Trait parquet::arrow::array_reader::ArrayReader

pub trait ArrayReader {
    fn as_any(&self) -> &dyn Any;
    fn get_data_type(&self) -> &ArrowType;
    fn next_batch(&mut self, batch_size: usize) -> Result<ArrayRef>;
    fn get_def_levels(&self) -> Option<&[i16]>;
    fn get_rep_levels(&self) -> Option<&[i16]>;
}

Array reader reads parquet data into arrow array.

Required methods

fn as_any(&self) -> &dyn Any

fn get_data_type(&self) -> &ArrowType

Returns the arrow type of this array reader.

fn next_batch(&mut self, batch_size: usize) -> Result<ArrayRef>

Reads at most batch_size records into an arrow array and return it.

fn get_def_levels(&self) -> Option<&[i16]>

Returns the definition levels of data from last call of next_batch. The result is used by parent array reader to calculate its own definition levels and repetition levels, so that its parent can calculate null bitmap.

fn get_rep_levels(&self) -> Option<&[i16]>

Return the repetition levels of data from last call of next_batch. The result is used by parent array reader to calculate its own definition levels and repetition levels, so that its parent can calculate null bitmap.

Implementors

impl ArrayReader for MapArrayReader

impl ArrayReader for StructArrayReader

impl<C: ArrayConverter> ArrayReader for ArrowArrayReader<'static, C>

impl<OffsetSize: OffsetSizeTrait> ArrayReader for ListArrayReader<OffsetSize>

Implementation of ListArrayReader. Nested lists and lists of structs are not yet supported.

impl<T, C> ArrayReader for ComplexObjectArrayReader<T, C> where
    T: DataType,
    C: Converter<Vec<Option<T::T>>, ArrayRef> + 'static, 

impl<T: DataType> ArrayReader for NullArrayReader<T>

Implementation of primitive array reader.

impl<T: DataType> ArrayReader for PrimitiveArrayReader<T>

Implementation of primitive array reader.