Struct LabelSet 

pub struct LabelSet(/* private fields */);

Shared, copy-on-write set of labels carried by one record.

Wraps an Arc<BTreeSet<LabelId>>. Cloning a record — and therefore the overlay delta maps that hold records, which a fresh writer seeds by cloning its parent’s — shares the same allocation instead of deep-copying the set. The first Self::insert into a SHARED set copies it once (Arc::make_mut); a uniquely owned set mutates in place. The serde representation is the plain label set, unchanged from the owned form.

Performance

clone is O(1) (an Arc increment). Self::insert is O(log labels) plus a one-time O(labels) copy when the set is still shared (copy-on-write). Self::contains is O(log labels); Self::len and Self::is_empty are O(1).

Implementations

impl LabelSet

pub fn iter(&self) -> impl Iterator<Item = LabelId> + '_

Iterates the labels in ascending order.

Performance

Creating the iterator is O(1); a full walk is O(labels).

pub fn contains(&self, label: &LabelId) -> bool

Returns whether label is present.

Performance

This method is O(log labels).

pub fn len(&self) -> usize

Returns the number of labels.

Performance

This method is O(1).

pub fn is_empty(&self) -> bool

Returns whether the set is empty.

Performance

This method is O(1).

pub fn insert(&mut self, label: LabelId) -> bool

Inserts label, returning whether it was newly added.

A no-op insert (the label is already present) never copies, so re-asserting a label on a record whose set is still shared with a parent overlay stays O(log labels).

Performance

This method is O(log labels), plus a one-time O(labels) copy-on-write when the set is shared and the label is new.

Trait Implementations

impl Clone for LabelSet

fn clone(&self) -> LabelSet

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LabelSet

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

Formats the value using the given formatter.

impl Default for LabelSet

fn default() -> LabelSet

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for LabelSet

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for LabelSet

impl FromIterator<LabelId> for LabelSet

fn from_iter<I: IntoIterator<Item = LabelId>>(iter: I) -> Self

Collects labels into a freshly owned (unshared) set.

Performance

This function is O(labels × log labels).

impl PartialEq for LabelSet

fn eq(&self, other: &LabelSet) -> 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 Serialize for LabelSet

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for LabelSet