Enum RowCells 

pub enum RowCells<'a> {
    Refs(&'a [&'a Value<'static>]),
    Values(&'a [Value<'static>]),
}

One row’s cells, in whichever shape the producer already holds them.

The channel used to be &[&Value] only, which cost a Vec<&Value> per row at the two producers that build their cells into a contiguous buffer: they had a &[Value] in hand and collected a second vector of pointers into it purely to satisfy the type. That is one heap allocation and one free per row — measured at 400k rows (round 957) as 9 ns/row, which on a narrow scan was 54-56% of the whole walk and on a wide one 8-19%.

The reason it could not simply reuse one buffer is that the values buffer is refilled each row, so any pointers into it die at the top of the next iteration; only an owner of the storage (the materialising path, whose rows outlive the loop) can hoist the pointer vector out. Handing the contiguous slice over directly removes the question instead of answering it.

Refs stays for producers whose cells really are scattered (a join projecting out of several rows).

Variants

Refs(&'a [&'a Value<'static>])

Values(&'a [Value<'static>])

Implementations

impl<'a> RowCells<'a>

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn get(&self, i: usize) -> Option<&'a Value<'static>>

Trait Implementations

impl<'a> Clone for RowCells<'a>

fn clone(&self) -> RowCells<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for RowCells<'a>

impl<'a> Debug for RowCells<'a>

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

Formats the value using the given formatter.