datafusion-datasource 46.0.1

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//   http://www.apache.org/licenses/LICENSE-2.0
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//! Common behaviors that every file format needs to implement

use std::any::Any;
use std::fmt;
use std::fmt::Formatter;
use std::sync::Arc;

use crate::file_groups::FileGroupPartitioner;
use crate::file_scan_config::FileScanConfig;
use crate::file_stream::FileOpener;
use arrow::datatypes::SchemaRef;
use datafusion_common::Statistics;
use datafusion_physical_expr::LexOrdering;
use datafusion_physical_plan::metrics::ExecutionPlanMetricsSet;
use datafusion_physical_plan::DisplayFormatType;

use object_store::ObjectStore;

/// Common file format behaviors needs to implement.
///
/// See implementation examples such as `ParquetSource`, `CsvSource`
pub trait FileSource: Send + Sync {
    /// Creates a `dyn FileOpener` based on given parameters
    fn create_file_opener(
        &self,
        object_store: Arc<dyn ObjectStore>,
        base_config: &FileScanConfig,
        partition: usize,
    ) -> Arc<dyn FileOpener>;
    /// Any
    fn as_any(&self) -> &dyn Any;
    /// Initialize new type with batch size configuration
    fn with_batch_size(&self, batch_size: usize) -> Arc<dyn FileSource>;
    /// Initialize new instance with a new schema
    fn with_schema(&self, schema: SchemaRef) -> Arc<dyn FileSource>;
    /// Initialize new instance with projection information
    fn with_projection(&self, config: &FileScanConfig) -> Arc<dyn FileSource>;
    /// Initialize new instance with projected statistics
    fn with_statistics(&self, statistics: Statistics) -> Arc<dyn FileSource>;
    /// Return execution plan metrics
    fn metrics(&self) -> &ExecutionPlanMetricsSet;
    /// Return projected statistics
    fn statistics(&self) -> datafusion_common::Result<Statistics>;
    /// String representation of file source such as "csv", "json", "parquet"
    fn file_type(&self) -> &str;
    /// Format FileType specific information
    fn fmt_extra(&self, _t: DisplayFormatType, _f: &mut Formatter) -> fmt::Result {
        Ok(())
    }

    /// If supported by the [`FileSource`], redistribute files across partitions according to their size.
    /// Allows custom file formats to implement their own repartitioning logic.
    ///
    /// Provides a default repartitioning behavior, see comments on [`FileGroupPartitioner`] for more detail.
    fn repartitioned(
        &self,
        target_partitions: usize,
        repartition_file_min_size: usize,
        output_ordering: Option<LexOrdering>,
        config: &FileScanConfig,
    ) -> datafusion_common::Result<Option<FileScanConfig>> {
        if config.file_compression_type.is_compressed() || config.new_lines_in_values {
            return Ok(None);
        }

        let repartitioned_file_groups_option = FileGroupPartitioner::new()
            .with_target_partitions(target_partitions)
            .with_repartition_file_min_size(repartition_file_min_size)
            .with_preserve_order_within_groups(output_ordering.is_some())
            .repartition_file_groups(&config.file_groups);

        if let Some(repartitioned_file_groups) = repartitioned_file_groups_option {
            let mut source = config.clone();
            source.file_groups = repartitioned_file_groups;
            return Ok(Some(source));
        }
        Ok(None)
    }
}