Struct TraceState

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

TraceState carries system-specific configuration data, represented as a list of key-value pairs. TraceState allows multiple tracing systems to participate in the same trace.

Please review the W3C specification for details on this field.

Implementations

impl TraceState

pub const NONE: TraceState

The default TraceState, as a constant

pub fn from_key_value<T, K, V>(trace_state: T) -> Result<TraceState, TraceError>

where T: IntoIterator<Item = (K, V)>, K: ToString, V: ToString,

Creates a new TraceState from the given key-value collection.

Examples

use opentelemetry::trace::TraceState;

let kvs = vec![("foo", "bar"), ("apple", "banana")];
let trace_state = TraceState::from_key_value(kvs);

assert!(trace_state.is_ok());
assert_eq!(trace_state.unwrap().header(), String::from("foo=bar,apple=banana"))

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

Retrieves a value for a given key from the TraceState if it exists.

pub fn insert<K, V>(&self, key: K, value: V) -> Result<TraceState, TraceError>

where K: Into<String>, V: Into<String>,

Inserts the given key-value pair into the TraceState. If a value already exists for the given key, this updates the value and updates the value’s position. If the key or value are invalid per the W3 Spec an Err is returned, else a new TraceState with the updated key/value is returned.

pub fn delete<K>(&self, key: K) -> Result<TraceState, TraceError>

where K: Into<String>,

Removes the given key-value pair from the TraceState. If the key is invalid per the W3 Spec an Err is returned. Else, a new TraceState with the removed entry is returned.

If the key is not in TraceState. The original TraceState will be cloned and returned.

pub fn header(&self) -> String

Creates a new TraceState header string, delimiting each key and value with a = and each entry with a ,.

pub fn header_delimited( &self, entry_delimiter: &str, list_delimiter: &str, ) -> String

Creates a new TraceState header string, with the given key/value delimiter and entry delimiter.

Trait Implementations

impl Clone for TraceState

fn clone(&self) -> TraceState

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for TraceState

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

Formats the value using the given formatter.

impl Default for TraceState

fn default() -> TraceState

Returns the “default value” for a type.

impl FromStr for TraceState

type Err = TraceError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<TraceState, <TraceState as FromStr>::Err>

Parses a string s to return a value of this type.

impl Hash for TraceState

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 PartialEq for TraceState

fn eq(&self, other: &TraceState) -> 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 Eq for TraceState

impl StructuralPartialEq for TraceState