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
  12 #ifndef GIT_WIN32
  13 # include <ctype.h>
  14 #endif
  15
  16 #include "git2/buffer.h"
  17
  18 #include "buffer.h"
  19 #include "common.h"
  20 #include "strnlen.h"
  21 #include "thread.h"
  22
  23 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
  24 #define bitsizeof(x) (CHAR_BIT * sizeof(x))
  25 #define MSB(x, bits) ((x) & (~UINT64_C(0) << (bitsizeof(x) - (bits))))
  26 #ifndef min
  27 # define min(a,b) ((a) < (b) ? (a) : (b))
  28 #endif
  29 #ifndef max
  30 # define max(a,b) ((a) > (b) ? (a) : (b))
  31 #endif
  32
  33 #if defined(__GNUC__)
  34 # define GIT_CONTAINER_OF(ptr, type, member) \
  35         __builtin_choose_expr( \
  36             __builtin_offsetof(type, member) == 0 && \
  37             __builtin_types_compatible_p(__typeof__(&((type *) 0)->member), __typeof__(ptr)), \
  38                 ((type *) (ptr)), \
  39                 (void)0)
  40 #else
  41 # define GIT_CONTAINER_OF(ptr, type, member) (type *)(ptr)
  42 #endif
  43
  44 #define GIT_DATE_RFC2822_SZ  32
  45
  46 /**
  47  * Return the length of a constant string.
  48  * We are aware that `strlen` performs the same task and is usually
  49  * optimized away by the compiler, whilst being safer because it returns
  50  * valid values when passed a pointer instead of a constant string; however
  51  * this macro will transparently work with wide-char and single-char strings.
  52  */
  53 #define CONST_STRLEN(x) ((sizeof(x)/sizeof(x[0])) - 1)
  54
  55 #define STRCMP_CASESELECT(IGNORE_CASE, STR1, STR2) \
  56         ((IGNORE_CASE) ? strcasecmp((STR1), (STR2)) : strcmp((STR1), (STR2)))
  57
  58 #define CASESELECT(IGNORE_CASE, ICASE, CASE) \
  59         ((IGNORE_CASE) ? (ICASE) : (CASE))
  60
  61 extern int git__prefixcmp(const char *str, const char *prefix);
  62 extern int git__prefixcmp_icase(const char *str, const char *prefix);
  63 extern int git__prefixncmp(const char *str, size_t str_n, const char *prefix);
  64 extern int git__prefixncmp_icase(const char *str, size_t str_n, const char *prefix);
  65 extern int git__suffixcmp(const char *str, const char *suffix);
  66
  67 GIT_INLINE(int) git__signum(int val)
  68 {
  69         return ((val > 0) - (val < 0));
  70 }
  71
  72 extern int git__strntol32(int32_t *n, const char *buff, size_t buff_len, const char **end_buf, int base);
  73 extern int git__strntol64(int64_t *n, const char *buff, size_t buff_len, const char **end_buf, int base);
  74
  75
  76 extern void git__hexdump(const char *buffer, size_t n);
  77 extern uint32_t git__hash(const void *key, int len, uint32_t seed);
  78
  79 /* 32-bit cross-platform rotl */
  80 #ifdef _MSC_VER /* use built-in method in MSVC */
  81 #       define git__rotl(v, s) (uint32_t)_rotl(v, s)
  82 #else /* use bitops in GCC; with o2 this gets optimized to a rotl instruction */
  83 #       define git__rotl(v, s) (uint32_t)(((uint32_t)(v) << (s)) | ((uint32_t)(v) >> (32 - (s))))
  84 #endif
  85
  86 extern char *git__strtok(char **end, const char *sep);
  87 extern char *git__strsep(char **end, const char *sep);
  88
  89 extern void git__strntolower(char *str, size_t len);
  90 extern void git__strtolower(char *str);
  91
  92 #ifdef GIT_WIN32
  93 GIT_INLINE(int) git__tolower(int c)
  94 {
  95         return (c >= 'A' && c <= 'Z') ? (c + 32) : c;
  96 }
  97 #else
  98 # define git__tolower(a) tolower(a)
  99 #endif
 100
 101 extern size_t git__linenlen(const char *buffer, size_t buffer_len);
 102
 103 GIT_INLINE(const char *) git__next_line(const char *s)
 104 {
 105         while (*s && *s != '\n') s++;
 106         while (*s == '\n' || *s == '\r') s++;
 107         return s;
 108 }
 109
 110 GIT_INLINE(const void *) git__memrchr(const void *s, int c, size_t n)
 111 {
 112         const unsigned char *cp;
 113
 114         if (n != 0) {
 115                 cp = (unsigned char *)s + n;
 116                 do {
 117                         if (*(--cp) == (unsigned char)c)
 118                                 return cp;
 119                 } while (--n != 0);
 120         }
 121
 122         return NULL;
 123 }
 124
 125 extern const void * git__memmem(const void *haystack, size_t haystacklen,
 126                                 const void *needle, size_t needlelen);
 127
 128 typedef int (*git__tsort_cmp)(const void *a, const void *b);
 129
 130 extern void git__tsort(void **dst, size_t size, git__tsort_cmp cmp);
 131
 132 typedef int (*git__sort_r_cmp)(const void *a, const void *b, void *payload);
 133
 134 extern void git__tsort_r(
 135         void **dst, size_t size, git__sort_r_cmp cmp, void *payload);
 136
 137 extern void git__qsort_r(
 138         void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload);
 139
 140 /**
 141  * @param position If non-NULL, this will be set to the position where the
 142  *              element is or would be inserted if not found.
 143  * @return 0 if found; GIT_ENOTFOUND if not found
 144  */
 145 extern int git__bsearch(
 146         void **array,
 147         size_t array_len,
 148         const void *key,
 149         int (*compare)(const void *key, const void *element),
 150         size_t *position);
 151
 152 extern int git__bsearch_r(
 153         void **array,
 154         size_t array_len,
 155         const void *key,
 156         int (*compare_r)(const void *key, const void *element, void *payload),
 157         void *payload,
 158         size_t *position);
 159
 160 #define git__strcmp strcmp
 161 #define git__strncmp strncmp
 162
 163 extern int git__strcmp_cb(const void *a, const void *b);
 164 extern int git__strcasecmp_cb(const void *a, const void *b);
 165
 166 extern int git__strcasecmp(const char *a, const char *b);
 167 extern int git__strncasecmp(const char *a, const char *b, size_t sz);
 168
 169 extern int git__strcasesort_cmp(const char *a, const char *b);
 170
 171 /*
 172  * Compare some NUL-terminated `a` to a possibly non-NUL terminated
 173  * `b` of length `b_len`; like `strncmp` but ensuring that
 174  * `strlen(a) == b_len` as well.
 175  */
 176 GIT_INLINE(int) git__strlcmp(const char *a, const char *b, size_t b_len)
 177 {
 178         int cmp = strncmp(a, b, b_len);
 179         return cmp ? cmp : (int)a[b_len];
 180 }
 181
 182 typedef struct {
 183         git_atomic32 refcount;
 184         void *owner;
 185 } git_refcount;
 186
 187 typedef void (*git_refcount_freeptr)(void *r);
 188
 189 #define GIT_REFCOUNT_INC(r) { \
 190         git_atomic32_inc(&(r)->rc.refcount);    \
 191 }
 192
 193 #define GIT_REFCOUNT_DEC(_r, do_free) { \
 194         git_refcount *r = &(_r)->rc; \
 195         int val = git_atomic32_dec(&r->refcount); \
 196         if (val <= 0 && r->owner == NULL) { do_free(_r); } \
 197 }
 198
 199 #define GIT_REFCOUNT_OWN(r, o) { \
 200         (void)git_atomic_swap((r)->rc.owner, o); \
 201 }
 202
 203 #define GIT_REFCOUNT_OWNER(r) git_atomic_load((r)->rc.owner)
 204
 205 #define GIT_REFCOUNT_VAL(r) git_atomic32_get((r)->rc.refcount)
 206
 207
 208 static signed char from_hex[] = {
 209 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 00 */
 210 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 10 */
 211 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 20 */
 212  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /* 30 */
 213 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 40 */
 214 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 50 */
 215 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 60 */
 216 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 70 */
 217 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 80 */
 218 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* 90 */
 219 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* a0 */
 220 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* b0 */
 221 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* c0 */
 222 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* d0 */
 223 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* e0 */
 224 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /* f0 */
 225 };
 226
 227 GIT_INLINE(int) git__fromhex(char h)
 228 {
 229         return from_hex[(unsigned char) h];
 230 }
 231
 232 GIT_INLINE(int) git__ishex(const char *str)
 233 {
 234         unsigned i;
 235         for (i=0; str[i] != '\0'; i++)
 236                 if (git__fromhex(str[i]) < 0)
 237                         return 0;
 238         return 1;
 239 }
 240
 241 GIT_INLINE(size_t) git__size_t_bitmask(size_t v)
 242 {
 243         v--;
 244         v |= v >> 1;
 245         v |= v >> 2;
 246         v |= v >> 4;
 247         v |= v >> 8;
 248         v |= v >> 16;
 249
 250         return v;
 251 }
 252
 253 GIT_INLINE(size_t) git__size_t_powerof2(size_t v)
 254 {
 255         return git__size_t_bitmask(v) + 1;
 256 }
 257
 258 GIT_INLINE(bool) git__isupper(int c)
 259 {
 260         return (c >= 'A' && c <= 'Z');
 261 }
 262
 263 GIT_INLINE(bool) git__isalpha(int c)
 264 {
 265         return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
 266 }
 267
 268 GIT_INLINE(bool) git__isdigit(int c)
 269 {
 270         return (c >= '0' && c <= '9');
 271 }
 272
 273 GIT_INLINE(bool) git__isspace(int c)
 274 {
 275         return (c == ' ' || c == '\t' || c == '\n' || c == '\f' || c == '\r' || c == '\v');
 276 }
 277
 278 GIT_INLINE(bool) git__isspace_nonlf(int c)
 279 {
 280         return (c == ' ' || c == '\t' || c == '\f' || c == '\r' || c == '\v');
 281 }
 282
 283 GIT_INLINE(bool) git__iswildcard(int c)
 284 {
 285         return (c == '*' || c == '?' || c == '[');
 286 }
 287
 288 GIT_INLINE(bool) git__isxdigit(int c)
 289 {
 290         return ((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'));
 291 }
 292
 293 /*
 294  * Parse a string value as a boolean, just like Core Git does.
 295  *
 296  * Valid values for true are: 'true', 'yes', 'on'
 297  * Valid values for false are: 'false', 'no', 'off'
 298  */
 299 extern int git__parse_bool(int *out, const char *value);
 300
 301 /*
 302  * Parse a string into a value as a git_time_t.
 303  *
 304  * Sample valid input:
 305  * - "yesterday"
 306  * - "July 17, 2003"
 307  * - "2003-7-17 08:23"
 308  */
 309 extern int git__date_parse(git_time_t *out, const char *date);
 310
 311 /*
 312  * Format a git_time as a RFC2822 string
 313  *
 314  * @param out buffer to store formatted date; a '\\0' terminator will automatically be added.
 315  * @param len size of the buffer; should be atleast `GIT_DATE_RFC2822_SZ` in size;
 316  * @param date the date to be formatted
 317  * @return 0 if successful; -1 on error
 318  */
 319 extern int git__date_rfc2822_fmt(char *out, size_t len, const git_time *date);
 320
 321 /*
 322  * Unescapes a string in-place.
 323  *
 324  * Edge cases behavior:
 325  * - "jackie\" -> "jacky\"
 326  * - "chan\\" -> "chan\"
 327  */
 328 extern size_t git__unescape(char *str);
 329
 330 /*
 331  * Safely zero-out memory, making sure that the compiler
 332  * doesn't optimize away the operation.
 333  */
 334 GIT_INLINE(void) git__memzero(void *data, size_t size)
 335 {
 336 #ifdef _MSC_VER
 337         SecureZeroMemory((PVOID)data, size);
 338 #else
 339         volatile uint8_t *scan = (volatile uint8_t *)data;
 340
 341         while (size--)
 342                 *scan++ = 0x0;
 343 #endif
 344 }
 345
 346 #ifdef GIT_WIN32
 347
 348 GIT_INLINE(double) git__timer(void)
 349 {
 350         /* GetTickCount64 returns the number of milliseconds that have
 351          * elapsed since the system was started. */
 352         return (double) GetTickCount64() / (double) 1000;
 353 }
 354
 355 #elif __APPLE__
 356
 357 #include <mach/mach_time.h>
 358
 359 GIT_INLINE(double) git__timer(void)
 360 {
 361    uint64_t time = mach_absolute_time();
 362    static double scaling_factor = 0;
 363
 364    if (scaling_factor == 0) {
 365        mach_timebase_info_data_t info;
 366        (void)mach_timebase_info(&info);
 367        scaling_factor = (double)info.numer / (double)info.denom;
 368    }
 369
 370    return (double)time * scaling_factor / 1.0E9;
 371 }
 372
 373 #elif defined(__amigaos4__)
 374
 375 #include <proto/timer.h>
 376
 377 GIT_INLINE(double) git__timer(void)
 378 {
 379         struct TimeVal tv;
 380         ITimer->GetUpTime(&tv);
 381         return (double)tv.Seconds + (double)tv.Microseconds / 1.0E6;
 382 }
 383
 384 #else
 385
 386 #include <sys/time.h>
 387
 388 GIT_INLINE(double) git__timer(void)
 389 {
 390         struct timeval tv;
 391
 392 #ifdef CLOCK_MONOTONIC
 393         struct timespec tp;
 394         if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0)
 395                 return (double) tp.tv_sec + (double) tp.tv_nsec / 1.0E9;
 396 #endif
 397
 398         /* Fall back to using gettimeofday */
 399         gettimeofday(&tv, NULL);
 400         return (double)tv.tv_sec + (double)tv.tv_usec / 1.0E6;
 401 }
 402
 403 #endif
 404
 405 extern int git__getenv(git_buf *out, const char *name);
 406
 407 extern int git__online_cpus(void);
 408
 409 GIT_INLINE(int) git__noop(void) { return 0; }
 410
 411 #include "alloc.h"
 412
 413 #endif