basenc: buffer base16 encoded output

[myunbin]

Base16 encoding currently writes output in small chunks(~2 KiB).
Buffer these writes with a 32 KiB BufWriter to reduce the number of write system calls.

Output	Before	After
/dev/null	12.049 ms	11.048 ms (-8.3%)
Regular file	25.853 ms	20.406 ms (-21.1%)

[codspeed-hq]

Merging this PR will degrade performance by 31.56%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 1 improved benchmark
❌ 5 regressed benchmarks
✅ 341 untouched benchmarks
🆕 10 new benchmarks
⏩ 46 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Memory	b64_decode_ignore_garbage_synthetic	12.1 KB	36.1 KB	-66.46%
❌	Memory	b64_decode_synthetic	12.1 KB	36.1 KB	-66.46%
❌	Simulation	du_max_depth_balanced_tree[(6, 4, 10)]	62.1 ms	65.2 ms	-4.75%
❌	Simulation	du_summarize_balanced_tree[(5, 4, 10)]	16 ms	16.7 ms	-4.23%
❌	Simulation	numfmt_large_numbers_si[10000]	94.7 ms	98.1 ms	-3.4%
⚡	Simulation	complex_relative_date	330.2 µs	318.6 µs	+3.65%
🆕	Memory	ptx_input_references_short_lines[100000]	N/A	222.2 MB	N/A
🆕	Memory	ptx_long_lines[100]	N/A	29.5 MB	N/A
🆕	Memory	ptx_short_lines[100000]	N/A	240.1 MB	N/A
🆕	Memory	ptx_input_references_long_lines[1000]	N/A	29.1 MB	N/A
🆕	Memory	ptx_tex[10000]	N/A	20.6 MB	N/A
🆕	Simulation	ptx_input_references_short_lines[100000]	N/A	16.2 s	N/A
🆕	Simulation	ptx_long_lines[100]	N/A	1.7 s	N/A
🆕	Simulation	ptx_short_lines[100000]	N/A	14 s	N/A
🆕	Simulation	ptx_input_references_long_lines[1000]	N/A	2.1 s	N/A
🆕	Simulation	ptx_tex[10000]	N/A	2.9 s	N/A

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing myunbin:basenc-bufwriter-32k (6196f97) with main (66cf72b)²}

Footnotes

1. 46 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on main (e6561b5) during the generation of this report, so 66cf72b was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[oech3]

Can we align DEFAULT_BUF_SIZE to same size too?

[myunbin]

Aligned DEFAULT_BUF_SIZE to 32 KiB as well. Thanks!

[sylvestre]

In a new pr, could you please add a new benchmark covering these cases? Thanks

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/cut/bounded-memory (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/date/resolution (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/symlink (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/dd/no-allocate is now passing!