Minor: refactor probe check into function should_skip_aggregation (#11821)

Author: alamb

datafusion/physical-plan/src/aggregates/row_hash.rs

@@ -635,11 +635,7 @@ impl Stream for GroupedHashAggregateStream {
                         (
                             if self.input_done {
                                 ExecutionState::Done
-                            } else if self
-                                .skip_aggregation_probe
-                                .as_ref()
-                                .is_some_and(|probe| probe.should_skip())
-                            {
+                            } else if self.should_skip_aggregation() {
                                 ExecutionState::SkippingAggregation
                             } else {
                                 ExecutionState::ReadingInput
@@ -955,12 +951,13 @@ impl GroupedHashAggregateStream {
         Ok(())
     }
 
-    // Updates skip aggregation probe state.
-    // In case stream has any spills, the probe is forcefully set to
-    // forbid aggregation skipping, and locked, since spilling resets
-    // total number of unique groups.
-    //
-    // Note: currently spilling is not supported for Partial aggregation
+    /// Updates skip aggregation probe state.
+    ///
+    /// In case stream has any spills, the probe is forcefully set to
+    /// forbid aggregation skipping, and locked, since spilling resets
+    /// total number of unique groups.
+    ///
+    /// Note: currently spilling is not supported for Partial aggregation
     fn update_skip_aggregation_probe(&mut self, input_rows: usize) {
         if let Some(probe) = self.skip_aggregation_probe.as_mut() {
             if !self.spill_state.spills.is_empty() {
@@ -971,8 +968,8 @@ impl GroupedHashAggregateStream {
         };
     }
 
-    // In case the probe indicates that aggregation may be
-    // skipped, forces stream to produce currently accumulated output.
+    /// In case the probe indicates that aggregation may be
+    /// skipped, forces stream to produce currently accumulated output.
     fn switch_to_skip_aggregation(&mut self) -> Result<()> {
         if let Some(probe) = self.skip_aggregation_probe.as_mut() {
             if probe.should_skip() {
@@ -984,7 +981,15 @@ impl GroupedHashAggregateStream {
         Ok(())
     }
 
-    // Transforms input batch to intermediate aggregate state, without grouping it
+    /// Returns true if the aggregation probe indicates that aggregation
+    /// should be skipped.
+    fn should_skip_aggregation(&self) -> bool {
+        self.skip_aggregation_probe
+            .as_ref()
+            .is_some_and(|probe| probe.should_skip())
+    }
+
+    /// Transforms input batch to intermediate aggregate state, without grouping it
     fn transform_to_states(&self, batch: RecordBatch) -> Result<RecordBatch> {
         let group_values = evaluate_group_by(&self.group_by, &batch)?;
         let input_values = evaluate_many(&self.aggregate_arguments, &batch)?;