fs: add c++ fast path for writeFileSync string utf8

[CanadaHonk]

Summary

Added fast path in almost entirely C++ for writeFileSync with UTF8 encoding and string data. Also improves appendFileSync as it just uses writeFileSync under the hood. Only string data as Buffer seems questionable in benchmarks for this so I'll just leave it for strings for now.

TL;DR: This makes writeFileSync(path, data: string) UTF8 up to ~2.5x faster depending on data size, especially when using file descriptors

Bench results

Benchmark in this PR

Note: running locally on Linux/i9/SSD

                                                                                                                 confidence improvement accuracy (*)   (**)  (***)
fs/bench-writeFileSync.js n=1000 func='writeFile' useBuffer='false' length=1024 useFd='false' encoding='utf8'                   -0.37 %       ±4.40% ±5.90% ±7.77%
fs/bench-writeFileSync.js n=1000 func='writeFile' useBuffer='false' length=1024 useFd='true' encoding='utf8'            ***     49.15 %       ±5.11% ±6.82% ±8.91%
fs/bench-writeFileSync.js n=1000 func='writeFile' useBuffer='false' length=102400 useFd='false' encoding='utf8'         ***      6.69 %       ±1.67% ±2.22% ±2.89%
fs/bench-writeFileSync.js n=1000 func='writeFile' useBuffer='false' length=102400 useFd='true' encoding='utf8'          ***     74.52 %       ±4.35% ±5.85% ±7.74%
fs/bench-writeFileSync.js n=1000 func='writeFile' useBuffer='false' length=1048576 useFd='false' encoding='utf8'        ***     16.05 %       ±1.60% ±2.14% ±2.81%
fs/bench-writeFileSync.js n=1000 func='writeFile' useBuffer='false' length=1048576 useFd='true' encoding='utf8'         ***     85.82 %       ±3.58% ±4.77% ±6.23%

Benchmark CI (old): https://ci.nodejs.org/view/Node.js%20benchmark/job/benchmark-node-micro-benchmarks/1421/

Alternative benchmark

Alternative benchmark using Bun's bench for fs.copyFileSync (string data, using paths)

Current (main)

benchmark           time (avg)             (min … max)       p75       p99      p995
------------------------------------------------------ -----------------------------
12 ascii          2.19 µs/iter     (2.07 µs … 2.67 µs)   2.21 µs   2.67 µs   2.67 µs
12 utf8           2.23 µs/iter     (2.08 µs … 2.32 µs)   2.26 µs   2.32 µs   2.32 µs
12288 ascii       6.14 µs/iter     (5.97 µs … 6.62 µs)   6.14 µs   6.62 µs   6.62 µs
18432 utf8       40.02 µs/iter  (36.13 µs … 204.16 µs)  40.05 µs   63.6 µs  69.01 µs

This PR

Long ascii: 6.14µs -> 3.46µs (~1.8x speedup)
Long utf8: 40.02µs -> 18.25µs (~2.2x speedup)

benchmark           time (avg)             (min … max)       p75       p99      p995
------------------------------------------------------ -----------------------------
12 ascii          1.97 µs/iter      (1.9 µs … 2.03 µs)   1.98 µs   2.03 µs   2.03 µs
12 utf8           1.95 µs/iter        (1.91 µs … 2 µs)   1.97 µs      2 µs      2 µs
12288 ascii       3.46 µs/iter      (3.39 µs … 3.6 µs)   3.47 µs    3.6 µs    3.6 µs
18432 utf8       18.25 µs/iter  (16.06 µs … 147.95 µs)  18.48 µs  21.77 µs  24.03 µs

[github-actions]

The notable-change PRs with changes that should be highlighted in changelogs. label has been added by @anonrig.

Please suggest a text for the release notes if you'd like to include a more detailed summary, then proceed to update the PR description with the text or a link to the notable change suggested text comment.

[CanadaHonk]

Rebased on latest main and addressed various review comments. Should be good for review fully now.

[anonrig]

Benchmark CI: https://ci.nodejs.org/view/Node.js%20benchmark/job/benchmark-node-micro-benchmarks/1421/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/54266/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/54269/

[CanadaHonk]

@santigimeno and/or @bnoordhuis, would you mind checking/reviewing the latest revision? Uses a write loop like original JS source now. Thanks!

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/55876/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/55913/

[CanadaHonk]

Rebased on latest main (+ poking flaky GH CI)

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/55928/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/55930/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/55940/

[nodejs-github-bot]

Landed in 4466dee

[RafaelGSS]

@CanadaHonk Do you have benchmark results from our CI? I don't we should mention local benchmarks in the changelog.

[CanadaHonk]

@RafaelGSS Not any recent/existing :p

[jeremymeng]

Some of our tests using writeFileSync are now broken in 21.3.0 #50989

Is this related?

[ChALkeR]

Was flush option considered here?
This landed after #50009

[ChALkeR]

base64 writes are also a thing, as it covers binary writes when content is already in base64
and could also be optimized via a fast path (e.g. by adding an encoding parameter here)

7113870	selenium-webdriver-4.38.0.tgz/lib/webdriver.js:1742:    fs.writeFileSync(zipFilePath, Buffer.from(base64Content, 'base64'))
1563070	cucumber-html-reporter-7.2.0.tgz/lib/reporter.js:320:                  fs.writeFileSync(filename, embedding.data, 'base64');
1563070	cucumber-html-reporter-7.2.0.tgz/lib/reporter.js:334:                  fs.writeFileSync(filename, embedding.data, 'base64');
313200	@loki/diff-looks-same-0.35.0.tgz/src/create-looks-same-differ.spec.js:13:  fs.writeFileSync(outputPath, imageData, { encoding: 'base64' });
307699	@loki/diff-pixelmatch-0.35.0.tgz/src/create-pixelmatch-differ.spec.js:13:  fs.writeFileSync(outputPath, imageData, { encoding: 'base64' });
204239	backstopjs-6.3.25.tgz/core/util/compare/store-failed-diff-stub.js:10:  fs.writeFileSync(getFailedDiffFilename(testPath), BASE64_PNG_STUB, 'base64');
195127	vscode-extension-tester-8.19.0.tgz/out/browser.js:233:        fs.writeFileSync(path.join(dir, `${name}.png`), data, 'base64');
82614	base64-img-1.0.4.tgz/base64-img.js:113:  fs.writeFileSync(filepath, result.base64, { encoding: 'base64' });
74527	remove.bg-1.3.0.tgz/index.js:77:                fs.writeFileSync(options.outputFile, result.body.data.result_b64, { encoding: "base64" });
73121	pxt-core-12.2.3.tgz/built/cli.js:2936:            nodeutil.writeFileSync(p, contents, { encoding: "base64" });
73121	pxt-core-12.2.3.tgz/built/pxt.js:165454:            nodeutil.writeFileSync(p, contents, { encoding: "base64" });
...

Left column is downloads/month

selenium-webdriver needs a fix though: SeleniumHQ/selenium#16542