feat(primitives): decoding with signer lookups

[thedevbirb]

📝 Summary

Modifies the rbuilder-primitives crate so that it is possible to decode bundles specifying a signer lookup, to save on signature recovery compute.

💡 Motivation and Context

Most bundles received contain transactions already heard, as such we can reduce a lot of compute from the hot path.

Summary of the changes:

• RawBundle now feature a decode_with_signer_lookup that allows to specify a closure to check whether the signer is already known for a certain hash.
  • It calls an underlying RawBundle::decode_inner that takes this the closure as an Option.
• Inside RawBundle::decode_inner, an helper struct RawTransactionDecodable (naming can be improved) that contains the raw bytes, the TxEncoding and the optional signer lookup is used for decoding. Transaction decoding and recovering can't really be decoupled from bundle decoding because it's required for parsing refunds data.
• A RawBundleMetadata struct has been introduced to simplify a bit the code and for separation of concerns.

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✅ I have completed the following steps:

• Run make lint
• Run make test
• Added tests (if applicable)

[mempirate]

Initial pass

[Copilot]

Pull Request Overview

Enhances the rbuilder-primitives crate to support bundle decoding with signer lookups, allowing reuse of known transaction signers to reduce signature recovery computation in the hot path.

• Adds decode_with_signer_lookup method to RawBundle for specifying signer lookup closures
• Introduces RawTransactionDecodable struct to handle transaction decoding with optional signer lookup
• Refactors RawBundle structure by extracting metadata into separate RawBundleMetadata struct

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
rust-toolchain.toml	Updates Rust toolchain configuration format
crates/rbuilder/src/live_builder/order_input/txpool_fetcher.rs	Updates transaction decoding to use new RawTransactionDecodable API
crates/rbuilder/src/backtest/store.rs	Updates test code to use new RawBundleMetadata structure
crates/rbuilder/src/backtest/results_store.rs	Refactors slice creation for consistency
crates/rbuilder/src/backtest/backtest_build_range.rs	Refactors slice creation for consistency
crates/rbuilder-primitives/src/serialize.rs	Implements core signer lookup functionality and bundle metadata refactoring
crates/rbuilder-primitives/src/lib.rs	Adds RawTransactionDecodable struct and related transaction decoding improvements

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[efbig]

lgtm

[mempirate]

lgtm