compat-util.h

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