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
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
package imap
import (
"fmt"
"sync"
"time"
"git.sr.ht/~rjarry/aerc/logging"
"git.sr.ht/~rjarry/aerc/worker/types"
"github.com/emersion/go-imap"
"github.com/emersion/go-imap/client"
)
var (
errIdleTimeout = fmt.Errorf("idle timeout")
errIdleModeHangs = fmt.Errorf("idle mode hangs; waiting to reconnect")
)
// idler manages the idle mode of the imap server. Enter idle mode if there's
// no other task and leave idle mode when a new task arrives. Idle mode is only
// used when the client is ready and connected. After a connection loss, make
// sure that idling returns gracefully and the worker remains responsive.
type idler struct {
sync.Mutex
config imapConfig
client *imapClient
worker *types.Worker
stop chan struct{}
done chan error
waiting bool
idleing bool
}
func newIdler(cfg imapConfig, w *types.Worker) *idler {
return &idler{config: cfg, worker: w, done: make(chan error)}
}
func (i *idler) SetClient(c *imapClient) {
i.Lock()
i.client = c
i.Unlock()
}
func (i *idler) setWaiting(wait bool) {
i.Lock()
i.waiting = wait
i.Unlock()
}
func (i *idler) isWaiting() bool {
i.Lock()
defer i.Unlock()
return i.waiting
}
func (i *idler) isReady() bool {
i.Lock()
defer i.Unlock()
return (!i.waiting && i.client != nil &&
i.client.State() == imap.SelectedState)
}
func (i *idler) Start() {
if i.isReady() {
i.stop = make(chan struct{})
go func() {
defer logging.PanicHandler()
select {
case <-i.stop:
// debounce idle
i.log("=>(idle) [debounce]")
i.done <- nil
case <-time.After(i.config.idle_debounce):
// enter idle mode
i.idleing = true
i.log("=>(idle)")
now := time.Now()
err := i.client.Idle(i.stop,
&client.IdleOptions{
LogoutTimeout: 0,
PollInterval: 0,
})
i.idleing = false
i.done <- err
i.log("elapsed idle time: %v", time.Since(now))
}
}()
} else if i.isWaiting() {
i.log("not started: wait for idle to exit")
} else {
i.log("not started: client not ready")
}
}
func (i *idler) Stop() error {
var reterr error
if i.isReady() {
close(i.stop)
select {
case err := <-i.done:
if err == nil {
i.log("<=(idle)")
} else {
i.log("<=(idle) with err: %v", err)
}
reterr = nil
case <-time.After(i.config.idle_timeout):
i.log("idle err (timeout); waiting in background")
i.log("disconnect done->")
i.worker.PostMessage(&types.Done{
Message: types.RespondTo(&types.Disconnect{}),
}, nil)
i.waitOnIdle()
reterr = errIdleTimeout
}
} else if i.isWaiting() {
i.log("not stopped: still idleing/hanging")
reterr = errIdleModeHangs
} else {
i.log("not stopped: client not ready")
reterr = nil
}
return reterr
}
func (i *idler) waitOnIdle() {
i.setWaiting(true)
i.log("wait for idle in background")
go func() {
defer logging.PanicHandler()
err := <-i.done
if err == nil {
i.log("<=(idle) waited")
i.log("connect done->")
i.worker.PostMessage(&types.Done{
Message: types.RespondTo(&types.Connect{}),
}, nil)
} else {
i.log("<=(idle) waited; with err: %v", err)
}
i.setWaiting(false)
i.stop = make(chan struct{})
i.log("restart")
i.Start()
}()
}
func (i *idler) log(format string, v ...interface{}) {
msg := fmt.Sprintf(format, v...)
logging.Debugf("idler (%p) [idle:%t,wait:%t] %s", i, i.idleing, i.waiting, msg)
}
|
