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
|
# Responsible for ensuring the cable connection is in good health by validating the heartbeat pings sent from the server, and attempting
# revival reconnections if things go astray. Internal class, not intended for direct user manipulation.
class Cable.ConnectionMonitor
identifier: Cable.PING_IDENTIFIER
pollInterval:
min: 2
max: 30
staleThreshold:
startedAt: 4
pingedAt: 8
constructor: (@consumer) ->
@consumer.subscriptions.add(this)
@start()
connected: ->
@reset()
@pingedAt = now()
disconnected: ->
received: ->
@pingedAt = now()
reset: ->
@reconnectAttempts = 0
start: ->
@reset()
delete @stoppedAt
@startedAt = now()
@poll()
document.addEventListener("visibilitychange", @visibilityDidChange)
stop: ->
@stoppedAt = now()
document.removeEventListener("visibilitychange", @visibilityDidChange)
poll: ->
setTimeout =>
unless @stoppedAt
@reconnectIfStale()
@poll()
, @getInterval()
getInterval: ->
{min, max} = @pollInterval
interval = 4 * Math.log(@reconnectAttempts + 1)
clamp(interval, min, max) * 1000
reconnectIfStale: ->
if @connectionIsStale()
@reconnectAttempts++
@consumer.connection.reopen()
connectionIsStale: ->
if @pingedAt
secondsSince(@pingedAt) > @staleThreshold.pingedAt
else
secondsSince(@startedAt) > @staleThreshold.startedAt
visibilityDidChange: =>
if document.visibilityState is "visible"
setTimeout =>
if @connectionIsStale() or not @consumer.connection.isOpen()
@consumer.connection.reopen()
, 200
toJSON: ->
interval = @getInterval()
connectionIsStale = @connectionIsStale()
{@startedAt, @stoppedAt, @pingedAt, @reconnectAttempts, connectionIsStale, interval}
now = ->
new Date().getTime()
secondsSince = (time) ->
(now() - time) / 1000
clamp = (number, min, max) ->
Math.max(min, Math.min(max, number))
|