Struct RowMask

pub struct RowMask { /* private fields */ }

A RowMask captures a set of selected rows within a range.

The range itself can be u64, but the length of the range must fit into a usize, this allows us to use a usize filter mask within a much larger file.

Implementations

impl RowMask

pub fn new(mask: Mask, begin: u64) -> Self

Define a new RowMask with the given mask and offset into the file.

pub fn new_valid_between(begin: u64, end: u64) -> Self

Construct a RowMask which is valid in the given range.

Panics

If the size of the range is too large to fit into a usize.

pub fn new_invalid_between(begin: u64, end: u64) -> Self

Construct a RowMask which is invalid everywhere in the given range.

pub fn from_array(array: &dyn Array, begin: u64, end: u64) -> VortexResult<Self>

Creates a RowMask from an array, only supported boolean and integer types.

pub fn is_disjoint(&self, range: impl RangeBounds<u64>) -> bool

Whether the mask is disjoint with the given range.

This function may return false negatives, but never false positives.

TODO(ngates): improve this function to take into account the Mask.

pub fn begin(&self) -> u64

The beginning of the masked range.

pub fn end(&self) -> u64

The end of the masked range.

pub fn len(&self) -> usize

The length of the mask is the number of possible rows between the begin and end, regardless of how many appear in the mask. For the number of masked rows, see true_count.

pub fn filter_mask(&self) -> &Mask

Returns the Mask whose true values are relative to the range of this RowMask.

pub fn slice(&self, begin: u64, end: u64) -> VortexResult<Self>

Limit mask to [begin..end) range

pub fn filter_array(&self, array: &dyn Array) -> VortexResult<Option<ArrayRef>>

Filter array with this RowMask.

This function assumes that Array is no longer than the mask length and that the mask starts on same offset as the array, i.e. the beginning of the array corresponds to the beginning of the mask with begin = 0

pub fn shift(self, offset: u64) -> VortexResult<RowMask>

Shift the RowMask down by the given offset.

pub fn true_count(&self) -> usize

The number of masked rows within the range.

Trait Implementations

impl Clone for RowMask

fn clone(&self) -> RowMask

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RowMask

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for RowMask

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.