4.0.0 Release Notes

[antiochp]

tl;dr

• New Cuckarooz PoW and header version 4 for latest hardfork.
• TUI optimizations and overal code improvements
• Server and backend DB code optimizations and improvements
• BlockHeader via API now includes all relevant fields (including MMR size)
• Feature flagged NRD kernel support (enabled in floonet, remains disabled in mainnet)

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Highlights (non-exhaustive) from PRs included since 3.1.1 -

• header version 4 accompanied by new AR PoW (https://github.com/mimblewimble/grin/pull/3334)
• Enable NRD kernel support (noop) feature flagged (https://github.com/mimblewimble/grin/pull/3303)
• Some optimizsations in TUI (https://github.com/mimblewimble/grin/pull/3325)
• Reduce memory allocations in PMMR (https://github.com/mimblewimble/grin/pull/3328)
• Adding kernel_mmr_size and output_mmr_size to BlockHeaderPrintable (https://github.com/mimblewimble/grin/pull/3329)
• Fix miminum share difficulty in Stratum Server (https://github.com/mimblewimble/grin/pull/3323)
• Always return a typed structure from lmdb store (https://github.com/mimblewimble/grin/pull/3312)
• Use generic types instead of trait objects in tx pool (https://github.com/mimblewimble/grin/pull/3308)
• Reduce number of allocations in Headers message read (https://github.com/mimblewimble/grin/pull/3301)
• Update Cursive to 0.14 and update backend (https://github.com/mimblewimble/grin/pull/3291)
• go back to storing header_head in the db (https://github.com/mimblewimble/grin/pull/3268)
• Use croaring-mw with 'compat' feature (https://github.com/mimblewimble/grin/pull/3274)
• Add better LMDB error output (https://github.com/mimblewimble/grin/pull/3263)