readstream pipe does not close

问题

I am using sax-js to read large xml files. I cannot get the program to exit when the parser is finished. Here is the shape of the script, with parser logic removed.

    var fs = require('fs');
    var sax = require('sax');

    var feedFile = 'foo.xml';
    var saxStream = sax.createStream(true)
    .on('opentag', function(node) { // do stuff })
    .on('end', function() {
         console.log("parser end event");
    });

    var options = {
         flags: 'r',
         encoding: 'utf8',
         mode: 0666,
         bufferSize: 1024
    };

    fs.createReadStream(feedFile, options, function(err) {
        throw err;
    })
    .on('end', function() {
        console.log("read stream end event");
    })
    .pipe(saxStream);

Everything works properly. And the console gets the messages like this

    read stream end event
    parser end event

And then the process should exit. It does not. What am I missing?

---

EDIT: What I am missing. There was a resource still open so that node could not exit. The temptation is to start trying to call process.exit() somewhere, anywhere. I tried it myself in this case and it broke stuff.

My script could not exit because I had an open mongodb connection (managed by mongoose). Here is essentially (not in detail) what fixed it:

    saxStream.on('end', function() {
        console.log("parser end event");
        mongoose.disconnect();
    };

来源：https://stackoverflow.com/questions/16399476/readstream-pipe-does-not-close