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