spdlog-rs

A fast and combinable Rust logging crate, inspired by the C++ logging library [spdlog].

Features

• Very fast (see Benchmarks below).
• Various log targets:
  • Standard streams with optional colors.
  • Files.
  • Rotating log files by file size.
  • Rotating log files hourly.
  • Rotating log files daily.
  • ... (more targets are implementing, PRs are welcome)
  • Extendable with custom log targets.
• Compatible with [log crate] (optional).
• Configured via environment variable.
• Custom formatting.
• Log filtering - log levels can be modified in runtime as well as in compile time.

Getting started

Add this to Cargo.toml: toml [dependencies] spdlog-rs = "0.2"

The documentation of this crate is hosted on [docs.rs], and you can find examples under [./examples] directory.

If you have any questions or need help while using this crate, feel free to [open a discussion]. For feature requests or bug reports, please [open an issue].

Benchmarks

Run cargo +nightly bench in the root directory of this repository for benchmarking.

The following results are generated with Windows 10 64 bit and Intel i9-10900KF CPU @ 3.70GHz.

Disclaimer, I'm not entirely familiar with using the other Rust crates below, so if you find a bug or something worth improving in the benchmark code, feel free to open an issue to let me know.

spdlog-rs (0.1.0)

Default features test bench_file ... bench: 376 ns/iter (+/- 12) test bench_level_off ... bench: 1 ns/iter (+/- 0) test bench_rotating_daily ... bench: 380 ns/iter (+/- 12) test bench_rotating_file_size ... bench: 379 ns/iter (+/- 50)

Enable flexible-string feature test bench_file ... bench: 166 ns/iter (+/- 10) test bench_level_off ... bench: 1 ns/iter (+/- 0) test bench_rotating_daily ... bench: 172 ns/iter (+/- 7) test bench_rotating_file_size ... bench: 176 ns/iter (+/- 20)

Compare with slog (2.7.0)

test bench_file ... bench: 469 ns/iter (+/- 19) test bench_level_off ... bench: 2 ns/iter (+/- 0) test bench_rotating_daily ... bench: unavailable test bench_rotating_file_size ... bench: 480 ns/iter (+/- 13)

Compare with flexi_logger (0.22.2)

test bench_file ... bench: 673 ns/iter (+/- 11) test bench_level_off ... bench: 0 ns/iter (+/- 0) test bench_rotating_daily ... bench: 746 ns/iter (+/- 40) test bench_rotating_file_size ... bench: 676 ns/iter (+/- 38)

Compare with log4rs (1.0.0)

test bench_file ... bench: 3,769 ns/iter (+/- 95) test bench_level_off ... bench: 0 ns/iter (+/- 0) test bench_rotating_daily ... bench: unavailable test bench_rotating_file_size ... bench: 3,773 ns/iter (+/- 117)

Compare with fern (0.6.0)

test bench_file ... bench: 3,687 ns/iter (+/- 101) test bench_level_off ... bench: unavailable test bench_rotating_daily ... bench: unavailable test bench_rotating_file_size ... bench: unavailable

Compare with C++ spdlog

spdlog-rs (0.1.0)

Default features (corresponds to C++ spdlog using standard <format>) [info] ********************************************************************** [info] Multi threaded: 1 threads, 250000 messages [info] ********************************************************************** [info] basic_mt Elapsed: 0.13 secs 1940870/sec [info] rotating_mt Elapsed: 0.13 secs 1894612/sec [info] daily_mt Elapsed: 0.13 secs 1920024/sec [info] level-off Elapsed: 0.00 secs 444919024/sec [info] ********************************************************************** [info] Multi threaded: 4 threads, 250000 messages [info] ********************************************************************** [info] basic_mt Elapsed: 0.14 secs 1825379/sec [info] rotating_mt Elapsed: 0.14 secs 1845651/sec [info] daily_mt Elapsed: 0.13 secs 1854885/sec [info] level-off Elapsed: 0.00 secs 485625485/sec

Enable flexible-string feature (corresponds to C++ spdlog using fmt library) [info] ********************************************************************** [info] Multi threaded: 1 threads, 250000 messages [info] ********************************************************************** [info] basic_mt Elapsed: 0.08 secs 3003511/sec [info] rotating_mt Elapsed: 0.08 secs 3006090/sec [info] daily_mt Elapsed: 0.08 secs 3032813/sec [info] level-off Elapsed: 0.00 secs 484871993/sec [info] ********************************************************************** [info] Multi threaded: 4 threads, 250000 messages [info] ********************************************************************** [info] basic_mt Elapsed: 0.06 secs 4266393/sec [info] rotating_mt Elapsed: 0.06 secs 4271496/sec [info] daily_mt Elapsed: 0.06 secs 4164993/sec [info] level-off Elapsed: 0.00 secs 462962962/sec

C++ spdlog ([4cfdc8c])

Using standard <format> (compiled with cmake -G "Visual Studio 16 2019" -A x64 -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_STANDARD=20 -DCMAKE_CXX_STANDARD_REQUIRED=ON -DSPDLOG_BUILD_BENCH=ON -DSPDLOG_BUILD_EXAMPLE=OFF -DSPDLOG_USE_STD_FORMAT=ON) [info] ************************************************************** [info] Multi threaded: 1 threads, 250,000 messages [info] ************************************************************** [info] basic_mt Elapsed: 0.15 secs 1,654,676/sec [info] rotating_mt Elapsed: 0.16 secs 1,576,156/sec [info] daily_mt Elapsed: 0.15 secs 1,671,424/sec [info] level-off Elapsed: 0.00 secs 132,597,857/sec [info] ************************************************************** [info] Multi threaded: 4 threads, 250,000 messages [info] ************************************************************** [info] basic_mt Elapsed: 0.26 secs 965,885/sec [info] rotating_mt Elapsed: 0.26 secs 964,368/sec [info] daily_mt Elapsed: 0.25 secs 981,449/sec [info] level-off Elapsed: 0.00 secs 135,310,673/sec

Using fmt library (compiled with cmake -G "Visual Studio 16 2019" -A x64 -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_STANDARD=20 -DCMAKE_CXX_STANDARD_REQUIRED=ON -DSPDLOG_BUILD_BENCH=ON -DSPDLOG_BUILD_EXAMPLE=OFF) [info] ************************************************************** [info] Multi threaded: 1 threads, 250,000 messages [info] ************************************************************** [info] basic_mt Elapsed: 0.06 secs 3,917,304/sec [info] rotating_mt Elapsed: 0.06 secs 3,942,073/sec [info] daily_mt Elapsed: 0.07 secs 3,784,707/sec [info] level-off Elapsed: 0.00 secs 148,174,490/sec [info] ************************************************************** [info] Multi threaded: 4 threads, 250,000 messages [info] ************************************************************** [info] basic_mt Elapsed: 0.11 secs 2,356,303/sec [info] rotating_mt Elapsed: 0.12 secs 2,138,911/sec [info] daily_mt Elapsed: 0.12 secs 2,163,183/sec [info] level-off Elapsed: 0.00 secs 148,060,408/sec

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.