Struct Db 

pub struct Db { /* private fields */ }

An immutable value of a database at one basis transaction and time view.

Implementations

impl Db

pub fn new(schema: Schema) -> Self

Creates an empty database with the supplied schema.

pub fn from_current_snapshot( basis_t: u64, schema: Schema, idents: Idents, interner: KeywordInterner, datoms: Vec<Datom>, ) -> Self

Creates a current database value from a published EAVT snapshot.

datoms must be the live facts at basis_t. Their original transaction ids are retained, but transactions before basis_t that no longer contribute a live fact are not reconstructed. This makes the value suitable for current queries and for applying the log tail; complete historical views still require replaying the full log.

pub fn with_naming(self, idents: Idents, interner: KeywordInterner) -> Self

Attaches ident and keyword naming registries, returning the named value.

pub const fn basis_t(&self) -> u64

Current transaction basis.

pub const fn schema(&self) -> &Schema

Schema at this basis.

pub fn idents(&self) -> &Idents

Ident registry.

pub fn interner(&self) -> &KeywordInterner

Keyword interner used by keyword values in this database.

pub const fn view(&self) -> DbView

The time view this value presents.

pub fn recorded_datoms(&self) -> &[Datom]

Every recorded assertion and retraction, in transaction order.

pub fn as_of(&self, t: u64) -> Self

Returns the as-of view at basis t: facts as they stood then.

pub fn since(&self, t: u64) -> Self

Returns the since view: only live facts added after t.

pub fn history(&self) -> Self

Returns the history view: all assertions and retractions ever.

pub fn tx_range(&self, start: u64, end: Option<u64>) -> Vec<(u64, Vec<Datom>)>

Groups recorded datoms by transaction over the half-open range [start, end).

pub fn datoms(&self) -> Vec<Datom>

Returns this view’s facts, deterministically ordered by EAVT.

pub fn datoms_at(&self, order: IndexOrder) -> impl Iterator<Item = &Datom>

Iterates this view’s datoms in one index order.

AVET covers only indexed/unique attributes and VAET only reference values, mirroring Datomic’s covering-index composition.

pub fn datoms_for_attribute(&self, a: AttrId) -> impl Iterator<Item = &Datom>

Iterates this view’s datoms for one attribute in AEVT order.

Unlike AVET, AEVT covers every installed attribute. Callers can use this as the fallback for attribute predicates that do not have AVET coverage.

pub fn datoms_prefix<'a>( &'a self, order: IndexOrder, prefix: &'a [u8], ) -> impl Iterator<Item = &'a Datom>

Iterates datoms whose key in order starts with prefix.

pub fn seek_datoms<'a>( &'a self, order: IndexOrder, start: &[u8], ) -> impl Iterator<Item = &'a Datom>

Iterates datoms in order starting from the first key at or after start.

pub fn index_range<'a>( &'a self, a: AttrId, start: Option<&Value>, end: Option<&'a Value>, ) -> impl Iterator<Item = &'a Datom>

Iterates the AVET index for a over the value range [start, end).

Only indexed/unique attributes appear in AVET.

pub fn values(&self, e: EntityId, a: AttrId) -> Vec<Value>

Current values for an entity/attribute pair.

pub fn lookup(&self, a: AttrId, v: &Value) -> Option<EntityId>

Resolves a unique attribute/value pair to its entity.

pub fn with_transaction(&self, t: u64, datoms: &[Datom]) -> Self

Applies a committed record, returning a new database value.

Only meaningful for the current view; time views are read-only.

pub fn stats(&self) -> DbStats

Computes basic statistics over this view’s facts.

pub fn planner_stats(&self) -> &PlannerStats

Planner statistics for this view, built lazily and cached.

Trait Implementations

impl Clone for Db

fn clone(&self) -> Db

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Db

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

Formats the value using the given formatter.

impl Default for Db

fn default() -> Db

Returns the “default value” for a type.