[Rust] arithmetic without SIMD does unnecesary copy

[asfimport]

The arithmetic kernels that don't use SIMD create a vec in memory and later copy that data into a Buffer. Maybe we could directly write the arithmetic result to a mutable buffer and prevent this redundant copy?

 

 

    let values = (0..left.len())
                .map(|i| op(left.value(i), right.value(i))) 
                .collect::<Vec<T::Native>>();
     
      
            let data = ArrayData::new(
          T::get_data_type(),
                left.len(),
                None,
                null_bit_buffer,
                0,
                vec![Buffer::from(values.to_byte_slice())],
                vec![],
            );

 

Reporter: Ritchie / @ritchie46

_{Note: This issue was originally created as ARROW-10274. Please see the migration documentation for further details.}

[asfimport]

Jorge Leitão / @jorgecarleitao:

Maybe we could directly write the arithmetic result to a mutable buffer and prevent this redundant copy?

Yes :)

[asfimport]

Andrew Lamb / @alamb:
Migrated to github: apache/arrow-rs#110