1 unstable release
0.1.0 | Jan 6, 2021 |
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#18 in #individual
20KB
132 lines
tracing-line-filter
A tracing
filter for enabling individual spans and events by line
number.
tracing
is a framework for instrumenting Rust programs to collect
scoped, structured, and async-aware diagnostics. The tracing-subscriber
crate's EnvFilter
type provides a mechanism for controlling what
tracing
spans and events are collected by matching their targets,
verbosity levels, and fields. In some cases, though, it can be useful to
toggle on or off individual spans or events with a higher level of
granularity. Therefore, this crate provides a filtering Layer
that
enables individual spans and events based on their module path/file path and
line numbers.
Since the implementation of this filter is rather simple, the source code of
this crate is also useful as an example to tracing
users who want to
implement their own filtering logic.
Usage
First, add this to your Cargo.toml:
tracing-line-filter = "0.1"
Examples
Enabling events by line:
use tracing_line_filter::LineFilter;
mod some_module {
pub fn do_stuff() {
tracing::info!("i'm doing stuff");
tracing::debug!("i'm also doing stuff!");
}
}
fn main() {
use tracing_subscriber::prelude::*;
let mut filter = LineFilter::default();
filter
.enable_by_mod("my_crate::some_module", 6)
.enable_by_mod("my_crate", 25)
.enable_by_mod("my_crate", 27);
tracing_subscriber::registry()
.with(tracing_subscriber::fmt::layer().pretty())
.with(filter)
.init();
tracing::info!("i'm not enabled");
tracing::debug!("i'm enabled!");
some_module::do_stuff();
tracing::trace!("hi!");
}
Chaining a LineFilter
with a tracing_subscriber
EnvFilter
:
use tracing_line_filter::LineFilter;
use tracing_subscriber::EnvFilter;
mod some_module {
pub fn do_stuff() {
tracing::info!("i'm doing stuff");
tracing::debug!("i'm also doing stuff!");
// This won't be enabled, because it's at the TRACE level, and the
// `EnvFilter` only enables up to the DEBUG level.
tracing::trace!("doing very verbose stuff");
}
}
fn main() {
use tracing_subscriber::prelude::*;
let mut filter = LineFilter::default();
filter
.enable_by_mod("with_env_filter", 30)
.enable_by_mod("with_env_filter", 33)
// use an `EnvFilter` that enables DEBUG and lower in `some_module`,
// and everything at the ERROR level.
.with_env_filter(EnvFilter::new("error,with_env_filter::some_module=debug"));
tracing_subscriber::registry()
.with(tracing_subscriber::fmt::layer().pretty())
.with(filter)
.init();
tracing::info!("i'm not enabled");
tracing::debug!("i'm enabled!!");
some_module::do_stuff();
tracing::trace!("hi!");
// This will be enabled by the `EnvFilter`.
tracing::error!("an error!");
}
Dependencies
~2.1–8MB
~46K SLoC