git ssb

1
var pull = require('pull-stream')
2
var pullPushable = require('pull-pushable')
3
var pullNext = require('pull-next')
4
var SortedArray = require('sorted-array-functions')
5
6
module.exports = FeedSummary
7
8
function FeedSummary (source, opts, cb) {
9
  var bumpFilter = opts && opts.bumpFilter
10
  var windowSize = opts && opts.windowSize || 1000
11
  var last = null
12
  var returned = false
13
  var done = false
14
  return pullNext(() => {
15
    if (!done) {
16
      var next = {reverse: true, limit: windowSize, live: false}
17
      if (last) {
18
        next.lt = last.timestamp || last.value.sequence
19
      }
20
      var pushable = pullPushable()
21
      pull(
22
        source(next),
23
        pull.collect((err, values) => {
24
          if (err) throw err
25
          if (!values.length) {
26
            done = true
27
            pushable.end()
28
            if (!returned) cb && cb()
29
            returned = true
30
          } else {
31
            var fromTime = last && last.timestamp || Date.now()
32
            last = values[values.length - 1]
33
            groupMessages(values, fromTime, bumpFilter, (err, result) => {
34
              if (err) throw err
35
              result.forEach(v => pushable.push(v))
36
              pushable.end()
37
              if (!returned) cb && cb()
38
              returned = true
39
            })
40
          }
41
        })
42
      )
43
    }
44
    return pushable
45
  })
46
}
47
48
function groupMessages (messages, fromTime, bumpFilter, cb) {
49
  var follows = {}
50
  var messageUpdates = {}
51
  reverseForEach(messages, function (msg) {
52
    if (!msg.value) return
53
    var c = msg.value.content
54
    if (c.type === 'contact') {
55
      updateContact(msg, follows)
56
    } else if (c.type === 'vote') {
57
      if (c.vote && c.vote.link) {
58
        // only show digs of posts added in the current window
59
        // and only for the main post
60
        const group = messageUpdates[c.vote.link]
61
        if (group) {
62
          if (c.vote.value > 0) {
63
            group.lastUpdateType = 'dig'
64
            group.digs.add(msg.value.author)
65
            // only bump when filter passes
66
            if (!bumpFilter || bumpFilter(msg, group)) {
67
              group.updated = msg.timestamp
68
            }
69
          } else {
70
            group.digs.delete(msg.value.author)
71
            if (group.lastUpdateType === 'dig' && !group.digs.size && !group.replies.length) {
72
              group.lastUpdateType = 'reply'
73
            }
74
          }
75
        }
76
      }
77
    } else {
78
      if (c.root) {
79
        const group = ensureMessage(c.root, messageUpdates)
80
        group.fromTime = fromTime
81
        group.lastUpdateType = 'reply'
82
        group.repliesFrom.add(msg.value.author)
83
        //SortedArray.add(group.replies, msg, compareUserTimestamp)
84
        group.replies.push(msg)
85
        group.channel = group.channel || msg.value.content.channel
86
87
        // only bump when filter passes
88
        if (!bumpFilter || bumpFilter(msg, group)) {
89
          group.updated = msg.timestamp || msg.value.sequence
90
        }
91
      } else {
92
        const group = ensureMessage(msg.key, messageUpdates)
93
        group.fromTime = fromTime
94
        group.lastUpdateType = 'post'
95
        group.updated = msg.timestamp || msg.value.sequence
96
        group.author = msg.value.author
97
        group.channel = msg.value.content.channel
98
        group.message = msg
99
      }
100
    }
101
  }, () => {
102
    var result = []
103
    Object.keys(follows).forEach((key) => {
104
      if (follows[key].updated) {
105
        SortedArray.add(result, follows[key], compareUpdated)
106
      }
107
    })
108
    Object.keys(messageUpdates).forEach((key) => {
109
      if (messageUpdates[key].updated) {
110
        SortedArray.add(result, messageUpdates[key], compareUpdated)
111
      }
112
    })
113
    cb(null, result)
114
  })
115
}
116
117
function compareUpdated (a, b) {
118
  return b.updated - a.updated
119
}
120
121
function reverseForEach (items, fn, cb) {
122
  var i = items.length - 1
123
  nextBatch()
124
125
  function nextBatch () {
126
    var start = Date.now()
127
    while (i >= 0) {
128
      fn(items[i], i)
129
      i -= 1
130
      if (Date.now() - start > 10) break
131
    }
132
133
    if (i > 0) {
134
      setImmediate(nextBatch)
135
    } else {
136
      cb && cb()
137
    }
138
  }
139
}
140
141
function updateContact (msg, groups) {
142
  var c = msg.value.content
143
  var id = msg.value.author
144
  var group = groups[id]
145
  if (c.contact) {
146
    if (c.following) {
147
      if (!group) {
148
        group = groups[id] = {
149
          type: 'follow',
150
          lastUpdateType: null,
151
          contacts: new Set(),
152
          updated: 0,
153
          author: id,
154
          id: id
155
        }
156
      }
157
      group.contacts.add(c.contact)
158
      group.updated = msg.timestamp || msg.value.sequence
159
    } else {
160
      if (group) {
161
        group.contacts.delete(c.contact)
162
        if (!group.contacts.size) {
163
          delete groups[id]
164
        }
165
      }
166
    }
167
  }
168
}
169
170
function ensureMessage (id, groups) {
171
  var group = groups[id]
172
  if (!group) {
173
    group = groups[id] = {
174
      type: 'message',
175
      repliesFrom: new Set(),
176
      replies: [],
177
      message: null,
178
      messageId: id,
179
      digs: new Set(),
180
      updated: 0
181
    }
182
  }
183
  return group
184
}
185