tra-analysis/website/node_modules/npm/lib/utils/gunzip-maybe.js
2019-01-06 13:14:45 -06:00

23 lines
556 B
JavaScript

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
}