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