-
Notifications
You must be signed in to change notification settings - Fork 7
/
io_uring.go
103 lines (83 loc) · 2.69 KB
/
io_uring.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
// go-pst is a library for reading Personal Storage Table (.pst) files (written in Go/Golang).
//
// Copyright 2023 Marten Mooij
//
// 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.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build linux
package pst
import (
"context"
"github.com/godzie44/go-uring/reactor"
"github.com/godzie44/go-uring/uring"
"os"
"os/signal"
)
// NewAsync uses io_uring on Linux.
func NewAsync(name string) (*File, error) {
asyncReader, err := NewReaderAsync(name)
if err != nil {
return nil, err
}
return New(asyncReader)
}
type AsyncReader struct {
ring *uring.Ring
eventLoop *reactor.Reactor
eventLoopContext context.Context
eventLoopCancel context.CancelFunc
reader *os.File
}
// NewReaderAsync uses io_uring on Linux for asynchronous I/O operations.
func NewReaderAsync(name string) (*AsyncReader, error) {
reader, err := os.Open(name)
if err != nil {
return nil, err
}
ring, err := uring.New(8)
if err != nil {
return nil, err
}
eventLoop, err := reactor.New([]*uring.Ring{ring})
if err != nil {
return nil, err
}
eventLoopContext, eventLoopCancel := signal.NotifyContext(context.Background(), os.Interrupt)
go func() {
eventLoop.Run(eventLoopContext)
}()
return &AsyncReader{
ring: ring,
eventLoop: eventLoop,
eventLoopContext: eventLoopContext,
eventLoopCancel: eventLoopCancel,
reader: reader,
}, nil
}
// ReadAtAsync io_uring operation.
// The callback function is called when a CQE is received.
// Returns uint64 which can be used as the SQE identifier.
func (asyncReader *AsyncReader) ReadAtAsync(outputBuffer []byte, offset uint64, callback func(err error)) (uint64, error) {
readOperation := uring.Read(asyncReader.reader.Fd(), outputBuffer, offset)
return asyncReader.eventLoop.Queue(readOperation, func(event uring.CQEvent) {
callback(event.Error())
})
}
// ReadAt is a fall-back for where we haven't added async disk I/O support yet.
func (asyncReader *AsyncReader) ReadAt(outputBuffer []byte, offset int64) (int, error) {
return asyncReader.reader.ReadAt(outputBuffer, offset)
}
// Close closes the event loop.
func (asyncReader *AsyncReader) Close() {
<-asyncReader.eventLoopContext.Done()
asyncReader.eventLoopCancel()
}