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win32pread.c File Reference
#include "c.h"
#include <windows.h>
Include dependency graph for win32pread.c:

Go to the source code of this file.

Functions

ssize_t pg_pread (int fd, void *buf, size_t size, off_t offset)
 

Function Documentation

◆ pg_pread()

ssize_t pg_pread ( int  fd,
void *  buf,
size_t  size,
off_t  offset 
)

Definition at line 20 of file win32pread.c.

21{
22 OVERLAPPED overlapped = {0};
23 HANDLE handle;
24 DWORD result;
25
26 handle = (HANDLE) _get_osfhandle(fd);
27 if (handle == INVALID_HANDLE_VALUE)
28 {
29 errno = EBADF;
30 return -1;
31 }
32
33 /* Avoid overflowing DWORD. */
34 size = Min(size, 1024 * 1024 * 1024);
35
36 /* Note that this changes the file position, despite not using it. */
37 overlapped.Offset = offset;
38 if (!ReadFile(handle, buf, size, &result, &overlapped))
39 {
40 if (GetLastError() == ERROR_HANDLE_EOF)
41 return 0;
42
43 _dosmaperr(GetLastError());
44 return -1;
45 }
46
47 return result;
48}
#define Min(x, y)
Definition: c.h:961
static char * buf
Definition: pg_test_fsync.c:72
static int fd(const char *x, int i)
Definition: preproc-init.c:105
static pg_noinline void Size size
Definition: slab.c:607
void _dosmaperr(unsigned long)
Definition: win32error.c:177

References _dosmaperr(), buf, fd(), Min, and size.