chore: remove DataPtr trait since Arc::ptr_eq ignores pointer metadata (#10378)

* chore: remove DataPtr trait since Arc::ptr_eq ignores pointer metadata

* fix: remove DataPtr unit tests

Author: intoraw

datafusion/common/src/utils.rs

@@ -525,34 +525,6 @@ pub fn list_ndims(data_type: &DataType) -> u64 {
     }
 }
 
-/// An extension trait for smart pointers. Provides an interface to get a
-/// raw pointer to the data (with metadata stripped away).
-///
-/// This is useful to see if two smart pointers point to the same allocation.
-pub trait DataPtr {
-    /// Returns a raw pointer to the data, stripping away all metadata.
-    fn data_ptr(this: &Self) -> *const ();
-
-    /// Check if two pointers point to the same data.
-    fn data_ptr_eq(this: &Self, other: &Self) -> bool {
-        // Discard pointer metadata (including the v-table).
-        let this = Self::data_ptr(this);
-        let other = Self::data_ptr(other);
-
-        std::ptr::eq(this, other)
-    }
-}
-
-// Currently, it's brittle to compare `Arc`s of dyn traits with `Arc::ptr_eq`
-// due to this check including v-table equality. It may be possible to use
-// `Arc::ptr_eq` directly if a fix to https://github.com/rust-lang/rust/issues/103763
-// is stabilized.
-impl<T: ?Sized> DataPtr for Arc<T> {
-    fn data_ptr(this: &Self) -> *const () {
-        Arc::as_ptr(this) as *const ()
-    }
-}
-
 /// Adopted from strsim-rs for string similarity metrics
 pub mod datafusion_strsim {
     // Source: https://github.com/dguo/strsim-rs/blob/master/src/lib.rs
@@ -974,26 +946,6 @@ mod tests {
         assert_eq!(longest_consecutive_prefix([1, 2, 3, 4]), 0);
     }
 
-    #[test]
-    fn arc_data_ptr_eq() {
-        let x = Arc::new(());
-        let y = Arc::new(());
-        let y_clone = Arc::clone(&y);
-
-        assert!(
-            Arc::data_ptr_eq(&x, &x),
-            "same `Arc`s should point to same data"
-        );
-        assert!(
-            !Arc::data_ptr_eq(&x, &y),
-            "different `Arc`s should point to different data"
-        );
-        assert!(
-            Arc::data_ptr_eq(&y, &y_clone),
-            "cloned `Arc` should point to same data as the original"
-        );
-    }
-
     #[test]
     fn test_merge_and_order_indices() {
         assert_eq!(

datafusion/core/src/physical_optimizer/join_selection.rs

@@ -1544,7 +1544,6 @@ mod hash_join_tests {
 
     use arrow::datatypes::{DataType, Field};
     use arrow::record_batch::RecordBatch;
-    use datafusion_common::utils::DataPtr;
 
     struct TestCase {
         case: String,
@@ -1937,8 +1936,8 @@ mod hash_join_tests {
             ..
         }) = plan.as_any().downcast_ref::<HashJoinExec>()
         {
-            let left_changed = Arc::data_ptr_eq(left, &right_exec);
-            let right_changed = Arc::data_ptr_eq(right, &left_exec);
+            let left_changed = Arc::ptr_eq(left, &right_exec);
+            let right_changed = Arc::ptr_eq(right, &left_exec);
             // If this is not equal, we have a bigger problem.
             assert_eq!(left_changed, right_changed);
             assert_eq!(

datafusion/physical-expr-common/src/physical_expr.rs

@@ -24,7 +24,6 @@ use arrow::array::BooleanArray;
 use arrow::compute::filter_record_batch;
 use arrow::datatypes::{DataType, Schema};
 use arrow::record_batch::RecordBatch;
-use datafusion_common::utils::DataPtr;
 use datafusion_common::{internal_err, not_impl_err, Result};
 use datafusion_expr::interval_arithmetic::Interval;
 use datafusion_expr::ColumnarValue;
@@ -188,7 +187,7 @@ pub fn with_new_children_if_necessary(
         || children
             .iter()
             .zip(old_children.iter())
-            .any(|(c1, c2)| !Arc::data_ptr_eq(c1, c2))
+            .any(|(c1, c2)| !Arc::ptr_eq(c1, c2))
     {
         Ok(expr.with_new_children(children)?)
     } else {

datafusion/physical-plan/src/lib.rs

@@ -30,7 +30,6 @@ use crate::sorts::sort_preserving_merge::SortPreservingMergeExec;
 use arrow::datatypes::SchemaRef;
 use arrow::record_batch::RecordBatch;
 use datafusion_common::config::ConfigOptions;
-use datafusion_common::utils::DataPtr;
 use datafusion_common::Result;
 use datafusion_execution::TaskContext;
 use datafusion_physical_expr::{
@@ -684,7 +683,7 @@ pub fn with_new_children_if_necessary(
         || children
             .iter()
             .zip(old_children.iter())
-            .any(|(c1, c2)| !Arc::data_ptr_eq(c1, c2))
+            .any(|(c1, c2)| !Arc::ptr_eq(c1, c2))
     {
         plan.with_new_children(children)
     } else {