Fjord: Add FastLZ compression into L1CostFunc#249
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sebastianst merged 13 commits intoethereum-optimism:optimismfrom May 15, 2024
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Fjord: Add FastLZ compression into L1CostFunc#249sebastianst merged 13 commits intoethereum-optimism:optimismfrom
sebastianst merged 13 commits intoethereum-optimism:optimismfrom
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Generally looks good. FlzCompressLen is difficult to review in isolation, but the tests in the monorepo for it look good. Still looking into the differences with Brotli.
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Co-authored-by: Michael de Hoog <michael.dehoog@coinbase.com> Co-authored-by: Yukai Tu <yukai.tu@coinbase.com> Co-authored-by: Danyal Prout <danyal.prout@coinbase.com>
…e same hardfork block
Co-authored-by: Sebastian Stammler <stammler.s@gmail.com>
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Description
We found that the FastLZ algorithm is a pretty good estimate for the actual results we'd see from zlib compressing the batches we write to L1 (albeit with a different
scalaras the compression ratios aren't quite as good). See https://github.com/roberto-bayardo/compression-analysis and this sheet.This PR introduces a
flzCompresscall into theDataGaspart of theL1CostFunc. CompanionoptimismPR is here: ethereum-optimism/optimism#9618Tests
TODO
Additional context
The current naive L1Cost approach:
works pretty well on average, but penalizes very compressible txs (e.g.), and undercharges incompressible txs (e.g.). This change makes the
L1CostFuncmuch fairer compared to real-world L1 costs.