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 /* 32-bit cross-platform rotl */
 137 #ifdef _MSC_VER /* use built-in method in MSVC */
 138 #       define git__rotl(v, s) (uint32_t)_rotl(v, s)
 139 #else /* use bitops in GCC; with o2 this gets optimized to a rotl instruction */
 140 #       define git__rotl(v, s) (uint32_t)(((uint32_t)(v) << (s)) | ((uint32_t)(v) >> (32 - (s))))
 141 #endif
 142
 143 extern char *git__strtok(char **end, const char *sep);
 144 extern char *git__strsep(char **end, const char *sep);
 145
 146 extern void git__strntolower(char *str, size_t len);
 147 extern void git__strtolower(char *str);
 148
 149 GIT_INLINE(const char *) git__next_line(const char *s)
 150 {
 151         while (*s && *s != '\n') s++;
 152         while (*s == '\n' || *s == '\r') s++;
 153         return s;
 154 }
 155
 156 GIT_INLINE(const void *) git__memrchr(const void *s, int c, size_t n)
 157 {
 158         const unsigned char *cp;
 159
 160         if (n != 0) {
 161                 cp = (unsigned char *)s + n;
 162                 do {
 163                         if (*(--cp) == (unsigned char)c)
 164                                 return cp;
 165                 } while (--n != 0);
 166         }
 167
 168         return NULL;
 169 }
 170
 171 typedef int (*git__tsort_cmp)(const void *a, const void *b);
 172
 173 extern void git__tsort(void **dst, size_t size, git__tsort_cmp cmp);
 174
 175 typedef int (*git__sort_r_cmp)(const void *a, const void *b, void *payload);
 176
 177 extern void git__tsort_r(
 178         void **dst, size_t size, git__sort_r_cmp cmp, void *payload);
 179
 180 extern void git__qsort_r(
 181         void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload);
 182
 183 extern void git__insertsort_r(
 184         void *els, size_t nel, size_t elsize, void *swapel,
 185         git__sort_r_cmp cmp, void *payload);
 186
 187 /**
 188  * @param position If non-NULL, this will be set to the position where the
 189  *              element is or would be inserted if not found.
 190  * @return 0 if found; GIT_ENOTFOUND if not found
 191  */
 192 extern int git__bsearch(
 193         void **array,
 194         size_t array_len,
 195         const void *key,
 196         int (*compare)(const void *key, const void *element),
 197         size_t *position);
 198
 199 extern int git__bsearch_r(
 200         void **array,
 201         size_t array_len,
 202         const void *key,
 203         int (*compare_r)(const void *key, const void *element, void *payload),
 204         void *payload,
 205         size_t *position);
 206
 207 extern int git__strcmp_cb(const void *a, const void *b);
 208 extern int git__strcasecmp_cb(const void *a, const void *b);
 209
 210 extern int git__strcmp(const char *a, const char *b);
 211 extern int git__strcasecmp(const char *a, const char *b);
 212 extern int git__strncmp(const char *a, const char *b, size_t sz);
 213 extern int git__strncasecmp(const char *a, const char *b, size_t sz);
 214
 215 extern int git__strcasesort_cmp(const char *a, const char *b);
 216
 217 #include "thread-utils.h"
 218
 219 typedef struct {
 220         git_atomic refcount;
 221         void *owner;
 222 } git_refcount;
 223
 224 typedef void (*git_refcount_freeptr)(void *r);
 225
 226 #define GIT_REFCOUNT_INC(r) { \
 227         git_atomic_inc(&((git_refcount *)(r))->refcount);       \
 228 }
 229
 230 #define GIT_REFCOUNT_DEC(_r, do_free) { \
 231         git_refcount *r = (git_refcount *)(_r); \
 232         int val = git_atomic_dec(&r->refcount); \
 233         if (val <= 0 && r->owner == NULL) { do_free(_r); } \
 234 }
 235
 236 #define GIT_REFCOUNT_OWN(r, o) { \
 237         ((git_refcount *)(r))->owner = o; \
 238 }
 239
 240 #define GIT_REFCOUNT_OWNER(r) (((git_refcount *)(r))->owner)
 241
 242 #define GIT_REFCOUNT_VAL(r) git_atomic_get(&((git_refcount *)(r))->refcount)
 243
 244
 245 static signed char from_hex[] = {
 246 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 00 */
 247 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 10 */
 248 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 20 */
 249  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /* 30 */
 250 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 40 */
 251 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 50 */
 252 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 60 */
 253 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 70 */
 254 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 80 */
 255 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 90 */
 256 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* a0 */
 257 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* b0 */
 258 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* c0 */
 259 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* d0 */
 260 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* e0 */
 261 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* f0 */
 262 };
 263
 264 GIT_INLINE(int) git__fromhex(char h)
 265 {
 266         return from_hex[(unsigned char) h];
 267 }
 268
 269 GIT_INLINE(int) git__ishex(const char *str)
 270 {
 271         unsigned i;
 272         for (i=0; i<strlen(str); i++)
 273                 if (git__fromhex(str[i]) < 0)
 274                         return 0;
 275         return 1;
 276 }
 277
 278 GIT_INLINE(size_t) git__size_t_bitmask(size_t v)
 279 {
 280         v--;
 281         v |= v >> 1;
 282         v |= v >> 2;
 283         v |= v >> 4;
 284         v |= v >> 8;
 285         v |= v >> 16;
 286
 287         return v;
 288 }
 289
 290 GIT_INLINE(size_t) git__size_t_powerof2(size_t v)
 291 {
 292         return git__size_t_bitmask(v) + 1;
 293 }
 294
 295 GIT_INLINE(bool) git__isupper(int c)
 296 {
 297         return (c >= 'A' && c <= 'Z');
 298 }
 299
 300 GIT_INLINE(bool) git__isalpha(int c)
 301 {
 302         return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
 303 }
 304
 305 GIT_INLINE(bool) git__isdigit(int c)
 306 {
 307         return (c >= '0' && c <= '9');
 308 }
 309
 310 GIT_INLINE(bool) git__isspace(int c)
 311 {
 312         return (c == ' ' || c == '\t' || c == '\n' || c == '\f' || c == '\r' || c == '\v' || c == 0x85 /* Unicode CR+LF */);
 313 }
 314
 315 GIT_INLINE(bool) git__isspace_nonlf(int c)
 316 {
 317         return (c == ' ' || c == '\t' || c == '\f' || c == '\r' || c == '\v' || c == 0x85 /* Unicode CR+LF */);
 318 }
 319
 320 GIT_INLINE(bool) git__iswildcard(int c)
 321 {
 322         return (c == '*' || c == '?' || c == '[');
 323 }
 324
 325 /*
 326  * Parse a string value as a boolean, just like Core Git does.
 327  *
 328  * Valid values for true are: 'true', 'yes', 'on'
 329  * Valid values for false are: 'false', 'no', 'off'
 330  */
 331 extern int git__parse_bool(int *out, const char *value);
 332
 333 /*
 334  * Parse a string into a value as a git_time_t.
 335  *
 336  * Sample valid input:
 337  * - "yesterday"
 338  * - "July 17, 2003"
 339  * - "2003-7-17 08:23"
 340  */
 341 extern int git__date_parse(git_time_t *out, const char *date);
 342
 343 /*
 344  * Format a git_time as a RFC2822 string
 345  *
 346  * @param out buffer to store formatted date; a '\\0' terminator will automatically be added.
 347  * @param len size of the buffer; should be atleast `GIT_DATE_RFC2822_SZ` in size;
 348  * @param date the date to be formatted
 349  * @return 0 if successful; -1 on error
 350  */
 351 extern int git__date_rfc2822_fmt(char *out, size_t len, const git_time *date);
 352
 353 /*
 354  * Unescapes a string in-place.
 355  *
 356  * Edge cases behavior:
 357  * - "jackie\" -> "jacky\"
 358  * - "chan\\" -> "chan\"
 359  */
 360 extern size_t git__unescape(char *str);
 361
 362 /*
 363  * Safely zero-out memory, making sure that the compiler
 364  * doesn't optimize away the operation.
 365  */
 366 GIT_INLINE(void) git__memzero(void *data, size_t size)
 367 {
 368 #ifdef _MSC_VER
 369         SecureZeroMemory((PVOID)data, size);
 370 #else
 371         volatile uint8_t *scan = (volatile uint8_t *)data;
 372
 373         while (size--)
 374                 *scan++ = 0x0;
 375 #endif
 376 }
 377
 378 #ifdef GIT_WIN32
 379
 380 GIT_INLINE(double) git__timer(void)
 381 {
 382         /* We need the initial tick count to detect if the tick
 383          * count has rolled over. */
 384         static DWORD initial_tick_count = 0;
 385
 386         /* GetTickCount returns the number of milliseconds that have
 387          * elapsed since the system was started. */
 388         DWORD count = GetTickCount();
 389
 390         if(initial_tick_count == 0) {
 391                 initial_tick_count = count;
 392         } else if (count < initial_tick_count) {
 393                 /* The tick count has rolled over - adjust for it. */
 394                 count = (0xFFFFFFFF - initial_tick_count) + count;
 395         }
 396
 397         return (double) count / (double) 1000;
 398 }
 399
 400 #elif __APPLE__
 401
 402 #include <mach/mach_time.h>
 403
 404 GIT_INLINE(double) git__timer(void)
 405 {
 406    uint64_t time = mach_absolute_time();
 407    static double scaling_factor = 0;
 408
 409    if (scaling_factor == 0) {
 410        mach_timebase_info_data_t info;
 411        (void)mach_timebase_info(&info);
 412        scaling_factor = (double)info.numer / (double)info.denom;
 413    }
 414
 415    return (double)time * scaling_factor / 1.0E-9;
 416 }
 417
 418 #else
 419
 420 #include <sys/time.h>
 421
 422 GIT_INLINE(double) git__timer(void)
 423 {
 424         struct timespec tp;
 425
 426         if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
 427                 return (double) tp.tv_sec + (double) tp.tv_nsec / 1E-9;
 428         } else {
 429                 /* Fall back to using gettimeofday */
 430                 struct timeval tv;
 431                 struct timezone tz;
 432                 gettimeofday(&tv, &tz);
 433                 return (double)tv.tv_sec + (double)tv.tv_usec / 1E-6;
 434         }
 435 }
 436
 437 #endif
 438
 439 #endif /* INCLUDE_util_h__ */