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__prefixncmp_icase(const char *str, size_t str_n, const char *prefix);
 110 extern int git__suffixcmp(const char *str, const char *suffix);
 111
 112 GIT_INLINE(int) git__signum(int val)
 113 {
 114         return ((val > 0) - (val < 0));
 115 }
 116
 117 extern int git__strtol32(int32_t *n, const char *buff, const char **end_buf, int base);
 118 extern int git__strtol64(int64_t *n, const char *buff, const char **end_buf, int base);
 119
 120 extern void git__hexdump(const char *buffer, size_t n);
 121 extern uint32_t git__hash(const void *key, int len, uint32_t seed);
 122
 123 /** @return true if p fits into the range of a size_t */
 124 GIT_INLINE(int) git__is_sizet(git_off_t p)
 125 {
 126         size_t r = (size_t)p;
 127         return p == (git_off_t)r;
 128 }
 129
 130 /** @return true if p fits into the range of a uint32_t */
 131 GIT_INLINE(int) git__is_uint32(size_t p)
 132 {
 133         uint32_t r = (uint32_t)p;
 134         return p == (size_t)r;
 135 }
 136
 137 /** @return true if p fits into the range of an unsigned long */
 138 GIT_INLINE(int) git__is_ulong(git_off_t p)
 139 {
 140         unsigned long r = (unsigned long)p;
 141         return p == (git_off_t)r;
 142 }
 143
 144 /* 32-bit cross-platform rotl */
 145 #ifdef _MSC_VER /* use built-in method in MSVC */
 146 #       define git__rotl(v, s) (uint32_t)_rotl(v, s)
 147 #else /* use bitops in GCC; with o2 this gets optimized to a rotl instruction */
 148 #       define git__rotl(v, s) (uint32_t)(((uint32_t)(v) << (s)) | ((uint32_t)(v) >> (32 - (s))))
 149 #endif
 150
 151 extern char *git__strtok(char **end, const char *sep);
 152 extern char *git__strsep(char **end, const char *sep);
 153
 154 extern void git__strntolower(char *str, size_t len);
 155 extern void git__strtolower(char *str);
 156
 157 GIT_INLINE(const char *) git__next_line(const char *s)
 158 {
 159         while (*s && *s != '\n') s++;
 160         while (*s == '\n' || *s == '\r') s++;
 161         return s;
 162 }
 163
 164 GIT_INLINE(const void *) git__memrchr(const void *s, int c, size_t n)
 165 {
 166         const unsigned char *cp;
 167
 168         if (n != 0) {
 169                 cp = (unsigned char *)s + n;
 170                 do {
 171                         if (*(--cp) == (unsigned char)c)
 172                                 return cp;
 173                 } while (--n != 0);
 174         }
 175
 176         return NULL;
 177 }
 178
 179 typedef int (*git__tsort_cmp)(const void *a, const void *b);
 180
 181 extern void git__tsort(void **dst, size_t size, git__tsort_cmp cmp);
 182
 183 typedef int (*git__sort_r_cmp)(const void *a, const void *b, void *payload);
 184
 185 extern void git__tsort_r(
 186         void **dst, size_t size, git__sort_r_cmp cmp, void *payload);
 187
 188 extern void git__qsort_r(
 189         void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload);
 190
 191 extern void git__insertsort_r(
 192         void *els, size_t nel, size_t elsize, void *swapel,
 193         git__sort_r_cmp cmp, void *payload);
 194
 195 /**
 196  * @param position If non-NULL, this will be set to the position where the
 197  *              element is or would be inserted if not found.
 198  * @return 0 if found; GIT_ENOTFOUND if not found
 199  */
 200 extern int git__bsearch(
 201         void **array,
 202         size_t array_len,
 203         const void *key,
 204         int (*compare)(const void *key, const void *element),
 205         size_t *position);
 206
 207 extern int git__bsearch_r(
 208         void **array,
 209         size_t array_len,
 210         const void *key,
 211         int (*compare_r)(const void *key, const void *element, void *payload),
 212         void *payload,
 213         size_t *position);
 214
 215 extern int git__strcmp_cb(const void *a, const void *b);
 216 extern int git__strcasecmp_cb(const void *a, const void *b);
 217
 218 extern int git__strcmp(const char *a, const char *b);
 219 extern int git__strcasecmp(const char *a, const char *b);
 220 extern int git__strncmp(const char *a, const char *b, size_t sz);
 221 extern int git__strncasecmp(const char *a, const char *b, size_t sz);
 222
 223 extern int git__strcasesort_cmp(const char *a, const char *b);
 224
 225 #include "thread-utils.h"
 226
 227 typedef struct {
 228         git_atomic refcount;
 229         void *owner;
 230 } git_refcount;
 231
 232 typedef void (*git_refcount_freeptr)(void *r);
 233
 234 #define GIT_REFCOUNT_INC(r) { \
 235         git_atomic_inc(&((git_refcount *)(r))->refcount);       \
 236 }
 237
 238 #define GIT_REFCOUNT_DEC(_r, do_free) { \
 239         git_refcount *r = (git_refcount *)(_r); \
 240         int val = git_atomic_dec(&r->refcount); \
 241         if (val <= 0 && r->owner == NULL) { do_free(_r); } \
 242 }
 243
 244 #define GIT_REFCOUNT_OWN(r, o) { \
 245         ((git_refcount *)(r))->owner = o; \
 246 }
 247
 248 #define GIT_REFCOUNT_OWNER(r) (((git_refcount *)(r))->owner)
 249
 250 #define GIT_REFCOUNT_VAL(r) git_atomic_get(&((git_refcount *)(r))->refcount)
 251
 252
 253 static signed char from_hex[] = {
 254 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 00 */
 255 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 10 */
 256 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 20 */
 257  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /* 30 */
 258 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 40 */
 259 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 50 */
 260 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 60 */
 261 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 70 */
 262 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 80 */
 263 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 90 */
 264 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* a0 */
 265 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* b0 */
 266 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* c0 */
 267 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* d0 */
 268 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* e0 */
 269 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* f0 */
 270 };
 271
 272 GIT_INLINE(int) git__fromhex(char h)
 273 {
 274         return from_hex[(unsigned char) h];
 275 }
 276
 277 GIT_INLINE(int) git__ishex(const char *str)
 278 {
 279         unsigned i;
 280         for (i=0; i<strlen(str); i++)
 281                 if (git__fromhex(str[i]) < 0)
 282                         return 0;
 283         return 1;
 284 }
 285
 286 GIT_INLINE(size_t) git__size_t_bitmask(size_t v)
 287 {
 288         v--;
 289         v |= v >> 1;
 290         v |= v >> 2;
 291         v |= v >> 4;
 292         v |= v >> 8;
 293         v |= v >> 16;
 294
 295         return v;
 296 }
 297
 298 GIT_INLINE(size_t) git__size_t_powerof2(size_t v)
 299 {
 300         return git__size_t_bitmask(v) + 1;
 301 }
 302
 303 GIT_INLINE(bool) git__isupper(int c)
 304 {
 305         return (c >= 'A' && c <= 'Z');
 306 }
 307
 308 GIT_INLINE(bool) git__isalpha(int c)
 309 {
 310         return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
 311 }
 312
 313 GIT_INLINE(bool) git__isdigit(int c)
 314 {
 315         return (c >= '0' && c <= '9');
 316 }
 317
 318 GIT_INLINE(bool) git__isspace(int c)
 319 {
 320         return (c == ' ' || c == '\t' || c == '\n' || c == '\f' || c == '\r' || c == '\v');
 321 }
 322
 323 GIT_INLINE(bool) git__isspace_nonlf(int c)
 324 {
 325         return (c == ' ' || c == '\t' || c == '\f' || c == '\r' || c == '\v');
 326 }
 327
 328 GIT_INLINE(bool) git__iswildcard(int c)
 329 {
 330         return (c == '*' || c == '?' || c == '[');
 331 }
 332
 333 /*
 334  * Parse a string value as a boolean, just like Core Git does.
 335  *
 336  * Valid values for true are: 'true', 'yes', 'on'
 337  * Valid values for false are: 'false', 'no', 'off'
 338  */
 339 extern int git__parse_bool(int *out, const char *value);
 340
 341 /*
 342  * Parse a string into a value as a git_time_t.
 343  *
 344  * Sample valid input:
 345  * - "yesterday"
 346  * - "July 17, 2003"
 347  * - "2003-7-17 08:23"
 348  */
 349 extern int git__date_parse(git_time_t *out, const char *date);
 350
 351 /*
 352  * Format a git_time as a RFC2822 string
 353  *
 354  * @param out buffer to store formatted date; a '\\0' terminator will automatically be added.
 355  * @param len size of the buffer; should be atleast `GIT_DATE_RFC2822_SZ` in size;
 356  * @param date the date to be formatted
 357  * @return 0 if successful; -1 on error
 358  */
 359 extern int git__date_rfc2822_fmt(char *out, size_t len, const git_time *date);
 360
 361 /*
 362  * Unescapes a string in-place.
 363  *
 364  * Edge cases behavior:
 365  * - "jackie\" -> "jacky\"
 366  * - "chan\\" -> "chan\"
 367  */
 368 extern size_t git__unescape(char *str);
 369
 370 /*
 371  * Iterate through an UTF-8 string, yielding one
 372  * codepoint at a time.
 373  *
 374  * @param str current position in the string
 375  * @param str_len size left in the string; -1 if the string is NULL-terminated
 376  * @param dst pointer where to store the current codepoint
 377  * @return length in bytes of the read codepoint; -1 if the codepoint was invalid
 378  */
 379 extern int git__utf8_iterate(const uint8_t *str, int str_len, int32_t *dst);
 380
 381 /*
 382  * Safely zero-out memory, making sure that the compiler
 383  * doesn't optimize away the operation.
 384  */
 385 GIT_INLINE(void) git__memzero(void *data, size_t size)
 386 {
 387 #ifdef _MSC_VER
 388         SecureZeroMemory((PVOID)data, size);
 389 #else
 390         volatile uint8_t *scan = (volatile uint8_t *)data;
 391
 392         while (size--)
 393                 *scan++ = 0x0;
 394 #endif
 395 }
 396
 397 #ifdef GIT_WIN32
 398
 399 GIT_INLINE(double) git__timer(void)
 400 {
 401         /* We need the initial tick count to detect if the tick
 402          * count has rolled over. */
 403         static DWORD initial_tick_count = 0;
 404
 405         /* GetTickCount returns the number of milliseconds that have
 406          * elapsed since the system was started. */
 407         DWORD count = GetTickCount();
 408
 409         if(initial_tick_count == 0) {
 410                 initial_tick_count = count;
 411         } else if (count < initial_tick_count) {
 412                 /* The tick count has rolled over - adjust for it. */
 413                 count = (0xFFFFFFFF - initial_tick_count) + count;
 414         }
 415
 416         return (double) count / (double) 1000;
 417 }
 418
 419 #elif __APPLE__
 420
 421 #include <mach/mach_time.h>
 422
 423 GIT_INLINE(double) git__timer(void)
 424 {
 425    uint64_t time = mach_absolute_time();
 426    static double scaling_factor = 0;
 427
 428    if (scaling_factor == 0) {
 429        mach_timebase_info_data_t info;
 430        (void)mach_timebase_info(&info);
 431        scaling_factor = (double)info.numer / (double)info.denom;
 432    }
 433
 434    return (double)time * scaling_factor / 1.0E9;
 435 }
 436
 437 #elif defined(AMIGA)
 438
 439 #include <proto/timer.h>
 440
 441 GIT_INLINE(double) git__timer(void)
 442 {
 443         struct TimeVal tv;
 444         ITimer->GetUpTime(&tv);
 445         return (double)tv.Seconds + (double)tv.Microseconds / 1.0E6;
 446 }
 447
 448 #else
 449
 450 #include <sys/time.h>
 451
 452 GIT_INLINE(double) git__timer(void)
 453 {
 454         struct timespec tp;
 455
 456         if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
 457                 return (double) tp.tv_sec + (double) tp.tv_nsec / 1.0E9;
 458         } else {
 459                 /* Fall back to using gettimeofday */
 460                 struct timeval tv;
 461                 struct timezone tz;
 462                 gettimeofday(&tv, &tz);
 463                 return (double)tv.tv_sec + (double)tv.tv_usec / 1.0E6;
 464         }
 465 }
 466
 467 #endif
 468
 469 #endif /* INCLUDE_util_h__ */