Crate spacedb_store 

spacedb-store — SpaceDB Layer 0

The per-node storage primitive: a typed, transactional, order-preserving key/value store that everything else in SpaceDB rests on. Getting this small and correct is the whole game — every layer above inherits its guarantees.

What S1 ships

• KvEngine — the engine seam, with two implementations that share identical transaction semantics: RedbEngine (durable) and MemEngine (in-memory, for tests).
• codec — a deterministic postcard value codec and an order-preserving key codec (a < b ⟺ encode(a) < encode(b)), each a verified bijection.
• Table — the typed Table<K, V> primitive that applies both codecs once so layers above never touch raw bytes.

Guarantees

• Atomic multi-table writes. One WriteTx spans many tables and commits all-or-nothing; dropping it rolls back.
• Logical-order range scans, courtesy of the order-preserving key codec.
• Single-writer / snapshot reads, identical across both engines.

Open-core boundary

spacedb-store is MIT and depends on no MATA crate. MATA-specific capabilities (the vault key, identity, mesh replication, settlement) enter later through seams this crate defines — e.g. the KeyProvider for the AEAD boundary in S2 — which MATA implements in its proprietary hosted product. The dependency arrow is MATA → SpaceDB, never the reverse.

Re-exports

pub use codec::decode_value;

pub use codec::encode_value;

pub use codec::KeyDecode;

pub use codec::KeyEncode;

pub use engine::Durability;

pub use engine::KvEngine;

pub use engine::ReadTx;

pub use engine::Readable;

pub use engine::WriteTx;

pub use mem_engine::MemEngine;

pub use redb_engine::RedbEngine;

pub use table::Table;

pub use crypto::open_row;

pub use crypto::rewrap_dek;

pub use crypto::seal_row;

pub use crypto::unwrap_dek;

pub use crypto::wrap_fresh_dek;

pub use crypto::CryptoError;

pub use crypto::KeyProvider;

pub use crypto::StaticKeyProvider;

pub use crypto::WrappedDek;

pub use crypto::KEY_LEN;

pub use crypto::NONCE_LEN;

pub use collection::Collection;

pub use meta::open_meta;

pub use meta::open_meta_with;

pub use meta::read_store_version;

pub use meta::write_store_version;

pub use meta::MetaStatus;

pub use meta::Migration;

pub use meta::STORE_FORMAT_VERSION;

pub use extern_value::classify;

pub use extern_value::content_hash;

pub use extern_value::should_externalize;

pub use extern_value::ExternRef;

pub use extern_value::ValuePlacement;

Modules

codec

The two codecs every layer above rests on: a value codec and an order-preserving key codec.

collection

Collection<K, V> — the encrypted typed table.

crypto

The AEAD value boundary — the zero-knowledge linchpin.

engine

The storage engine seam — the one trait everything in SpaceDB rests on.

extern_value

Large-value externalization (the seam, stubbed).

mem_engine

In-memory KvEngine — the test/ephemeral engine.

meta

The _meta schema gate — refuse or migrate, never silently open.

redb_engine

redb-backed KvEngine — the durable engine.

table

Table<K, V> — the typed primitive every layer above uses.

Enums

StoreError

Type Aliases

StoreResult

The result type returned throughout spacedb-store.