Trait SpanExt

pub trait SpanExt {
    // Required methods
    fn from_request(req: &Request, opt_in: bool) -> Self;
    fn add_header_fields(&self, headers: &HeaderMap);
    fn finalize_with_response(&self, response: &mut Response);
    fn finalize_with_error<E>(&self, error: &mut E)
       where E: Error;

    // Provided method
    fn finalize<E>(&self, result: &mut Result<Response, E>)
       where E: Error { ... }
}

This trait provides various helper functions to create a [Span] out of an HTTP [Request].

Required Methods

fn from_request(req: &Request, opt_in: bool) -> Self

Create a span according to the semantic conventions for HTTP spans from an Axum [Request].

The individual fields are defined in this specification. Some of them are:

• http.request.method
• http.response.status_code
• network.protocol.version

Setting the opt_in parameter to true enables various fields marked as opt-in by the specification. This will require more computing power and will increase the latency.

fn add_header_fields(&self, headers: &HeaderMap)

Adds HTTP request headers to the span as a http.request.header.<key> field.

NOTE: This is currently not supported, because [tracing] doesn’t support recording dynamic fields.

fn finalize_with_response(&self, response: &mut Response)

Finalize the [Span] with an Axum [Response].

fn finalize_with_error<E>(&self, error: &mut E)

where E: Error,

Finalize the [Span] with an error.

Provided Methods

fn finalize<E>(&self, result: &mut Result<Response, E>)

where E: Error,

Finalize the [Span] with a result.

The default implementation internally calls:

• SpanExt::finalize_with_response when Ok
• SpanExt::finalize_with_error when Err

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl SpanExt for Span

fn from_request(req: &Request, opt_in: bool) -> Self

fn add_header_fields(&self, headers: &HeaderMap)

fn finalize_with_response(&self, response: &mut Response)

fn finalize_with_error<E>(&self, error: &mut E)

where E: Error,

Implementors