Enum SignedRoaringBitmap 

pub enum SignedRoaringBitmap {
    Include(RoaringBitmap),
    Exclude(RoaringBitmap),
}

This enum helps to delay the evaluation of set minus in metadata filtering:

• Include(rbm) suggests the result contains the specified ids in rbm. For example, <k>: {$eq: <v>} will result in a Include(<record ids with k=v>).
• Exclude(rbm) suggests the result exludes the specified ids in rbm. For example, <k>: {$ne: <v>} will result in a Exclude(<record ids with k=v>)

Without this, we need to figure out the set of existing ids when we evaluate $ne, $nin, and $not_contains, but this is not always necessary and may lead to overheads. Let’s consider the following where clause as an example:

{$and: [{<k0>: {$gt: <v0>}}, {<k1>: {$ne: <v1>}}]}

The naive way is to evaluate the $gt and $ne seperately and take the conjunction, but this requires us to know the full set of existing ids because it is needed to evaluate $ne. However, we can first evaluate $gt and then exclude the offset ids for records with metadata k1=v1. This behavior is captured in the BitAnd::bitand operator of SignedRoaringBitmap:

• A bitand between Include(...) and Exclude(...) will always result in Include(...)
• This process does not require the knowledge of the full domain
• The domain is needed only when we have to convert an Exclude(...) to the actual result in the end.

In summary, this enum distinguishes the results that depends on the domain and those that do not:

• Include(...) does not depend on the domain
• Exclude(...) depends on the domain We only need to figure out the domain (i.e. the set of ids for existing records) when it is necessary to do so.

Variants

Include(RoaringBitmap)

Exclude(RoaringBitmap)

Implementations

impl SignedRoaringBitmap

pub fn empty() -> Self

pub fn full() -> Self

pub fn contains(&self, value: u32) -> bool

pub fn flip(self) -> Self

Trait Implementations

impl BitAnd for SignedRoaringBitmap

type Output = SignedRoaringBitmap

The resulting type after applying the & operator.

fn bitand(self, rhs: Self) -> Self

Performs the & operation.

impl BitOr for SignedRoaringBitmap

type Output = SignedRoaringBitmap

The resulting type after applying the | operator.

fn bitor(self, rhs: Self) -> Self::Output

Performs the | operation.

impl Clone for SignedRoaringBitmap

fn clone(&self) -> SignedRoaringBitmap

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SignedRoaringBitmap

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

Formats the value using the given formatter.

impl PartialEq for SignedRoaringBitmap

fn eq(&self, other: &SignedRoaringBitmap) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for SignedRoaringBitmap