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 #if defined(GIT_MSVC_CRTDBG)
  11 /* Enable MSVC CRTDBG memory leak reporting.
  12  *
  13  * We DO NOT use the "_CRTDBG_MAP_ALLOC" macro described in the MSVC
  14  * documentation because all allocs/frees in libgit2 already go through
  15  * the "git__" routines defined in this file.  Simply using the normal
  16  * reporting mechanism causes all leaks to be attributed to a routine
  17  * here in util.h (ie, the actual call to calloc()) rather than the
  18  * caller of git__calloc().
  19  *
  20  * Therefore, we declare a set of "git__crtdbg__" routines to replace
  21  * the corresponding "git__" routines and re-define the "git__" symbols
  22  * as macros.  This allows us to get and report the file:line info of
  23  * the real caller.
  24  *
  25  * We DO NOT replace the "git__free" routine because it needs to remain
  26  * a function pointer because it is used as a function argument when
  27  * setting up various structure "destructors".
  28  *
  29  * We also DO NOT use the "_CRTDBG_MAP_ALLOC" macro because it causes
  30  * "free" to be remapped to "_free_dbg" and this causes problems for
  31  * structures which define a field named "free".
  32  *
  33  * Finally, CRTDBG must be explicitly enabled and configured at program
  34  * startup.  See tests/main.c for an example.
  35  */
  36 #include <stdlib.h>
  37 #include <crtdbg.h>
  38 #endif
  39
  40 #include "common.h"
  41 #include "strnlen.h"
  42
  43 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
  44 #define bitsizeof(x) (CHAR_BIT * sizeof(x))
  45 #define MSB(x, bits) ((x) & (~0ULL << (bitsizeof(x) - (bits))))
  46 #ifndef min
  47 # define min(a,b) ((a) < (b) ? (a) : (b))
  48 #endif
  49 #ifndef max
  50 # define max(a,b) ((a) > (b) ? (a) : (b))
  51 #endif
  52
  53 #define GIT_DATE_RFC2822_SZ  32
  54
  55 /**
  56  * Return the length of a constant string.
  57  * We are aware that `strlen` performs the same task and is usually
  58  * optimized away by the compiler, whilst being safer because it returns
  59  * valid values when passed a pointer instead of a constant string; however
  60  * this macro will transparently work with wide-char and single-char strings.
  61  */
  62 #define CONST_STRLEN(x) ((sizeof(x)/sizeof(x[0])) - 1)
  63
  64 #if defined(GIT_MSVC_CRTDBG)
  65 GIT_INLINE(void *) git__crtdbg__malloc(size_t len, const char *file, int line)
  66 {
  67         void *ptr = _malloc_dbg(len, _NORMAL_BLOCK, file, line);
  68         if (!ptr) giterr_set_oom();
  69         return ptr;
  70 }
  71
  72 GIT_INLINE(void *) git__crtdbg__calloc(size_t nelem, size_t elsize, const char *file, int line)
  73 {
  74         void *ptr = _calloc_dbg(nelem, elsize, _NORMAL_BLOCK, file, line);
  75         if (!ptr) giterr_set_oom();
  76         return ptr;
  77 }
  78
  79 GIT_INLINE(char *) git__crtdbg__strdup(const char *str, const char *file, int line)
  80 {
  81         char *ptr = _strdup_dbg(str, _NORMAL_BLOCK, file, line);
  82         if (!ptr) giterr_set_oom();
  83         return ptr;
  84 }
  85
  86 GIT_INLINE(char *) git__crtdbg__strndup(const char *str, size_t n, const char *file, int line)
  87 {
  88         size_t length = 0, alloclength;
  89         char *ptr;
  90
  91         length = p_strnlen(str, n);
  92
  93         if (GIT_ADD_SIZET_OVERFLOW(&alloclength, length, 1) ||
  94                 !(ptr = git__crtdbg__malloc(alloclength, file, line)))
  95                 return NULL;
  96
  97         if (length)
  98                 memcpy(ptr, str, length);
  99
 100         ptr[length] = '\0';
 101
 102         return ptr;
 103 }
 104
 105 GIT_INLINE(char *) git__crtdbg__substrdup(const char *start, size_t n, const char *file, int line)
 106 {
 107         char *ptr;
 108         size_t alloclen;
 109
 110         if (GIT_ADD_SIZET_OVERFLOW(&alloclen, n, 1) ||
 111                 !(ptr = git__crtdbg__malloc(alloclen, file, line)))
 112                 return NULL;
 113
 114         memcpy(ptr, start, n);
 115         ptr[n] = '\0';
 116         return ptr;
 117 }
 118
 119 GIT_INLINE(void *) git__crtdbg__realloc(void *ptr, size_t size, const char *file, int line)
 120 {
 121         void *new_ptr = _realloc_dbg(ptr, size, _NORMAL_BLOCK, file, line);
 122         if (!new_ptr) giterr_set_oom();
 123         return new_ptr;
 124 }
 125
 126 GIT_INLINE(void *) git__crtdbg__reallocarray(void *ptr, size_t nelem, size_t elsize, const char *file, int line)
 127 {
 128         size_t newsize;
 129         return GIT_MULTIPLY_SIZET_OVERFLOW(&newsize, nelem, elsize) ?
 130                 NULL : _realloc_dbg(ptr, newsize, _NORMAL_BLOCK, file, line);
 131 }
 132
 133 GIT_INLINE(void *) git__crtdbg__mallocarray(size_t nelem, size_t elsize, const char *file, int line)
 134 {
 135         return git__crtdbg__reallocarray(NULL, nelem, elsize, file, line);
 136 }
 137
 138 #define git__malloc(len)                      git__crtdbg__malloc(len, __FILE__, __LINE__)
 139 #define git__calloc(nelem, elsize)            git__crtdbg__calloc(nelem, elsize, __FILE__, __LINE__)
 140 #define git__strdup(str)                      git__crtdbg__strdup(str, __FILE__, __LINE__)
 141 #define git__strndup(str, n)                  git__crtdbg__strndup(str, n, __FILE__, __LINE__)
 142 #define git__substrdup(str, n)                git__crtdbg__substrdup(str, n, __FILE__, __LINE__)
 143 #define git__realloc(ptr, size)               git__crtdbg__realloc(ptr, size, __FILE__, __LINE__)
 144 #define git__reallocarray(ptr, nelem, elsize) git__crtdbg__reallocarray(ptr, nelem, elsize, __FILE__, __LINE__)
 145 #define git__mallocarray(nelem, elsize)       git__crtdbg__mallocarray(nelem, elsize, __FILE__, __LINE__)
 146
 147 #else
 148
 149 /*
 150  * Custom memory allocation wrappers
 151  * that set error code and error message
 152  * on allocation failure
 153  */
 154 GIT_INLINE(void *) git__malloc(size_t len)
 155 {
 156         void *ptr = malloc(len);
 157         if (!ptr) giterr_set_oom();
 158         return ptr;
 159 }
 160
 161 GIT_INLINE(void *) git__calloc(size_t nelem, size_t elsize)
 162 {
 163         void *ptr = calloc(nelem, elsize);
 164         if (!ptr) giterr_set_oom();
 165         return ptr;
 166 }
 167
 168 GIT_INLINE(char *) git__strdup(const char *str)
 169 {
 170         char *ptr = strdup(str);
 171         if (!ptr) giterr_set_oom();
 172         return ptr;
 173 }
 174
 175 GIT_INLINE(char *) git__strndup(const char *str, size_t n)
 176 {
 177         size_t length = 0, alloclength;
 178         char *ptr;
 179
 180         length = p_strnlen(str, n);
 181
 182         if (GIT_ADD_SIZET_OVERFLOW(&alloclength, length, 1) ||
 183                 !(ptr = git__malloc(alloclength)))
 184                 return NULL;
 185
 186         if (length)
 187                 memcpy(ptr, str, length);
 188
 189         ptr[length] = '\0';
 190
 191         return ptr;
 192 }
 193
 194 /* NOTE: This doesn't do null or '\0' checking.  Watch those boundaries! */
 195 GIT_INLINE(char *) git__substrdup(const char *start, size_t n)
 196 {
 197         char *ptr;
 198         size_t alloclen;
 199
 200         if (GIT_ADD_SIZET_OVERFLOW(&alloclen, n, 1) ||
 201                 !(ptr = git__malloc(alloclen)))
 202                 return NULL;
 203
 204         memcpy(ptr, start, n);
 205         ptr[n] = '\0';
 206         return ptr;
 207 }
 208
 209 GIT_INLINE(void *) git__realloc(void *ptr, size_t size)
 210 {
 211         void *new_ptr = realloc(ptr, size);
 212         if (!new_ptr) giterr_set_oom();
 213         return new_ptr;
 214 }
 215
 216 /**
 217  * Similar to `git__realloc`, except that it is suitable for reallocing an
 218  * array to a new number of elements of `nelem`, each of size `elsize`.
 219  * The total size calculation is checked for overflow.
 220  */
 221 GIT_INLINE(void *) git__reallocarray(void *ptr, size_t nelem, size_t elsize)
 222 {
 223         size_t newsize;
 224         return GIT_MULTIPLY_SIZET_OVERFLOW(&newsize, nelem, elsize) ?
 225                 NULL : realloc(ptr, newsize);
 226 }
 227
 228 /**
 229  * Similar to `git__calloc`, except that it does not zero memory.
 230  */
 231 GIT_INLINE(void *) git__mallocarray(size_t nelem, size_t elsize)
 232 {
 233         return git__reallocarray(NULL, nelem, elsize);
 234 }
 235
 236 #endif /* !MSVC_CTRDBG */
 237
 238 GIT_INLINE(void) git__free(void *ptr)
 239 {
 240         free(ptr);
 241 }
 242
 243 #define STRCMP_CASESELECT(IGNORE_CASE, STR1, STR2) \
 244         ((IGNORE_CASE) ? strcasecmp((STR1), (STR2)) : strcmp((STR1), (STR2)))
 245
 246 #define CASESELECT(IGNORE_CASE, ICASE, CASE) \
 247         ((IGNORE_CASE) ? (ICASE) : (CASE))
 248
 249 extern int git__prefixcmp(const char *str, const char *prefix);
 250 extern int git__prefixcmp_icase(const char *str, const char *prefix);
 251 extern int git__prefixncmp_icase(const char *str, size_t str_n, const char *prefix);
 252 extern int git__suffixcmp(const char *str, const char *suffix);
 253
 254 GIT_INLINE(int) git__signum(int val)
 255 {
 256         return ((val > 0) - (val < 0));
 257 }
 258
 259 extern int git__strtol32(int32_t *n, const char *buff, const char **end_buf, int base);
 260 extern int git__strtol64(int64_t *n, const char *buff, const char **end_buf, int base);
 261
 262 extern void git__hexdump(const char *buffer, size_t n);
 263 extern uint32_t git__hash(const void *key, int len, uint32_t seed);
 264
 265 /* 32-bit cross-platform rotl */
 266 #ifdef _MSC_VER /* use built-in method in MSVC */
 267 #       define git__rotl(v, s) (uint32_t)_rotl(v, s)
 268 #else /* use bitops in GCC; with o2 this gets optimized to a rotl instruction */
 269 #       define git__rotl(v, s) (uint32_t)(((uint32_t)(v) << (s)) | ((uint32_t)(v) >> (32 - (s))))
 270 #endif
 271
 272 extern char *git__strtok(char **end, const char *sep);
 273 extern char *git__strsep(char **end, const char *sep);
 274
 275 extern void git__strntolower(char *str, size_t len);
 276 extern void git__strtolower(char *str);
 277
 278 #ifdef GIT_WIN32
 279 GIT_INLINE(int) git__tolower(int c)
 280 {
 281         return (c >= 'A' && c <= 'Z') ? (c + 32) : c;
 282 }
 283 #else
 284 # define git__tolower(a) tolower(a)
 285 #endif
 286
 287 GIT_INLINE(const char *) git__next_line(const char *s)
 288 {
 289         while (*s && *s != '\n') s++;
 290         while (*s == '\n' || *s == '\r') s++;
 291         return s;
 292 }
 293
 294 GIT_INLINE(const void *) git__memrchr(const void *s, int c, size_t n)
 295 {
 296         const unsigned char *cp;
 297
 298         if (n != 0) {
 299                 cp = (unsigned char *)s + n;
 300                 do {
 301                         if (*(--cp) == (unsigned char)c)
 302                                 return cp;
 303                 } while (--n != 0);
 304         }
 305
 306         return NULL;
 307 }
 308
 309 typedef int (*git__tsort_cmp)(const void *a, const void *b);
 310
 311 extern void git__tsort(void **dst, size_t size, git__tsort_cmp cmp);
 312
 313 typedef int (*git__sort_r_cmp)(const void *a, const void *b, void *payload);
 314
 315 extern void git__tsort_r(
 316         void **dst, size_t size, git__sort_r_cmp cmp, void *payload);
 317
 318 extern void git__qsort_r(
 319         void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload);
 320
 321 extern void git__insertsort_r(
 322         void *els, size_t nel, size_t elsize, void *swapel,
 323         git__sort_r_cmp cmp, void *payload);
 324
 325 /**
 326  * @param position If non-NULL, this will be set to the position where the
 327  *              element is or would be inserted if not found.
 328  * @return 0 if found; GIT_ENOTFOUND if not found
 329  */
 330 extern int git__bsearch(
 331         void **array,
 332         size_t array_len,
 333         const void *key,
 334         int (*compare)(const void *key, const void *element),
 335         size_t *position);
 336
 337 extern int git__bsearch_r(
 338         void **array,
 339         size_t array_len,
 340         const void *key,
 341         int (*compare_r)(const void *key, const void *element, void *payload),
 342         void *payload,
 343         size_t *position);
 344
 345 extern int git__strcmp_cb(const void *a, const void *b);
 346 extern int git__strcasecmp_cb(const void *a, const void *b);
 347
 348 extern int git__strcmp(const char *a, const char *b);
 349 extern int git__strcasecmp(const char *a, const char *b);
 350 extern int git__strncmp(const char *a, const char *b, size_t sz);
 351 extern int git__strncasecmp(const char *a, const char *b, size_t sz);
 352
 353 extern int git__strcasesort_cmp(const char *a, const char *b);
 354
 355 #include "thread-utils.h"
 356
 357 typedef struct {
 358         git_atomic refcount;
 359         void *owner;
 360 } git_refcount;
 361
 362 typedef void (*git_refcount_freeptr)(void *r);
 363
 364 #define GIT_REFCOUNT_INC(r) { \
 365         git_atomic_inc(&((git_refcount *)(r))->refcount);       \
 366 }
 367
 368 #define GIT_REFCOUNT_DEC(_r, do_free) { \
 369         git_refcount *r = (git_refcount *)(_r); \
 370         int val = git_atomic_dec(&r->refcount); \
 371         if (val <= 0 && r->owner == NULL) { do_free(_r); } \
 372 }
 373
 374 #define GIT_REFCOUNT_OWN(r, o) { \
 375         ((git_refcount *)(r))->owner = o; \
 376 }
 377
 378 #define GIT_REFCOUNT_OWNER(r) (((git_refcount *)(r))->owner)
 379
 380 #define GIT_REFCOUNT_VAL(r) git_atomic_get(&((git_refcount *)(r))->refcount)
 381
 382
 383 static signed char from_hex[] = {
 384 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 00 */
 385 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 10 */
 386 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 20 */
 387  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /* 30 */
 388 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 40 */
 389 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 50 */
 390 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 60 */
 391 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 70 */
 392 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 80 */
 393 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 90 */
 394 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* a0 */
 395 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* b0 */
 396 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* c0 */
 397 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* d0 */
 398 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* e0 */
 399 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* f0 */
 400 };
 401
 402 GIT_INLINE(int) git__fromhex(char h)
 403 {
 404         return from_hex[(unsigned char) h];
 405 }
 406
 407 GIT_INLINE(int) git__ishex(const char *str)
 408 {
 409         unsigned i;
 410         for (i=0; str[i] != '\0'; i++)
 411                 if (git__fromhex(str[i]) < 0)
 412                         return 0;
 413         return 1;
 414 }
 415
 416 GIT_INLINE(size_t) git__size_t_bitmask(size_t v)
 417 {
 418         v--;
 419         v |= v >> 1;
 420         v |= v >> 2;
 421         v |= v >> 4;
 422         v |= v >> 8;
 423         v |= v >> 16;
 424
 425         return v;
 426 }
 427
 428 GIT_INLINE(size_t) git__size_t_powerof2(size_t v)
 429 {
 430         return git__size_t_bitmask(v) + 1;
 431 }
 432
 433 GIT_INLINE(bool) git__isupper(int c)
 434 {
 435         return (c >= 'A' && c <= 'Z');
 436 }
 437
 438 GIT_INLINE(bool) git__isalpha(int c)
 439 {
 440         return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
 441 }
 442
 443 GIT_INLINE(bool) git__isdigit(int c)
 444 {
 445         return (c >= '0' && c <= '9');
 446 }
 447
 448 GIT_INLINE(bool) git__isspace(int c)
 449 {
 450         return (c == ' ' || c == '\t' || c == '\n' || c == '\f' || c == '\r' || c == '\v');
 451 }
 452
 453 GIT_INLINE(bool) git__isspace_nonlf(int c)
 454 {
 455         return (c == ' ' || c == '\t' || c == '\f' || c == '\r' || c == '\v');
 456 }
 457
 458 GIT_INLINE(bool) git__iswildcard(int c)
 459 {
 460         return (c == '*' || c == '?' || c == '[');
 461 }
 462
 463 /*
 464  * Parse a string value as a boolean, just like Core Git does.
 465  *
 466  * Valid values for true are: 'true', 'yes', 'on'
 467  * Valid values for false are: 'false', 'no', 'off'
 468  */
 469 extern int git__parse_bool(int *out, const char *value);
 470
 471 /*
 472  * Parse a string into a value as a git_time_t.
 473  *
 474  * Sample valid input:
 475  * - "yesterday"
 476  * - "July 17, 2003"
 477  * - "2003-7-17 08:23"
 478  */
 479 extern int git__date_parse(git_time_t *out, const char *date);
 480
 481 /*
 482  * Format a git_time as a RFC2822 string
 483  *
 484  * @param out buffer to store formatted date; a '\\0' terminator will automatically be added.
 485  * @param len size of the buffer; should be atleast `GIT_DATE_RFC2822_SZ` in size;
 486  * @param date the date to be formatted
 487  * @return 0 if successful; -1 on error
 488  */
 489 extern int git__date_rfc2822_fmt(char *out, size_t len, const git_time *date);
 490
 491 /*
 492  * Unescapes a string in-place.
 493  *
 494  * Edge cases behavior:
 495  * - "jackie\" -> "jacky\"
 496  * - "chan\\" -> "chan\"
 497  */
 498 extern size_t git__unescape(char *str);
 499
 500 /*
 501  * Iterate through an UTF-8 string, yielding one
 502  * codepoint at a time.
 503  *
 504  * @param str current position in the string
 505  * @param str_len size left in the string; -1 if the string is NULL-terminated
 506  * @param dst pointer where to store the current codepoint
 507  * @return length in bytes of the read codepoint; -1 if the codepoint was invalid
 508  */
 509 extern int git__utf8_iterate(const uint8_t *str, int str_len, int32_t *dst);
 510
 511 /*
 512  * Safely zero-out memory, making sure that the compiler
 513  * doesn't optimize away the operation.
 514  */
 515 GIT_INLINE(void) git__memzero(void *data, size_t size)
 516 {
 517 #ifdef _MSC_VER
 518         SecureZeroMemory((PVOID)data, size);
 519 #else
 520         volatile uint8_t *scan = (volatile uint8_t *)data;
 521
 522         while (size--)
 523                 *scan++ = 0x0;
 524 #endif
 525 }
 526
 527 #ifdef GIT_WIN32
 528
 529 GIT_INLINE(double) git__timer(void)
 530 {
 531         /* We need the initial tick count to detect if the tick
 532          * count has rolled over. */
 533         static DWORD initial_tick_count = 0;
 534
 535         /* GetTickCount returns the number of milliseconds that have
 536          * elapsed since the system was started. */
 537         DWORD count = GetTickCount();
 538
 539         if(initial_tick_count == 0) {
 540                 initial_tick_count = count;
 541         } else if (count < initial_tick_count) {
 542                 /* The tick count has rolled over - adjust for it. */
 543                 count = (0xFFFFFFFF - initial_tick_count) + count;
 544         }
 545
 546         return (double) count / (double) 1000;
 547 }
 548
 549 #elif __APPLE__
 550
 551 #include <mach/mach_time.h>
 552
 553 GIT_INLINE(double) git__timer(void)
 554 {
 555    uint64_t time = mach_absolute_time();
 556    static double scaling_factor = 0;
 557
 558    if (scaling_factor == 0) {
 559        mach_timebase_info_data_t info;
 560        (void)mach_timebase_info(&info);
 561        scaling_factor = (double)info.numer / (double)info.denom;
 562    }
 563
 564    return (double)time * scaling_factor / 1.0E9;
 565 }
 566
 567 #elif defined(AMIGA)
 568
 569 #include <proto/timer.h>
 570
 571 GIT_INLINE(double) git__timer(void)
 572 {
 573         struct TimeVal tv;
 574         ITimer->GetUpTime(&tv);
 575         return (double)tv.Seconds + (double)tv.Microseconds / 1.0E6;
 576 }
 577
 578 #else
 579
 580 #include <sys/time.h>
 581
 582 GIT_INLINE(double) git__timer(void)
 583 {
 584         struct timespec tp;
 585
 586         if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
 587                 return (double) tp.tv_sec + (double) tp.tv_nsec / 1.0E9;
 588         } else {
 589                 /* Fall back to using gettimeofday */
 590                 struct timeval tv;
 591                 struct timezone tz;
 592                 gettimeofday(&tv, &tz);
 593                 return (double)tv.tv_sec + (double)tv.tv_usec / 1.0E6;
 594         }
 595 }
 596
 597 #endif
 598
 599 #endif /* INCLUDE_util_h__ */