compat-util.h

   1 #ifndef OS_COMPAT_H
   2 #define OS_COMPAT_H
   3
   4 #define _LARGE_FILES
   5 #define _FILE_OFFSET_BITS 64
   6 #define _BSD_SOURCE /* for mincore */
   7 #define _XOPEN_SOURCE 600 /* for posix_fadvise */
   8 #include <sys/types.h>
   9 #include <sys/stat.h>
  10 #include <fcntl.h>
  11 #include <unistd.h>
  12 #include <sys/mman.h>
  13 #include <string.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <errno.h>
  17 #include <assert.h>
  18 #include <stdint.h>
  19
  20 #ifndef O_NOATIME
  21 #  define O_NOATIME 0
  22 #endif /* O_NOATIME */
  23
  24 #define PAGE_MASK               (~(page_size() -1))
  25 #define PAGE_ALIGN(addr)        (((addr) + page_size() - 1) & PAGE_MASK)
  26 #define PAGE_ALIGN_DOWN(addr) \
  27         (addr > page_size() ? PAGE_ALIGN(addr) - page_size() : 0)
  28
  29 static inline size_t page_size(void)
  30 {
  31         static size_t size;
  32
  33         if (!size)
  34                 size = sysconf(_SC_PAGESIZE);
  35
  36         return size;
  37 }
  38
  39 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
  40
  41 /*
  42  * converts a C string to a non-negative off_t value, taking base into
  43  * account.  On error, it'll return a negative value and set errno
  44  * to EINVAL
  45  */
  46 static inline off_t cstr_to_off_t(const char *nptr, char **endptr, int base)
  47 {
  48         if (sizeof(long) == 8 || (sizeof(long) == 4 && sizeof(off_t) == 4))
  49                 return (off_t)strtol(nptr, endptr, base);
  50         else if (sizeof(off_t) == 8 && sizeof(long) == 4)
  51                 return (off_t)strtoll(nptr, endptr, base);
  52
  53         fprintf(stderr, "unrecognized sizes:\n\toff_t: %u\n\tlong: %u\n",
  54                         (unsigned)sizeof(off_t), (unsigned)sizeof(long));
  55         exit(1);
  56 }
  57
  58 #endif /* OS_COMPAT_H */