quicklog

Fast single-threaded logging framework, almost 200x faster than tracing and delog for large structs.

Supports standard logging macros like trace!, debug!, info!, warn! and error!.

Flushing is deferred until flush!() macro is called.

Objectives

• Deferred formatting
• Deferred I/O
• Low call site latency

While tracing is a popular library for event tracing and are really good at what they do, quicklog is optimized for low callsite latency, paying the cost of formatting and I/O on a separate thread, away from the hot path.

Installation

Install using Cargo

cargo add quicklog

Add to Cargo.toml

# Cargo.toml
[dependencies]
quicklog = "0.1.18"
# ...

Usage

Quick Start

use quicklog::{info, init, flush};

fn main() {
    // initialise required resources, called near application entry point
    init!();

    // adds item to logging queue
    info!("hello world");

    let some_var = 10;
    // variables are passed by copy
    info!("value of some_var: {}", some_var);

    // flushes everything in queue
    flush!();
}

Utilising Serialize

In order to avoid cloning a large struct, you can implement the Serialize trait.

This allows you to copy specific parts of your struct onto a circular byte buffer and avoid copying the rest by encoding providing a function to decode your struct from a byte buffer.

For a complete example, refer to ~/quicklog/benches/logger_benchmark.rs.

use quicklog::serialize::{Serialize, Store};

struct SomeStruct {
    num: i64
}

impl Serialize for SomeStruct {
   fn encode(&self, write_buf: &'static mut [u8]) -> Store { /* some impl */ }
   fn buffer_size_required(&self) -> usize { /* some impl */ }
}

fn main() {
    let s = SomeStruct { num: 1_000_000 };
    info!("some struct: {}", ^s);
}

Utilising different flushing mechanisms

use quicklog_flush::stdout_flusher::StdoutFlusher;
use quicklog::{info, init, flush, with_flush_into_file, with_flush};

fn main() {
    init!();

    // flush into stdout
    with_flush!(StdoutFlusher);

    // item goes into logging queue
    info!("hello world");

    // flushed into stdout
    flush!()

    // flush into a file path specified
    with_flush_into_file!("logs/my_log.log");

    info!("shave yaks");

    // flushed into file
    flush!();
}

Benchmark

Measurements are made on a 2020 16 core M1 Macbook Air with 16 GB RAM.

Logging a struct with a vector of 10 large structs

Logging a single struct with 100 array elements

Logging a small struct with primitives

Contribution & Support

We are open to contributions and requests!

Please post your bug reports or feature requests on Github Issues.

Roadmap

• [] add single-threaded and multi-threaded variants
• [] Try to remove nested lazy_format in recursion
• [] Check number of copies of data made in each log line and possibly reduce it
• [] Review uses of unsafe code
• [] Benchmark multi-threaded performance
• [] Statically assert that strings inside Level and LevelFilter are the same size

Authors and acknowledgment

Zack Ng, Tien Dat Nguyen, Michiel van Slobbe, Dheeraj Oswal

Crates

• Lucretiel/lazy_format
• japaric/heapless

References

• tokio-rs/tracing
• trussed-dev/delog

License

Copyright 2023 Grasshopper Asia

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.