Struct TraceContext

pub struct TraceContext { /* private fields */ }

Extract and apply Trace-Context headers.

Specifications

• Trace-Context (Working Draft)

Examples

use http_types_rs::trace::TraceContext;

let mut res = http_types_rs::Response::new(200);

res.insert_header(
    "traceparent",
    "00-0af7651916cd43dd8448eb211c80319c-00f067aa0ba902b7-01"
);

let context = TraceContext::from_headers(&res)?.unwrap();

let trace_id = u128::from_str_radix("0af7651916cd43dd8448eb211c80319c", 16);
let parent_id = u64::from_str_radix("00f067aa0ba902b7", 16);

assert_eq!(context.trace_id(), trace_id.unwrap());
assert_eq!(context.parent_id(), parent_id.ok());
assert!(context.sampled());

Implementations

impl TraceContext

pub fn new() -> Self

Generate a new TraceContext object without a parent.

By default root TraceContext objects are sampled. To mark it unsampled, call context.set_sampled(false).

Examples

use http_types_rs::trace::TraceContext;

let context = TraceContext::new();

assert_eq!(context.parent_id(), None);
assert!(context.sampled());

pub fn from_headers(headers: impl AsRef<Headers>) -> Result<Option<Self>>

Create and return TraceContext object based on traceparent HTTP header.

Errors

This function may error if the header is malformed. An error with a status code of 400: Bad Request will be generated.

Examples

use http_types_rs::trace::TraceContext;

let mut res = http_types_rs::Response::new(200);
res.insert_header(
  "traceparent",
  "00-0af7651916cd43dd8448eb211c80319c-00f067aa0ba902b7-01"
);

let context = TraceContext::from_headers(&res)?.unwrap();

let trace_id = u128::from_str_radix("0af7651916cd43dd8448eb211c80319c", 16);
let parent_id = u64::from_str_radix("00f067aa0ba902b7", 16);

assert_eq!(context.trace_id(), trace_id.unwrap());
assert_eq!(context.parent_id(), parent_id.ok());
assert!(context.sampled());

pub fn child(&self) -> Self

Generate a child of the current TraceContext and return it.

The child will have a new randomly genrated id and its parent_id will be set to the id of this TraceContext.

pub fn id(&self) -> u64

Return the id of the TraceContext.

pub fn version(&self) -> u8

Return the version of the TraceContext spec used.

You probably don’t need this.

pub fn trace_id(&self) -> u128

Return the trace id of the TraceContext.

All children will have the same trace_id.

pub fn parent_id(&self) -> Option<u64>

Return the id of the parent TraceContext.

pub fn sampled(&self) -> bool

Returns true if the trace is sampled

Examples

use http_types_rs::trace::TraceContext;
use http_types_rs::Response;

let mut res = Response::new(200);
res.insert_header("traceparent", "00-00000000000000000000000000000001-0000000000000002-01");
let context = TraceContext::from_headers(&res)?.unwrap();
assert!(context.sampled());

pub fn set_sampled(&mut self, sampled: bool)

Change sampled flag

Examples

use http_types_rs::trace::TraceContext;

let mut context = TraceContext::new();
assert!(context.sampled());
context.set_sampled(false);
assert!(!context.sampled());

Trait Implementations

impl Debug for TraceContext

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

Formats the value using the given formatter.

impl Display for TraceContext

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

Formats the value using the given formatter.

impl Header for TraceContext

fn header_name(&self) -> HeaderName

Access the header’s name.

fn header_value(&self) -> HeaderValue

Access the header’s value.

fn apply_header<H: AsMut<Headers>>(&self, headers: H)

Insert the header name and header value into something that looks like a Headers map.