Macro timer

macro_rules! timer {
    ($level:expr, $string:expr) => { ... };
    ($string:expr) => { ... };
}

Macro to create a RAII timer that will log on Drop how long its covered section took to execute.

The tracing level can be specified as a first argument, but it’s optional. If it’s missing, this will use the debug level.

use matrix_sdk_common::timer;

// It's possible to specify the tracing level we want to be used for the log message on drop.
{
    let _timer = timer!(tracing::Level::TRACE, "do long computation");
    // But it's optional; by default it's set to `DEBUG`.
    let _debug_timer = timer!("do long computation but time it in DEBUG");
    // The macro doesn't support formatting / structured events (yet?), but you can use
    // `format!()` for that.
    let other_timer = timer!(format!("do long computation for parameter = {}", 123));
    do_long_computation(123);
} // The log statements will happen here.