Struct RowGroupFrontier 

pub(crate) struct RowGroupFrontier {
    pub(super) parquet_metadata: Arc<ParquetMetaData>,
    queued: QueuedRowGroups,
    pub(super) budget: RowBudget,
    pub(super) has_predicates: bool,
}

Fields

parquet_metadata: Arc<ParquetMetaData>

Metadata used to resolve row counts for queued row groups.

queued: QueuedRowGroups

Row groups not yet handed to the builder.

budget: RowBudget

Offset/limit budget before the next readable row group is planned.

has_predicates: bool

If predicates are present, row groups with selected rows must be read so the predicate can decide whether they are actually needed.

Implementations

impl RowGroupFrontier

pub(crate) fn new( parquet_metadata: Arc<ParquetMetaData>, row_group_plan: RowGroupPlan, budget: RowBudget, has_predicates: bool, ) -> Result<Self, ParquetError>

pub(crate) fn queued_row_groups(&self) -> impl Iterator<Item = usize> + '_

The queued row groups, in no specific order and without duplicates.

pub(crate) fn is_queued(&self, row_group_idx: usize) -> bool

Returns true if row_group_idx is still queued to be read.

pub(crate) fn update_budget_after_row_group(&mut self, budget: RowBudget)

pub(crate) fn peek_next_row_group(&self) -> Result<Option<usize>, ParquetError>

Peek at the next row-group index Self::next_readable_row_group would hand out, without mutating any state. Returns None if every remaining row group would be skipped under the current selection/budget, or if the queue is empty.

Runs the real Self::next_readable_row_group advance logic on a throwaway clone of the frontier, so peek can never drift from the read path. The clone copies the queued row-group plan and selections; see RemainingRowGroups::peek_next_row_group.

pub(crate) fn row_groups_remaining(&self) -> usize

Number of row groups not yet handed to the builder.

pub(crate) fn into_parts( self, ) -> (Arc<ParquetMetaData>, RowGroupPlan, RowBudget)

Decompose into the metadata, the row groups not yet handed to the builder, and the remaining offset/limit budget.

fn clear_remaining(&mut self)

fn plan_selected_row_group( &self, next_row_group: NextRowGroup, selected_rows: usize, ) -> QueuedRowGroupDecision

Plan whether a selected row group should be read or skipped.

Selection-only skips are handled before this method is called. This method applies the remaining offset/limit budget and predicate conservatism.

pub(crate) fn next_readable_row_group( &mut self, ) -> Result<Option<NextRowGroup>, ParquetError>

Advance queued row groups until one should be handed to the builder.

Trait Implementations

impl Clone for RowGroupFrontier

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RowGroupFrontier

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

Formats the value using the given formatter.