mirror of https://github.com/tokio-rs/tracing.git synced 2025-10-02 07:20:35 +00:00

chore: fix nightly clippy warnings (#991 ) (#1025 )

This backports PR #991 to v0.1.x. This is primarily necessary for the MSRV
bump, since some dependencies no longer compile on Rust 1.40.0.

This has already been approved on `master`, in PR #991, so it should be 
fine to ship.

## Motivation

This will avoid breaking CI on new releases of clippy. It also makes the
code a little easier to read.

## Solution

- Convert `match val { pat => true, _ => false }` to `matches!(val, pat)`
- Remove unnecessary closures
- Convert `self: &mut Self` to `&mut self`

This bumps the MSRV to 1.42.0 for `matches!`.
The latest version of rust is 1.46.0, so as per
https://github.com/tokio-rs/tracing#supported-rust-versions this is not
considered a breaking change.

I didn't fix the following warning because the fix was not trivial/needed
a decision:

```
warning: you are deriving `Ord` but have implemented `PartialOrd` explicitly
   --> tracing-subscriber/src/filter/env/field.rs:16:32
    |
16  | #[derive(Debug, Eq, PartialEq, Ord)]
    |                                ^^^
    |
    = note: `#[warn(clippy::derive_ord_xor_partial_ord)]` on by default
note: `PartialOrd` implemented here
   --> tracing-subscriber/src/filter/env/field.rs:98:1
    |
98  | / impl PartialOrd for Match {
99  | |     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
100 | |         // Ordering for `Match` directives is based first on _whether_ a value
101 | |         // is matched or not. This is semantically meaningful --- we would
...   |
121 | |     }
122 | | }
    | |_^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#derive_ord_xor_partial_ord
```

As a side note, this found a bug in clippy 😆 https://github.com/rust-lang/rust-clippy/issues/6089

2020-10-07 14:10:49 -07:00

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Tracing OpenTelemetry

Utilities for adding OpenTelemetry interoperability to tracing.

Documentation | Chat

Overview

tracing is a framework for instrumenting Rust programs to collect structured, event-based diagnostic information. This crate provides a layer that connects spans from multiple systems into a trace and emits them to OpenTelemetry-compatible distributed tracing systems for processing and visualization.

The crate provides the following types:

OpenTelemetryLayer adds OpenTelemetry context to all tracing spans.
OpenTelemetrySpanExt allows OpenTelemetry parent trace information to be injected and extracted from a tracing span.

Compiler support: requires rustc 1.42+

Examples

Basic Usage

use opentelemetry::{api::Provider, sdk};
use tracing::{error, span};
use tracing_subscriber::layer::SubscriberExt;
use tracing_subscriber::Registry;

fn main() {
    // Create a new tracer
    let tracer = sdk::Provider::default().get_tracer("component_name");

    // Create a new OpenTelemetry tracing layer
    let telemetry = tracing_opentelemetry::layer().with_tracer(tracer);

    let subscriber = Registry::default().with(telemetry);

    // Trace executed code
    tracing::subscriber::with_default(subscriber, || {
        let root = span!(tracing::Level::TRACE, "app_start", work_units = 2);
        let _enter = root.enter();

        error!("This event will be logged in the root span.");
    });
}

Visualization example

# Run a supported collector like jaeger in the background
$ docker run -d -p6831:6831/udp -p6832:6832/udp -p16686:16686 jaegertracing/all-in-one:latest

# Run example to produce spans (from parent examples directory)
$ cargo run --example opentelemetry

# View spans (see the image below)
$ firefox http://localhost:16686/

Supported Rust Versions

Tracing is built against the latest stable release. The minimum supported version is 1.42. The current Tracing version is not guaranteed to build on Rust versions earlier than the minimum supported version.

Tracing follows the same compiler support policies as the rest of the Tokio project. The current stable Rust compiler and the three most recent minor versions before it will always be supported. For example, if the current stable compiler version is 1.45, the minimum supported version will not be increased past 1.42, three minor versions prior. Increasing the minimum supported compiler version is not considered a semver breaking change as long as doing so complies with this policy.

License

This project is licensed under the MIT license.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Tracing by you, shall be licensed as MIT, without any additional terms or conditions.

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