Limit and split production logs

2026-10-07 22:06:38 +08:00 · 2026-06-16 12:58:27 +08:00
parent 877912fe4b
commit 3f40b18909
7 changed files with 287 additions and 16 deletions
@@ -0,0 +1,135 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+
+	"github.com/ShukeBta/MediaStationGo/internal/config"
+)
+
+const defaultLogMaxSizeMB = 20
+
+type rotatingFileWriter struct {
+	mu         sync.Mutex
+	path       string
+	maxSize    int64
+	maxBackups int
+	maxAge     time.Duration
+	file       *os.File
+	size       int64
+}
+
+func newRotatingFileWriter(path string, cfg config.LoggingConfig) (*rotatingFileWriter, error) {
+	if path == "" {
+		return nil, fmt.Errorf("log path required")
+	}
+	if err := os.MkdirAll(filepath.Dir(path), 0o750); err != nil {
+		return nil, fmt.Errorf("create log dir: %w", err)
+	}
+	maxSizeMB := cfg.MaxSizeMB
+	if maxSizeMB <= 0 {
+		maxSizeMB = defaultLogMaxSizeMB
+	}
+	w := &rotatingFileWriter{
+		path:       path,
+		maxBackups: cfg.MaxBackups,
+	}
+	if cfg.EnableRotation {
+		w.maxSize = int64(maxSizeMB) * 1024 * 1024
+	}
+	if w.maxBackups < 0 {
+		w.maxBackups = 0
+	}
+	if cfg.MaxAgeDays > 0 {
+		w.maxAge = time.Duration(cfg.MaxAgeDays) * 24 * time.Hour
+	}
+	if err := w.open(); err != nil {
+		return nil, err
+	}
+	return w, nil
+}
+
+func (w *rotatingFileWriter) Write(p []byte) (int, error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.file == nil {
+		if err := w.open(); err != nil {
+			return 0, err
+		}
+	}
+	if w.maxSize > 0 && w.size > 0 && w.size+int64(len(p)) > w.maxSize {
+		if err := w.rotate(); err != nil {
+			return 0, err
+		}
+	}
+	n, err := w.file.Write(p)
+	w.size += int64(n)
+	return n, err
+}
+
+func (w *rotatingFileWriter) Sync() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.file == nil {
+		return nil
+	}
+	err := w.file.Sync()
+	closeErr := w.file.Close()
+	w.file = nil
+	w.size = 0
+	if err != nil {
+		return err
+	}
+	return closeErr
+}
+
+func (w *rotatingFileWriter) open() error {
+	file, err := os.OpenFile(w.path, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0o640)
+	if err != nil {
+		return fmt.Errorf("open log file %s: %w", w.path, err)
+	}
+	w.file = file
+	if stat, err := file.Stat(); err == nil {
+		w.size = stat.Size()
+	}
+	return nil
+}
+
+func (w *rotatingFileWriter) rotate() error {
+	if w.file != nil {
+		_ = w.file.Close()
+		w.file = nil
+	}
+	if w.maxBackups == 0 {
+		_ = os.Remove(w.path)
+		return w.open()
+	}
+	for i := w.maxBackups - 1; i >= 1; i-- {
+		oldPath := fmt.Sprintf("%s.%d", w.path, i)
+		newPath := fmt.Sprintf("%s.%d", w.path, i+1)
+		if _, err := os.Stat(oldPath); err == nil {
+			_ = os.Rename(oldPath, newPath)
+		}
+	}
+	if _, err := os.Stat(w.path); err == nil {
+		_ = os.Rename(w.path, fmt.Sprintf("%s.1", w.path))
+	}
+	w.pruneByAge()
+	return w.open()
+}
+
+func (w *rotatingFileWriter) pruneByAge() {
+	if w.maxAge <= 0 {
+		return
+	}
+	cutoff := time.Now().Add(-w.maxAge)
+	for i := 1; i <= w.maxBackups; i++ {
+		path := fmt.Sprintf("%s.%d", w.path, i)
+		if stat, err := os.Stat(path); err == nil && stat.ModTime().Before(cutoff) {
+			_ = os.Remove(path)
+		}
+	}
+}