Struct parquet::arrow::arrow_reader::ArrowReaderMetadata

pub struct ArrowReaderMetadata { /* private fields */ }

The cheaply clone-able metadata necessary to construct a ArrowReaderBuilder

This allows loading the metadata for a file once and then using this to construct multiple separate readers, for example, to distribute readers across multiple threads

Implementations

impl ArrowReaderMetadata

pub fn load<T: ChunkReader>( reader: &T, options: ArrowReaderOptions ) -> Result<Self>

Loads ArrowReaderMetadata from the provided ChunkReader

See ParquetRecordBatchReaderBuilder::new_with_metadata for how this can be used

pub fn metadata(&self) -> &Arc<ParquetMetaData>

Returns a reference to the ParquetMetaData for this parquet file

pub fn parquet_schema(&self) -> &SchemaDescriptor

Returns the parquet SchemaDescriptor for this parquet file

pub fn schema(&self) -> &SchemaRef

Returns the arrow SchemaRef for this parquet file

impl ArrowReaderMetadata

pub async fn load_async<T: AsyncFileReader>( input: &mut T, options: ArrowReaderOptions ) -> Result<Self>

Returns a new ArrowReaderMetadata for this builder

See ParquetRecordBatchStreamBuilder::new_with_metadata for how this can be used

Trait Implementations

impl Clone for ArrowReaderMetadata

fn clone(&self) -> ArrowReaderMetadata

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ArrowReaderMetadata

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

Formats the value using the given formatter.