remove more code

Author: adriangb

datafusion/datasource-parquet/src/row_filter.rs

@@ -366,22 +366,6 @@ fn pushdown_columns(
         .then_some(checker.required_columns.into_iter().collect()))
 }
 
-/// creates a PushdownChecker for a single use to check a given column with the given schemes. Used
-/// to check preemptively if a column name would prevent pushdowning.
-/// effectively does the inverse of [`pushdown_columns`] does, but with a single given column
-/// (instead of traversing the entire tree to determine this)
-fn would_column_prevent_pushdown(column_name: &str, file_schema: &Schema) -> bool {
-    let mut checker = PushdownChecker::new(file_schema);
-
-    // the return of this is only used for [`PushdownChecker::f_down()`], so we can safely ignore
-    // it here. I'm just verifying we know the return type of this so nobody accidentally changes
-    // the return type of this fn and it gets implicitly ignored here.
-    let _: Option<TreeNodeRecursion> = checker.check_single_column(column_name);
-
-    // and then return a value based on the state of the checker
-    checker.prevents_pushdown()
-}
-
 /// Recurses through expr as a tree, finds all `column`s, and checks if any of them would prevent
 /// this expression from being predicate pushed down. If any of them would, this returns false.
 /// Otherwise, true.
@@ -391,21 +375,7 @@ pub(crate) fn can_expr_be_pushed_down_with_schemas(
     expr: &Arc<dyn PhysicalExpr>,
     file_schema: &Schema,
 ) -> bool {
-    let mut can_be_pushed = true;
-    expr.apply(|expr| {
-        if let Some(column) = expr.as_any().downcast_ref::<Column>() {
-            can_be_pushed &= !would_column_prevent_pushdown(column.name(), file_schema);
-            Ok(if can_be_pushed {
-                TreeNodeRecursion::Jump
-            } else {
-                TreeNodeRecursion::Stop
-            })
-        } else {
-            Ok(TreeNodeRecursion::Continue)
-        }
-    })
-    .unwrap(); // we never return an Err, so we can safely unwrap this
-    can_be_pushed
+    pushdown_columns(expr, file_schema).is_ok()
 }
 
 /// Calculate the total compressed size of all `Column`'s required for