Trait parquet::file::reader::RowGroupReader [−][src]
pub trait RowGroupReader { fn metadata(&self) -> RowGroupMetaDataPtr; fn num_columns(&self) -> usize; fn get_column_page_reader(&self, i: usize) -> Result<Box<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<PageReader>>
Get page reader for the i
th column chunk.
fn get_column_reader(&self, i: usize) -> Result<ColumnReader>
Get value reader for the i
th column chunk.
fn get_row_iter(&self, projection: Option<SchemaType>) -> Result<RowIter>
Get iterator of Row
s 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 RowGroupReader for SerializedRowGroupReader