mirror of
https://github.com/tokio-rs/tracing.git
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2520f97964
## Motivation As discussed in #308, there are a large number of crates in this repository, which can be confusing for users and can increase the maintainance burden for maintainers. Also, the `tracing-fmt` and `tracing-subscriber` crates both contain filtering implementations with similar behaviour and APIs, but `tracing-subscriber`'s filter module offers more advanced features (filtering on field values), and is usable with any subscriber implementation. Two separate filter implementations also has the potential to be confusing for users. ## Solution This branch moves most of the code from `tracing-fmt` into a module in `tracing-subscriber`, and changes the `tracing-fmt` builder APIs to use the `Filter` type in `tracing-subscriber`. The `tracing-subscriber/fmt` feature flag can be used to disable the formatting subscriber when it is not used. The `tracing-fmt` crate has been updated to re-export the APIs from `tracing-subscriber`, and marked as deprecated. Once we've published a new version of `tracing-subscriber` with the format APIs, we can publish a final release of `tracing-fmt` that will update the documentation & mark all APIs as deprecated, so that users know to move to the `tracing-subscriber` crate. Refs: #308 Signed-off-by: Eliza Weisman <eliza@buoyant.io>
40 lines
1.2 KiB
Rust
40 lines
1.2 KiB
Rust
#![deny(rust_2018_idioms)]
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use futures::future::{self, Future};
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use tracing::{debug, info, span, Level};
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use tracing_futures::Instrument;
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fn parent_task(subtasks: usize) -> impl Future<Item = (), Error = ()> {
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future::lazy(move || {
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info!("spawning subtasks...");
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let subtasks = (1..=subtasks)
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.map(|number| {
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debug!(message = "creating subtask;", number);
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subtask(number)
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})
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.collect::<Vec<_>>();
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future::join_all(subtasks)
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})
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.map(|result| {
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debug!("all subtasks completed");
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let sum: usize = result.into_iter().sum();
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info!(sum = sum);
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})
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.instrument(span!(Level::TRACE, "parent_task", subtasks))
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}
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fn subtask(number: usize) -> impl Future<Item = usize, Error = ()> {
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future::lazy(move || {
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info!("polling subtask...");
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Ok(number)
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})
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.instrument(span!(Level::TRACE, "subtask", number))
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}
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fn main() {
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use tracing_subscriber::fmt;
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let subscriber = fmt::Subscriber::builder().with_filter("trace").finish();
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let _ = tracing::subscriber::set_global_default(subscriber);
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tokio::run(parent_task(10));
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}
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