From ee6c11876aa0064a34420eb5039bdc6c509fcff6 Mon Sep 17 00:00:00 2001
From: isaacs <i@izs.me>
Date: Tue, 15 May 2012 17:02:39 -0700
Subject: [PATCH] benchmark for fs.readfile

---
 benchmark/fs-readfile.js | 72 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 benchmark/fs-readfile.js

diff --git a/benchmark/fs-readfile.js b/benchmark/fs-readfile.js
new file mode 100644
index 0000000000..3aa72e1a45
--- /dev/null
+++ b/benchmark/fs-readfile.js
@@ -0,0 +1,72 @@
+// Call fs.readFile over and over again really fast.
+// Then see how many times it got called.
+// Yes, this is a silly benchmark.  Most benchmarks are silly.
+
+var path = require('path');
+var filename = path.resolve(__dirname, 'http.sh');
+var fs = require('fs');
+var count = 0;
+var go = true;
+var len = -1;
+var assert = require('assert');
+
+var concurrency = 1;
+var encoding = null;
+var time = 10;
+
+for (var i = 2; i < process.argv.length; i++) {
+  var arg = process.argv[i];
+  if (arg.match(/^-e$/)) {
+    encoding = process.argv[++i] || null;
+  } else if (arg.match(/^-c$/)) {
+    concurrency = ~~process.argv[++i];
+    if (concurrency < 1) concurrency = 1;
+  } else if (arg === '-t') {
+    time = ~~process.argv[++i];
+    if (time < 1) time = 1;
+  }
+}
+
+
+setTimeout(function() {
+  go = false;
+}, time * 1000);
+
+function round(n) {
+  return Math.floor(n * 100) / 100;
+}
+
+var start = process.hrtime();
+while (concurrency--) readFile();
+
+function readFile() {
+  if (!go) {
+    process.stdout.write('\n');
+    console.log('read the file %d times (higher is better)', count);
+    var end = process.hrtime();
+    var elapsed = [end[0] - start[0], end[1] - start[1]];
+    var ns = elapsed[0] * 1E9 + elapsed[1];
+    var nsper = round(ns / count);
+    console.log('%d ns per read (lower is better)', nsper);
+    var readsper = round(count / (ns / 1E9));
+    console.log('%d reads per sec (higher is better)', readsper);
+    process.exit(0);
+    return;
+  }
+
+  if (!(count % 1000)) {
+    process.stdout.write('.');
+  }
+
+  if (encoding) fs.readFile(filename, encoding, then);
+  else fs.readFile(filename, then);
+
+  function then(er, data) {
+    assert.ifError(er);
+    count++;
+    // basic sanity test: we should get the same number of bytes each time.
+    if (count === 1) len = data.length;
+    else assert(len === data.length);
+    readFile();
+  }
+}