Struct DisplacedTableWithProvenance 

pub struct DisplacedTableWithProvenance { /* private fields */ }

A variant of DisplacedTable that also stores “provenance” information that can be used to generate proofs of equality.

This table expects a fourth “proof” column, though the values it hands back are not the proofs that come in and generally should not be used directly. To generate a proof that two values are equal, this table exports a separate get_proof method.

Implementations

impl DisplacedTableWithProvenance

pub fn get_proof(&self, l: Value, r: Value) -> Option<Vec<ProofStep>>

A simple proof generation algorithm that searches for the shortest path in the proof graph between l and r.

The path in the graph is restricted to the timestamps at or before l and r first became equal. This is to avoid cycles during proof reconstruction.

Trait Implementations

impl Clone for DisplacedTableWithProvenance

fn clone(&self) -> DisplacedTableWithProvenance

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Default for DisplacedTableWithProvenance

fn default() -> DisplacedTableWithProvenance

Returns the “default value” for a type.

impl Table for DisplacedTableWithProvenance

fn refine_one(&self, subset: Subset, c: &Constraint) -> Subset

Filter a given subset of the table for the rows matching the single constraint.

fn scan_generic_bounded( &self, subset: SubsetRef<'_>, start: Offset, n: usize, cs: &[Constraint], f: impl FnMut(RowId, &[Value]), ) -> Option<Offset>

where Self: Sized,

Iterate over the given subset of the table, starting at an opaque start token, ending after up to n rows, returning the next start token if more rows remain. Only invoke f on rows that match the given constraints.

fn spec(&self) -> TableSpec

The schema of the table.

fn merge(&mut self, exec_state: &mut ExecutionState<'_>) -> TableChange

Merge any updates to the table, and potentially update the generation for the table.

fn get_row(&self, key: &[Value]) -> Option<Row>

Look up a single row by the given key values, if it is in the table.

fn get_row_column(&self, key: &[Value], col: ColumnId) -> Option<Value>

Look up the given column of single row by the given key values, if it is in the table.

fn new_buffer(&self) -> Box<dyn MutationBuffer>

Create a new buffer for staging mutations on this table.

fn dyn_clone(&self) -> Box<dyn Table>

A variant of clone that returns a boxed trait object; this trait object must contain all of the data associated with the current table.

fn as_any(&self) -> &dyn Any

A boilerplate method to make it easier to downcast values of Table.

fn clear(&mut self)

Clear all table contents. If the table is nonempty, this will change the generation of the table. This method also clears any pending data.

fn all(&self) -> Subset

Get a subset corresponding to all rows in the table.

fn len(&self) -> usize

Get the length of the table.

fn updates_since(&self, offset: Offset) -> Subset

Get the subset of the table that has appeared since the last offset.

fn version(&self) -> TableVersion

Get the current version for the table. RowIds and Subsets are only valid for a given major generation.

fn fast_subset(&self, c: &Constraint) -> Option<Subset>

An optional method for quickly generating a subset from a constraint. The standard use-case here is to apply constraints based on a column that is known to be sorted.

fn rebuilder<'a>( &'a self, _cols: &[ColumnId], ) -> Option<Box<dyn Rebuilder + 'a>>

If this table can perform a table-level rebuild, construct a Rebuilder for it.

fn apply_rebuild( &mut self, _table_id: TableId, _table: &WrappedTable, _next_ts: Value, _exec_state: &mut ExecutionState<'_>, )

Rebuild the table according to the given Rebuilder implemented by table, if there is one. Applying a rebuild can cause more mutations to be buffered, which can in turn be flushed by a call to Table::merge.

fn is_empty(&self) -> bool

Check if the table is empty.

fn scan_generic(&self, subset: SubsetRef<'_>, f: impl FnMut(RowId, &[Value]))

where Self: Sized,

Iterate over the given subset of the table.

fn refine_live(&self, subset: Subset) -> Subset

Filter a given subset of the table for the rows that are live

fn refine(&self, subset: Subset, cs: &[Constraint]) -> Subset

Filter a given subset of the table for the rows matching the given constraints.

fn split_fast_slow( &self, cs: &[Constraint], ) -> (Subset, Pooled<Vec<Constraint>>, Pooled<Vec<Constraint>>)

A helper routine that leverages the existing fast_subset method to preprocess a set of constraints into “fast” and “slow” ones, returning the subet of indexes that match the fast one.