Struct Labels 

pub struct Labels { /* private fields */ }

An immutable set of key-value label pairs.

Implementations

impl Labels

pub fn empty() -> Self

pub fn of(key: impl Into<String>, value: impl Into<String>) -> Self

pub fn with(&self, key: impl Into<String>, value: impl Into<String>) -> Self

pub fn extend(&self, child: &Labels) -> Labels

pub fn get(&self, key: &str) -> Option<&str>

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn iter(&self) -> impl Iterator<Item = (&str, &str)>

pub fn to_prometheus(&self) -> String

pub fn to_dotted(&self) -> String

pub fn identity_hash(&self) -> u64

Content-defined identity hash for this label set.

Stability contract:

• Order-independent — pairs are sorted by key before hashing, so Labels::of("a","1").with("b","2") and Labels::of("b","2").with("a","1") hash to the same value. Without this, two code paths that construct “the same” label set in different orders create two distinct metric_instance rows in the sqlite sink — a silent double-count on every aggregate query.
• Uses FNV-1a 64 (defined inline). DefaultHasher (SipHasher13) is deterministic within a Rust version but the std docs explicitly reserve the right to change it — anything that writes a hash to durable storage needs a hasher that we own.

pub fn sorted_pairs(&self) -> Vec<(&str, &str)>

Canonical sorted-by-key view of the pairs, borrowed. Used by reporters that need a stable serialised form (filename, db spec, etc.) so the on-disk identity matches identity_hash.

pub fn to_canonical_spec(&self, metric_name: &str) -> String

Build the OpenMetrics-canonical sample identifier for this label set under the given metric family name — the text form used by Prometheus, OpenMetrics, and VictoriaMetrics for uniquely naming a time series.

Shape: metric_name{key="value",key="value"}

• Labels are sorted by name (canonical: two label dicts that are equal as a mapping produce equal spec text).
• __name__ is excluded from the labels block (the metric name is the prefix, per spec); other code paths still see __name__ as a regular label row in the database for query uniformity.
• Empty label values are dropped (OpenMetrics spec §“Label”: “Empty label values SHOULD be treated as if the label was not present”).
• Values are escaped per OpenMetrics §“Escaping”: \ → \\, " → \", \n → \n literal.

Trait Implementations

impl Clone for Labels

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Labels

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

Formats the value using the given formatter.

impl Default for Labels

fn default() -> Self

Returns the “default value” for a type.

impl Display for Labels

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

Formats the value using the given formatter.

impl Eq for Labels

impl Hash for Labels

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Labels

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Labels