1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
#include "map.h"
#include <errno.h>
static DWORD get_page_size(void)
{
static DWORD page_size;
SYSTEM_INFO sys;
if (!page_size) {
GetSystemInfo(&sys);
page_size = sys.dwAllocationGranularity;
}
return page_size;
}
int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offset)
{
HANDLE fh = (HANDLE)_get_osfhandle(fd);
DWORD page_size = get_page_size();
DWORD fmap_prot = 0;
DWORD view_prot = 0;
DWORD off_low = 0;
DWORD off_hi = 0;
git_off_t page_start;
git_off_t page_offset;
assert((out != NULL) && (len > 0));
if ((out == NULL) || (len == 0)) {
errno = EINVAL;
return git__throw(GIT_ERROR, "Failed to mmap. No map or zero length");
}
out->data = NULL;
out->len = 0;
out->fmh = NULL;
if (fh == INVALID_HANDLE_VALUE) {
errno = EBADF;
return git__throw(GIT_ERROR, "Failed to mmap. Invalid handle value");
}
if (prot & GIT_PROT_WRITE)
fmap_prot |= PAGE_READWRITE;
else if (prot & GIT_PROT_READ)
fmap_prot |= PAGE_READONLY;
else {
errno = EINVAL;
return git__throw(GIT_ERROR, "Failed to mmap. Invalid protection parameters");
}
if (prot & GIT_PROT_WRITE)
view_prot |= FILE_MAP_WRITE;
if (prot & GIT_PROT_READ)
view_prot |= FILE_MAP_READ;
if (flags & GIT_MAP_FIXED) {
errno = EINVAL;
return git__throw(GIT_ERROR, "Failed to mmap. FIXED not set");
}
page_start = (offset / page_size) * page_size;
page_offset = offset - page_start;
if (page_offset != 0) { /* offset must be multiple of page size */
errno = EINVAL;
return git__throw(GIT_ERROR, "Failed to mmap. Offset must be multiple of page size");
}
out->fmh = CreateFileMapping(fh, NULL, fmap_prot, 0, 0, NULL);
if (!out->fmh || out->fmh == INVALID_HANDLE_VALUE) {
/* errno = ? */
out->fmh = NULL;
return git__throw(GIT_ERROR, "Failed to mmap. Invalid handle value");
}
assert(sizeof(git_off_t) == 8);
off_low = (DWORD)(page_start);
off_hi = (DWORD)(page_start >> 32);
out->data = MapViewOfFile(out->fmh, view_prot, off_hi, off_low, len);
if (!out->data) {
/* errno = ? */
CloseHandle(out->fmh);
out->fmh = NULL;
return git__throw(GIT_ERROR, "Failed to mmap. No data written");
}
out->len = len;
return GIT_SUCCESS;
}
int p_munmap(git_map *map)
{
assert(map != NULL);
if (!map)
return git__throw(GIT_ERROR, "Failed to munmap. Map does not exist");
if (map->data) {
if (!UnmapViewOfFile(map->data)) {
/* errno = ? */
CloseHandle(map->fmh);
map->data = NULL;
map->fmh = NULL;
return git__throw(GIT_ERROR, "Failed to munmap. Could not unmap view of file");
}
map->data = NULL;
}
if (map->fmh) {
if (!CloseHandle(map->fmh)) {
/* errno = ? */
map->fmh = NULL;
return git__throw(GIT_ERROR, "Failed to munmap. Could not close handle");
}
map->fmh = NULL;
}
return GIT_SUCCESS;
}
|
