Watch memory and dump heaps in Node.js

memory.js

function startWatchingMemory() {
    if (process.env.MEMWATCH) {
        var memwatch = require('memwatch-next');
        var heapdump = process.env.HEAPDUMP && require('heapdump');

        var hd = null;

        memwatch.on('leak', function(info) {
            log(info);

            if (hd) {
                var diff = hd.end();
                log(util.inspect(diff, true, null));
            }

            hd = new memwatch.HeapDiff();

            if (process.env.HEAPDUMP) {
                var file = 'upload-' + process.pid + '-' + Date.now() + '.heapsnapshot';

                heapdump.writeSnapshot(file, function(err) {
                    if (err) log(err);
                });
            }
        });
    }
}