(arrow-rs) branch main updated: Remove some `unsafe` and allocations when creating PrimitiveArrays from Vec and `from_trusted_len_iter` (#9299)

[alamb]

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alamb pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/arrow-rs.git


The following commit(s) were added to refs/heads/main by this push:
     new 1db1053901 Remove some `unsafe` and allocations when creating 
PrimitiveArrays from Vec and `from_trusted_len_iter` (#9299)
1db1053901 is described below

commit 1db105390144427604b5713a07e7ca8a745839b5
Author: Andrew Lamb <and...@nerdnetworks.org>
AuthorDate: Fri Jan 30 08:18:15 2026 -0500

    Remove some `unsafe` and allocations when creating PrimitiveArrays from Vec 
and `from_trusted_len_iter` (#9299)
    
    # Which issue does this PR close?
    
    - part of https://github.com/apache/arrow-rs/issues/9298
    
    
    # Rationale for this change
    
    While reviewing https://github.com/apache/arrow-rs/pull/9294 from
    @Dandandan I noticed some other places where we can avoid making
    ArrayData and thus save some allocations (and `unsafe`)
    
    I don't expect this to make a huge performance difference, but every
    little allocation helps, and I think the change is justified simply from
    the perspective of avoiding some more `unsafe`
    
    
    # What changes are included in this PR?
    
    Construct primitive arrays directly
    
    # Are these changes tested?
    
    By existing CI
    # Are there any user-facing changes?
    
    <!--
    If there are user-facing changes then we may require documentation to be
    updated before approving the PR.
    
    If there are any breaking changes to public APIs, please call them out.
    -->
---
 arrow-array/src/array/primitive_array.rs | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/arrow-array/src/array/primitive_array.rs 
b/arrow-array/src/array/primitive_array.rs
index 186bfca2d4..29189b450a 100644
--- a/arrow-array/src/array/primitive_array.rs
+++ b/arrow-array/src/array/primitive_array.rs
@@ -25,7 +25,9 @@ use crate::timezone::Tz;
 use crate::trusted_len::trusted_len_unzip;
 use crate::types::*;
 use crate::{Array, ArrayAccessor, ArrayRef, Scalar};
-use arrow_buffer::{ArrowNativeType, Buffer, NullBuffer, NullBufferBuilder, 
ScalarBuffer, i256};
+use arrow_buffer::{
+    ArrowNativeType, BooleanBuffer, Buffer, NullBuffer, NullBufferBuilder, 
ScalarBuffer, i256,
+};
 use arrow_data::bit_iterator::try_for_each_valid_idx;
 use arrow_data::{ArrayData, ArrayDataBuilder};
 use arrow_schema::{ArrowError, DataType};
@@ -1488,10 +1490,9 @@ impl<T: ArrowPrimitiveType> PrimitiveArray<T> {
 
         let (null, buffer) = unsafe { trusted_len_unzip(iterator) };
 
-        let data = unsafe {
-            ArrayData::new_unchecked(T::DATA_TYPE, len, None, Some(null), 0, 
vec![buffer], vec![])
-        };
-        PrimitiveArray::from(data)
+        let nulls =
+            Some(NullBuffer::new(BooleanBuffer::new(null, 0, len))).filter(|n| 
n.null_count() > 0);
+        PrimitiveArray::new(ScalarBuffer::from(buffer), nulls)
     }
 }
 
@@ -1502,11 +1503,9 @@ macro_rules! def_numeric_from_vec {
     ( $ty:ident ) => {
         impl From<Vec<<$ty as ArrowPrimitiveType>::Native>> for 
PrimitiveArray<$ty> {
             fn from(data: Vec<<$ty as ArrowPrimitiveType>::Native>) -> Self {
-                let array_data = ArrayData::builder($ty::DATA_TYPE)
-                    .len(data.len())
-                    .add_buffer(Buffer::from_vec(data));
-                let array_data = unsafe { array_data.build_unchecked() };
-                PrimitiveArray::from(array_data)
+                let buffer = ScalarBuffer::from(Buffer::from_vec(data));
+                let nulls = None;
+                PrimitiveArray::new(buffer, nulls)
             }
         }