Struct DbRoot 

pub struct DbRoot {
    pub format_version: u32,
    pub lease_version: u64,
    pub owner: String,
    pub lease_expires_unix_ms: i64,
    pub owner_endpoint: String,
    pub index_basis_t: u64,
    pub roots: Option<[BlobId; 4]>,
    pub next_entity_id: u64,
    pub last_tx_instant: i64,
}

Published durable index-root metadata carrying the write lease (see docs/design/log-and-transactor.md).

The lease fields and the index fields live in one record on purpose: every mutation — lease acquisition, renewal, release, index publication — is a CAS on these bytes, so a writer whose ownership has changed hands always fails its next CAS and can never install a root. No cross-record atomicity is required of the store.

Fields

format_version: u32

On-disk format version. Readers reject roots from newer formats.

lease_version: u64

Fencing version; increments on every change of lease ownership.

owner: String

Owning transactor id; empty when the lease has never been acquired under format 2.

lease_expires_unix_ms: i64

Lease expiry as Unix milliseconds; 0 when released/never held.

owner_endpoint: String

Client endpoint advertised by the owner (for peer lease-holder rediscovery); empty when the owner does not advertise one.

index_basis_t: u64

Highest indexed transaction.

roots: Option<[BlobId; 4]>

EAVT, AEVT, AVET, and VAET blob ids; None before the first index publication (a bare fence bump).

next_entity_id: u64

Next unallocated user-partition entity id as of index_basis_t.

A transactor recovering from the index root replays only the log tail, so entities created and fully retracted before the snapshot carry no live datom and are invisible to it. Persisting the writer’s allocation high-water lets recovery resume past those ids instead of reusing them. 0 in roots written before this field existed (and in a bare fence bump with no published snapshot); such roots force full-log replay, which reconstructs the allocator exactly.

last_tx_instant: i64

Largest :db/txInstant (Unix ms) committed through index_basis_t.

Preserves :db/txInstant monotonicity across a recovery whose log tail is empty (the snapshot alone does not carry the last commit’s instant). i64::MIN when absent, which is dominated by any real instant and so is a safe floor.

Implementations

impl DbRoot

pub fn encode(&self) -> Vec<u8>

Encodes the root for the root store.

pub fn decode(bytes: &[u8]) -> Option<DbRoot>

Decodes stored root bytes (any format up to FORMAT_VERSION; newer formats still yield their fence fields so old binaries fence correctly, and callers reject them via format_version).

Trait Implementations

impl Clone for DbRoot

fn clone(&self) -> DbRoot

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DbRoot

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Eq for DbRoot

impl PartialEq for DbRoot

fn eq(&self, other: &DbRoot) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for DbRoot