git ssb

1
var Graphmitter = require('graphmitter')
2
var pull        = require('pull-stream')
3
var mlib        = require('ssb-msgs')
4
var memview     = require('level-memview')
5
var pushable    = require('pull-pushable')
6
var mdm         = require('mdmanifest')
7
var valid       = require('scuttlebot/lib/validators')
8
var apidoc      = require('scuttlebot/lib/apidocs').friends
9
10
// friends plugin
11
// methods to analyze the social graph
12
// maintains a 'follow' and 'flag' graph
13
14
function isFunction (f) {
15
  return 'function' === typeof f
16
}
17
18
function isString (s) {
19
  return 'string' === typeof s
20
}
21
22
function isFriend (friends, a, b) {
23
  return friends[a] && friends[b] && friends[a][b] && friends[b][a]
24
}
25
26
exports.name = 'friends'
27
exports.version = '1.0.0'
28
exports.manifest = mdm.manifest(apidoc)
29
30
exports.init = function (sbot, config) {
31
32
  var graphs = {
33
    follow: new Graphmitter(),
34
    flag: new Graphmitter()
35
  }
36
37
  // view processor
38
  var syncCbs = []
39
  function awaitSync (cb) {
40
    if (syncCbs) syncCbs.push(cb)
41
    else cb()
42
  }
43
44
  // read/watch the log for changes to the social graph
45
  pull(sbot.createLogStream({ live: true }), pull.drain(function (msg) {
46
47
    if (msg.sync) {
48
      syncCbs.forEach(function (cb) { cb() })
49
      syncCbs = null
50
51
      if (sbot.gossip) {
52
        // prioritize friends
53
        var friends = graphs['follow'].toJSON()
54
        sbot.gossip.peers().forEach(function(peer) {
55
          if (isFriend(friends, sbot.id, peer.key)) {
56
            sbot.gossip.add(peer, 'friends')
57
          }
58
        })
59
      }
60
61
      return
62
    }
63
64
    var c = msg.value.content
65
    if (c.type == 'contact') {
66
      mlib.asLinks(c.contact, 'feed').forEach(function (link) {
67
        if ('following' in c) {
68
          if (c.following)
69
            graphs.follow.edge(msg.value.author, link.link, true)
70
          else
71
            graphs.follow.del(msg.value.author, link.link)
72
73
        }
74
        if ('flagged' in c) {
75
          if (c.flagged)
76
            graphs.flag.edge(msg.value.author, link.link, c.flagged)
77
          else
78
            graphs.flag.del(msg.value.author, link.link)
79
        }
80
      })
81
    }
82
  }))
83
84
  return {
85
86
    get: valid.sync(function (opts) {
87
      var g = graphs[opts.graph || 'follow']
88
      if(!g) throw new Error('opts.graph must be provided')
89
      return g.get(opts.source, opts.dest)
90
    }, 'object?'),
91
92
    all: valid.async(function (graph, cb) {
93
      if (typeof graph == 'function') {
94
        cb = graph
95
        graph = null
96
      }
97
      if (!graph)
98
        graph = 'follow'
99
      awaitSync(function () {
100
        cb(null, graphs[graph] ? graphs[graph].toJSON() : null)
101
      })
102
    }, 'string?'),
103
104
    path: valid.sync(function (opts) {
105
      if(isString(opts))
106
        opts = {source: sbot.id, dest: opts}
107
      return graphs.follow.path(opts)
108
109
    }, 'string|object'),
110
111
    createFriendStream: valid.source(function (opts) {
112
      opts = opts || {}
113
      var live = opts.live === true
114
      var meta = opts.meta === true
115
      var start = opts.start || sbot.id
116
      var graph = graphs[opts.graph || 'follow']
117
      if(!graph)
118
        return pull.error(new Error('unknown graph:' + opts.graph))
119
      var cancel, ps = pushable(function () {
120
        cancel && cancel()
121
      })
122
123
      function push (to, hops) {
124
        return ps.push(meta ? {id: to, hops: hops} : to)
125
      }
126
127
      if (live) {
128
        awaitSync(function () {
129
          ps.push({sync: true})
130
        })
131
      }
132
133
      //by default, also emit your own key.
134
      if(opts.self !== false)
135
        push(start, 0)
136
137
      var conf = config.friends || {}
138
      cancel = graph.traverse({
139
        start: start,
140
        hops: opts.hops || conf.hops || 3,
141
        max: opts.dunbar || conf.dunbar || 150,
142
        each: function (_, to, hops) {
143
          if(to !== start) push(to, hops)
144
        }
145
      })
146
147
      if(!live) { cancel(); ps.end() }
148
149
      return ps
150
    }, 'createFriendStreamOpts?'),
151
152
    hops: valid.async(function (start, graph, opts, cb) {
153
      if (typeof opts == 'function') { // (start|opts, graph, cb)
154
        cb = opts
155
        opts = null
156
      } else if (typeof graph == 'function') { // (start|opts, cb)
157
        cb = graph
158
        opts = graph = null
159
      }
160
      opts = opts || {}
161
      if(isString(start)) { // (start, ...)
162
        // first arg is id string
163
        opts.start = start
164
      } else if (start && typeof start == 'object') { // (opts, ...)
165
        // first arg is opts
166
        for (var k in start)
167
          opts[k] = start[k]
168
      }
169
170
      var conf = config.friends || {}
171
      opts.start  = opts.start  || sbot.id
172
      opts.dunbar = opts.dunbar || conf.dunbar || 150
173
      opts.hops   = opts.hops   || conf.hops   || 3
174
175
      var g = graphs[graph || 'follow']
176
      if (!g)
177
        return cb(new Error('Invalid graph type: '+graph))
178
179
      awaitSync(function () {
180
        cb(null, g.traverse(opts))
181
      })
182
    }, ['feedId', 'string?', 'object?'], ['createFriendStreamOpts'])
183
  }
184
}
185