Trait parquet::file::reader::FileReader

pub trait FileReader: Send + Sync {
    // Required methods
    fn metadata(&self) -> &ParquetMetaData;
    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) -> &ParquetMetaData

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 an iterator over the row in this file, see RowIter for caveats.

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 + ChunkReader> FileReader for SerializedFileReader<R>