How can I rotate the file I'm writing to in node.js?

Question

I'm writing records to a file in node.js and I need to rotate the file with a new one every so many lines or after a duration but I can't lose any lines in the process. If I try with fs.createWriteStream to create a new stream I end up losing lines by overwriting the old stream. Any advise would be much appreciated.

Answer 1

Don't overwrite the old stream. Create the new stream as a separate resource.

var activestream;

function startup() {
    activestream = fs.createWriteStream('path');
}

function record(line) {
    activestream.write(line);
}

function rotate() {
    var newstream = fs.createWriteStream('path2');
    activestream.end();
    activestream = newstream;
}

... something like that should work. Obviously you'll have to figure out how to manage the paths.