Struct ScanMetrics 

pub struct ScanMetrics { /* private fields */ }

Aggregate work counters for one scan. These expose only logical scan accounting; physical descriptor tables and decoder state remain private.

The two byte counters answer different questions and are deliberately kept apart. Self::stream_bytes_decoded is the work projection removes: the stored size of the streams the scan actually decoded. Self::bytes_read is what the scan cost the file system, and it is larger, because reading a block verifies the whole frame body against its commit trailer before any stream is decoded. Projection narrows the first number, not the second.

Implementations

impl ScanMetrics

pub fn blocks_considered(&self) -> u64

Number of committed blocks examined by the scan planner.

pub fn blocks_pruned(&self) -> u64

Number of blocks skipped using primary bounds before stream decoding.

pub fn streams_decoded(&self) -> u64

Number of physical streams successfully decoded.

pub fn stream_bytes_decoded(&self) -> u64

Stored byte count of the streams this scan decoded.

This is the measure projection and pruning reduce. It excludes every byte read for framing, block headers, and statistics; for the total cost of the scan use Self::bytes_read.

pub fn bytes_read(&self) -> u64

Total bytes this scan read from the file.

This counts every byte of every candidate block the scan touched: the frame envelope streamed to verify the body checksum, the block header, the decoded streams, and any statistics that were verified. Pruned blocks contribute nothing. It is a byte count taken from the lengths the reader actually reads, not an estimate from the file size.

pub fn rows_returned(&self) -> u64

Number of rows returned in yielded batches.

Trait Implementations

impl Clone for ScanMetrics

fn clone(&self) -> ScanMetrics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ScanMetrics

impl Debug for ScanMetrics

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

Formats the value using the given formatter.

impl Default for ScanMetrics

fn default() -> ScanMetrics

Returns the “default value” for a type.

impl Eq for ScanMetrics

impl PartialEq for ScanMetrics

fn eq(&self, other: &ScanMetrics) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ScanMetrics