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42 lines
874 B
42 lines
874 B
'use strict'
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/*!
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* Canvas - JPEGStream
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* Copyright (c) 2010 LearnBoost <tj@learnboost.com>
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* MIT Licensed
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*/
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const { Readable } = require('stream')
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function noop () {}
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class JPEGStream extends Readable {
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constructor (canvas, options) {
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super()
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if (canvas.streamJPEGSync === undefined) {
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throw new Error('node-canvas was built without JPEG support.')
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}
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this.options = options
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this.canvas = canvas
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}
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_read () {
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// For now we're not controlling the c++ code's data emission, so we only
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// call canvas.streamJPEGSync once and let it emit data at will.
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this._read = noop
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this.canvas.streamJPEGSync(this.options, (err, chunk) => {
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if (err) {
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this.emit('error', err)
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} else if (chunk) {
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this.push(chunk)
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} else {
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this.push(null)
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}
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})
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}
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};
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module.exports = JPEGStream
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