Module tracing_appender::non_blocking
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A non-blocking, off-thread writer.
This spawns a dedicated worker thread which is responsible for writing log
lines to the provided writer. When a line is written using the returned
NonBlocking struct’s make_writer method, it will be enqueued to be
written by the worker thread.
The queue has a fixed capacity, and if it becomes full, any logs written
to it will be dropped until capacity is once again available. This may
occur if logs are consistently produced faster than the worker thread can
output them. The queue capacity and behavior when full (i.e., whether to
drop logs or to exert backpressure to slow down senders) can be configured
using NonBlockingBuilder::default().
This function returns the default configuration. It is equivalent to:
tracing_appender::non_blocking(std::io::stdout())
This function returns a tuple of NonBlocking and WorkerGuard.
NonBlocking implements MakeWriter which integrates with tracing_subscriber.
WorkerGuard is a drop guard that is responsible for flushing any remaining logs when
the program terminates.
Note that the WorkerGuard returned by non_blocking must be assigned to a binding that
is not _, as _ will result in the WorkerGuard being dropped immediately.
Unintentional drops of WorkerGuard remove the guarantee that logs will be flushed
during a program’s termination, in a panic or otherwise.
See WorkerGuard for examples of using the guard.
Examples
let (non_blocking, _guard) = tracing_appender::non_blocking(std::io::stdout());
let subscriber = tracing_subscriber::fmt().with_writer(non_blocking);
tracing::subscriber::with_default(subscriber.finish(), || {
tracing::event!(tracing::Level::INFO, "Hello");
});Structs
Tracks the number of times a log line was dropped by the background thread.
A non-blocking writer.
A builder for NonBlocking.
A guard that flushes spans/events associated to a NonBlocking on a drop
Constants
The default maximum number of buffered log lines.