Unify Get/Scan preparation logic for transaction reads and Serializable validation

[brfrn169]

Description

This PR unifies the Get/Scan preparation logic used during transaction reads and Serializable validation by introducing common utility methods in ConsensusCommitUtils. Previously, these two processes prepared Get/Scan objects differently, which could result in inconsistent ordering and cause Serializable validation failures.

Related issues and/or PRs

N/A

Changes made

• Added ConsensusCommitUtils.prepareGetForStorage()
• Added ConsensusCommitUtils.prepareScanForStorage()
• Updated CrudHander and Snapshot to use ConsensusCommitUtils.prepareGetForStorage() and ConsensusCommitUtils.prepareScanForStorage() to use the same Scan and Get between transaction reads and Serializable validation.

Checklist

The following is a best-effort checklist. If any items in this checklist are not applicable to this PR or are dependent on other, unmerged PRs, please still mark the checkboxes after you have read and understood each item.

• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation to reflect the changes.
• I have considered whether similar issues could occur in other products, components, or modules if this PR is for bug fixes.
• Any remaining open issues linked to this PR are documented and up-to-date (Jira, GitHub, etc.).
• Tests (unit, integration, etc.) have been added for the changes.
• My changes generate no new warnings.
• Any dependent changes in other PRs have been merged and published.

Additional notes (optional)

N/A

Release notes

Fixed an inconsistency where Get and Scan operations were prepared differently for transaction reads and Serializable validation, which could result in inconsistent ordering and cause Serializable validation failures.

[gemini-code-assist]

Summary of Changes

Hello @brfrn169, 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 significant refactoring to centralize and unify the preparation logic for Get and Scan operations within the Consensus Commit transaction protocol. By moving this logic to ConsensusCommitUtils, the CrudHandler becomes cleaner and more focused on its core responsibilities. This change particularly enhances the handling of conditional expressions and before-image columns during storage reads and serializable validation, ensuring correctness and improving maintainability.

Highlights

• Unification of Get/Scan Preparation Logic: The logic for preparing Get and Scan operations for storage reads, including handling conditional expressions and before-image columns for serializable validation, has been centralized into ConsensusCommitUtils.
• Refactored CrudHandler: The CrudHandler methods (get, scan, readUnread, read, getFromStorage, scanFromStorage, getScanner, put, delete, readIfImplicitPreReadEnabled) now delegate the storage preparation to the new utility methods in ConsensusCommitUtils. This simplifies CrudHandler and improves modularity.
• Improved Scan Limit Handling: The prepareScanForStorage method now explicitly removes any set limit from Scan operations when conjunctions are present. This ensures that all relevant records, including those with before-images, are retrieved from storage before filtering, which is crucial for correct recovery and validation.
• Simplified Serializable Validation: The Snapshot validation logic for serializable isolation now leverages the unified prepareGetForStorage and prepareScanForStorage methods, ensuring consistent preparation of operations during validation checks.

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[gemini-code-assist]

Code Review

This pull request is a nice refactoring that unifies the logic for preparing Get and Scan operations. However, this unification has introduced a performance regression in the validation logic for serializable transactions. The validation scans and gets now fetch all columns from storage, whereas previously they only fetched the columns necessary for validation. I've added a couple of review comments with suggestions to address this inefficiency while retaining the benefits of the refactoring.

[Copilot]

Pull Request Overview

This PR refactors how Get and Scan operations are prepared for storage in consensus commit transactions. The main changes include:

• Extracting conjunction conversion logic from CrudHandler to ConsensusCommitUtils for reusability
• Moving projection clearing and consistency setting to new utility methods prepareGetForStorage and prepareScanForStorage
• Updating test expectations to reflect that operations passed to storage now use the original Get/Scan for snapshot tracking instead of the storage-prepared version

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
ConsensusCommitSpecificIntegrationTestBase.java	Fixed bug where manager.get() was incorrectly called instead of transaction.get()
SnapshotTest.java	Removed redundant consistency settings and updated test expectations to use original operations for tracking
CrudHandlerTest.java	Updated test expectations to pass original operations to snapshot methods and added conjunction handling tests
ConsensusCommitUtilsTest.java	Added comprehensive tests for new prepareGetForStorage and prepareScanForStorage utility methods
Snapshot.java	Refactored validation logic to use new utility methods and added conjunction filtering
CrudHandler.java	Refactored to use new utility methods and pass original operations to snapshot
ConsensusCommitUtils.java	Added new utility methods for preparing Get/Scan operations for storage with conjunction conversion

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[komamitsu]

LGTM! 👍

[Torch3333]

LGTM, thank you!

[feeblefakie]

LGTM! Thank you!