Reduced memory consumption

[xiongsongsong]

Such as immediately after writer.addRow send content to the browser may be able to reduce the memory footprint?

thanks.

[xiongsongsong]

var koa = require('koa');
var app = koa();
var XLSXWriter = require('xlsx-writestream');

app.use(function *() {

  var writer = new XLSXWriter();
  this.body = writer.getReadStream();
  var timer = 0;
  var cl = setInterval(function () {
    timer++;
    for (var i = 0; i < 5000; i++) {
      writer.addRow({
        "date": new Date().toString(),
        "string": 'super long string'
      });
    }
    if (timer > 500) {
      clearTimeout(cl);
      writer.finalize();
    }
  }, 500);
});

app.listen(3000);

<--- Last few GCs --->

  549171 ms: Scavenge 1399.0 (1458.1) -> 1399.0 (1458.1) MB, 0.8 / 0 ms (+ 2.7 ms in 1 steps since last GC) [allocation failure] [incremental marking delaying mark-sweep].
  550436 ms: Mark-sweep 1399.0 (1458.1) -> 1398.9 (1458.1) MB, 1265.5 / 0 ms (+ 4.2 ms in 2 steps since start of marking, biggest step 2.7 ms) [last resort gc].
  551605 ms: Mark-sweep 1398.9 (1458.1) -> 1398.9 (1458.1) MB, 1168.8 / 0 ms [last resort gc].


<--- JS stacktrace --->

==== JS stack trace =========================================

Security context: 0x280d020e3ac1 <JS Object>
    1: startRow [/Users/song/WebstormProjects/stream-excel/node_modules/xlsx-writestream/lib/blobs.js:~20] [pc=0x2378a7d8c20e] (this=0xe4b320ec419 <an Object with map 0x269ea5754649>,row=2272519)
    2: _repeat [/Users/song/WebstormProjects/stream-excel/app.js:~12] [pc=0x2378a7dcbb67] (this=0x25f51a4d9ce1 <JS Object>)
    3: _onTimeout(aka wrapper) [timers.js:~274] [pc=0x2378a7de9e75] (this=0x2...

FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - process out of memory
Abort trap: 6