node/benchmark
Andrew Casey 3772cf56ae
lib: add throws option to fs.f/l/statSync
For consumers that aren't interested in *why* a `statSync` call failed,
allocating and throwing an exception is an unnecessary expense.  This PR
adds an option that will cause it to return `undefined` in such cases
instead.

As a motivating example, the JavaScript & TypeScript language service
shared between Visual Studio and Visual Studio Code is stuck with
synchronous file IO for architectural and backward-compatibility
reasons.  It frequently needs to speculatively check for the existence
of files and directories that may not exist (and cares about file vs
directory, so `existsSync` is insufficient), but ignores file system
entries it can't access, regardless of the reason.

Benchmarking the language service is difficult because it's so hard to
get good coverage of both code bases and user behaviors, but, as a
representative metric, we measured batch compilation of a few hundred
popular projects (by star count) from GitHub and found that, on average,
we saved about 1-2% of total compilation time.  We speculate that the
savings could be even more significant in interactive (language service
or watch mode) scenarios, where the same (non-existent) files need to be
polled over and over again.  It's not a huge improvement, but it's a
very small change and it will affect a lot of users (and CI runs).

For reference, our measurements were against `v12.x` (3637a061a at the
time) on an Ubuntu Server desktop with an SSD.

PR-URL: https://github.com/nodejs/node/pull/33716
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
2020-11-18 16:19:33 -05:00
..
assert
async_hooks benchmark: always throw the same Error instance 2020-07-29 10:59:26 +03:00
buffers
child_process
cluster
crypto crypto: refactoring internals, add WebCrypto 2020-10-07 17:27:05 -07:00
dgram
diagnostics_channel http: report request start and end with diagnostics_channel 2020-10-31 21:24:12 +00:00
dns
domain
es tools: update ESLint to 7.2.0 2020-06-13 16:44:03 -04:00
esm module: use Wasm CJS lexer when available 2020-10-12 04:24:41 -07:00
events benchmark: fix EventTarget benchmark 2020-06-23 17:08:13 -07:00
fixtures benchmark: remove modules that require intl 2020-11-05 07:23:47 +00:00
fs lib: add throws option to fs.f/l/statSync 2020-11-18 16:19:33 -05:00
http
http2
misc benchmark: add startup benchmark for loading public modules 2020-11-04 10:39:13 +08:00
module
napi benchmark: ignore build artifacts for napi addons 2020-11-07 02:57:54 +00:00
net
os
path
perf_hooks perf_hooks: add idleTime and event loop util 2020-08-29 07:02:31 -07:00
policy policy: add startup benchmark and make SRI lazier 2020-07-14 13:03:04 -05:00
process benchmark: add benchmark script for resourceUsage 2020-08-13 22:33:07 +08:00
querystring querystring: improve stringify() performance 2020-06-12 18:21:44 -04:00
streams benchmark,test: remove output from readable-async-iterator benchmark 2020-07-17 08:41:15 -07:00
string_decoder
timers
tls tls: allow reading data into a static buffer 2020-10-28 16:07:29 +03:00
url
util
v8
vm
worker worker: add eventLoopUtilization() 2020-10-27 09:43:20 +01:00
zlib
_benchmark_progress.js
_cli.js
_cli.R
_http-benchmarkers.js
_test-double-benchmarker.js
.eslintrc.yaml
common.js benchmark: make the benchmark tool work with Node 10 2020-11-04 10:40:14 +08:00
compare.js
compare.R
README.md perf_hooks: add idleTime and event loop util 2020-08-29 07:02:31 -07:00
run.js
scatter.js
scatter.R

Node.js Core Benchmarks

This folder contains code and data used to measure performance of different Node.js implementations and different ways of writing JavaScript run by the built-in JavaScript engine.

For a detailed guide on how to write and run benchmarks in this directory, see the guide on benchmarks.

Table of Contents

Benchmark Directories

Directory Purpose
assert Benchmarks for the assert subsystem.
buffers Benchmarks for the buffer subsystem.
child_process Benchmarks for the child_process subsystem.
crypto Benchmarks for the crypto subsystem.
dgram Benchmarks for the dgram subsystem.
domain Benchmarks for the domain subsystem.
es Benchmarks for various new ECMAScript features and their pre-ES2015 counterparts.
events Benchmarks for the events subsystem.
fixtures Benchmarks fixtures used in various benchmarks throughout the benchmark suite.
fs Benchmarks for the fs subsystem.
http Benchmarks for the http subsystem.
http2 Benchmarks for the http2 subsystem.
misc Miscellaneous benchmarks and benchmarks for shared internal modules.
module Benchmarks for the module subsystem.
net Benchmarks for the net subsystem.
path Benchmarks for the path subsystem.
perf_hooks Benchmarks for the perf_hooks subsystem.
process Benchmarks for the process subsystem.
querystring Benchmarks for the querystring subsystem.
streams Benchmarks for the streams subsystem.
string_decoder Benchmarks for the string_decoder subsystem.
timers Benchmarks for the timers subsystem, including setTimeout, setInterval, .etc.
tls Benchmarks for the tls subsystem.
url Benchmarks for the url subsystem, including the legacy url implementation and the WHATWG URL implementation.
util Benchmarks for the util subsystem.
vm Benchmarks for the vm subsystem.

Other Top-level files

The top-level files include common dependencies of the benchmarks and the tools for launching benchmarks and visualizing their output. The actual benchmark scripts should be placed in their corresponding directories.

  • _benchmark_progress.js: implements the progress bar displayed when running compare.js
  • _cli.js: parses the command line arguments passed to compare.js, run.js and scatter.js
  • _cli.R: parses the command line arguments passed to compare.R
  • _http-benchmarkers.js: selects and runs external tools for benchmarking the http subsystem.
  • common.js: see Common API.
  • compare.js: command line tool for comparing performance between different Node.js binaries.
  • compare.R: R script for statistically analyzing the output of compare.js
  • run.js: command line tool for running individual benchmark suite(s).
  • scatter.js: command line tool for comparing the performance between different parameters in benchmark configurations, for example to analyze the time complexity.
  • scatter.R: R script for visualizing the output of scatter.js with scatter plots.

Common API

The common.js module is used by benchmarks for consistency across repeated tasks. It has a number of helpful functions and properties to help with writing benchmarks.

createBenchmark(fn, configs[, options])

See the guide on writing benchmarks.

default_http_benchmarker

The default benchmarker used to run HTTP benchmarks. See the guide on writing HTTP benchmarks.

PORT

The default port used to run HTTP benchmarks. See the guide on writing HTTP benchmarks.

sendResult(data)

Used in special benchmarks that can't use createBenchmark and the object it returns to accomplish what they need. This function reports timing data to the parent process (usually created by running compare.js, run.js or scatter.js).