Struct spacetimedb_vm::expr::SourceId

pub struct SourceId(pub usize);

An identifier for a data source (i.e. a table) in a query plan.

When compiling a query plan, rather than embedding the inputs in the plan, we annotate each input with a SourceId, and the compiled plan refers to its inputs by id. This allows the plan to be re-used with distinct inputs, assuming the inputs obey the same schema.

Note that re-using a query plan is only a good idea if the new inputs are similar to those used for compilation in terms of cardinality and distribution.

Tuple Fields

0: usize

Trait Implementations

impl Clone for SourceId

fn clone(&self) -> SourceId

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for SourceId

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

Formats the value using the given formatter.

impl From<usize> for SourceId

fn from(original: usize) -> SourceId

Converts to this type from the input type.

impl Hash for SourceId

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T, const N: usize> Index<SourceId> for SourceSet<T, N>

type Output = Option<T>

The returned type after indexing.

fn index(&self, idx: SourceId) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<T, const N: usize> IndexMut<SourceId> for SourceSet<T, N>

fn index_mut(&mut self, idx: SourceId) -> &mut Self::Output

Performs the mutable indexing (container[index]) operation.

impl PartialEq for SourceId

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for SourceId

impl Eq for SourceId

impl StructuralPartialEq for SourceId