LLKV Storage Adapters

Work in Progress

llkv-storage defines the pager abstraction that underpins persistence for the LLKV stack. It offers both in-memory and persistent implementations with zero-copy reads for Arrow workloads.

Pager Trait

• Exposes batch get/put operations over PhysicalKey/EntryHandle pairs so callers can read and write blobs efficiently.
• Supports atomic multi-key updates, which the column store relies on when committing append transactions.
• Keeps higher layers agnostic to the backing medium (memory, file-backed, or custom stores).

Implementations

• MemPager: lightweight, heap-backed pager used for tests, temporary namespaces, and staging contexts during transactions.
• SimdRDrivePager: wraps simd_r_drive::DataStore, enabling zero-copy reads with SIMD-aligned buffers backed by a persistent file.
• Additional pagers can be implemented by consumers if they satisfy the trait contract.

Integration Points

• llkv-column-map uses pagers to persist column chunks, catalogs, and MVCC metadata.
• llkv-runtime instantiates both persistent and in-memory pagers to support dual-context transactions.
• Benchmark targets measure pager throughput as part of the Criterion suites consumed by CodSpeed.

License

Licensed under the Apache-2.0 License.