-
Notifications
You must be signed in to change notification settings - Fork 0
/
mmap_span.go
85 lines (74 loc) · 1.53 KB
/
mmap_span.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
package mmap_span
import (
"io"
"launchpad.net/gommap"
)
type segment struct {
gommap.MMap
}
func (me segment) Size() int64 {
return int64(len(me.MMap))
}
type MMapSpan struct {
span
}
func (me *MMapSpan) Append(mmap gommap.MMap) {
me.span = append(me.span, segment{mmap})
}
func (me MMapSpan) Close() {
for _, mMap := range me.span {
mMap.(segment).UnsafeUnmap()
}
}
func (me MMapSpan) Size() (ret int64) {
for _, seg := range me.span {
ret += seg.Size()
}
return
}
func (me MMapSpan) ReadAt(p []byte, off int64) (n int, err error) {
me.ApplyTo(off, func(intervalOffset int64, interval sizer) (stop bool) {
_n := copy(p, interval.(segment).MMap[intervalOffset:])
p = p[_n:]
n += _n
return len(p) == 0
})
if len(p) != 0 {
err = io.EOF
}
return
}
func (me MMapSpan) WriteSectionTo(w io.Writer, off, n int64) (written int64, err error) {
me.ApplyTo(off, func(intervalOffset int64, interval sizer) (stop bool) {
var _n int
p := interval.(segment).MMap[intervalOffset:]
if n < int64(len(p)) {
p = p[:n]
}
_n, err = w.Write(p)
written += int64(_n)
n -= int64(_n)
if err != nil {
return true
}
return n == 0
})
return
}
func (me MMapSpan) WriteAt(p []byte, off int64) (n int, err error) {
me.ApplyTo(off, func(iOff int64, i sizer) (stop bool) {
mMap := i.(segment)
_n := copy(mMap.MMap[iOff:], p)
// err = mMap.Sync(gommap.MS_ASYNC)
// if err != nil {
// return true
// }
p = p[_n:]
n += _n
return len(p) == 0
})
if err != nil && len(p) != 0 {
err = io.ErrShortWrite
}
return
}