Method downcast_to_file_source

datafusion/datasource/src/source.rs:597–608

Downcast the `DataSourceExec`'s `data_source` to a specific file source Returns `None` if 1. the datasource is not scanning files (`FileScanConfig`) 2. The [`FileScanConfig::file_source`] is not of type `T`

(
        &self,
    )

    /// 1. the datasource is not scanning files (`FileScanConfig`)
    /// 2. The [`FileScanConfig::file_source`] is not of type `T`
    pub fn downcast_to_file_source<T: FileSource>(
        &self,
    ) -> Option<(&FileScanConfig, &T)> {
        self.data_source()
            .downcast_ref::<FileScanConfig>()
            .and_then(|file_scan_conf| {
                file_scan_conf
                    .file_source()
                    .downcast_ref::<T>()
                    .map(|source| (file_scan_conf, source))
            })
    }
}

/// Create a new `DataSourceExec` from a `DataSource`