1ba88a7892
Fixes https://github.com/denoland/deno/issues/24323 - Use a Buffer pool for `fromString` - Implement fast call base64 writes - Direct from string `create` method for each encoding op ``` $ deno bench -A bench.mjs # 1.45.1+fee4d3a cpu: Apple M1 Pro runtime: deno 1.45.1+fee4d3a (aarch64-apple-darwin) benchmark time (avg) (min … max) p75 p99 p999 ----------------------------------------------------------- ----------------------------- Buffer.from base64 550 ns/iter (490 ns … 1'265 ns) 572 ns 606 ns 1'265 ns Buffer#write base64 285 ns/iter (259 ns … 371 ns) 307 ns 347 ns 360 ns $ ~/gh/deno/target/release/deno bench -A bench.mjs # this PR cpu: Apple M1 Pro runtime: deno dev (aarch64-apple-darwin) benchmark time (avg) (min … max) p75 p99 p999 ----------------------------------------------------------- ----------------------------- Buffer.from base64 151 ns/iter (145 ns … 770 ns) 148 ns 184 ns 648 ns Buffer#write base64 62.58 ns/iter (60.79 ns … 157 ns) 61.65 ns 75.79 ns 141 ns $ node bench.mjs # v22.4.0 cpu: Apple M1 Pro runtime: node v22.4.0 (arm64-darwin) benchmark time (avg) (min … max) p75 p99 p999 ----------------------------------------------------------- ----------------------------- Buffer.from base64 163 ns/iter (96.92 ns … 375 ns) 99.45 ns 127 ns 220 ns Buffer#write base64 75.48 ns/iter (74.97 ns … 134 ns) 75.17 ns 81.83 ns 96.84 ns ``` |
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.. | ||
_fs | ||
_process | ||
_util | ||
assert | ||
dns | ||
fs | ||
internal | ||
internal_binding | ||
path | ||
readline | ||
stream | ||
timers | ||
util | ||
00_globals.js | ||
01_require.js | ||
02_init.js | ||
_brotli.js | ||
_events.d.ts | ||
_events.mjs | ||
_global.d.ts | ||
_http_agent.mjs | ||
_http_common.ts | ||
_http_outgoing.ts | ||
_next_tick.ts | ||
_readline.d.ts | ||
_readline.mjs | ||
_readline_shared_types.d.ts | ||
_stream.d.ts | ||
_stream.mjs | ||
_tls_common.ts | ||
_tls_wrap.ts | ||
_utils.ts | ||
_zlib.mjs | ||
_zlib_binding.mjs | ||
assert.ts | ||
assertion_error.ts | ||
async_hooks.ts | ||
buffer.ts | ||
child_process.ts | ||
cluster.ts | ||
console.ts | ||
constants.ts | ||
crypto.ts | ||
dgram.ts | ||
diagnostics_channel.js | ||
dns.ts | ||
domain.ts | ||
events.ts | ||
fs.ts | ||
http.ts | ||
http2.ts | ||
https.ts | ||
inspector.ts | ||
net.ts | ||
os.ts | ||
path.ts | ||
perf_hooks.ts | ||
process.ts | ||
punycode.ts | ||
querystring.js | ||
readline.ts | ||
README.md | ||
repl.ts | ||
stream.ts | ||
string_decoder.ts | ||
sys.ts | ||
testing.ts | ||
timers.ts | ||
tls.ts | ||
tty.js | ||
url.ts | ||
util.ts | ||
v8.ts | ||
vm.ts | ||
wasi.ts | ||
worker_threads.ts | ||
zlib.ts |
Deno Node.js compatibility
This module is meant to have a compatibility layer for the Node.js standard library.
Warning: Any function of this module should not be referred anywhere in the Deno standard library as it's a compatibility module.
Supported modules
- assert
- assert/strict partly
- async_hooks partly
- buffer
- child_process partly
- cluster partly
- console partly
- constants partly
- crypto partly
- dgram partly
- diagnostics_channel partly
- dns partly
- events
- fs partly
- fs/promises partly
- http partly
- http2
- https partly
- inspector partly
- module
- net
- os partly
- path
- path/posix
- path/win32
- perf_hooks
- process partly
- punycode
- querystring
- readline
- repl partly
- stream
- stream/promises
- stream/web partly
- string_decoder
- sys
- timers
- timers/promises
- tls
- trace_events
- tty partly
- url
- util partly
- util/types partly
- v8
- vm partly
- wasi
- webcrypto
- worker_threads
- zlib
- node globals partly
Deprecated
These modules are deprecated in Node.js and will probably not be polyfilled:
- domain
- freelist
Experimental
These modules are experimental in Node.js and will not be polyfilled until they are stable:
- diagnostics_channel
- async_hooks
- policies
- trace_events
- wasi
- webcrypto
CommonJS modules loading
createRequire(...)
is provided to create a require
function for loading CJS
modules. It also sets supported globals.
import { createRequire } from "node:module";
const require = createRequire(import.meta.url);
// Loads native module polyfill.
const path = require("path");
// Loads extensionless module.
const cjsModule = require("./my_mod");
// Visits node_modules.
const leftPad = require("left-pad");
Contributing
Setting up the test runner and running tests
See tests/node_compat/runner/README.md.
Best practices
When converting from promise-based to callback-based APIs, the most obvious way is like this:
promise.then((value) => callback(null, value)).catch(callback);
This has a subtle bug - if the callback throws an error, the catch statement will also catch that error, and the callback will be called twice. The correct way to do it is like this:
promise.then((value) => callback(null, value), callback);
The second parameter of then
can also be used to catch errors, but only errors
from the existing promise, not the new one created by the callback.
If the Deno equivalent is actually synchronous, there's a similar problem with try/catch statements:
try {
const value = process();
callback(null, value);
} catch (err) {
callback(err);
}
Since the callback is called within the try
block, any errors from it will be
caught and call the callback again.
The correct way to do it is like this:
let err, value;
try {
value = process();
} catch (e) {
err = e;
}
if (err) {
callback(err); // Make sure arguments.length === 1
} else {
callback(null, value);
}
It's not as clean, but prevents the callback being called twice.
Remaining Tests
Node compatibility can be measured by how many native Node tests pass. If you'd like to know what you can work on, check out the list of Node tests remaining here.