High-performance logging library writing a log message in tens of nanoseconds.

Source code needs preprocessing to inject id values inline and emit a schema file, the postprocessor uses that schema to decode the binary stream back into human-readable log lines.

Quick start

Binary encoder

#include "bilog/bilog.hpp"

int main() {
  bilog::init(bilog::Level::kTrace, bilog::BinaryEncoder(), bilog::FileSink("app.bin"));

  bilog::log({}) // {} becomes {0, 0, 1} after preprocessing
      .info("Server started,")
      .i("port:", 8080U)
      .write();
}

Then use the preprocessor, run the executable, and decode with postprocessor:

# Assign IDs and generate schema
preproc -i src/ -o bilog.json

# Decode binary log to text
postproc -s bilog.json -i app.bin -o app.log

Text encoder

#include "bilog/codec/text.hpp"
#include "bilog/sink/stdout.hpp"

#define BILOG_ENCODER TextEncoder
#define BILOG_SINK StdoutSink
#include "bilog/bilog.hpp"

int main() {
  bilog::init(bilog::Level::kInfo, bilog::TextEncoder(), bilog::StdoutSink());

  bilog::log({})  // no preprocessing needed
      .info("Server started,")
      .i("port:", 8080U)
      .write();
  // Output: [INFO] Server started, port: 8080
}

Logging API

bilog::log({<event_id>, <tag_id>, <tag_id>, ...})
    .info("message")         // level + message (trace/debug/info/warn/error/fatal)
    .i("field:", 42)         // integer (signed or unsigned)
    .f("field:", 3.14)       // float or double
    .b("field:", true)       // boolean
    .s("field:", str_var)    // std::string
    .cs("field:", "literal") // constant string (tag-table reference)
    .write();                // finish record

The preprocessor owns the IDs in log({...}) and keeps them in sync with your code - add, remove, or reorder fields freely. DO NOT edit that list manually - it's better to keep it empty and let the preprocessor assign them.

More info in Architecture Overview

Benchmarks

Compares bilog against spdlog with the same message payload.

------------------------------------------------------------
Benchmark                  Time             CPU   Iterations
------------------------------------------------------------
bilog_write_file        54.7 ns         53.3 ns      13879526
bilog_write_ringbuff    51.9 ns         51.8 ns      13552759
spdlog_write_file        391 ns          386 ns      1822556

Build

conan install . --build=missing -s build_type=Debug
cmake --preset Debug
cmake --build --preset Debug

Testing

# Unit tests (C++)
./build/Debug/tests/bilog_test

# Integration tests (Python, requires clang to built binaries)
python3 -m unittest discover -s tests/integration -t . -p '*_test.py' -v