Vix Log

The log module provides a clean, stable, and high-level logging API for Vix applications.

It is built as a facade over the internal vix::utils::Logger, exposing a consistent and developer-friendly interface while reusing a powerful logging backend.

Philosophy

Logging in Vix follows strict principles:

• No duplication of logging engines
• Simple public API (vix::log)
• Structured logging by default
• Explicit configuration
• Thread-local context support
• High performance (delegated to utils)

The module is designed to be:

• easy to use
• easy to integrate
• stable across versions
• consistent across all Vix modules

Architecture

vix::utils::Logger → core logging engine
vix::log           → public facade (this module)

The log module does not implement logging itself. It delegates all operations to vix::utils::Logger.

Quick Start

#include <vix/log/Log.hpp>

int main()
{
  vix::log::info("Hello world");
  vix::log::warn("Low disk space");
  vix::log::error("Failed to open file");
}

Log Levels

vix::log::set_level(vix::log::LogLevel::Debug);

Available levels:

• Trace
• Debug
• Info
• Warn
• Error
• Critical
• Off

Structured Logging

vix::log::logf(
  vix::log::LogLevel::Info,
  "request completed",
  "status", 200,
  "method", "GET",
  "path", "/api/users"
);

Output Formats

vix::log::set_format(vix::log::LogFormat::KV);
vix::log::set_format(vix::log::LogFormat::JSON);
vix::log::set_format(vix::log::LogFormat::JSON_PRETTY);

Context (Thread-Local)

Attach metadata to all logs in a scope:

vix::log::LogContext ctx;
ctx.request_id = "req-123";
ctx.module = "auth";
ctx.fields["user_id"] = "42";

vix::log::set_context(ctx);

vix::log::info("user logged in");

vix::log::clear_context();

Configuration

vix::log::LogConfig config;
config.level = vix::log::LogLevel::Info;
config.format = vix::log::LogFormat::JSON;
config.async = true;

vix::log::configure(config);

Environment Configuration

vix::log::set_level_from_env();   // VIX_LOG_LEVEL
vix::log::set_format_from_env();  // VIX_LOG_FORMAT

Examples

Located in examples/:

• basic.cpp → basic logging
• context.cpp → context usage
• format.cpp → format switching

Tests

Located in test/:

• log_test.cpp

Run:

ctest

Dependencies

This module depends on:

• vix::utils (logging backend)

No direct dependency on spdlog is exposed publicly.

Design Goals Recap

• Simple API
• No duplication
• Structured logging first
• Context-aware
• High performance
• Stable interface

License

MIT Part of the Vix.cpp project.