使用golang及gorm通过MySQL实现消息队列，保证日志先行，持久化，失败补偿，事务性多客户端并发消费，可水平扩展...

代码目录：

main.go

go.mod

go.sum

makeData/makeData.go

main.go:

package main

import (  "fmt"  "strconv"  "strings"   //"mysqltaskdirdemo/makeData"   "gorm.io/driver/mysql"  "gorm.io/gorm" )  type VsTask struct {  ID uint  Sha256 string  FileType uint8 }  type VsDir struct {  ID uint  VsTaskId string }  func CreateVsDir(db *gorm.DB) error {  // Note the use of tx as the database handle once you are within a transaction  //get min id from vs_tasks  //get five records from vs_tasks  //insert into this five records to vs_dirs  //delete this five records from vs_tasks  //commit  tx := db.Begin()  defer func() {  if r := recover(); r != nil {  tx.Rollback()  }  }()   if err := tx.Error; err != nil {  return err  }   var ID string  if err := tx.Raw("SELECT MIN(ID) FROM vs_tasks").Scan(&ID).Error; err != nil {  tx.Rollback()  return err  }   var IDs []string  IDnum, err := strconv.Atoi(ID)  if err != nil {  panic(err)  }  upID := IDnum + 4  if err := tx.Raw("select ID from vs_tasks WHERE ID >= ? and ID <= ? for update", ID, upID).Scan(&IDs).Error; err != nil {  tx.Rollback()  return err  }   VsTaskIdStr := strings.Join(IDs