Secretz create hash stream scope issue

[nantas]

My solution:

var crypto = require('crypto');
var zlib = require('zlib');
var through = require('through');
var tar = require('tar');

var cipher = process.argv[2], pass = process.argv[3];
var decipher = crypto.createDecipher(cipher, pass);
var tarParser = tar.Parse();
var hasher = crypto.createHash('md5', {encoding: 'hex'});
tarParser.on('entry', function(e) {
    if (e.type !== "File") return;
    //e.pipe(tr);

    e.pipe(hasher).pipe(through(null, end)).pipe(process.stdout);
    function end() {
        this.queue(' ' + e.path + '\n');
    }
});

process.stdin.pipe(decipher).pipe(zlib.createGunzip()).pipe(tarParser);

If I run it it gives the following error:

stream.js:94
    throw er; // Unhandled stream error in pipe.

Error: write after end
    at writeAfterEnd (_stream_writable.js:132:12)
    at Hash.Writable.write(_stream_writable.js:180:5)
    at Entry.ondata(stream.js:51:26)
    at Entry.emit(events.js:117:20)

The only difference from official solution is that I put the create hash stream definition in the global scope other than function scope. Can someone explain to me what's going on here? I'm a beginner for node.js and javascript in general.

Many thanks.

[marani]

For your solution, you are piping multiple entries into a single hash transform stream. Imagine two entries emitting data at the same time, your single hash stream will be confused.

For the official solution, each entry has its own hash stream so it will be ok.