Trait parquet::file::reader::FileReader

pub trait FileReader {
    fn metadata(&self) -> ParquetMetaDataPtr;
    fn num_row_groups(&self) -> usize;
    fn get_row_group(&self, i: usize) -> Result<Box<dyn RowGroupReader>>;
    fn get_row_iter(&self, projection: Option<SchemaType>) -> Result<RowIter>;
}

Parquet file reader API. With this, user can get metadata information about the Parquet file, can get reader for each row group, and access record iterator.

Required Methods

fn metadata(&self) -> ParquetMetaDataPtr

Get metadata information about this file.

fn num_row_groups(&self) -> usize

Get the total number of row groups for this file.

fn get_row_group(&self, i: usize) -> Result<Box<dyn RowGroupReader>>

Get the ith row group reader. Note this doesn't do bound check.

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

Get full iterator of Rows from a file (over all row groups).

Iterator will automatically load the next row group to advance.

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> FileReader for SerializedFileReader<R>

fn metadata(&self) -> ParquetMetaDataPtr

fn num_row_groups(&self) -> usize

fn get_row_group(&self, i: usize) -> Result<Box<dyn RowGroupReader>>

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