src/util.h

   1 /*
   2  * Copyright (C) 2009-2011 the libgit2 contributors
   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 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
  11 #define bitsizeof(x) (CHAR_BIT * sizeof(x))
  12 #define MSB(x, bits) ((x) & (~0ULL << (bitsizeof(x) - (bits))))
  13 #ifndef min
  14 # define min(a,b) ((a) < (b) ? (a) : (b))
  15 #endif
  16
  17 /*
  18  * Custom memory allocation wrappers
  19  * that set error code and error message
  20  * on allocation failure
  21  */
  22 GIT_INLINE(void *) git__malloc(size_t len)
  23 {
  24         void *ptr = malloc(len);
  25         if (!ptr)
  26                 git__throw(GIT_ENOMEM, "Out of memory. Failed to allocate %d bytes.", (int)len);
  27         return ptr;
  28 }
  29
  30 GIT_INLINE(void *) git__calloc(size_t nelem, size_t elsize)
  31 {
  32         void *ptr = calloc(nelem, elsize);
  33         if (!ptr)
  34                 git__throw(GIT_ENOMEM, "Out of memory. Failed to allocate %d bytes.", (int)elsize);
  35         return ptr;
  36 }
  37
  38 GIT_INLINE(char *) git__strdup(const char *str)
  39 {
  40         char *ptr = strdup(str);
  41         if (!ptr)
  42                 git__throw(GIT_ENOMEM, "Out of memory. Failed to duplicate string");
  43         return ptr;
  44 }
  45
  46 GIT_INLINE(char *) git__strndup(const char *str, size_t n)
  47 {
  48         size_t length;
  49         char *ptr;
  50
  51         length = strlen(str);
  52         if (n < length)
  53                 length = n;
  54
  55         ptr = (char*)malloc(length + 1);
  56         if (!ptr) {
  57                 git__throw(GIT_ENOMEM, "Out of memory. Failed to duplicate string");
  58                 return NULL;
  59         }
  60
  61         memcpy(ptr, str, length);
  62         ptr[length] = '\0';
  63
  64         return ptr;
  65 }
  66
  67 GIT_INLINE(void *) git__realloc(void *ptr, size_t size)
  68 {
  69         void *new_ptr = realloc(ptr, size);
  70         if (!new_ptr)
  71                 git__throw(GIT_ENOMEM, "Out of memory. Failed to allocate %d bytes.", (int)size);
  72         return new_ptr;
  73 }
  74
  75 extern int git__prefixcmp(const char *str, const char *prefix);
  76 extern int git__suffixcmp(const char *str, const char *suffix);
  77
  78 extern int git__strtol32(long *n, const char *buff, const char **end_buf, int base);
  79
  80 extern void git__hexdump(const char *buffer, size_t n);
  81 extern uint32_t git__hash(const void *key, int len, uint32_t seed);
  82
  83 /** @return true if p fits into the range of a size_t */
  84 GIT_INLINE(int) git__is_sizet(git_off_t p)
  85 {
  86         size_t r = (size_t)p;
  87         return p == (git_off_t)r;
  88 }
  89
  90 /* 32-bit cross-platform rotl */
  91 #ifdef _MSC_VER /* use built-in method in MSVC */
  92 #       define git__rotl(v, s) (uint32_t)_rotl(v, s)
  93 #else /* use bitops in GCC; with o2 this gets optimized to a rotl instruction */
  94 #       define git__rotl(v, s) (uint32_t)(((uint32_t)(v) << (s)) | ((uint32_t)(v) >> (32 - (s))))
  95 #endif
  96
  97 extern char *git__strtok(char **end, const char *sep);
  98
  99 extern void git__strntolower(char *str, size_t len);
 100 extern void git__strtolower(char *str);
 101
 102 extern int git__fnmatch(const char *pattern, const char *name, int flags);
 103
 104 /*
 105  * Realloc the buffer pointed at by variable 'x' so that it can hold
 106  * at least 'nr' entries; the number of entries currently allocated
 107  * is 'alloc', using the standard growing factor alloc_nr() macro.
 108  *
 109  * DO NOT USE any expression with side-effect for 'x' or 'alloc'.
 110  */
 111 #define alloc_nr(x) (((x)+16)*3/2)
 112 #define ALLOC_GROW(x, nr, alloc) \
 113         do { \
 114                 if ((nr) > alloc) { \
 115                         if (alloc_nr(alloc) < (nr)) \
 116                                 alloc = (nr); \
 117                         else \
 118                                 alloc = alloc_nr(alloc); \
 119                         x = xrealloc((x), alloc * sizeof(*(x))); \
 120                 } \
 121         } while (0)
 122
 123 extern void git__tsort(void **dst, size_t size, int (*cmp)(const void *, const void *));
 124 extern void **git__bsearch(const void *key, void **base, size_t nmemb,
 125         int (*compar)(const void *, const void *));
 126
 127 extern int git__strcmp_cb(const void *a, const void *b);
 128
 129 #endif /* INCLUDE_util_h__ */