Enum spacetimedb_vm::expr::SourceExpr

pub enum SourceExpr {
    InMemory {
        source_id: SourceId,
        header: Arc<Header>,
        table_type: StTableType,
        table_access: StAccess,
        row_count: RowCount,
    },
    DbTable(DbTable),
}

A reference to a table within a query plan, used as the source for selections, scans, filters and joins.

Variants

InMemory

A plan for a “virtual” or projected table.

The actual in-memory table, e.g., MemTable or &'a [ProductValue] is not stored within the query plan; rather, the source_id is an index which corresponds to the table in e.g., a SourceSet.

This allows query plans to be reused by supplying e.g., a new SourceSet.

Fields

source_id: SourceId

header: Arc<Header>

table_type: StTableType

table_access: StAccess

row_count: RowCount

DbTable(DbTable)

A plan for a database table. Because DbTable is small and efficiently cloneable, no indirection into a SourceSet is required.

Implementations

impl SourceExpr

pub fn source_id(&self) -> Option<SourceId>

If self refers to a MemTable, returns the SourceId for its location in the plan’s SourceSet.

Returns None if self refers to a DbTable, as DbTables are stored directly in the SourceExpr, rather than indirected through the SourceSet.

pub fn table_name(&self) -> &str

pub fn table_type(&self) -> StTableType

pub fn table_access(&self) -> StAccess

pub fn head(&self) -> &Arc<Header>

pub fn is_mem_table(&self) -> bool

pub fn is_db_table(&self) -> bool

pub fn from_mem_table( header: Arc<Header>, table_access: StAccess, row_count: usize, id: SourceId ) -> Self

pub fn table_id(&self) -> Option<TableId>

pub fn get_db_table(&self) -> Option<&DbTable>

If self refers to a DbTable, get a reference to it.

Returns None if self refers to a MemTable. In that case, retrieving the MemTable requires inspecting the plan’s corresponding SourceSet via [SourceSet::take_mem_table] or SourceSet::take_table.

Trait Implementations

impl AuthAccess for SourceExpr

fn check_auth(&self, owner: Identity, caller: Identity) -> Result<(), AuthError>

impl Clone for SourceExpr

fn clone(&self) -> SourceExpr

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for SourceExpr

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

Formats the value using the given formatter.

impl Display for SourceExpr

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

Formats the value using the given formatter.

impl From<&TableSchema> for SourceExpr

fn from(value: &TableSchema) -> Self

Converts to this type from the input type.

impl From<SourceExpr> for QueryExpr

fn from(source: SourceExpr) -> Self

Converts to this type from the input type.

impl Hash for SourceExpr

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 PartialEq for SourceExpr

fn eq(&self, other: &SourceExpr) -> 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 Relation for SourceExpr

fn head(&self) -> &Arc<Header>

fn row_count(&self) -> RowCount

Specify the size in rows of the Relation.

impl Eq for SourceExpr

impl StructuralPartialEq for SourceExpr