对本地数据库文件进行加锁

internal/utils/fileutils/locker.go

@@ -0,0 +1,82 @@
+// Copyright 2023 Liuxiangchao iwind.liu@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package fileutils
+
+import (
+	"os"
+	"syscall"
+	"time"
+)
+
+type Locker struct {
+	path string
+	fp   *os.File
+}
+
+func NewLocker(path string) *Locker {
+	return &Locker{
+		path: path + ".lock",
+	}
+}
+
+func (this *Locker) TryLock() (ok bool, err error) {
+	if this.fp == nil {
+		fp, err := os.OpenFile(this.path, os.O_CREATE|os.O_WRONLY, 0666)
+		if err != nil {
+			return false, err
+		}
+		this.fp = fp
+	}
+	return this.tryLock()
+}
+
+func (this *Locker) Lock() error {
+	if this.fp == nil {
+		fp, err := os.OpenFile(this.path, os.O_CREATE|os.O_WRONLY, 0666)
+		if err != nil {
+			return err
+		}
+		this.fp = fp
+	}
+
+	for {
+		b, err := this.tryLock()
+		if err != nil {
+			_ = this.fp.Close()
+			return err
+		}
+		if b {
+			return nil
+		}
+		time.Sleep(100 * time.Millisecond)
+	}
+}
+
+func (this *Locker) Release() error {
+	err := this.fp.Close()
+	if err != nil {
+		return err
+	}
+	this.fp = nil
+	return nil
+}
+
+func (this *Locker) tryLock() (ok bool, err error) {
+	err = syscall.Flock(int(this.fp.Fd()), syscall.LOCK_EX|syscall.LOCK_NB)
+	if err == nil {
+		return true, nil
+	}
+
+	errno, isErrNo := err.(syscall.Errno)
+	if !isErrNo {
+		return
+	}
+
+	if !errno.Temporary() {
+		return
+	}
+
+	err = nil // 不提示错误
+
+	return
+}