Struct LoggingGuard 

pub struct LoggingGuard { /* private fields */ }

Holds resources that must outlive the logging system.

Critical: This guard owns the WorkerGuard for the non-blocking HFT file appender. If dropped, the background writer thread stops and any buffered log entries are lost.

Always bind this to a named variable in main():

let _guard = init_logging(config)?;

Implementations

impl LoggingGuard

pub fn ops_reload_handle(&self) -> Option<&Handle<EnvFilter, Registry>>

Get a reference to the reload handle for the operational (stdout) layer’s EnvFilter.

Returns None if the stdout layer was not installed with a reload handle (shouldn’t happen in normal operation).

Example

if let Some(handle) = guard.ops_reload_handle() {
    let new_filter = EnvFilter::new("debug,hyper=info");
    handle.reload(new_filter).expect("reload failed");
    tracing::info!("Log level changed to debug at runtime");
}

pub fn set_log_level(&self, filter_str: &str) -> Result<()>

Reload the operational log filter at runtime.

Accepts any string that EnvFilter can parse, e.g.:

• "debug"
• "info,janus=trace"
• "warn,janus::supervisor=debug"

Returns an error if the filter string is invalid or if the reload handle is missing.

pub fn create_controller(&self) -> Option<Box<dyn LogLevelController>>

Create a LogLevelController that can be installed into JanusState for the API to change log levels at runtime.

The returned controller shares the same reload handle as this guard — it does not take ownership of the guard, so the guard must still be held alive in main().

Returns None if no reload handle is available (shouldn’t happen in normal operation).

Example

let guard = init_logging(config)?;
if let Some(ctrl) = guard.create_controller() {
    state.set_log_level_controller(ctrl).await;
}

Trait Implementations

impl Debug for LoggingGuard

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.