insomnilog is an asynchronous Rust logging library designed for real-time and
latency-sensitive applications. All logging on the hot path is zero-allocation
and lock-free — log records are serialised as raw bytes into a per-thread
ring buffer and decoded by a background worker thread.
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Real-time safe hot path. The logging macros never allocate heap memory, never acquire a lock, and never block. They perform a level check, encode arguments directly into a pre-allocated ring buffer, and return. They never "sleep".
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Asynchronous by default. Formatting, sink dispatch, and I/O happen on a dedicated backend worker thread. The calling thread pays only the cost of the ring-buffer write.
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Explicit configuration, no global magic. You start the backend once with
insomnilog::start(opts), create named loggers and sinks explicitly, and pass a logger reference to each call site. There is no implicit global logger, no auto-start, and no hidden process-exit hook. -
Composable sinks. A
Sinkreceives a decodedLogRecordand decides its own output format. One sink can write human-readable text, another can write structured JSON, a third can forward to a metrics system — all from the same logger.
- User guide — Quick start, core concepts, formatters, sinks, preallocating thread queues, and more.
- Examples — Runnable examples covering common use cases.
- Contributing — Development tooling, CI pipeline, and how to extend the project.
- Architecture Decision Records — The reasoning behind the key architectural choices. A good entry point for understanding why the library is designed the way it is.
Contributions and bug reports are welcome. See CONTRIBUTING.md for the full details on tools, CI checks, and conventions.