Struct SimpleStructScheduler

pub struct SimpleStructScheduler { /* private fields */ }

A scheduler for structs

The implementation is actually a bit more tricky than one might initially think. We can’t just go through and schedule each column one after the other. This would mean our decode can’t start until nearly all the data has arrived (since we need data from each column)

Instead, we schedule in row-major fashion

Note: this scheduler is the starting point for all decoding. This is because we treat the top-level record batch as a non-nullable struct.

Implementations

impl SimpleStructScheduler

pub fn new(children: Vec<Arc<dyn FieldScheduler>>, child_fields: Fields) -> Self

Trait Implementations

impl Debug for SimpleStructScheduler

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

Formats the value using the given formatter.

impl FieldScheduler for SimpleStructScheduler

fn schedule_ranges<'a>( &'a self, ranges: &[Range<u64>], filter: &FilterExpression, ) -> Result<Box<dyn SchedulingJob + 'a>>

Schedules I/O for the requested portions of the field.

fn num_rows(&self) -> u64

The number of rows in this field

fn initialize<'a>( &'a self, _filter: &'a FilterExpression, _context: &'a SchedulerContext, ) -> BoxFuture<'a, Result<()>>

Called at the beginning of scheduling to initialize the scheduler