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Benchmark to show performance difference between fs sync and async calls
'use strict';
const MAX_DEPTH = 4;
const fs = require('fs');
const print = process._rawDebug;
const sep = require('path').sep;
const tmpdir = require('os').tmpdir() + sep + 'data-file-bench-' + genName();
const file_list = newDir();
var current_dir = file_list;
var current_path = [ tmpdir ];
var total_size = 0;
var total_files = 0;
var total_folders = 0;
// Making large Buffer so some files will be multi-sector. Also fill buf with
// random data.
const buf = Buffer.alloc(0x2000, Math.random().toString(36));
process.on('SIGINT', process.exit);
process.on('exit', () => {
cleanupFiles(file_list, [tmpdir]);
});
process.on('uncaughtException', (e) => {
if (!process._exiting)
cleanupFiles(file_list, [tmpdir]);
throw e;
});
{
const t = process.hrtime();
genFiles();
print('total_files: ', total_files);
print('total_folders:', total_folders);
print('total_size: ', total_size);
printTime('genFiles:', process.hrtime(t), 1);
}
// Do this so the system caches all the files. So perf test is level.
readAllFilesSync(tmpdir);
{
const t = process.hrtime();
readAllFilesSync(tmpdir);
printTime('readAllFilesSync:', process.hrtime(t), 1);
}
{
const t = process.hrtime();
readAllFilesAsync(
tmpdir, () => printTime('readAllFilesAsync:', process.hrtime(t), 1));
}
function readAllFilesSync(dir) {
const contents = fs.readdirSync(dir);
for (const val of contents) {
const new_path = dir + sep + val;
const file_stats = fs.lstatSync(new_path);
if (file_stats.isDirectory())
readAllFilesSync(new_path);
else if (file_stats.isFile())
fs.readFileSync(new_path);
else
throw new Error('wtf are you up to?');
}
}
function readAllFilesAsync(dir, cb) {
var remaining = null;
if (typeof cb !== 'function') cb = () => {};
fs.readdir(dir, (err, contents) => {
if (err) throw err;
remaining = contents.length;
for (const val of contents) {
const new_path = dir + sep + val;
fs.lstat(new_path, (err, file_stats) => {
if (err) throw err;
if (file_stats.isDirectory()) {
readAllFilesAsync(new_path, () => {
if (--remaining <= 0) cb();
});
} else if (file_stats.isFile()) {
fs.readFile(new_path, (err, data) => {
if (err) throw err;
if (--remaining <= 0) cb();
});
} else {
throw new Error('seriously?');
}
});
}
});
}
// Generate a lot of files of different sizes.
function genFiles() {
// First create the dir that all the others will go in.
fs.mkdirSync(tmpdir);
print(`tmp dir for bench is ${tmpdir}`);
createFilesNDirs();
}
function createFilesNDirs() {
// First create 16 files.
for (let i = 1; i <= 16; i++) {
let file_name = null;
while (file_name === null) {
try {
const tmp_name = genName();
fs.writeFileSync(ffPath(tmp_name), buf.slice(i * 0x200));
file_name = tmp_name;
total_files++;
total_size += i * 0x200;
} catch(e) { if (e.code !== 'EEXIST') throw e }
}
current_dir.files.push(file_name);
}
// All done if max depth has been reached.
if (current_path.length > MAX_DEPTH) {
current_path.pop();
current_dir = current_dir.parent;
return;
}
// Generate 4 folders and populate them.
for (let i = 0; i < 4; i++) {
let folder_name = null;
while (folder_name === null) {
try {
const tmp_name = genName();
fs.mkdirSync(ffPath(tmp_name));
folder_name = tmp_name;
total_folders++;
} catch(e) { if (e.code !== 'EEXIST') throw e }
}
current_dir = current_dir.folders[folder_name] = newDir();
current_path.push(folder_name);
createFilesNDirs();
}
current_path.pop();
current_dir = current_dir.parent;
}
function cleanupFiles(obj, fpath) {
for (let dir in obj.folders) {
fpath.push(dir);
cleanupFiles(obj.folders[dir], fpath);
}
for (const file_name of obj.files) {
const file_path = ffPath(fpath.join(sep) + sep + file_name);
try {
fs.unlinkSync(file_path);
} catch (e) { if (e.code !== 'ENOENT') throw e }
}
fs.rmdirSync(fpath.join(sep));
fpath.pop();
}
function genName() { return Math.random().toString(36).substr(-8) }
function newDir() { return { files: [], folders: {}, parent: current_dir } }
function ffPath(name) { return current_path.join(sep) + sep + name }
function printTime(msg, t, iter) {
const op_txt = (iter === 1) ? '' : '/op';
var ops = (t[0] + t[1] / 1e9) / iter;
if (ops >= 10) {
print(msg, ops.toFixed(2), 'sec' + op_txt);
} else if ((ops *= 1e3) >= 10) {
print(msg, ops.toFixed(2), 'ms' + op_txt);
} else if ((ops *= 1e3) >= 10) {
print(msg, ops.toFixed(2), 'us' + op_txt);
} else {
print(msg, (ops * 1e3).toFixed(2), 'ns' + op_txt);
}
}
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