Module filter_persistence 

Cuckoo filter persistence for fast startup.

Stores filter state alongside the merkle root that was current when the filter was saved. On startup, if the current merkle root matches the saved root, the filter is immediately trusted.

Storage

Uses the WAL SQLite database for storage (reuses existing connection).

CREATE TABLE cf_state (
    filter_id TEXT PRIMARY KEY,      -- "l2" or "l3"
    filter_bytes BLOB NOT NULL,      -- Exported filter data
    merkle_root BLOB NOT NULL,       -- 32-byte root hash when saved
    entry_count INTEGER NOT NULL,    -- Number of entries at save time
    saved_at INTEGER NOT NULL        -- Unix timestamp
);

Structs

FilterPersistence

Cuckoo filter persistence manager.

SavedFilterState

Saved filter state

Constants

L2_FILTER_ID

Filter IDs for persistence

L3_FILTER_ID