When create Buffer from a Buffer will copy data
from old to new even though length is zero.
This patch can improve edge case 4x faster.
following is benchmark results.
new: buffers/buffer_zero.js n=1024: 2463.53891
old: buffers/buffer_zero.js n=1024: 618.70801
PR-URL: https://github.com/nodejs/node/pull/4326
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
--- /dev/null
+'use strict';
+
+const common = require('../common.js');
+
+const bench = common.createBenchmark(main, {
+ n: [1024]
+});
+
+const zero = new Buffer(0);
+
+function main(conf) {
+ var n = +conf.n;
+ bench.start();
+ for (let i = 0; i < n * 1024; i++) {
+ new Buffer(zero);
+ }
+ bench.end(n);
+}
function fromObject(obj) {
if (obj instanceof Buffer) {
var b = allocate(obj.length);
+
+ if (b.length === 0)
+ return b;
+
obj.copy(b, 0, 0, obj.length);
return b;
}