-
Notifications
You must be signed in to change notification settings - Fork 2
/
mmap_win.go
112 lines (101 loc) · 2.02 KB
/
mmap_win.go
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
//go:build windows
package storage
import (
"fmt"
"reflect"
"syscall"
"unsafe"
)
// MmapFile ...
type MmapFile struct {
h syscall.Handle
obj syscall.Handle
addr uintptr
}
// Init ...
func (f *MmapFile) Init(filename string) (err error) {
f.h = syscall.InvalidHandle
f.obj = syscall.InvalidHandle
f.addr = 0
name, err := syscall.UTF16PtrFromString(filename)
if err != nil {
return err
}
// FILE_ATTRIBUTE_HIDDEN
// FILE_FLAG_NO_BUFFERING
// FILE_FLAG_SEQUENTIAL_SCAN
// FILE_FLAG_WRITE_THROUGH
h, err := syscall.CreateFile(name, syscall.GENERIC_READ|syscall.GENERIC_WRITE,
0, nil, syscall.OPEN_ALWAYS, syscall.FILE_ATTRIBUTE_NORMAL, 0)
if err != nil {
return err
}
defer func() {
if err != nil {
syscall.CloseHandle(h)
}
}()
// high and low can be 0
obj, err := syscall.CreateFileMapping(h, nil, syscall.PAGE_READWRITE, 0, 1024, nil)
if err != nil {
return err
}
defer func() {
if err != nil {
syscall.CloseHandle(obj)
}
}()
addr, err := syscall.MapViewOfFile(obj, syscall.FILE_MAP_WRITE, 0, 0, 0)
if err != nil {
return err
}
defer func() {
if err != nil {
syscall.UnmapViewOfFile(addr)
}
}()
f.obj = obj
f.h = h
f.addr = addr
// syscall.CreateFileMapping()
// syscall.MapViewOfFile()
// syscall.UnmapViewOfFile()
// syscall.SetFileTime()
return nil
}
// Close ...
func (f *MmapFile) Close() {
if f.addr != 0 {
err := syscall.UnmapViewOfFile(f.addr)
if err != nil {
fmt.Println(err)
}
f.addr = 0
}
if f.obj != syscall.InvalidHandle {
err := syscall.CloseHandle(f.obj)
if err != nil {
fmt.Println(err)
}
f.obj = syscall.InvalidHandle
}
if f.h != syscall.InvalidHandle {
err := syscall.CloseHandle(f.h)
if err != nil {
fmt.Println(err)
}
f.h = syscall.InvalidHandle
}
}
// AsSlice ...
func (f *MmapFile) AsSlice() []byte {
sh := reflect.SliceHeader{}
sh.Data = f.addr
sh.Cap = 1024
sh.Len = 1024
return *((*[]byte)(unsafe.Pointer(&sh)))
}
// Flush ...
func (f *MmapFile) Flush() error {
return syscall.FlushViewOfFile(f.addr, 1024)
}