git ssb

1
const pull = require('pull-stream')
2
const Abortable = require('pull-abortable')
3
const LazyWatcher = require('mutant/lib/lazy-watcher')
4
5
module.exports = createPullCollection
6
7
function createPullCollection (getStream, opts) {
8
  const state = { getStream }
9
  const binder = LazyWatcher.call(state, update, listen, unlisten)
10
  binder.value = []
11
  if (opts && opts.nextTick) binder.nextTick = true
12
  if (opts && opts.idle) binder.idle = true
13
  state.binder = binder
14
  return MutantPullCollection.bind(state)
15
}
16
17
function MutantPullCollection (listener) {
18
  if (!listener) {
19
    return this.binder.getValue()
20
  }
21
  return this.binder.addListener(listener)
22
}
23
24
function update () {
25
  // this is only run on the item when no one is listening (use a onceTrue instead of resolve)
26
  // since we don't have an synchronous way to check, ignore
27
}
28
29
function listen () {
30
  const abortable = Abortable()
31
  this.abort = abortable.abort
32
  pull(
33
    this.getStream(this.lastValue),
34
    abortable,
35
    pull.drain((value) => {
36
      if (value && value.sync) return
37
      this.lastValue = value
38
      this.binder.value.push(value)
39
      this.binder.broadcast()
40
    })
41
  )
42
}
43
44
function unlisten () {
45
  if (this.abort) {
46
    this.abort()
47
    this.abort = null
48
  }
49
}
50