Struct Label

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

Metadata for a metric key in the form of a key/value pair.

Metrics are always defined by a name, but can optionally be assigned “labels”, which are key/value pairs that provide metadata about the key. Labels are typically used for differentiating the context of when an where a metric are emitted.

For example, in a web service, you might wish to label metrics with the user ID responsible for the request currently being processed, or the request path being processed. Another example may be that if you were running a piece o code that was turned on or off by a feature toggle, you may wish to include a label in metrics to indicate whether or not they were using the feature toggle.

Implementations

impl Label

pub fn new<K, V>(key: K, value: V) -> Label

where K: Into<Cow<'static, str>>, V: Into<Cow<'static, str>>,

Creates a Label from a key and value.

pub const fn from_static_parts(key: &'static str, value: &'static str) -> Label

Creates a Label from a static key and value.

pub fn key(&self) -> &str

Key of this label.

pub fn value(&self) -> &str

Value of this label.

pub fn into_parts(self) -> (Cow<'static, str>, Cow<'static, str>)

Consumes this Label, returning the key and value.

Trait Implementations

impl Clone for Label

fn clone(&self) -> Label

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Label

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

Formats the value using the given formatter.

impl<K, V> From<&(K, V)> for Label

where K: Into<Cow<'static, str>> + Clone, V: Into<Cow<'static, str>> + Clone,

fn from(pair: &(K, V)) -> Label

Converts to this type from the input type.

impl Hash for Label

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

where __H: Hasher,

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 Ord for Label

fn cmp(&self, other: &Label) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Label

fn eq(&self, other: &Label) -> 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 PartialOrd for Label

fn partial_cmp(&self, other: &Label) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for Label

impl StructuralPartialEq for Label