feat: implement custom consensus for Rollkit to allow same timestamps#19
feat: implement custom consensus for Rollkit to allow same timestamps#19tac0turtle merged 7 commits intomainfrom
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This implements a custom consensus wrapper that allows multiple blocks to have the same timestamp, which is required for Rollkit's operation. The key changes: - Add RollkitConsensus that wraps EthBeaconConsensus - Override validate_header_against_parent to allow header.timestamp >= parent.timestamp - Integrate with node builder using RollkitConsensusBuilder - Add comprehensive unit tests for timestamp validation This addresses issue #15 where Rollkit needs to submit multiple blocks with the same timestamp. 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>
WalkthroughA custom consensus mechanism, Changes
Sequence Diagram(s)sequenceDiagram
participant Node
participant RollkitConsensusBuilder
participant RollkitConsensus
participant EthBeaconConsensus
Node->>RollkitConsensusBuilder: build_consensus()
RollkitConsensusBuilder->>RollkitConsensus: new(chain_spec)
RollkitConsensus->>EthBeaconConsensus: delegate validation (except timestamp)
RollkitConsensus->>RollkitConsensus: custom timestamp validation
RollkitConsensus-->>Node: consensus instance with custom logic
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Summary of Changes
Hello @tac0turtle, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!
This pull request introduces a specialized consensus mechanism tailored for Rollkit, enabling the creation of blocks with identical timestamps to their predecessors. This change is crucial for Rollkit's architecture, ensuring compatibility and proper block validation within its unique operational context. The implementation involves wrapping the existing Ethereum consensus and selectively modifying timestamp validation rules, along with integrating this custom logic into the node's build process.
Highlights
- Custom Consensus Implementation: Introduced
RollkitConsensus, a new consensus wrapper aroundEthBeaconConsensus, specifically designed to meet Rollkit's operational requirements. - Timestamp Validation Modification: Overrode the
validate_header_against_parentmethod withinRollkitConsensusto allow blocks to have a timestamp equal to or greater than their parent block's timestamp (header.timestamp >= parent.timestamp). This is a key deviation from standard Ethereum consensus, which requiresheader.timestamp > parent.timestamp. - Node Integration: Integrated the new custom consensus into the
lumennode by introducingRollkitConsensusBuilderand configuring the node to use this builder instead of the default Ethereum consensus builder. - Comprehensive Unit Tests: Added a new test suite (
consensus_tests.rs) to thoroughly validate theRollkitConsensusimplementation, specifically confirming that same timestamps are allowed while other critical consensus rules (like parent hash and block number validation) are still enforced.
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Code Review
This pull request introduces a custom consensus engine for Rollkit to allow blocks with identical timestamps. I've identified a critical issue in the consensus validation logic that bypasses important checks when timestamps are equal, and provided a suggestion for a more robust implementation. Additionally, I've pointed out some redundant code and suggested improvements to the test suite.
| fn validate_header_against_parent( | ||
| &self, | ||
| header: &SealedHeader, | ||
| parent: &SealedHeader, | ||
| ) -> Result<(), ConsensusError> { | ||
| // Custom validation that allows same timestamps | ||
| // This is the key difference from standard Ethereum consensus | ||
|
|
||
| // First validate parent hash and number | ||
| if header.parent_hash != parent.hash() { | ||
| return Err(ConsensusError::ParentHashMismatch(GotExpectedBoxed( | ||
| Box::new(GotExpected { | ||
| got: header.parent_hash, | ||
| expected: parent.hash(), | ||
| }), | ||
| ))); | ||
| } | ||
|
|
||
| if header.number != parent.number + 1 { | ||
| return Err(ConsensusError::ParentBlockNumberMismatch { | ||
| parent_block_number: parent.number, | ||
| block_number: header.number, | ||
| }); | ||
| } | ||
|
|
||
| // ROLLKIT MODIFICATION: Allow same timestamp | ||
| // Standard Ethereum requires: header.timestamp > parent.timestamp | ||
| // Rollkit allows: header.timestamp >= parent.timestamp | ||
| if header.timestamp < parent.timestamp { | ||
| return Err(ConsensusError::TimestampIsInPast { | ||
| parent_timestamp: parent.timestamp, | ||
| timestamp: header.timestamp, | ||
| }); | ||
| } | ||
| // NOTE: We explicitly do NOT check for header.timestamp == parent.timestamp | ||
| // as an error, which is the main change for Rollkit | ||
|
|
||
| // For all other validations, delegate to the inner consensus | ||
| // but skip it when timestamps are equal since the inner consensus | ||
| // would reject this case | ||
| if header.timestamp == parent.timestamp { | ||
| // Timestamps are equal, which we explicitly allow for Rollkit | ||
| // Skip the inner consensus validation that would reject this | ||
| Ok(()) | ||
| } else { | ||
| // Timestamps are different, so we can safely delegate to inner consensus | ||
| self.inner.validate_header_against_parent(header, parent) | ||
| } | ||
| } |
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The current implementation of validate_header_against_parent returns Ok(()) without performing other essential header validations when header.timestamp == parent.timestamp. This would allow invalid blocks to be accepted by the consensus. The logic should be refactored to ensure all validations are performed, only altering the timestamp check.
fn validate_header_against_parent(
&self,
header: &SealedHeader,
parent: &SealedHeader,
) -> Result<(), ConsensusError> {
match self.inner.validate_header_against_parent(header, parent) {
Ok(()) => Ok(()),
Err(ConsensusError::TimestampNotStrictlyIncreasing { .. }) => {
if header.timestamp == parent.timestamp {
Ok(())
} else {
Err(ConsensusError::TimestampIsInPast {
parent_timestamp: parent.timestamp,
timestamp: header.timestamp,
})
}
}
Err(e) => Err(e),
}
}
<!-- Please read and fill out this form before submitting your PR. Please make sure you have reviewed our contributors guide before submitting your first PR. NOTE: PR titles should follow semantic commits: https://www.conventionalcommits.org/en/v1.0.0/ --> ## Overview This pr removes the +1 timestamp in order to avoid clock drift between lumen and rollkit. closes #2464 based off of work from evstack/ev-reth#19 <!-- This is an auto-generated comment: release notes by coderabbit.ai --> ## Summary by CodeRabbit * **Refactor** * Simplified block timestamp handling to use the current block's timestamp directly, removing previous logic that enforced strictly increasing timestamps between blocks. <!-- end of auto-generated comment: release notes by coderabbit.ai --> Co-authored-by: tac0turtle <you@example.com>
2 participants
This implements a custom consensus wrapper that allows multiple blocks to have the same timestamp, which is required for Rollkit's operation.
The key changes:
This addresses issue #15 where Rollkit needs to submit multiple blocks with the same timestamp.
🤖 Generated with Claude Code
Summary by CodeRabbit
New Features
Documentation
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