mirrors/git
1
0
Fork 0
mirror of https://github.com/git/git.git synced 2024-10-28 12:59:41 +01:00
Code Activity

mmap(win32): avoid expensive fstat() call

Browse source 
On Windows, we have to emulate the fstat() call to fill out information
that takes extra effort to obtain, such as the file permissions/type.

If all we want is the file size, we can use the much cheaper
GetFileSizeEx() function (available since Windows XP).

Suggested by Philip Kelley.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Johannes Schindelin 2016-04-22 16:31:32 +02:00 committed by Junio C Hamano
parent 7ce7ee2d82
commit d5425d10ca
1 changed files with 7 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
compat/win32mmap.c
View file

@ -2,26 +2,24 @@
void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
HANDLE hmap;
HANDLE osfhandle, hmap;
void *temp;
off_t len;
struct stat st;
LARGE_INTEGER len;
uint64_t o = offset;
uint32_t l = o & 0xFFFFFFFF;
uint32_t h = (o >> 32) & 0xFFFFFFFF;
if (!fstat(fd, &st))
len = st.st_size;
else
osfhandle = (HANDLE)_get_osfhandle(fd);
if (!GetFileSizeEx(osfhandle, &len))
die("mmap: could not determine filesize");
if ((length + offset) > len)
length = xsize_t(len - offset);
if ((length + offset) > len.QuadPart)
length = xsize_t(len.QuadPart - offset);
if (!(flags & MAP_PRIVATE))
die("Invalid usage of mmap when built with USE_WIN32_MMAP");
hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), NULL,
hmap = CreateFileMapping(osfhandle, NULL,
prot == PROT_READ ? PAGE_READONLY : PAGE_WRITECOPY, 0, 0, NULL);
if (!hmap) {