FlexLog

FlexLog is a high-performance, thread-safe, and feature-rich logging library for modern C++ applications. Designed with flexibility and performance in mind, it supports structured logging formats, multiple output sinks, and advanced configuration options.

✨ Features

• High Performance - Lock-free message queues and thread pooling for minimal impact on application performance
• Thread Safety - Concurrent logging from multiple threads with hazard pointers and atomic operations
• Structured Logging - Support for JSON, XML, GELF, CloudWatch, LogStash, Elasticsearch, OpenTelemetry, and Splunk formats
• Multiple Sinks - Console and file outputs with rotation support, with an extensible architecture for custom sinks
• C++20 Features - Uses the latest C++ features including std::source_location and std::format
• Cross-Platform - Works on Windows, Linux, and macOS
• Configuration - Flexible configuration API with sensible defaults
• Memory Efficient - Message pooling for reduced memory allocations
• File Rotation - Size-based and time-based log file rotation

📦 Installation

Prerequisites

• C++20 compatible compiler
• Premake5 (for building)

Build from Source

git clone https://github.com/yourusername/flexlog.git
cd flexlog
premake5 vs2022    # For Visual Studio 2022
# OR
premake5 gmake2    # For GNU Make
# Then build using your generated build files

🚀 Quick Start

#include "Logging.h"

int main() {
    // Initialize the logging system
    auto& logManager = FlexLog::LogManager::GetInstance();
    logManager.Initialize();
    
    // Basic logging
    FLOG_INFO("Hello, World!");
    
    // Formatted logging (using std::format)
    FLOG_INFO("The answer is {}", 42);
    
    // Log with structured data
    FlexLog::StructuredData data;
    data.Add("user_id", 12345);
    data.Add("action", "login");
    FLOG_INFO("User login", data);
    
    // Clean shutdown
    logManager.Shutdown();
    return 0;
}

📝 Documentation

Basic Logging Macros

FLOG_TRACE("Trace message");
FLOG_DEBUG("Debug message");
FLOG_INFO("Info message");
FLOG_WARN("Warning message");
FLOG_ERROR("Error message");
FLOG_FATAL("Fatal message");

Named Loggers

// Create or get a logger
auto& logger = logManager.RegisterLogger("network");
logger.SetLevel(FlexLog::Level::Debug);

// Use the logger with macros
FLOG_DEBUG_LOGGER("network", "Connection established with {}", "server-01");

// Or directly
logger.Debug("Connection established");

Structured Logging

FlexLog::StructuredData data;
data.Add("latitude", 37.7749);
data.Add("longitude", -122.4194);
data.Add("timestamp", std::chrono::system_clock::now());
data.Add("tags", std::vector<std::string>{"location", "gps"});

FLOG_INFO("Location update", data);

Custom Sinks

// File sink with rotation
auto& logger = logManager.GetLogger("app");
logger.EmplaceSink<FlexLog::FileSink>(FlexLog::FileSink::Options()
    .SetFilePath("logs/app.log")
    .EnableRotation(true)
    .SetMaxFileSize(10 * 1024 * 1024)  // 10 MB
    .SetTimeRotation(FlexLog::RotationTimeUnit::Day));

// Console sink
logger.EmplaceSink<FlexLog::ConsoleSink>();

Formatting Options

// Set JSON formatting for structured logs
auto& format = logger.GetFormat();
format.SetLogFormat(FlexLog::LogFormat::JSON);

// Configure a formatter
auto& jsonFormatter = format.GetJsonFormatter();
jsonFormatter.GetOptions().SetPrettyPrint(true);

⚙️ Configuration

FlexLog provides several configuration options:

Log Manager Configuration

auto& logManager = FlexLog::LogManager::GetInstance();

// Set default log level
logManager.SetDefaultLevel(FlexLog::Level::Debug);

// Configure thread pool
logManager.SetThreadPoolSize(4);

// Set default logger name
logManager.SetDefaultLoggerName("application");

File Sink Options

FlexLog::FileSink::Options options;
options.SetFilePath("logs/app.log")
       .SetCreateDir(true)
       .SetAutoFlush(true)
       .EnableRotation(true)
       .SetRotationRule(FlexLog::RotationRule::SizeAndTime)
       .SetMaxFileSize(10 * 1024 * 1024)  // 10 MB
       .SetTimeRotation(FlexLog::RotationTimeUnit::Day)
       .SetMaxFiles(7);

Custom Pattern Formatting

auto& format = logger.GetFormat();
auto& patternFormatter = format.GetPatternFormatter();
patternFormatter.SetPattern("[{timestamp}] [{level}] [{name}.{function}] - {message}");
patternFormatter.SetTimeFormat("%Y-%m-%d %H:%M:%S.%f");

📄 License

FlexLog is distributed under the Mozilla Public License 2.0 (MPL 2.0)

🤝 Contributing

Contributions are welcome! Feel free to open issues or submit pull requests.