Struct RowFilter

Source

pub struct RowFilter { /* private fields */ }

Expand description

A lightweight, thread-safe row filter for closure-based filtering.

RowFilter pre-compiles the expression once and can be cloned cheaply (it uses CompactArc<Program> internally). Each thread should create its own ExprVM for execution.

§Example

// Create filter once
let filter = RowFilter::new(&where_expr, &columns)?;

// Use in closure (filter is cloned into closure)
let predicate = move |row: &Row| filter.matches(row);

// Or use with parallel iteration
rows.par_iter().filter(|row| filter.matches(row)).collect()

Implementations§

Source §

impl RowFilter

Source

pub fn new(expr: &Expression, columns: &[String]) -> Result<Self>

Create a new row filter by compiling the given expression.

§Arguments

expr - The boolean expression to use as filter
columns - Column names matching the row schema

Source

pub fn with_aliases( expr: &Expression, columns: &[String], aliases: &[(String, usize)], ) -> Result<Self>

Create a row filter with expression aliases for HAVING clause evaluation.

Expression aliases map expression strings (like “SUM(amount)”) to column indices in the result row. This is used for HAVING clauses where aggregate expressions need to reference pre-computed aggregate results.

§Arguments

expr - The boolean expression to use as filter
columns - Column names matching the row schema
aliases - Slice of (expression_name, column_index) pairs

§Example

// For HAVING SUM(amount) > 100, where SUM(amount) is at column 2
let aliases = vec![("sum(amount)".to_string(), 2)];
let filter = RowFilter::with_aliases(&having_expr, &columns, &aliases)?;

// Filter rows
for row in rows {
    if filter.matches(&row) {
        // row passes HAVING clause
    }
}

Source

pub fn with_aliases_and_context( expr: &Expression, columns: &[String], aliases: &[(String, usize)], execution: &ExecutionContext, ) -> Result<Self>

Compile a HAVING/filter expression with aliases and lexical outer scope bound at the same time. Compiling first and attaching only parameters later cannot emit LoadOuterColumn instructions.

Source

pub fn with_params(self, params: ParamVec) -> Self

Create a filter with query parameters.

Source

pub fn with_named_params(self, named_params: FxHashMap<String, Value>) -> Self

Create a filter with named parameters.

Source

pub fn with_context(self, ctx: &ExecutionContext) -> Self

Create a filter from execution context.

PERF: Both params and named_params share the Arc - zero cloning.

Source

pub fn from_program(program: SharedProgram) -> Self

Create a filter from a pre-compiled program.

Source

pub fn matches(&self, row: &Row) -> Result<bool>

Check if a row matches the filter condition.

This method is thread-safe and can be called from multiple threads. Each call uses a thread-local VM for execution.

Source

pub fn matches_checked(&self, row: &Row) -> Result<bool>

Explicit checked alias retained for callers that spell out fallibility. matches() and this method both propagate runtime and result-type errors.

Source

pub fn matches_deferred_checked(&self, row: &DeferredRow) -> Result<bool>

Evaluate a predicate over a compact JOIN row without materializing it.

Source

pub fn matches_row_ref_checked(&self, row: &RowRef) -> Result<bool>

Evaluate a predicate over a virtual executor row without materializing it.

Source

pub fn retain_checked(&self, rows: &mut RowVec) -> Result<()>

Filter a RowVec in-place, removing rows that don’t match. Returns Err if the filter expression produces a runtime error (e.g. invalid REGEXP pattern supplied via a parameter).

Source