对本地数据库文件进行加锁

internal/utils/agents/db.go

@@ -3,13 +3,12 @@
 package agents
 
 import (
-	"database/sql"
 	"errors"
 	"github.com/TeaOSLab/EdgeNode/internal/events"
 	"github.com/TeaOSLab/EdgeNode/internal/remotelogs"
+	"github.com/TeaOSLab/EdgeNode/internal/utils/dbs"
 	"github.com/iwind/TeaGo/Tea"
 	"github.com/iwind/TeaGo/types"
-	_ "github.com/mattn/go-sqlite3"
 	"log"
 	"os"
 	"path/filepath"
@@ -21,11 +20,11 @@ const (
 )
 
 type DB struct {
-	db   *sql.DB
+	db   *dbs.DB
 	path string
 
-	insertAgentIPStmt *sql.Stmt
-	listAgentIPsStmt  *sql.Stmt
+	insertAgentIPStmt *dbs.Stmt
+	listAgentIPsStmt  *dbs.Stmt
 }
 
 func NewDB(path string) *DB {
@@ -52,7 +51,7 @@ func (this *DB) Init() error {
 	}
 
 	// TODO 思考 data.db 的数据安全性
-	db, err := sql.Open("sqlite3", "file:"+this.path+"?cache=shared&mode=rwc&_journal_mode=WAL")
+	db, err := dbs.OpenWriter("file:" + this.path + "?cache=shared&mode=rwc&_journal_mode=WAL&_locking_mode=EXCLUSIVE")
 	if err != nil {
 		return err
 	}
@@ -135,7 +134,7 @@ func (this *DB) Close() error {
 		return nil
 	}
 
-	for _, stmt := range []*sql.Stmt{
+	for _, stmt := range []*dbs.Stmt{
 		this.insertAgentIPStmt,
 		this.listAgentIPsStmt,
 	} {

internal/utils/dbs/db.go

@@ -7,14 +7,56 @@ import (
 	"database/sql"
 	"fmt"
 	"github.com/TeaOSLab/EdgeNode/internal/events"
+	"github.com/TeaOSLab/EdgeNode/internal/remotelogs"
+	"github.com/TeaOSLab/EdgeNode/internal/utils/fileutils"
+	_ "github.com/mattn/go-sqlite3"
+	"strings"
 )
 
 type DB struct {
-	rawDB *sql.DB
+	locker *fileutils.Locker
+	rawDB  *sql.DB
 
 	enableStat bool
 }
 
+func OpenWriter(dsn string) (*DB, error) {
+	return open(dsn, true)
+}
+
+func OpenReader(dsn string) (*DB, error) {
+	return open(dsn, false)
+}
+
+func open(dsn string, lock bool) (*DB, error) {
+	// locker
+	var locker *fileutils.Locker
+	if lock {
+		var path = dsn
+		var queryIndex = strings.Index(dsn, "?")
+		if queryIndex >= 0 {
+			path = path[:queryIndex]
+		}
+		path = strings.TrimSpace(strings.TrimPrefix(path, "file:"))
+		locker = fileutils.NewLocker(path)
+		err := locker.Lock()
+		if err != nil {
+			remotelogs.Warn("DB", "lock '"+path+"' failed: "+err.Error())
+			locker = nil
+		}
+	}
+
+	// open
+	rawDB, err := sql.Open("sqlite3", dsn)
+	if err != nil {
+		return nil, err
+	}
+
+	var db = NewDB(rawDB)
+	db.locker = locker
+	return db, nil
+}
+
 func NewDB(rawDB *sql.DB) *DB {
 	var db = &DB{
 		rawDB: rawDB,
@@ -30,6 +72,10 @@ func NewDB(rawDB *sql.DB) *DB {
 	return db
 }
 
+func (this *DB) SetMaxOpenConns(n int) {
+	this.rawDB.SetMaxOpenConns(n)
+}
+
 func (this *DB) EnableStat(b bool) {
 	this.enableStat = b
 }
@@ -81,6 +127,13 @@ func (this *DB) QueryRow(query string, args ...interface{}) *sql.Row {
 
 func (this *DB) Close() error {
 	events.Remove(fmt.Sprintf("db_%p", this))
+
+	defer func() {
+		if this.locker != nil {
+			_ = this.locker.Release()
+		}
+	}()
+
 	return this.rawDB.Close()
 }
 

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
+}

internal/utils/fileutils/locker_test.go

@@ -0,0 +1,24 @@
+// Copyright 2023 Liuxiangchao iwind.liu@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package fileutils_test
+
+import (
+	"github.com/TeaOSLab/EdgeNode/internal/utils/fileutils"
+	"testing"
+)
+
+func TestLocker_Lock(t *testing.T) {
+	var path = "/tmp/file-test"
+	var locker = fileutils.NewLocker(path)
+	err := locker.Lock()
+	if err != nil {
+		t.Fatal(err)
+	}
+	_ = locker.Release()
+
+	var locker2 = fileutils.NewLocker(path)
+	err = locker2.Lock()
+	if err != nil {
+		t.Fatal(err)
+	}
+}