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datafusion_federation/schema_cast/
mod.rs

1use async_stream::stream;
2use datafusion::arrow::datatypes::SchemaRef;
3use datafusion::common::Statistics;
4use datafusion::config::ConfigOptions;
5use datafusion::error::{DataFusionError, Result};
6use datafusion::execution::{SendableRecordBatchStream, TaskContext};
7use datafusion::physical_plan::filter_pushdown::{FilterDescription, FilterPushdownPhase};
8use datafusion::physical_plan::metrics::{BaselineMetrics, ExecutionPlanMetricsSet, MetricsSet};
9use datafusion::physical_plan::stream::RecordBatchStreamAdapter;
10use datafusion::physical_plan::{
11    DisplayAs, DisplayFormatType, ExecutionPlan, ExecutionPlanProperties, PhysicalExpr,
12    PlanProperties,
13};
14use futures::StreamExt;
15use std::any::Any;
16use std::clone::Clone;
17use std::fmt;
18use std::sync::Arc;
19
20mod intervals_cast;
21mod lists_cast;
22pub mod record_convert;
23mod struct_cast;
24
25#[derive(Debug)]
26#[allow(clippy::module_name_repetitions)]
27pub struct SchemaCastScanExec {
28    input: Arc<dyn ExecutionPlan>,
29    schema: SchemaRef,
30    properties: PlanProperties,
31    metrics_set: ExecutionPlanMetricsSet,
32}
33
34impl SchemaCastScanExec {
35    pub fn new(input: Arc<dyn ExecutionPlan>, schema: SchemaRef) -> Self {
36        let eq_properties = input.equivalence_properties().clone();
37        let emission_type = input.pipeline_behavior();
38        let boundedness = input.boundedness();
39        let properties = PlanProperties::new(
40            eq_properties,
41            input.output_partitioning().clone(),
42            emission_type,
43            boundedness,
44        );
45        Self {
46            input,
47            schema,
48            properties,
49            metrics_set: ExecutionPlanMetricsSet::new(),
50        }
51    }
52}
53
54impl DisplayAs for SchemaCastScanExec {
55    fn fmt_as(&self, _t: DisplayFormatType, f: &mut fmt::Formatter) -> fmt::Result {
56        write!(f, "SchemaCastScanExec")
57    }
58}
59
60impl ExecutionPlan for SchemaCastScanExec {
61    fn name(&self) -> &str {
62        "SchemaCastScanExec"
63    }
64
65    fn as_any(&self) -> &dyn Any {
66        self
67    }
68
69    fn properties(&self) -> &PlanProperties {
70        &self.properties
71    }
72
73    fn schema(&self) -> SchemaRef {
74        Arc::clone(&self.schema)
75    }
76
77    fn children(&self) -> Vec<&Arc<dyn ExecutionPlan>> {
78        vec![&self.input]
79    }
80
81    /// Prevents the introduction of additional `RepartitionExec` and processing input in parallel.
82    /// This guarantees that the input is processed as a single stream, preserving the order of the data.
83    fn benefits_from_input_partitioning(&self) -> Vec<bool> {
84        vec![false]
85    }
86
87    fn with_new_children(
88        self: Arc<Self>,
89        children: Vec<Arc<dyn ExecutionPlan>>,
90    ) -> Result<Arc<dyn ExecutionPlan>> {
91        if children.len() == 1 {
92            Ok(Arc::new(Self::new(
93                Arc::clone(&children[0]),
94                Arc::clone(&self.schema),
95            )))
96        } else {
97            Err(DataFusionError::Execution(
98                "SchemaCastScanExec expects exactly one input".to_string(),
99            ))
100        }
101    }
102
103    fn execute(
104        &self,
105        partition: usize,
106        context: Arc<TaskContext>,
107    ) -> Result<SendableRecordBatchStream> {
108        let mut stream = self.input.execute(partition, context)?;
109        let schema = Arc::clone(&self.schema);
110        let baseline_metrics = BaselineMetrics::new(&self.metrics_set, partition);
111
112        Ok(Box::pin(RecordBatchStreamAdapter::new(
113            Arc::clone(&schema),
114            {
115                stream! {
116                    while let Some(batch) = stream.next().await {
117                        let _timer = baseline_metrics.elapsed_compute().timer();
118                        let batch = record_convert::try_cast_to(batch?, Arc::clone(&schema));
119                        let batch = batch.map_err(|e| { DataFusionError::External(Box::new(e)) });
120                        if let Ok(ref b) = batch {
121                            baseline_metrics.output_rows().add(b.num_rows());
122                        }
123                        yield batch;
124                    }
125                }
126            },
127        )))
128    }
129
130    fn partition_statistics(&self, partition: Option<usize>) -> Result<Statistics> {
131        self.input.partition_statistics(partition)
132    }
133
134    fn metrics(&self) -> Option<MetricsSet> {
135        Some(self.metrics_set.clone_inner())
136    }
137
138    fn gather_filters_for_pushdown(
139        &self,
140        _phase: FilterPushdownPhase,
141        parent_filters: Vec<Arc<dyn PhysicalExpr>>,
142        _config: &ConfigOptions,
143    ) -> Result<FilterDescription> {
144        FilterDescription::from_children(parent_filters, &self.children())
145    }
146}