bench: replace embedded raw block with configurable block generator #32554

1. 
   l0rinc commented at 9:39 pm on May 18, 2025: contributor

   Problem

   The hardcoded benchmark block 413567 has several issues:

   • embeds 1.1MB of binary data in the repository
   • mined in 2016, predates SegWit v0, Taproot, and modern script types
   • benchmarks cannot test different transaction patterns or script mixes
   • updating to a newer block (e.g., #32457) would still add binary bloat and would remain inflexible

   Fix

   Added configurable bench/block_generator.{h,cpp} that builds fully valid blocks at runtime providing blocks or raw serialized stream.

   Note that HexStrBench was simplified to work with random data - it doesn’t need to be block-related.

   ---

   This supersedes #32457 by eliminating the need for any hardcoded block data while enabling flexible benchmark scenarios.

2. 
   DrahtBot commented at 9:39 pm on May 18, 2025: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/32554.

   Reviews

   See the guideline for information on the review process.

   Type	Reviewers
   Concept ACK	laanwj, yuvicc, Raimo33

   If your review is incorrectly listed, please copy-paste <!–meta-tag:bot-skip–> into the comment that the bot should ignore.

   Conflicts

   Reviewers, this pull request conflicts with the following ones:

   • #34208 (bench: add fluent API for untimed setup steps in nanobench by l0rinc)
   • #32729 (test,refactor: extract script template helpers & widen sigop count coverage by l0rinc)
   • #31682 ([IBD] specialize CheckBlock’s input & coinbase checks by l0rinc)

   If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

3. 
   laanwj commented at 9:18 am on May 19, 2025: member

   Concept ACK
4. l0rinc marked this as ready for review on May 21, 2025
5. l0rinc renamed this:
   RFC: bench: replace embedded raw block with configurable block generator
   bench: replace embedded raw block with configurable block generator
   on May 21, 2025
6. DrahtBot added the label Tests on May 21, 2025
7. 
   yuvicc commented at 3:44 pm on June 29, 2025: contributor

   Concept ACK

   This one is pretty useful as I can test with up-to date test_data.

8. 
   Raimo33 commented at 2:37 pm on October 19, 2025: contributor

   Concept ACK for more realistic benchmarks
9. bench: replace hardcoded block with configurable generator

   Remove the bundled `block413567.raw` fixture and replace with runtime block generation via `bench/block_generator.{h,cpp}`.
   
   Expose `GetBlock()`/`GetBlockData()` with `ScriptRecipe` presets (`kLegacy`, `kWitness`) and deterministic seeding for reproducible benchmarks.

   0fbbefd017
10. l0rinc force-pushed on Dec 20, 2025
11. 
    l0rinc commented at 11:19 pm on December 20, 2025: contributor

    Rebased and applied the new block everywhere, removing the binary of block 413567 embedded in the benchmarks. Let me know what you think.

Contributors
l0rinc DrahtBot laanwj yuvicc Raimo33

Labels
Tests