Ensure all structs that implement an interface used as a type constraint implement all methods

[TedHartMS]

This pull request extends the fix in PR #1988 to eliminate unnecessary boxing by explicitly implementing interface members—particularly default interface methods (DIMs)—in key structs and record trigger implementations. By directly implementing these members, calls through generic constraints will resolve to the struct's own methods, improving performance and avoiding the overhead of boxing. Additionally, all key structs now explicitly implement the IsEmpty property.

The most important changes are:

Performance improvements through explicit interface implementations:

• Explicitly implemented default interface methods (DIMs) for IRecordTriggers and related interfaces in various structs (e.g., OnDispose, OnFlush, OnEvict, OnDiskRead, OnRecovery, OnCheckpoint, PostCopyToTail, OnTruncate) to ensure generic constraint calls resolve without boxing, both in production and test code. [1] [2] [3] [4] [5] [6] [7]

• Implemented PhysicalAddress explicitly in LogRecord and DiskLogRecord to avoid boxing when accessed through ISourceLogRecord. [1] [2]

Key interface consistency:

• Added an explicit implementation of the IsEmpty property (always returning false) to all IKey structs in both production and test code, ensuring interface contract consistency and avoiding default interface dispatch. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]

Code clarity and documentation:

• Added or updated comments to clarify the rationale for explicit interface implementations, highlighting the avoidance of boxing and improved performance. [1] [2] [3] [4]

These changes collectively improve runtime efficiency and code clarity by ensuring interface methods are resolved to struct implementations without incurring boxing costs.

[Copilot]

Pull request overview

This PR extends the earlier “avoid boxing via default interface methods (DIMs) on structs under generic constraints” work by adding concrete struct implementations for interface members that were previously relying on DIMs. This ensures constrained generic calls bind to the struct methods/properties (no boxing) across Tsavorite core, Garnet, and associated tests/benchmarks.

Changes:

• Added explicit struct implementations of IRecordTriggers members (no-ops/defaults) in core and test trigger structs to avoid DIM dispatch/boxing under TRecordTriggers : IRecordTriggers.
• Added explicit implementations for ISourceLogRecord.PhysicalAddress and IKey.IsEmpty in LogRecord/DiskLogRecord (and IsEmpty in various test/benchmark IKey structs) to avoid DIM dispatch/boxing under TKey : IKey / TSourceLogRecord : ISourceLogRecord.
• Added a no-op OnDisposeDiskRecord implementation in GarnetRecordTriggers to avoid DIM dispatch/boxing for disk-record disposal paths.

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
libs/storage/Tsavorite/cs/src/core/Index/StoreFunctions/IRecordTriggers.cs	Adds explicit no-op implementations in default trigger structs to prevent DIM-based boxing under TRecordTriggers.
libs/storage/Tsavorite/cs/src/core/Allocator/LogRecord.cs	Implements ISourceLogRecord.PhysicalAddress and IKey.IsEmpty directly on LogRecord.
libs/storage/Tsavorite/cs/src/core/Allocator/DiskLogRecord.cs	Implements ISourceLogRecord.PhysicalAddress and IKey.IsEmpty directly on DiskLogRecord.
libs/server/Storage/Functions/GarnetRecordTriggers.cs	Adds explicit no-op OnDisposeDiskRecord to avoid DIM dispatch/boxing.
libs/server/Resp/MGetReadArgBatch.cs	Keeps IReadArgBatch DIM-avoidance explicit implementations; minor formatting/comment adjustment.
libs/storage/Tsavorite/cs/test/TestTypes.cs	Adds IKey.IsEmpty implementation on test key structs.
libs/storage/Tsavorite/cs/test/TestSpanByteKey.cs	Adds IKey.IsEmpty implementation on test span-byte key.
libs/storage/Tsavorite/cs/test/test.session/ReadAddressTests.cs	Adds IKey.IsEmpty implementation on a local test key struct.
libs/storage/Tsavorite/cs/test/test.recordops/RecordLifecycleTests.cs	Adds explicit no-op/default IRecordTriggers members to avoid DIM boxing in tests.
libs/storage/Tsavorite/cs/test/test.recordops/DeleteDisposeTests.cs	Adds explicit no-op/default IRecordTriggers members to avoid DIM boxing in tests.
libs/storage/Tsavorite/cs/test/RecoveryTestTypes.cs	Adds IKey.IsEmpty implementation on recovery test key.
libs/storage/Tsavorite/cs/test/RecordTriggersExtTests.cs	Adds explicit no-op IRecordTriggers members to avoid DIM boxing in tests.
libs/storage/Tsavorite/cs/test/ObjectTestTypes.cs	Adds IKey.IsEmpty implementation on object test key.
libs/storage/Tsavorite/cs/benchmark/YCSB.benchmark/KeySpanByte.cs	Adds IKey.IsEmpty implementation for benchmark keys.
libs/storage/Tsavorite/cs/benchmark/YCSB.benchmark/FixedLengthKey.cs	Adds IKey.IsEmpty implementation for benchmark keys.
libs/storage/Tsavorite/cs/benchmark/KV.benchmark/KvKey.cs	Adds IKey.IsEmpty implementation for benchmark keys.