salog

salog

Safe Asynchronous Logging for Go - Crash-resistant, Non-blocking, High Performance

salog is a high-performance, crash-safe asynchronous logging library for Go. It ensures that your log messages are never lost, even when the process crashes unexpectedly.

🚀 Key Features

🔒 Crash-Safe by Design

• Zero data loss even on process crashes or power failures
• Memory-mapped buffers prevent log loss during unexpected terminations
• Atomic operations ensure log integrity

⚡ Non-Blocking Performance

• Lightning-fast logging that never blocks your application
• Smart backpressure: Small logs → async, Heavy logs → timely disk flush
• Configurable buffer sizes and flush intervals

📁 Intelligent Log Management

• Automatic log rotation by size, time, or both
• Configurable retention policies (file count, age-based cleanup)
• Gzip compression for archived logs

🎯 Quick Start

Installation

go get github.com/goexlib/salog

Usage

package main

import "github.com/goexlib/salog"

func main() {
    // Use the default logger
    defer salog.Close() // Ensure cleanup
    
    salog.Info("Hello salog!")
    
    salog.Debug("test debug log:", "hello world!") // Will not output
    salog.DefaultConfig().SetLevel(salog.LevelDebug)
    salog.Debugf("test default log again: %s", "hello world!") // Will output
    
    // Create a logger
    config := salog.NewConfig().
        SetFile("test.log").
        SetLevel(salog.LevelInfo).
        SetSize(8 * 1024 * 1024). // 8MB one file
        SetCount(4). // 4 log file
        SetBuffer(8 * 1024 * 1024). // 8MB async buffer
        SetFlush(200 * time.Millisecond). // flush per 200ms
        SetCaller(true) // enable caller output
    
    logger := salog.New(config)
    defer logger.Close() // Ensure flush and cleanup
    
    // Log messages safely - even if process crashes after this
    logger.Info("User logged in", "user_id=", 123, "ip=", "192.168.1.1")
    logger.Errorf("Database connection failed error: %v", err)
    
    // Dynamic change logger config
    config.SetLevel(salog.LevelDebug)
}

Output

2025-12-04 10:51:21.793163 22056 salog/log_test.go:188 INF | Hello salog!

🔧 Configuration Options

Log Levels

salog.DebugLevel    // Debug and above
salog.InfoLevel     // Info and above  
salog.WarnLevel     // Warn and above
salog.ErrorLevel    // Error and above

📊 Performance Characteristics

Non-Blocking Behavior

Small log volume:    ──→ Async Buffer ──→ Periodic Flush
                      (Never blocks caller)
                      
Large log volume:    ──→ Async Buffer ──→ Immediate Flush
                      (Prevents buffer overflow)

Crash Safety Guarantees

Normal Operation:    App → Map Memory Buffer → Periodic Disk Write
Process Crash:       App ✗ → Map Memory Buffer ✓ → Disk Recovery ✓

🤝 Contributing

We welcome contributions!

📄 License

salog is licensed under the MIT License. See LICENSE for details.

Never lose a log message again. salog ensures your application's story is always preserved, no matter what happens.