Module persistent_cache 

Persistent caching backends for OCR results.

This module provides persistent storage options for OCR results:

• Redis backend for distributed caching
• SQLite backend for local persistent cache
• Cache statistics and metrics
• Configurable eviction policies (LRU, LFU)

Structs

CacheStats

Cache statistics.

PersistentCache

Persistent cache wrapper that uses a backend.

RedisBackend

Redis cache backend (stub - full implementation requires redis crate).

RedisConfig

Redis cache backend configuration.

SqliteBackend

SQLite cache backend (stub - full implementation requires rusqlite crate).

SqliteConfig

SQLite cache backend configuration.

Enums

EvictionPolicy

Cache eviction policy.

Traits

CacheBackend

Cache backend trait for persistent storage.