Use Topological ordering during ProcessBundle in SDKHarness

[Suvrat1629]

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Fixes: #19062 Compute transforms in topological order with QueryablePipeline and use a LoadingCache keyed by descriptor id to avoid recomputing. Detect cycles by validating the topo list covers all transforms; the loader throws IllegalStateException on incomplete ordering. On loader failure (e.g., cycle), fall back to the prior descriptor-order path so ProcessBundle still succeeds. Add tests covering cache population/identity and cycle -> fallback behavior: testTopologicalCacheProducesAndCachesOrder testTopologicalCacheThrowsOnCycleAndProcessBundleFallsBackToDescriptorOrder Include transforms in the Components passed to QueryablePipeline in the cache loader so ordering can be computed correctly.

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Summary of Changes

Hello @Suvrat1629, I'm Gemini Code Assist[^1]! 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 significantly refines how pipeline transforms are processed within the SDKHarness by implementing topological sorting. This change ensures that operations are executed in their correct dependency order, which is crucial for data processing pipelines. To optimize performance, a caching layer has been added for the computed topological orders. Furthermore, the system is made more resilient by including robust cycle detection and a fallback mechanism that reverts to the prior processing method if any issues arise during topological sorting, ensuring continuous operation.

Highlights

• Topological Ordering: Transforms within ProcessBundle in the SDKHarness are now processed using topological ordering, ensuring correct dependency execution.
• Caching Mechanism: A LoadingCache is introduced to store the computed topological order, keyed by descriptor ID, preventing redundant computations.
• Cycle Detection and Fallback: The system detects cycles in the pipeline definition during topological sorting. If a cycle is found or the loader fails, it gracefully falls back to the previous descriptor-order processing to maintain stability.
• Enhanced QueryablePipeline: The QueryablePipeline now includes all relevant Components (coders, pcollections, transforms, windowing strategies) when computing the topological order, ensuring accuracy.
• New Tests: New unit tests (testTopologicalOrderRespectsDependency, testProcessBundleCreatesRunnersForAllTransformsUsingTopologicalCache) have been added to validate the topological ordering, caching, and fallback behavior.

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[Suvrat1629]

/gemini review

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[Suvrat1629]

/gemini review

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Reminder, please take a look at this pr: @Abacn

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