| 1 | events = require('events')
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| 2 |
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| 3 | class Aggregator
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| 4 | constructor: (name, implementation, opts) ->
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| 5 | @name = name
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| 6 | @implementation = implementation
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| 7 | @opts = opts
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| 8 | @implementation.init.call(this, @opts)
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| 9 | @cachedValue = null
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| 10 | @events = new events.EventEmitter()
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| 11 | on: (event, callback) ->
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| 12 | @events.on(event, callback)
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| 13 | push: (time, values) ->
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| 14 | values = [values] unless Array.isArray(values)
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| 15 | for value in values
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| 16 | value = @opts.before.call(this, value) if @opts.before
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| 17 | @implementation.push.call(this, time, value) unless value is undefined
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| 18 | oldValue = @cachedValue
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| 19 | @events.emit('change', @cachedValue, oldValue) unless @compute() is oldValue
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| 20 | compute: ->
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| 21 | @cachedValue = @implementation.compute.call(this)
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| 22 | @cachedValue = @opts.after.call(this, @cachedValue) if @opts.after
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| 23 | @cachedValue
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| 24 | value: ->
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| 25 | @cachedValue
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| 26 |
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| 27 | exports.buildAggregator = (name, implementation)-> ((opts) -> new Aggregator(name, implementation, opts)) |
| \ | No newline at end of file |