git ssb

1
var nonPrivate = require('non-private-ip')
2
var ip = require('ip')
3
var onWakeup = require('on-wakeup')
4
var onNetwork = require('on-change-network')
5
6
var Stats = require('statistics')
7
var os = require('os')
8
var pull = require('pull-stream')
9
var u = require('../../lib/util')
10
11
function rand(array) {
12
  return array[~~(Math.random()*array.length)]
13
}
14
15
function not (fn) {
16
  return function (e) { return !fn(e) }
17
}
18
19
function and () {
20
  var args = [].slice.call(arguments)
21
  return function (value) {
22
    return args.every(function (fn) { return fn.call(null, value) })
23
  }
24
}
25
26
//min delay (delay since last disconnect of most recent peer in unconnected set)
27
//unconnected filter delay peer < min delay
28
function delay (failures, factor, max) {
29
  return Math.min(Math.pow(2, failures)*factor, max || Infinity)
30
}
31
32
function maxStateChange (M, e) {
33
  return Math.max(M, e.stateChange || 0)
34
}
35
36
function peerNext(peer, opts) {
37
  return (peer.stateChange|0) + delay(peer.failure|0, opts.factor, opts.max)
38
}
39
40
41
//detect if not connected to wifi or other network
42
//(i.e. if there is only localhost)
43
44
function isOffline (e) {
45
  if(ip.isLoopback(e.host)) return false
46
  var lo = Object.keys(os.networkInterfaces())
47
  return lo.length === 1 && lo[0] === 'lo'
48
}
49
50
var isOnline = not(isOffline)
51
52
function isLocal (e) {
53
  // don't rely on private ip address, because
54
  // cjdns creates fake private ip addresses.
55
  return ip.isPrivate(e.host) && e.type === 'local'
56
}
57
58
function isUnattempted (e) {
59
  return !e.stateChange
60
}
61
62
//select peers which have never been successfully connected to yet,
63
//but have been tried.
64
function isInactive (e) {
65
  return e.stateChange && e.duration.mean == 0
66
}
67
68
function isLongterm (e) {
69
  return e.ping && e.ping.rtt.mean > 0
70
}
71
72
//peers which we can connect to, but are not upgraded.
73
//select peers which we can connect to, but are not upgraded to LT.
74
//assume any peer is legacy, until we know otherwise...
75
function isLegacy (peer) {
76
  return peer.duration.mean > 0 && !exports.isLongterm(peer)
77
}
78
79
function isConnect (e) {
80
  return 'connected' === e.state || 'connecting' === e.state
81
}
82
83
//sort oldest to newest then take first n
84
function earliest(peers, n) {
85
  return peers.sort(function (a, b) {
86
    return a.stateChange - b.stateChange
87
  }).slice(0, Math.max(n, 0))
88
}
89
90
function select(peers, ts, filter, opts) {
91
  if(opts.disable) return []
92
  //opts: { quota, groupMin, min, factor, max }
93
  var type = peers.filter(filter)
94
  var unconnect = type.filter(not(isConnect))
95
  var count = Math.max(opts.quota - type.filter(isConnect).length, 0)
96
  var min = unconnect.reduce(maxStateChange, 0) + opts.groupMin
97
  if(ts < min) return []
98
99
  return earliest(unconnect.filter(function (peer) {
100
    return peerNext(peer, opts) < ts
101
  }), count)
102
}
103
104
var schedule = exports = module.exports =
105
function (gossip, config, server) { 
106
107
  var min = 60e3, hour = 60*60e3
108
109
  //trigger hard reconnect after suspend or local network changes
110
  onWakeup(gossip.reconnect)
111
  onNetwork(gossip.reconnect)
112
113
  function conf(name, def) {
114
    if(!config.gossip) return def
115
    var value = config.gossip[name]
116
    return (value === undefined || value === '') ? def : value
117
  }
118
119
  function connect (peers, ts, name, filter, opts) {
120
    var connected = peers.filter(isConnect).filter(filter)
121
      .filter(function (peer) {
122
        return peer.stateChange + 10e3 < ts
123
      })
124
125
    if(connected.length > opts.quota) {
126
      return earliest(connected, connected.length - opts.quota)
127
        .forEach(function (peer) {
128
          gossip.disconnect(peer)
129
        })
130
    }
131
132
    select(peers, ts, and(filter, isOnline), opts)
133
      .forEach(function (peer) {
134
        gossip.connect(peer)
135
      })
136
  }
137
138
139
  var connecting = false
140
  function connections () {
141
    if(connecting) return
142
    connecting = true
143
    setTimeout(function () {
144
    connecting = false
145
    var ts = Date.now()
146
    var peers = gossip.peers()
147
148
//    if(Math.random() > 0.1) return
149
150
    connect(peers, ts, 'attempt', exports.isUnattempted, {
151
        min: 0, quota: 10, factor: 0, max: 0, groupMin: 0,
152
        disable: !conf('global', true)
153
    })
154
155
    //quota, groupMin, min, factor, max
156
    connect(peers, ts, 'retry', exports.isInactive, {
157
        min: 0,
158
        quota: 3, factor: 5*60e3, max: 3*60*60e3, groupMin: 5*50e3
159
      })
160
161
    connect(peers, ts, 'legacy', exports.isLegacy, {
162
        quota: 3, factor: 5*min, max: 3*hour, groupMin: 5*min,
163
        disable: !conf('global', true)
164
      })
165
166
    connect(peers, ts, 'longterm', exports.isLongterm, {
167
      quota: 3, factor: 10e3, max: 10*min, groupMin: 5e3,
168
      disable: !conf('global', true)
169
    })
170
171
    connect(peers, ts, 'local', exports.isLocal, {
172
      quota: 3, factor: 2e3, max: 10*min, groupMin: 1e3,
173
      disable: !conf('local', true)
174
    })
175
176
    }, 100*Math.random())
177
178
  }
179
180
    pull(
181
      gossip.changes(),
182
      pull.drain(function (ev) {
183
        if(ev.type == 'disconnect')
184
          connections()
185
      })
186
    )
187
188
    var int = setInterval(connections, 2e3)
189
    if(int.unref) int.unref()
190
191
    connections()
192
193
}
194
195
exports.isUnattempted = isUnattempted
196
exports.isInactive = isInactive
197
exports.isLongterm = isLongterm
198
exports.isLegacy = isLegacy
199
exports.isLocal = isLocal
200
exports.isConnectedOrConnecting = isConnect
201
exports.select = select
202
203
204
205