Trait FilterKernel

Source

pub trait FilterKernel: VTable {
    // Required method
    fn filter(
        &self,
        array: &Self::Array,
        selection_mask: &Mask,
    ) -> VortexResult<ArrayRef>;
}

Required Methods§

Source

fn filter( &self, array: &Self::Array, selection_mask: &Mask, ) -> VortexResult<ArrayRef>

Filter an array by the provided predicate.

§Preconditions

The entrypoint filter functions will handle Mask::AllTrue and Mask::AllFalse on the selection mask, leaving only Mask::Values to be handled by this function.

Additionally, the array length is guaranteed to have the same length as the selection mask.

Finally, the array validity mask is guaranteed not to have a true count of 0 (all nulls).

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§

Source §

impl FilterKernel for FixedSizeListVTable

Filter implementation for FixedSizeListArray.

Expands the selection mask to cover all elements within selected lists and pushes the expanded mask down to the child elements array.

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impl FilterKernel for ListVTable

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impl FilterKernel for ListViewVTable

ListViewArray filter implementation.

This implementation is deliberately simple and read-optimized. We just filter the offsets and sizes arrays and reuse the original elements array. This works because ListView (unlike List) allows non-contiguous and out-of-order lists.

We don’t slice the elements array because it would require computing min/max offsets and adjusting all offsets accordingly, which is not really worth the small potential memory we would be able to get back.

The trade-off is that we may keep unreferenced elements in memory, but this is acceptable since we’re optimizing for read performance and the data isn’t being copied.

Source §