Shared Log-Structured Datastore for Flash Memory Concurrency

The patent segments the storage system into a log-structured append-only flash storage layer and a virtual file system layer. The log stores data in immutable sequential segments, while the virtual file system provides the illusion of update-in-place by managing pointers to log entries. This segmentation allows flash memory to operate in its optimal append-only mode while presenting a traditional file system interface to users.

The patent implements a dynamic log-structured file system that adapts to different access patterns. Rather than using a static B-tree structure, the system dynamically manages log segments and uses wear-leveling algorithms to distribute writes across multiple physical blocks. This dynamic approach optimizes for flash memory's strengths in sequential writes while maintaining acceptable random access performance through intelligent data layout and caching strategies.

The patent employs preliminary actions in the form of write buffering and caching mechanisms. Before actual data is written to flash memory, writes are accumulated in volatile memory buffers. The system performs batch writes to flash storage, consolidating multiple small writes into larger sequential operations. This preliminary buffering approach reduces the total number of erase cycles required while maintaining high write throughput by minimizing the frequency of physical write operations to flash memory.