perf: cache mined commitment for quorum merkle root calculation #6756

knst · 2025-07-15T08:18:34Z

Issue being fixed or feature implemented

Every time when list of quorum is changed, the quorum final commitments for multiple active quorums are re-read from database.
It's a heavy operation in a current implementation due to heavy database reading, heavy BLS deserialization and multiple in-memory copies.

What was done?

add cache for active quorums, see llmq::utils::InitQuorumsCache(qc_hashes_cached)
use RVO for GetMinedCommitment, avoid extra allocation by unique_ptr
adjust return value of GetLastMinedCommitmentsPerQuorumIndexUntilBlock to avoid extra data copies and transformations

How Has This Been Tested?

Time of calculation CheckCbTxMerkleRoots is shortened for 40%, and this step is a significant part of block validation.
Expected impact to total time for block validation and re-index is 3-4%.

develop:

[bench]             - CachedGetQcHashesQcIndexedHashes: 1.16ms [5.22s]
[bench]       - CheckCbTxMerkleRoots: 1.30ms [6.04s]

vs PR:

[bench]             - CachedGetQcHashesQcIndexedHashes: 1.20ms [2.65s]
[bench]       - CheckCbTxMerkleRoots: 1.34ms [3.44s]

Breaking Changes

N/A

Checklist:

I have performed a self-review of my own code
I have commented my code, particularly in hard-to-understand areas
I have added or updated relevant unit/integration/functional/e2e tests
I have made corresponding changes to the documentation
I have assigned this pull request to a milestone

coderabbitai · 2025-07-15T08:21:52Z

Walkthrough

This set of changes refactors and modernizes the handling of quorum commitments and their associated caches throughout the codebase. The main updates include changing the return type of GetMinedCommitment from a pointer with an output parameter to a structured std::pair containing the commitment and its block hash. Related methods that previously returned vectors of pairs now return vectors of block indices only, simplifying data flow. A new static LRU cache is introduced in CachedGetQcHashesQcIndexedHashes to optimize repeated serialization and quorum index extraction. Several functions are updated to use these new return types and caching mechanisms, and explicit template instantiations are added for the new cache type.

Estimated code review effort

3 (~45 minutes)

📜 Recent review details

Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between a2cc53c and eeb577b.

📒 Files selected for processing (7)

src/evo/cbtx.cpp (4 hunks)
src/evo/smldiff.cpp (2 hunks)
src/llmq/blockprocessor.cpp (4 hunks)
src/llmq/blockprocessor.h (1 hunks)
src/llmq/quorums.cpp (1 hunks)
src/llmq/snapshot.cpp (1 hunks)
src/llmq/utils.cpp (1 hunks)

📓 Path-based instructions (2)

src/**/*.{cpp,h,cc,cxx,hpp}

📄 CodeRabbit Inference Engine (CLAUDE.md)

src/**/*.{cpp,h,cc,cxx,hpp}: Dash Core C++ codebase must be written in C++20 and require at least Clang 16 or GCC 11.1
Dash uses unordered_lru_cache for efficient caching with LRU eviction

Files:

src/evo/smldiff.cpp

src/{masternode,evo}/**/*.{cpp,h,cc,cxx,hpp}

📄 CodeRabbit Inference Engine (CLAUDE.md)

Masternode lists must use immutable data structures (Immer library) for thread safety

Files:

src/evo/smldiff.cpp

🧠 Learnings (2)

📓 Common learnings

Learnt from: kwvg
PR: dashpay/dash#6543
File: src/wallet/receive.cpp:240-251
Timestamp: 2025-02-06T14:34:30.466Z
Learning: Pull request #6543 is focused on move-only changes and refactoring, specifically backporting from Bitcoin. Behavior changes should be proposed in separate PRs.

Learnt from: kwvg
PR: dashpay/dash#6718
File: test/functional/test_framework/test_framework.py:2102-2102
Timestamp: 2025-06-09T16:43:20.996Z
Learning: In the test framework consolidation PR (#6718), user kwvg prefers to limit functional changes to those directly related to MasternodeInfo, avoiding scope creep even for minor improvements like error handling consistency.

src/evo/smldiff.cpp (6)

Learnt from: CR
PR: dashpay/dash#0
File: CLAUDE.md:0-0
Timestamp: 2025-07-20T18:42:49.794Z
Learning: Applies to src/{masternode,evo}/**/*.{cpp,h,cc,cxx,hpp} : Masternode lists must use immutable data structures (Immer library) for thread safety

Learnt from: kwvg
PR: #6543
File: src/wallet/receive.cpp:240-251
Timestamp: 2025-02-06T14:34:30.466Z
Learning: Pull request #6543 is focused on move-only changes and refactoring, specifically backporting from Bitcoin. Behavior changes should be proposed in separate PRs.

Learnt from: knst
PR: #6511
File: src/evo/deterministicmns.cpp:1369-1373
Timestamp: 2025-01-07T18:50:44.838Z
Learning: The functions MigrateDBIfNeeded and MigrateDBIfNeeded2 in src/evo/deterministicmns.cpp are temporary and will be removed in a future version. Refactoring suggestions for these functions should be avoided.

Learnt from: kwvg
PR: #6718
File: test/functional/test_framework/test_framework.py:2102-2102
Timestamp: 2025-06-09T16:43:20.996Z
Learning: In the test framework consolidation PR (#6718), user kwvg prefers to limit functional changes to those directly related to MasternodeInfo, avoiding scope creep even for minor improvements like error handling consistency.

Learnt from: CR
PR: dashpay/dash#0
File: CLAUDE.md:0-0
Timestamp: 2025-07-20T18:42:49.794Z
Learning: Applies to src/evo/specialtx.h : Special transactions use payload extensions defined in src/evo/specialtx.h

Learnt from: kwvg
PR: #6665
File: src/evo/providertx.h:82-82
Timestamp: 2025-06-06T11:53:09.094Z
Learning: In ProTx serialization code (SERIALIZE_METHODS), version checks should use hardcoded maximum flags (/is_basic_scheme_active=/true, /is_extended_addr=/true) rather than deployment-based flags. This is because serialization code should be able to deserialize any structurally valid ProTx up to the maximum version the code knows how to handle, regardless of current consensus validity. Validation code, not serialization code, is responsible for checking whether a ProTx version is consensus-valid based on deployment status.

🚧 Files skipped from review as they are similar to previous changes (6)

src/llmq/quorums.cpp
src/llmq/blockprocessor.h
src/llmq/blockprocessor.cpp
src/llmq/utils.cpp
src/llmq/snapshot.cpp
src/evo/cbtx.cpp

🧰 Additional context used

📓 Path-based instructions (2)

src/**/*.{cpp,h,cc,cxx,hpp}

📄 CodeRabbit Inference Engine (CLAUDE.md)

src/**/*.{cpp,h,cc,cxx,hpp}: Dash Core C++ codebase must be written in C++20 and require at least Clang 16 or GCC 11.1
Dash uses unordered_lru_cache for efficient caching with LRU eviction

Files:

src/evo/smldiff.cpp

src/{masternode,evo}/**/*.{cpp,h,cc,cxx,hpp}

📄 CodeRabbit Inference Engine (CLAUDE.md)

Masternode lists must use immutable data structures (Immer library) for thread safety

Files:

src/evo/smldiff.cpp

🧠 Learnings (2)

📓 Common learnings

Learnt from: kwvg
PR: dashpay/dash#6543
File: src/wallet/receive.cpp:240-251
Timestamp: 2025-02-06T14:34:30.466Z
Learning: Pull request #6543 is focused on move-only changes and refactoring, specifically backporting from Bitcoin. Behavior changes should be proposed in separate PRs.

Learnt from: kwvg
PR: dashpay/dash#6718
File: test/functional/test_framework/test_framework.py:2102-2102
Timestamp: 2025-06-09T16:43:20.996Z
Learning: In the test framework consolidation PR (#6718), user kwvg prefers to limit functional changes to those directly related to MasternodeInfo, avoiding scope creep even for minor improvements like error handling consistency.

src/evo/smldiff.cpp (6)

Learnt from: CR
PR: dashpay/dash#0
File: CLAUDE.md:0-0
Timestamp: 2025-07-20T18:42:49.794Z
Learning: Applies to src/{masternode,evo}/**/*.{cpp,h,cc,cxx,hpp} : Masternode lists must use immutable data structures (Immer library) for thread safety

Learnt from: kwvg
PR: #6543
File: src/wallet/receive.cpp:240-251
Timestamp: 2025-02-06T14:34:30.466Z
Learning: Pull request #6543 is focused on move-only changes and refactoring, specifically backporting from Bitcoin. Behavior changes should be proposed in separate PRs.

Learnt from: knst
PR: #6511
File: src/evo/deterministicmns.cpp:1369-1373
Timestamp: 2025-01-07T18:50:44.838Z
Learning: The functions MigrateDBIfNeeded and MigrateDBIfNeeded2 in src/evo/deterministicmns.cpp are temporary and will be removed in a future version. Refactoring suggestions for these functions should be avoided.

Learnt from: kwvg
PR: #6718
File: test/functional/test_framework/test_framework.py:2102-2102
Timestamp: 2025-06-09T16:43:20.996Z
Learning: In the test framework consolidation PR (#6718), user kwvg prefers to limit functional changes to those directly related to MasternodeInfo, avoiding scope creep even for minor improvements like error handling consistency.

Learnt from: CR
PR: dashpay/dash#0
File: CLAUDE.md:0-0
Timestamp: 2025-07-20T18:42:49.794Z
Learning: Applies to src/evo/specialtx.h : Special transactions use payload extensions defined in src/evo/specialtx.h

Learnt from: kwvg
PR: #6665
File: src/evo/providertx.h:82-82
Timestamp: 2025-06-06T11:53:09.094Z
Learning: In ProTx serialization code (SERIALIZE_METHODS), version checks should use hardcoded maximum flags (/is_basic_scheme_active=/true, /is_extended_addr=/true) rather than deployment-based flags. This is because serialization code should be able to deserialize any structurally valid ProTx up to the maximum version the code knows how to handle, regardless of current consensus validity. Validation code, not serialization code, is responsible for checking whether a ProTx version is consensus-valid based on deployment status.

🔇 Additional comments (3)

src/evo/smldiff.cpp (3)

59-59: Excellent modernization using structured binding.

The change from pointer/output parameter to structured binding with std::pair return is a significant improvement:

Eliminates pointer null-checking complexities

Makes the return values explicit and type-safe

Uses modern C++17 structured binding syntax appropriately

60-63: Correct null check adaptation and efficient use of move semantics.

The changes properly adapt to the new return type:

Checking minedBlockHash == uint256::ZERO is the appropriate equivalent to the previous null pointer check

Using std::move(qc) avoids unnecessary copying of commitment objects, improving performance

Error handling logic is preserved correctly

25-26: Forward declaration signature confirmed correct

The forward declaration in src/evo/smldiff.cpp exactly matches the signature in:

src/llmq/utils.cpp

src/evo/cbtx.h

src/evo/cbtx.cpp

Removing the full include and using this forward declaration is safe. No further changes needed.

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github-actions · 2025-07-22T14:49:05Z

This pull request has conflicts, please rebase.

…terface

…lock and related code

… RVO CFinalCommitment is a heavy object to create and copy

…ommitment

github-actions · 2025-07-22T15:11:44Z

✅ No Merge Conflicts Detected

This PR currently has no conflicts with other open PRs.

knst added this to the 23 milestone Jul 15, 2025

github-actions bot mentioned this pull request Jul 19, 2025

perf: use cache for SML #6738

Merged

5 tasks

github-actions bot added the needs rebase label Jul 22, 2025

knst added 7 commits July 22, 2025 22:09

refactor: simplify GetLastMinedCommitmentsPerQuorumIndexUntilBlock in…

40f3d98

…terface

refactor: futher simplification of GetMinedAndActiveCommitmentsUntilB…

6d90189

…lock and related code

perf: replace re-creation of CFinalCommitment and extra unique_ptr to…

d78fb02

… RVO CFinalCommitment is a heavy object to create and copy

refactor: avoid code duplication due to 2 implementation of GetMinedC…

f2b2479

…ommitment

perf: cache mined commitment for quorum merkle root calculation

8958152

refactor: resolve freshly introduced circular dependency

8254e06

perf: swap arrays instead assigments to save allocation

eeb577b

knst force-pushed the perf-qc-mined branch from a2cc53c to eeb577b Compare July 22, 2025 15:11

github-actions bot removed the needs rebase label Jul 22, 2025

knst requested review from PastaPastaPasta and UdjinM6 July 24, 2025 12:46

This was referenced Jul 24, 2025

perf: using asynchronous worker to validate BLS signatures in quorum commitments #6692

Open

backport: trivial batch 380 #6779

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Issue being fixed or feature implemented

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