git ssb

1
var LazyWatcher = require('./lib/lazy-watcher')
2
3
module.exports = Set
4
5
function Set (defaultValues, opts) {
6
  var instance = new ProtoSet(defaultValues, opts)
7
  var observable = instance.MutantSet.bind(instance)
8
  observable.add = instance.add.bind(instance)
9
  observable.clear = instance.clear.bind(instance)
10
  observable.delete = instance.delete.bind(instance)
11
  observable.has = instance.has.bind(instance)
12
  observable.set = instance.set.bind(instance)
13
  observable.get = instance.get.bind(instance)
14
  observable.getLength = instance.getLength.bind(instance)
15
  return observable
16
}
17
18
// optimise memory usage
19
function ProtoSet (defaultValues, opts) {
20
  var self = this
21
  self.object = []
22
  self.sources = []
23
  self.releases = []
24
  self.binder = LazyWatcher.call(self, self._update, self._listen, self._unlisten)
25
  self.binder.value = this.object
26
27
  if (opts && opts.nextTick) self.binder.nextTick = true
28
  if (opts && opts.idle) self.binder.idle = true
29
30
  if (defaultValues && defaultValues.length) {
31
    defaultValues.forEach(function (valueOrObs) {
32
      if (!~self.sources.indexOf(valueOrObs)) {
33
        self.sources.push(valueOrObs)
34
      }
35
    })
36
    this._update()
37
  }
38
}
39
40
ProtoSet.prototype.MutantSet = function (listener) {
41
  if (!listener) {
42
    return this.binder.getValue()
43
  }
44
  return this.binder.addListener(listener)
45
}
46
47
ProtoSet.prototype.add = function (valueOrObs) {
48
  if (!~this.sources.indexOf(valueOrObs)) {
49
    this.sources.push(valueOrObs)
50
    if (this.binder.live) {
51
      this.releases[this.sources.length - 1] = this._bind(valueOrObs)
52
    }
53
    this.binder.onUpdate()
54
  }
55
}
56
57
ProtoSet.prototype.clear = function () {
58
  this.releases.forEach(tryInvoke)
59
  this.sources.length = 0
60
  this.releases.length = 0
61
  this.binder.onUpdate()
62
}
63
64
ProtoSet.prototype.delete = function (valueOrObs) {
65
  var index = this.sources.indexOf(valueOrObs)
66
  if (~index) {
67
    this.sources.splice(index, 1)
68
    this.releases.splice(index, 1).forEach(tryInvoke)
69
    this.binder.onUpdate()
70
  }
71
}
72
73
ProtoSet.prototype.has = function (valueOrObs) {
74
  return !!~this.object.indexOf(valueOrObs)
75
}
76
77
ProtoSet.prototype.set = function (values) {
78
  var self = this
79
  var changed = false
80
81
  if (Array.isArray(values)) {
82
    for (var i = this.sources.length - 1; i >= 0; i -= 1) {
83
      if (!~values.indexOf(this.sources[i])) {
84
        changed = true
85
        self.sources.splice(i, 1)
86
      }
87
    }
88
    values.forEach(function (value) {
89
      if (!~self.sources.indexOf(value)) {
90
        changed = true
91
        self.sources.push(value)
92
      }
93
    })
94
  } else {
95
    if (self.sources.length > 0) {
96
      self.sources.length = 0
97
      changed = true
98
    }
99
  }
100
101
  if (changed) {
102
    self.binder.onUpdate()
103
  }
104
}
105
106
ProtoSet.prototype.get = function (index) {
107
  return this.sources[index]
108
}
109
110
ProtoSet.prototype.getLength = function () {
111
  return this.sources.length
112
}
113
114
ProtoSet.prototype._bind = function (valueOrObs) {
115
  return typeof valueOrObs === 'function' ? valueOrObs(this.binder.onUpdate) : null
116
}
117
118
ProtoSet.prototype._listen = function () {
119
  var self = this
120
  self.sources.forEach(function (obs, i) {
121
    self.releases[i] = self._bind(obs)
122
  })
123
}
124
125
ProtoSet.prototype._unlisten = function () {
126
  this.releases.forEach(tryInvoke)
127
  this.releases.length = 0
128
}
129
130
ProtoSet.prototype._update = function () {
131
  var currentValues = this.object.map(get)
132
  var newValues = this.sources.map(resolve)
133
  currentValues.filter(notIncluded, newValues).forEach(removeFrom, this.object)
134
  newValues.filter(notIncluded, currentValues).forEach(addTo, this.object)
135
  return true
136
}
137
138
function get (value) {
139
  return value
140
}
141
142
function resolve (source) {
143
  return typeof source === 'function' ? source() : source
144
}
145
146
function notIncluded (value) {
147
  return !~this.indexOf(value)
148
}
149
150
function removeFrom (item) {
151
  var index = this.indexOf(item)
152
  if (~index) {
153
    this.splice(index, 1)
154
  }
155
}
156
157
function addTo (item) {
158
  this.push(item)
159
}
160
161
function tryInvoke (func) {
162
  if (typeof func === 'function') {
163
    func()
164
  }
165
}
166