git/compat/win32mmap.c
Ian McLean 60890cc60c Fix "Out of memory? mmap failed" for files larger than 4GB on Windows
The git_mmap implementation was broken for file sizes that wouldn't fit
into a size_t (32 bits).  This was caused by intermediate variables that
were only 32 bits wide when they should be 64 bits.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-05-20 16:11:06 -07:00

42 lines
903 B
C

#include "../git-compat-util.h"
void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
HANDLE hmap;
void *temp;
off_t len;
struct stat st;
uint64_t o = offset;
uint32_t l = o & 0xFFFFFFFF;
uint32_t h = (o >> 32) & 0xFFFFFFFF;
if (!fstat(fd, &st))
len = st.st_size;
else
die("mmap: could not determine filesize");
if ((length + offset) > len)
length = xsize_t(len - offset);
if (!(flags & MAP_PRIVATE))
die("Invalid usage of mmap when built with USE_WIN32_MMAP");
hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), 0, PAGE_WRITECOPY,
0, 0, 0);
if (!hmap)
return MAP_FAILED;
temp = MapViewOfFileEx(hmap, FILE_MAP_COPY, h, l, length, start);
if (!CloseHandle(hmap))
warning("unable to close file mapping handle\n");
return temp ? temp : MAP_FAILED;
}
int git_munmap(void *start, size_t length)
{
return !UnmapViewOfFile(start);
}