc2822_fmt(char *out, size_t len, const git_time *date);
 359
 360 /*
 361  * Unescapes a string in-place.
 362  *
 363  * Edge cases behavior:
 364  * - "jackie\" -> "jacky\"
 365  * - "chan\\" -> "chan\"
 366  */
 367 extern size_t git__unescape(char *str);
 368
 369 /*
 370  * Safely zero-out memory, making sure that the compiler
 371  * doesn't optimize away the operation.
 372  */
 373 GIT_INLINE(void) git__memzero(void *data, size_t size)
 374 {
 375 #ifdef _MSC_VER
 376         SecureZeroMemory((PVOID)data, size);
 377 #else
 378         volatile uint8_t *scan = (volatile uint8_t *)data;
 379
 380         while (size--)
 381                 *scan++ = 0x0;
 382 #endif
 383 }
 384
 385 #ifdef GIT_WIN32
 386
 387 GIT_INLINE(double) git__timer(void)
 388 {
 389         /* We need the initial tick count to detect if the tick
 390          * count has rolled over. */
 391         static DWORD initial_tick_count = 0;
 392
 393         /* GetTickCount returns the number of milliseconds that have
 394          * elapsed since the system was started. */
 395         DWORD count = GetTickCount();
 396
 397         if(initial_tick_count == 0) {
 398                 initial_tick_count = count;
 399         } else if (count < initial_tick_count) {
 400                 /* The tick count has rolled over - adjust for it. */
 401                 count = (0xFFFFFFFF - initial_tick_count) + count;
 402         }
 403
 404         return (double) count / (double) 1000;
 405 }
 406
 407 #elif __APPLE__
 408
 409 #include <mach/mach_time.h>
 410
 411 GIT_INLINE(double) git__timer(void)
 412 {
 413    uint64_t time = mach_absolute_time();
 414    static double scaling_factor = 0;
 415
 416    if (scaling_factor == 0) {
 417        mach_timebase_info_data_t info;
 418        (void)mach_timebase_info(&info);
 419        scaling_factor = (double)info.numer / (double)info.denom;
 420    }
 421
 422    return (double)time * scaling_factor / 1.0E9;
 423 }
 424
 425 #else
 426
 427 #include <sys/time.h>
 428
 429 GIT_INLINE(double) git__timer(void)
 430 {
 431         struct timespec tp;
 432
 433         if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
 434                 return (double) tp.tv_sec + (double) tp.tv_nsec / 1.0E9;
 435         } else {
 436                 /* Fall back to using gettimeofday */
 437                 struct timeval tv;
 438                 struct timezone tz;
 439                 gettimeofday(&tv, &tz);
 440                 return (double)tv.tv_sec + (double)tv.tv_usec / 1.0E6;
 441         }
 442 }
 443
 444 #endif
 445
 446 #endif /* INCLUDE_util_h__ */