Uint8Array to UTF8 conversion

[anonrig]

I see that undici is mostly using Buffer.from(name).toString('utf8'). This crosses the JS-C++ boundary 2 times. 1 for initializing, and 1 for toString.

I recommend implementing a function like this:

• Buffer.asString(name, encoding) which returns string
• Buffer.asStrings([first, second], encoding) which returns string[]

[mcollina]

Sure thing, let's do it!

[anonrig]

Here's the current state of TextDecoder in main branch.

➜  node-test git:(main) ✗ npm run text-decoder

> [email protected] text-decoder
> ~/Developer/node/out/Release/node ./text-decoder/index.mjs && bun run ./text-decoder/index.mjs && deno run -A ./text-decoder/deno.js

cpu: Apple M1 Max
runtime: node v20.0.0-pre (arm64-darwin)

benchmark       time (avg)             (min … max)       p75       p99      p995
-------------------------------------------------- -----------------------------
smallUint8  308.17 ns/iter  (298.6 ns … 336.38 ns) 308.96 ns 335.55 ns 336.38 ns
bigUint8       2.6 µs/iter      (2.57 µs … 2.7 µs)   2.61 µs    2.7 µs    2.7 µs
cpu: Apple M1 Max
runtime: bun 0.2.2 (arm64-darwin)

benchmark       time (avg)             (min … max)       p75       p99      p995
-------------------------------------------------- -----------------------------
smallUint8  212.16 ns/iter (197.05 ns … 441.18 ns) 212.43 ns  224.1 ns  238.8 ns
bigUint8      1.14 µs/iter     (1.05 µs … 1.27 µs)   1.18 µs   1.27 µs   1.27 µs
cpu: Apple M1 Max
runtime: deno 1.27.2 (aarch64-apple-darwin)

benchmark       time (avg)             (min … max)       p75       p99      p995
-------------------------------------------------- -----------------------------
smallUint8  466.08 ns/iter (444.89 ns … 481.87 ns) 469.58 ns 481.26 ns 481.87 ns
bigUint8      3.76 µs/iter     (3.72 µs … 3.82 µs)   3.77 µs   3.82 µs   3.82 µs

[ronag]

Do you have a benchmark comparing it to Buffer.toString?

[anonrig]

I did run yesterday: https://twitter.com/yagiznizipli/status/1592002375572942848?s=61&t=dl_-MRHDHZ6ui5f3LwG5yg

[ronag]

Do you have a link to the benchmark code?

[ronag]

Also do you compare buf.toString() vs TextEncoder.encode(buf), i.e. excluding the Buffer.from overhead?

[anonrig]

Also do you compare buf.toString() vs TextEncoder.encode(buf), i.e. excluding the Buffer.from overhead?

Here's the full benchmark: https:/anonrig/node-benchmarks/blob/main/text-encoder/index.mjs

[anonrig]

I'm closing now, since the text decoder is much more performant right now for utf-8.