Struct StructuredRowReader

pub struct StructuredRowReader<'a> { /* private fields */ }

Reads rows from ORC files to a tree of vectors (one for each column)

Wrapper for RowReader which provides an alternative to RowReader::row_batch and RowReader::read_into, by returning an enum of VectorBatches whose type is dynamically chosen based on the file’s schema.

This avoids manually casting vector::OwnedColumnVectorBatch to vector::StructVectorBatch, vector::StringVectorBatch, … before reading its values.

Implementations

impl<'a> StructuredRowReader<'a>

pub fn new(row_reader: &'a mut RowReader, size: u64) -> StructuredRowReader<'a>

Consumes a RowReader to return a StructuredRowReader

size is the number of rows to read at once.

pub fn next<'b>(&'b mut self) -> Option<ColumnTree<'b>>

where 'a: 'b,

Returns the next batch of columns, if any.

This slightly differs from Iterator::next as only one value can exist at any time (because they reuse the same data buffer).