Matrix: Enable rollback and local server stress

[anthony-murphy]

This pull request introduces significant changes to the SharedMatrix implementation to improve handling of pending cell changes and rollback operations, updates related utility classes, and enhances testing. Below is a summary of the most important changes grouped by theme.

Enhancements to SharedMatrix functionality:

• Introduced a new PendingCellChanges<T> interface to track both local changes and the latest consensus value for a cell. This replaces the previous approach of tracking pending writes with a single number. (matrix.ts, [1] [2]
• Modified the sendSetCellOp method to return PendingCellChanges<T> instead of a single localSeq value, enabling more granular tracking of pending operations. (matrix.ts, [1] [2]
• Added a rollback method to handle undoing operations, ensuring that the matrix state can revert to the previous value or consensus value when necessary. (matrix.ts, packages/dds/matrix/src/matrix.tsR882-R922)

Improvements to operation handling:

• Updated the logic for processing ACKs to correctly handle and clean up pending changes, ensuring that the consensus value is updated and remaining pending changes are managed appropriately. (matrix.ts, [1] [2]
• Adjusted how adjustPosition in PermutationVector handles removed segments, allocating handles for rows/columns that may be reactivated during rollbacks. (permutationvector.ts, [1] [2]

Code cleanup and refactoring:

• Removed the isLatestPendingWrite method from SharedMatrix, as its functionality is now integrated into the improved pending changes tracking system. (matrix.ts, packages/dds/matrix/src/matrix.tsL1109-L1137)
• Simplified and clarified logic in PermutationVector for handling INSERT and REMOVE operations, including rollback scenarios. (permutationvector.ts, [1] [2]

Testing and dependencies:

• Added @fluidframework/matrix as a dependency in the local-server-stress-tests package and integrated the baseSharedMatrixModel into the stress tests to ensure thorough validation of the updated SharedMatrix behavior. (package.json, [1] [2]

These changes collectively enhance the robustness and maintainability of the SharedMatrix component, particularly in scenarios involving concurrent edits, rollbacks, and acknowledgments.

[Copilot]

Pull Request Overview

This pull request improves the SharedMatrix implementation by adding rollback support, updating the pending operations tracking to handle multiple pending operations, and introducing a fuzz testing framework to validate the matrix behavior under stress.

• Added rollback capabilities in SharedMatrix and updated the setCellCore method to handle rollback scenarios.
• Modified pending operation storage from a single value to arrays for better multi-operation tracking.
• Introduced a new fuzz testing framework and updated test configurations/package.json accordingly.

Reviewed Changes

Copilot reviewed 10 out of 11 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
packages/test/local-server-stress-tests/src/test/localServerStressOrderSequentially.spec.ts	Adjusted test skip settings for rollback scenarios.
packages/test/local-server-stress-tests/src/test/localServerStress.spec.ts	Updated skip configuration to include additional test IDs.
packages/test/local-server-stress-tests/src/ddsModels.ts	Added import for baseSharedMatrixModel to support matrix tests.
packages/test/local-server-stress-tests/package.json	Added dependency and build/test configuration for matrix support.
packages/dds/matrix/src/test/matrix.fuzz.spec.ts	Replaced custom fuzz model setup with baseSharedMatrixModel integration.
packages/dds/matrix/src/test/index.ts	New export to expose the shared matrix test model.
packages/dds/matrix/src/test/fuzz.ts	New file implementing the fuzz testing framework for SharedMatrix.
packages/dds/matrix/src/permutationvector.ts	Inserted rollback check to prevent unnecessary handle allocation during rollback ops.
packages/dds/matrix/src/matrix.ts	Updated rollback handling, pending op tracking, and added a dedicated rollback method.
packages/dds/matrix/package.json	Updated package configuration to include internal test exports for the matrix module.

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

[Copilot]

Pull Request Overview

This PR enhances the SharedMatrix implementation by introducing rollback support, improving pending operation tracking, and adding a fuzz testing framework.

• Implements a rollback mechanism in SharedMatrix with changes to setCellCore and sendSetCellOp.
• Updates the pending operation tracking by switching from a single number to an array of sequence numbers.
• Adds new fuzz tests and updates package configuration for local server stress testing.

Reviewed Changes

Copilot reviewed 10 out of 11 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/test/local-server-stress-tests/src/test/localServerStressOrderSequentially.spec.ts	Adjusts test skip configuration for rollback stress tests.
packages/test/local-server-stress-tests/src/test/localServerStress.spec.ts	Updates skip arrays for stress test cases.
packages/test/local-server-stress-tests/src/ddsModels.ts	Adds import for baseSharedMatrixModel to support new fuzz tests.
packages/test/local-server-stress-tests/package.json	Includes the matrix package and its build test in test configuration.
packages/dds/matrix/src/test/matrix.fuzz.spec.ts	Refactors fuzz tests to use baseSharedMatrixModel.
packages/dds/matrix/src/test/index.ts	Exports the new baseSharedMatrixModel for reuse in test suites.
packages/dds/matrix/src/test/fuzz.ts	Introduces a comprehensive fuzz testing framework for SharedMatrix.
packages/dds/matrix/src/permutationvector.ts	Wraps segment JSON maintenance in a rollback check.
packages/dds/matrix/src/matrix.ts	Implements rollback support and updates pending operation handling via arrays.
packages/dds/matrix/package.json	Updates internal test exports configuration for matrix testing.

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported