Function get_last_offset

arrow-data/src/transform/utils.rs:49–59

(offset_buffer: &MutableBuffer)

#[inline]
pub(super) unsafe fn get_last_offset<T: ArrowNativeType>(offset_buffer: &MutableBuffer) -> T {
    // JUSTIFICATION
    //  Benefit
    //      20% performance improvement extend of variable sized arrays (see bench `mutable_array`)
    //  Soundness
    //      * offset buffer is always extended in slices of T and aligned accordingly.
    //      * Buffer[0] is initialized with one element, 0, and thus `mutable_offsets.len() - 1` is always valid.
    let (prefix, offsets, suffix) = unsafe { offset_buffer.as_slice().align_to::<T>() };
    debug_assert!(prefix.is_empty() && suffix.is_empty());
    *unsafe { offsets.get_unchecked(offsets.len() - 1) }
}

#[cfg(test)]
mod tests {