git ssb

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const pull = require('pull-stream')
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const Abortable = require('pull-abortable')
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const LazyWatcher = require('mutant/lib/lazy-watcher')
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const Value = require('mutant/value')
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module.exports = createPullValue
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function createPullValue (getStream, {
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  nextTick = false,
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  idle = false,
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  onListen = null,
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  onUnlisten = null,
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  defaultValue = null,
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  sync = null
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} = {}) {
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  const state = { getStream, onListen, onUnlisten }
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  const binder = LazyWatcher.call(state, update, listen, unlisten)
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  binder.value = defaultValue
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  if (nextTick) binder.nextTick = true
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  if (idle) binder.idle = true
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  state.binder = binder
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  const result = MutantPullValue.bind(state)
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  if (sync) {
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    state.sync = result.sync = Value(false)
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  }
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  return result
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}
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function MutantPullValue (listener) {
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  if (!listener) {
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    return this.binder.getValue()
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  }
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  return this.binder.addListener(listener)
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}
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function update () {
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  // this is only run on the item when no one is listening (use a onceTrue instead of resolve)
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  // since we don't have an synchronous way to check, ignore
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}
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function listen () {
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  const abortable = Abortable()
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  this.abort = abortable.abort
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  pull(
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    this.getStream(),
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    abortable,
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    pull.drain((value) => {
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      if (this.sync && !this.sync()) this.sync.set(true)
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      this.binder.value = value
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      this.binder.broadcast()
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    })
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  )
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  if (typeof this.onListen === 'function') {
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    this.onListen()
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  }
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}
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function unlisten () {
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  if (this.abort) {
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    this.abort()
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    this.abort = null
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  }
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  if (typeof this.onUnlisten === 'function') {
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    this.onUnlisten()
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  }
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}
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