Struct ListLayoutStrategy 

pub struct ListLayoutStrategy { /* private fields */ }

Strategy for writing list-typed arrays, with a fallback for non-list dtypes.

This is a structural writer that decomposes a list column into independent elements, offsets, and (when nullable) validity sub-columns, each written through its own downstream strategy, producing a single ListLayout.

For list-typed input the strategy transposes the whole column stream into three sub-streams:

1. Each chunk is canonicalized to a ListArray (rebuilding a ListView via list_from_list_view when necessary).
2. offsets are rebased to global u64 positions (cumulative across chunks) so the single offsets child indexes into the concatenated elements child.
3. elements, offsets, and validity are streamed to their child strategies concurrently.

For input whose dtype is not DType::List, the stream is forwarded unchanged to the configured fallback strategy.

Implementations

impl ListLayoutStrategy

pub fn with_elements(self, elements: Arc<dyn LayoutStrategy>) -> Self

Strategy for the elements child.

pub fn with_offsets(self, offsets: Arc<dyn LayoutStrategy>) -> Self

Strategy for the offsets child.

pub fn with_validity(self, validity: Arc<dyn LayoutStrategy>) -> Self

Strategy for the validity child (written only when the list is nullable).

pub fn with_fallback(self, fallback: Arc<dyn LayoutStrategy>) -> Self

Strategy for non-list input, which is forwarded through this strategy unchanged.

Trait Implementations

impl Clone for ListLayoutStrategy

fn clone(&self) -> ListLayoutStrategy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Default for ListLayoutStrategy

fn default() -> Self

Routes every child (elements, offsets, validity) and the non-list fallback through FlatLayoutStrategy. Override individual children with the with_* builder methods.

impl LayoutStrategy for ListLayoutStrategy

fn write_stream<'life0, 'life1, 'async_trait>( &'life0 self, ctx: ArrayContext, segment_sink: SegmentSinkRef, stream: SendableSequentialStream, eof: SequencePointer, session: &'life1 VortexSession, ) -> Pin<Box<dyn Future<Output = VortexResult<LayoutRef>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Asynchronously process an ordered stream of array chunks, emitting them into a sink and returning the Layout instance that can be parsed to retrieve the data from rest.

fn buffered_bytes(&self) -> u64

Returns the number of bytes currently buffered by this strategy and any child strategies.