Struct opentelemetry::api::correlation::CorrelationContext

pub struct CorrelationContext { /* fields omitted */ }

A set of name/value pairs describing user-defined properties across systems.

Implementations

impl CorrelationContext

pub fn new() -> Self

Creates an empty CorrelationContext.

pub fn get<T: Into<Key>>(&self, key: T) -> Option<&Value>

Returns a reference to the value associated with a given name

Examples

use opentelemetry::api::{CorrelationContext, Value};

let mut cc = CorrelationContext::new();
let _ = cc.insert("my-name", "my-value");

assert_eq!(cc.get("my-name"), Some(&Value::String("my-value".to_string())))

pub fn insert<K, V>(&mut self, key: K, value: V) -> Option<Value> where
    K: Into<Key>,
    V: Into<Value>, 

Inserts a name-value pair into the correlation context.

If the name was not present, None is returned. If the name was present, the value is updated, and the old value is returned.

Examples

use opentelemetry::api::{CorrelationContext, Value};

let mut cc = CorrelationContext::new();
let _ = cc.insert("my-name", "my-value");

assert_eq!(cc.get("my-name"), Some(&Value::String("my-value".to_string())))

pub fn remove<K: Into<Key>>(&mut self, key: K) -> Option<Value>

Removes a name from the correlation context, returning the value corresponding to the name if the pair was previously in the map.

pub fn len(&self) -> usize

Returns the number of attributes for this correlation context

pub fn is_empty(&self) -> bool

Returns true if the correlation context contains no items.

pub fn iter(&self) -> Iterⓘ

Important traits for Iter<'a>

impl<'a> Iterator for Iter<'a> type Item = (&'a Key, &'a Value);

Gets an iterator over the correlation context items, sorted by name.

Trait Implementations

impl Debug for CorrelationContext

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

Formats the value using the given formatter.

impl Default for CorrelationContext

fn default() -> CorrelationContext

Returns the "default value" for a type.

impl FromIterator<(Key, Value)> for CorrelationContext

fn from_iter<I: IntoIterator<Item = (Key, Value)>>(iter: I) -> Self

Creates a value from an iterator.

impl FromIterator<KeyValue> for CorrelationContext

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

Creates a value from an iterator.

impl<'a> IntoIterator for &'a CorrelationContext

type Item = (&'a Key, &'a Value)

The type of the elements being iterated over.

type IntoIter = Iter<'a>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.