[storage/bmt] Add multi-proof support

[clabby]

Overview

Adds multi-proof support to storage::bmt.

This PR also breaks the API of the MMR Proof's Read impl - the Read::Cfg is now the max number of items, rather than the max number of digests in the proof. The upper bound is inferred.

closes #2221
closes #2506

zoda::encode

mmr -> bmt, large change in perf.

zoda::encode/msg_len=1048576 chunks=50 conc=1
                        time:   [34.751 ms 35.043 ms 35.257 ms]
                        change: [−14.404% −13.989% −13.572%] (p = 0.00 < 0.05)
                        Performance has improved.

zoda::encode/msg_len=1048576 chunks=50 conc=4
                        time:   [21.227 ms 21.269 ms 21.304 ms]
                        change: [−30.137% −29.321% −28.654%] (p = 0.00 < 0.05)
                        Performance has improved.

zoda::encode/msg_len=1048576 chunks=50 conc=8
                        time:   [19.397 ms 19.447 ms 19.499 ms]
                        change: [−31.636% −31.395% −31.165%] (p = 0.00 < 0.05)
                        Performance has improved.

reed_solomon::encode

Still using bmt, now forced to use the multi-proof path. No significant change in perf.

reed_solomon::encode/msg_len=1048576 chunks=50 conc=1
                        time:   [6.2472 ms 6.2612 ms 6.2816 ms]
                        change: [+0.0229% +0.5795% +1.0971%] (p = 0.07 > 0.05)
                        No change in performance detected.

reed_solomon::encode/msg_len=1048576 chunks=50 conc=4
                        time:   [2.0799 ms 2.0854 ms 2.0896 ms]
                        change: [+0.6271% +1.0928% +1.5377%] (p = 0.00 < 0.05)
                        Change within noise threshold.

reed_solomon::encode/msg_len=1048576 chunks=50 conc=8
                        time:   [1.4275 ms 1.4370 ms 1.4451 ms]
                        change: [+0.1988% +0.9165% +1.6285%] (p = 0.03 < 0.05)
                        Change within noise threshold.

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[patrick-ogrady]

I think we're using NonZeroRange now? forgot

[danlaine]

Chunk could also be parameterized on D: Digest and verify updated to take in a &mut Hasher like the proof verify methods. If we decide to do that, I think it's fine to defer to a future PR to keep this diff smaller.

[clabby]

Let's do that in a follow-up - #2753

[danlaine]

It seems we always call this with leaf_count > 0 -- should we make the 0 case unreachable! instead of returning 1? Not a big deal either way but I was a bit surprised that levels_in_tree(0) == 1.

[clabby]

Rationale for levels_in_tree(0) == 1 is that a tree with 0 leaves does still have a root. I think we should probably keep all leaf_counts valid inputs for that reason

[codecov]

Codecov Report

❌ Patch coverage is 97.05240% with 27 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.22%. Comparing base (5ca1fb0) to head (9d9c468).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
storage/src/bmt/mod.rs	97.58%	20 Missing ⚠️
storage/src/mmr/proof.rs	87.27%	7 Missing ⚠️

@@            Coverage Diff             @@
##             main    #2733      +/-   ##
==========================================
+ Coverage   93.20%   93.22%   +0.02%     
==========================================
  Files         372      372              
  Lines      113359   114143     +784     
==========================================
+ Hits       105655   106413     +758     
- Misses       7704     7730      +26     

Files with missing lines	Coverage Δ
coding/src/reed_solomon.rs	97.39% <100.00%> (ø)
coding/src/zoda.rs	94.68% <100.00%> (+0.05%)	⬆️
storage/src/mmr/proof.rs	94.82% <87.27%> (-0.38%)	⬇️
storage/src/bmt/mod.rs	97.68% <97.58%> (-0.01%)	⬇️

... and 1 file with indirect coverage changes

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