buffer: improve copy() performance

PR-URL: https://github.com/nodejs/node/pull/29066
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/benchmark/buffers/buffer-copy.js b/benchmark/buffers/buffer-copy.js
new file mode 100644
index 0000000000..164f314207
--- /dev/null
+++ b/benchmark/buffers/buffer-copy.js
@@ -0,0 +1,19 @@
+'use strict';
+const common = require('../common.js');
+
+const bench = common.createBenchmark(main, {
+  bytes: [0, 8, 128, 32 * 1024],
+  partial: ['true', 'false'],
+  n: [6e6]
+});
+
+function main({ n, bytes, partial }) {
+  const source = Buffer.allocUnsafe(bytes);
+  const target = Buffer.allocUnsafe(bytes);
+  const sourceStart = (partial === 'true' ? Math.floor(bytes / 2) : 0);
+  bench.start();
+  for (let i = 0; i < n; i++) {
+    source.copy(target, 0, sourceStart);
+  }
+  bench.end(n);
+}