-
Notifications
You must be signed in to change notification settings - Fork 0
/
mmap_unix.go
67 lines (55 loc) · 1.91 KB
/
mmap_unix.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
// Copyright 2019 shimingyah.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// ee the License for the specific language governing permissions and
// limitations under the License.
// +build linux darwin
package ioengine
import (
"os"
"golang.org/x/sys/unix"
)
// Mmap use the mmap system call to memory mapped file or device.
func Mmap(fd *os.File, offset int64, length int, writable bool) ([]byte, error) {
prot := unix.PROT_READ
if writable {
prot |= unix.PROT_WRITE
}
return unix.Mmap(int(fd.Fd()), offset, length, prot, unix.MAP_SHARED)
}
// Madvise advises the kernel about how to handle the mapped slice.
func Madvise(b []byte) error {
return unix.Madvise(b, unix.MADV_NORMAL)
}
// Lock locks the maped slice, preventing it from being swapped out.
func Lock(b []byte) error {
return unix.Mlock(b)
}
// Unlock unlocks the mapped slice, allowing it to swap out again.
func Unlock(b []byte) error {
return unix.Munlock(b)
}
// Sync flushes mmap slice's all changes back to the device.
func Sync(b []byte) error {
return unix.Msync(b, unix.MS_SYNC)
}
// Munmap unmaps mapped slice, this will also flush any remaining changes.
func Munmap(b []byte) error {
return unix.Munmap(b)
}
// WriteAtv like linux pwritev, write to the specifies offset and dose not change the file offset.
func (mmap *MemoryMap) WriteAtv(bs [][]byte, off int64) (int, error) {
return genericWriteAtv(mmap, bs, off)
}
// Append write data to the end of file.
func (mmap *MemoryMap) Append(bs [][]byte) (int, error) {
return genericAppend(mmap, bs)
}