datafusion 1.0.1

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//   http://www.apache.org/licenses/LICENSE-2.0
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//! ExecutionPlan implementation for DataFusion data sources

use std::sync::{Arc, Mutex};

use crate::error::Result;
use crate::execution::physical_plan::{ExecutionPlan, Partition};
use arrow::datatypes::SchemaRef;
use arrow::record_batch::RecordBatchReader;

/// Datasource execution plan
pub struct DatasourceExec {
    schema: SchemaRef,
    partitions: Vec<Arc<Mutex<dyn RecordBatchReader + Send + Sync>>>,
}

impl DatasourceExec {
    /// Create a new data source execution plan
    pub fn new(
        schema: SchemaRef,
        partitions: Vec<Arc<Mutex<dyn RecordBatchReader + Send + Sync>>>,
    ) -> Self {
        Self { schema, partitions }
    }
}

impl ExecutionPlan for DatasourceExec {
    fn schema(&self) -> SchemaRef {
        self.schema.clone()
    }

    fn partitions(&self) -> Result<Vec<Arc<dyn Partition>>> {
        Ok(self
            .partitions
            .iter()
            .map(|it| {
                Arc::new(DatasourcePartition::new(it.clone())) as Arc<dyn Partition>
            })
            .collect::<Vec<_>>())
    }
}

/// Wrapper to convert a `SendableRecordBatchReader` into a `Partition`.
pub struct DatasourcePartition {
    batch_iter: Arc<Mutex<dyn RecordBatchReader + Send + Sync>>,
}

impl DatasourcePartition {
    fn new(batch_iter: Arc<Mutex<dyn RecordBatchReader + Send + Sync>>) -> Self {
        Self { batch_iter }
    }
}

impl Partition for DatasourcePartition {
    fn execute(&self) -> Result<Arc<Mutex<dyn RecordBatchReader + Send + Sync>>> {
        Ok(self.batch_iter.clone())
    }
}