aiondb-storage-engine

The default storage backend. Implements the StorageDDL, StorageDML, StorageTxnParticipant, and StorageCapabilities traits from aiondb-storage-api on top of WAL, the buffer pool, an LSM SSTable layer, and an HNSW vector index. Owns table heap data, B-Tree and HNSW secondary indexes, GIN indexes, adjacency indexes for graph edges, and the paged-snapshot stores used at checkpoint time. Recovery replays WAL records into this state at startup.

cargo

[dependencies]
aiondb-storage-engine = { path = "../aiondb-storage-engine" }

modules

The crate exposes a single public surface from lib.rs. The internal engine, backend, layout, lsm_sstable, and replication modules are not directly re-exported; their public types are surfaced through the items listed below.

key types

type	role
`StorageEngine`	type alias for `InMemoryStorage`; the engine entry point.
`InMemoryStorage`	the storage backend; holds tables, indexes, WAL integration, paged snapshot stores.
`StorageOptions`	full configuration: WAL config, commit policy, memory limit, paged root dir, snapshot mirror, checkpoint manifest dir, eviction threshold, WAL retention.
`StorageBufferPoolConfig`	frame counts for the table, snapshot, and index buffer pools.
`WalCommitPolicy`	`Always`, `Every(N)`, or `Never`.
`RecoveryReport`, `RecoveredStatistics`	replay output and per-table statistics recovered from WAL.
`StorageMetrics`	runtime counters surfaced by the engine.
`HnswIndexStats`, `HnswSearchStats`, `HnswSearchStatsSummary`	vector-index statistics.
`StorageBackendKind`, `StorageBackendSpec`, `StorageBackendHandle`	backend selection (`InMemory`, `Durable`, `Disk`, `PageEngine`, `Lsm`).
`DiskBackendConfig`, `DiskSyncPolicy`	direct-disk backend tuning.
`PageEngineBackendConfig`, `PageSyncPolicy`	buffer-pool-backed page engine tuning.
`LsmBackendConfig`	LSM-tree backend tuning.
`DiskTableStore`, `DiskTableStoreConfig`	disk-resident heap store.
`RowLockTable`, `RowLockMode`, `IntentLockMode`, `DmlPrecheck`	row-level lock manager.
`StorageReplicationSeedManifest`	manifest describing a replication seed installed by `install_replication_seed`.
`install_replication_seed`	install an exported seed (storage state + manifest) into a target data dir. Used by `aiondb-engine` when seeding a fresh replica with a non-empty catalog.
`doctor_data_dir` / `StorageDoctorReport`	inspect a data dir without opening it; surfaces format version, stable artefacts, WAL segments, snapshots, page-file kinds, and detected experimental files. Backs the `aiondb doctor` subcommand.
`upgrade_data_dir`	back up the data dir, then write the current storage manifest. Backs the `aiondb upgrade` subcommand.
`ensure_storage_contract_for_open`	called by the engine builder before opening a persistent backend. Writes the manifest into a fresh data dir; rejects existing dirs that contain stable artefacts but no manifest.
`PageStoreStorage`	type alias for `StorageEngine`. Kept for legacy callers that referred to the page-store-backed storage by name.
`WalConfig`, `WalLsnMode`	re-exported from `aiondb-wal` for convenience.

constructors

constructor	use
`StorageEngine::new(StorageOptions)`	WAL-backed engine with full durability.
`StorageEngine::new_without_wal()`	non-durable in-memory engine.
`StorageEngine::new_without_wal_with_memory_limit(limit)`	non-durable, with a memory cap.

example

use aiondb_storage_engine::{StorageEngine, StorageOptions, WalCommitPolicy};
use aiondb_wal::WalConfig;

let options = StorageOptions {
    wal_config: WalConfig {
        dir: "/var/lib/aiondb/wal".into(),
        ..Default::default()
    },
    wal_commit_policy: WalCommitPolicy::Always,
    ..StorageOptions::durable(WalConfig::default())
};

let _engine = StorageEngine::new(options).expect("open storage engine");