atcheck/lsscanner/new_ubuntu/node_modules/npm/lib/utils/gunzip-maybe.js

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2019-12-16 18:42:21 +01:00
var duplex = require('mississippi').duplex
var through = require('mississippi').through
var zlib = require('zlib')
function hasGzipHeader (c) {
return c[0] === 0x1F && c[1] === 0x8B && c[2] === 0x08
}
module.exports = gunzip
function gunzip () {
var stream = duplex()
var peeker = through(function (chunk, enc, cb) {
var newStream = hasGzipHeader(chunk)
? zlib.createGunzip()
: through()
stream.setReadable(newStream)
stream.setWritable(newStream)
stream.write(chunk)
})
stream.setWritable(peeker)
return stream
}