Method into_builder

arrow-array/src/array/primitive_array.rs:1121–1175

Returns a `PrimitiveBuilder` for this array, suitable for mutating values in place. # Buffer Reuse If the underlying data buffer has no other outstanding references, the buffer is used without copying. If the underlying data buffer does have outstanding references, returns `Err(self)`

(self)

    /// If the underlying data buffer does have outstanding references, returns
    /// `Err(self)`
    pub fn into_builder(self) -> Result<PrimitiveBuilder<T>, Self> {
        let len = self.len();
        let data = self.into_data();
        let null_bit_buffer = data.nulls().map(|b| b.inner().sliced());

        let element_len = std::mem::size_of::<T::Native>();
        let buffer =
            data.buffers()[0].slice_with_length(data.offset() * element_len, len * element_len);

        drop(data);

        let try_mutable_null_buffer = match null_bit_buffer {
            None => Ok(None),
            Some(null_buffer) => {
                // Null buffer exists, tries to make it mutable
                null_buffer.into_mutable().map(Some)
            }
        };

        let try_mutable_buffers = match try_mutable_null_buffer {
            Ok(mutable_null_buffer) => {
                // Got mutable null buffer, tries to get mutable value buffer
                let try_mutable_buffer = buffer.into_mutable();

                // try_mutable_buffer.map(...).map_err(...) doesn't work as the compiler complains
                // mutable_null_buffer is moved into map closure.
                match try_mutable_buffer {
                    Ok(mutable_buffer) => Ok(PrimitiveBuilder::<T>::new_from_buffer(
                        mutable_buffer,
                        mutable_null_buffer,
                    )),
                    Err(buffer) => Err((buffer, mutable_null_buffer.map(|b| b.into()))),
                }
            }
            Err(mutable_null_buffer) => {
                // Unable to get mutable null buffer
                Err((buffer, Some(mutable_null_buffer)))
            }
        };

        match try_mutable_buffers {
            Ok(builder) => Ok(builder),
            Err((buffer, null_bit_buffer)) => {
                let builder = ArrayData::builder(T::DATA_TYPE)
                    .len(len)
                    .add_buffer(buffer)
                    .null_bit_buffer(null_bit_buffer);

                let array_data = unsafe { builder.build_unchecked() };
                let array = PrimitiveArray::<T>::from(array_data);

                Err(array)
            }
        }
    }
}

impl<T: ArrowPrimitiveType> From<PrimitiveArray<T>> for ArrayData {