81 lines
2.0 KiB
JavaScript
81 lines
2.0 KiB
JavaScript
'use strict'
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var ProbeError = require('./lib/common').ProbeError
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var parsers = require('./lib/parsers_stream')
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var PassThrough = require('stream').PassThrough
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var pipeline = require('stream').pipeline
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module.exports = function probeStream (src, keepOpen) {
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var proxy = new PassThrough()
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// increase max number of listeners to stop memory leak warning
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proxy.setMaxListeners(Object.keys(parsers).length + 10)
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var result = new Promise(function (resolve, reject) {
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src.on('error', reject)
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proxy.on('error', reject)
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var alive_parsers = []
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var last_error
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function parserEnd (err) {
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var idx = alive_parsers.indexOf[this]
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/* istanbul ignore if */
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if (idx < 0) return
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/* istanbul ignore if */
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if (err) last_error = err
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proxy.unpipe(this)
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this.removeAllListeners()
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alive_parsers.splice(idx, 1)
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if (alive_parsers.length) return
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// if all parsers finished without success -> fail.
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reject(last_error || new ProbeError('unrecognized file format', 'ECONTENT'))
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}
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Object.keys(parsers).forEach(function (type) {
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var pStream = parsers[type]()
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alive_parsers.push(pStream)
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pStream.once('data', function (data) {
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if (data.width > 0 && data.height > 0) {
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resolve(data)
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return
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}
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// Manually finish parser to get standars "unrecognized" error.
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parserEnd.call(pStream)
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})
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pStream.once('end', parserEnd)
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// User does not need to know that something wrong in parser
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// Process error the same was unrecognized format (end without data)
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pStream.on('error', parserEnd)
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proxy.pipe(pStream)
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})
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})
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function cleanup () {
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// request stream doesn't have unpipe, https://github.com/request/request/issues/874
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if (keepOpen && typeof src.unpipe === 'function') src.unpipe(proxy)
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proxy.destroy()
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}
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result.then(cleanup).catch(cleanup)
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if (keepOpen) src.pipe(proxy)
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else pipeline(src, proxy, function () {})
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return result
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}
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module.exports.parsers = parsers
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