Storage and snapshots

State persistence is provided by the mazze-storage crate. It combines a Merkle Patricia Trie (MPT) with snapshotting and delta layers to balance performance and history retention.

Storage layers

• Delta MPTs: append-only changes between snapshots.

• Snapshot MPTs: compact state snapshots at selected epochs.

• State DB backend: MDBX by default, configurable via MdbxConfig.

StorageManager and state access

StorageManager and StateManager provide:

• Read/write access to the current state.

• Snapshot creation and pruning.

• Proof generation and state sync support.

Snapshot policy

StorageConfiguration controls:

• snapshot_epoch_count and era_epoch_count.

• Extra snapshots for sync (ProvideExtraSnapshotSyncConfig).

• Cache sizes and open snapshot limits.

• Directory layout under storage_db/.

Interaction with consensus

BlockDataManager keeps a StateAvailabilityBoundary describing which epoch states can be read. This allows full nodes to prune old state while still serving recent queries.

Key source files

• crates/dbs/storage/src/lib.rs

• crates/dbs/storage/src/state_manager.rs

• crates/dbs/storage/src/impls/storage_manager/snapshot_manager.rs

• crates/dbs/storage/src/impls/merkle_patricia_trie/mod.rs

• crates/mazzecore/core/src/block_data_manager/mod.rs