69 lines
1.4 KiB
JavaScript
69 lines
1.4 KiB
JavaScript
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'use strict';
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var Stream = require('stream')
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// from
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//
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// a stream that reads from an source.
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// source may be an array, or a function.
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// from handles pause behaviour for you.
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module.exports =
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function from (source) {
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if(Array.isArray(source)) {
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var source_index = 0, source_len = source.length;
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return from (function (i) {
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if(source_index < source_len)
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this.emit('data', source[source_index++])
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else
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this.emit('end')
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return true
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})
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}
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var s = new Stream(), i = 0
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s.ended = false
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s.started = false
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s.readable = true
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s.writable = false
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s.paused = false
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s.ended = false
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s.pause = function () {
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s.started = true
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s.paused = true
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}
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function next () {
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s.started = true
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if(s.ended) return
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while(!s.ended && !s.paused && source.call(s, i++, function () {
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if(!s.ended && !s.paused)
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process.nextTick(next);
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}))
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;
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}
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s.resume = function () {
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s.started = true
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s.paused = false
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next()
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}
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s.on('end', function () {
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s.ended = true
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s.readable = false
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process.nextTick(s.destroy)
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})
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s.destroy = function () {
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s.ended = true
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s.emit('close')
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}
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/*
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by default, the stream will start emitting at nextTick
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if you want, you can pause it, after pipeing.
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you can also resume before next tick, and that will also
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work.
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*/
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process.nextTick(function () {
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if(!s.started) s.resume()
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})
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return s
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}
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