Base64: Memory usage improvements

[mattsu2020]

Summary

Reworked base_common streaming so base64/basenc no longer slurp stdin into RAM; both encoder/decoder now read from any Read stream with bounded buffers, keep line-wrapping support, and reuse the SIMD wrapper.
Tightened the Base64SimdWrapper integration and added regression tests that cover streaming encode/decode behaviors plus chunked readers.
Fixed Clippy’s elidable lifetime warning and ensured Base58 handling no longer triggers gigantic buffer allocations.

Testing

cargo test -p uu_base32
cargo test -p uu_base64
cargo test -p uu_basenc
/usr/bin/time -l sh -c "cat benchmarks/bench_500mb.bin | /usr/bin/base64 > /dev/null" → max RSS 1.85 MB
/usr/bin/time -l sh -c "cat benchmarks/bench_500mb.bin | ./target/release/base64 > /dev/null" → max RSS 2.38 MB
/usr/bin/time -l sh -c "cat benchmarks/bench_500mb.b64 | /usr/bin/base64 -D > /dev/null" → max RSS 1.85 MB
/usr/bin/time -l sh -c "cat benchmarks/bench_500mb.b64 | ./target/release/base64 -d > /dev/null" → max RSS 2.33 MB

[sylvestre]

i wonder how we could check that in the CI to make sure we don't regress

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)

[sylvestre]

sorry, small conflict

[codspeed-hq]

CodSpeed Performance Report

Merging #9215 will not alter performance

_{Comparing mattsu2020:base64_performance (9170955) with main (a4701f4)}

Summary

✅ 127 untouched
⏩ 6 skipped¹

Footnotes

1. 6 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. ↩

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/tail/overlay-headers (passes in this run but fails in the 'main' branch)

[mattsu2020]

#9213

[sylvestre]

given that codspeed didn't detect performance improvement, i guess it is "only" memory usage, no?

[mattsu2020]

given that codspeed didn't detect performance improvement, i guess it is "only" memory usage, no?

Performance remains unchanged while reducing memory usage, so codespeed shows nothing.

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/tail/overlay-headers (passes in this run but fails in the 'main' branch)

[sylvestre]

so, the PR name should be updated, thanks!

[sylvestre]

dedup the code from line 487

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/cksum/cksum-c is no longer failing!

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/printf/printf-surprise is now passing!
Note: The gnu test tests/dd/no-allocate was skipped on 'main' but is now failing.
Note: The gnu test tests/misc/write-errors was skipped on 'main' but is now failing.

[sylvestre]

I think there is a mistake :)

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/timeout/timeout (fails in this run but passes in the 'main' branch)