Trait parquet::file::reader::RowGroupReader

pub trait RowGroupReader {
    fn metadata(&self) -> RowGroupMetaDataPtr;
    fn num_columns(&self) -> usize;
    fn get_column_page_reader(&self, i: usize) -> Result<Box<dyn PageReader>>;
    fn get_column_reader(&self, i: usize) -> Result<ColumnReader>;
    fn get_row_iter(&self, projection: Option<SchemaType>) -> Result<RowIter>;
}

Parquet row group reader API. With this, user can get metadata information about the row group, as well as readers for each individual column chunk.

Required Methods

fn metadata(&self) -> RowGroupMetaDataPtr

Get metadata information about this row group.

fn num_columns(&self) -> usize

Get the total number of column chunks in this row group.

fn get_column_page_reader(&self, i: usize) -> Result<Box<dyn PageReader>>

Get page reader for the ith column chunk.

fn get_column_reader(&self, i: usize) -> Result<ColumnReader>

Get value reader for the ith column chunk.

fn get_row_iter(&self, projection: Option<SchemaType>) -> Result<RowIter>

Get iterator of Rows from this row group.

Projected schema can be a subset of or equal to the file schema, when it is None, full file schema is assumed.

Implementors

impl<R: 'static + ParquetReader> RowGroupReader for SerializedRowGroupReader<R>

fn metadata(&self) -> RowGroupMetaDataPtr

fn num_columns(&self) -> usize

fn get_column_page_reader(&self, i: usize) -> Result<Box<dyn PageReader>>

fn get_column_reader(&self, i: usize) -> Result<ColumnReader>

fn get_row_iter(&self, projection: Option<SchemaType>) -> Result<RowIter>