Struct FileStatsLayoutReader 

pub struct FileStatsLayoutReader { /* private fields */ }

A LayoutReader decorator that prunes entire files based on file-level statistics.

This reader wraps an inner LayoutReader and intercepts pruning_evaluation calls. When file-level stats prove that a filter expression is false for the entire file, it returns an all-false mask immediately — avoiding all downstream I/O.

Pruning results are cached per-expression since file-level stats are global (the result is the same regardless of which row range is requested).

Implementations

impl FileStatsLayoutReader

pub fn new( child: LayoutReaderRef, file_stats: FileStatistics, session: VortexSession, ) -> Self

Creates a new FileStatsLayoutReader wrapping the given child reader.

The struct_fields are derived from the child reader’s dtype. If the dtype is not a struct, the available stats will be empty and no pruning will occur.

Pre-computes the set of available stat field paths from the struct fields and file stats.

Trait Implementations

impl LayoutReader for FileStatsLayoutReader

fn name(&self) -> &Arc<str>

Returns the name of the layout reader for debugging.

fn dtype(&self) -> &DType

Returns the un-projected dtype of the layout reader.

fn row_count(&self) -> u64

Returns the number of rows in the layout.

fn register_splits( &self, field_mask: &[FieldMask], row_range: &Range<u64>, splits: &mut BTreeSet<u64>, ) -> VortexResult<()>

Register the splits of this layout reader.

fn pruning_evaluation( &self, row_range: &Range<u64>, expr: &Expression, mask: Mask, ) -> VortexResult<MaskFuture>

Returns a mask where all false values are proven to be false in the given expression.

fn filter_evaluation( &self, row_range: &Range<u64>, expr: &Expression, mask: MaskFuture, ) -> VortexResult<MaskFuture>

Refines the given mask, returning a mask equal in length to the input mask.

fn projection_evaluation( &self, row_range: &Range<u64>, expr: &Expression, mask: MaskFuture, ) -> VortexResult<ArrayFuture>

Evaluates an expression against an array.

impl StatsCatalog for FileStatsLayoutReader

Implements StatsCatalog to provide file-level stats to expressions during pruning evaluation.

fn stats_ref(&self, field_path: &FieldPath, stat: Stat) -> Option<Expression>

Given a field path and statistic, return an expression that when evaluated over the catalog will return that stat for the referenced field.