src/util.h

   1 #ifndef INCLUDE_util_h__
   2 #define INCLUDE_util_h__
   3
   4 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
   5 #define bitsizeof(x)  (CHAR_BIT * sizeof(x))
   6 #define MSB(x, bits) ((x) & (~0ULL << (bitsizeof(x) - (bits))))
   7
   8 /*
   9  * Don't wrap malloc/calloc.
  10  * Use the default versions in glibc, and make
  11  * sure that any methods that allocate memory
  12  * return a GIT_ENOMEM error when allocation
  13  * fails.
  14  */
  15 #define git__malloc malloc
  16 #define git__calloc calloc
  17 #define git__realloc realloc
  18 #define git__strdup strdup
  19
  20 extern int git__fmt(char *, size_t, const char *, ...)
  21         GIT_FORMAT_PRINTF(3, 4);
  22 extern int git__prefixcmp(const char *str, const char *prefix);
  23 extern int git__suffixcmp(const char *str, const char *suffix);
  24
  25 /*
  26  * The dirname() function shall take a pointer to a character string
  27  * that contains a pathname, and return a pointer to a string that is a
  28  * pathname of the parent directory of that file. Trailing '/' characters
  29  * in the path are not counted as part of the path.
  30  *
  31  * If path does not contain a '/', then dirname() shall return a pointer to
  32  * the string ".". If path is a null pointer or points to an empty string,
  33  * dirname() shall return a pointer to the string "." .
  34  *
  35  * The `git__dirname` implementation is thread safe. The returned
  36  * string must be manually free'd.
  37  *
  38  * The `git__dirname_r` implementation expects a string allocated
  39  * by the user with big enough size.
  40  */
  41 extern char *git__dirname(const char *path);
  42 extern int git__dirname_r(char *buffer, size_t bufflen, const char *path);
  43
  44 /*
  45  * This function returns the basename of the file, which is the last
  46  * part of its full name given by fname, with the drive letter and
  47  * leading directories stripped off. For example, the basename of
  48  * c:/foo/bar/file.ext is file.ext, and the basename of a:foo is foo.
  49  *
  50  * Trailing slashes and backslashes are significant: the basename of
  51  * c:/foo/bar/ is an empty string after the rightmost slash.
  52  *
  53  * The `git__basename` implementation is thread safe. The returned
  54  * string must be manually free'd.
  55  *
  56  * The `git__basename_r` implementation expects a string allocated
  57  * by the user with big enough size.
  58  */
  59 extern char *git__basename(const char *path);
  60 extern int git__basename_r(char *buffer, size_t bufflen, const char *path);
  61
  62 extern const char *git__topdir(const char *path);
  63
  64 /**
  65  * Join two paths together. Takes care of properly fixing the
  66  * middle slashes and everything
  67  *
  68  * The paths are joined together into buffer_out; this is expected
  69  * to be an user allocated buffer of `GIT_PATH_MAX` size
  70  */
  71 extern void git__joinpath_n(char *buffer_out, int npath, ...);
  72
  73 GIT_INLINE(void) git__joinpath(char *buffer_out, const char *path_a, const char *path_b)
  74 {
  75         git__joinpath_n(buffer_out, 2, path_a, path_b);
  76 }
  77
  78 extern void git__hexdump(const char *buffer, size_t n);
  79 extern uint32_t git__hash(const void *key, int len, uint32_t seed);
  80
  81
  82 /** @return true if p fits into the range of a size_t */
  83 GIT_INLINE(int) git__is_sizet(git_off_t p)
  84 {
  85         size_t r = (size_t)p;
  86         return p == (git_off_t)r;
  87 }
  88
  89 /* 32-bit cross-platform rotl */
  90 #ifdef _MSC_VER /* use built-in method in MSVC */
  91 #       define git__rotl(v, s) (uint32_t)_rotl(v, s)
  92 #else /* use bitops in GCC; with o2 this gets optimized to a rotl instruction */
  93 #       define git__rotl(v, s) (uint32_t)(((uint32_t)(v) << (s)) | ((uint32_t)(v) >> (32 - (s))))
  94 #endif
  95
  96 extern char *git__strtok(char *output, char *src, char *delimit);
  97 extern char *git__strtok_keep(char *output, char *src, char *delimit);
  98
  99 #define STRLEN(str) (sizeof(str) - 1)
 100
 101 #define GIT_OID_LINE_LENGTH(header) (STRLEN(header) + 1 + GIT_OID_HEXSZ + 1)
 102
 103 /*
 104  * Realloc the buffer pointed at by variable 'x' so that it can hold
 105  * at least 'nr' entries; the number of entries currently allocated
 106  * is 'alloc', using the standard growing factor alloc_nr() macro.
 107  *
 108  * DO NOT USE any expression with side-effect for 'x' or 'alloc'.
 109  */
 110 #define alloc_nr(x) (((x)+16)*3/2)
 111 #define ALLOC_GROW(x, nr, alloc) \
 112         do { \
 113                 if ((nr) > alloc) { \
 114                         if (alloc_nr(alloc) < (nr)) \
 115                                 alloc = (nr); \
 116                         else \
 117                                 alloc = alloc_nr(alloc); \
 118                         x = xrealloc((x), alloc * sizeof(*(x))); \
 119                 } \
 120         } while (0)
 121
 122 #endif /* INCLUDE_util_h__ */