Init V4 community edition (#2265)

* Init V4 community edition

* Init V4 community edition

application/migrator/model/init.go

@@ -0,0 +1,91 @@
+package model
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/jinzhu/gorm"
+
+	"github.com/cloudreve/Cloudreve/v4/application/migrator/conf"
+	"github.com/cloudreve/Cloudreve/v4/pkg/util"
+	_ "github.com/jinzhu/gorm/dialects/mssql"
+	_ "github.com/jinzhu/gorm/dialects/mysql"
+	_ "github.com/jinzhu/gorm/dialects/postgres"
+)
+
+// DB 数据库链接单例
+var DB *gorm.DB
+
+// Init 初始化 MySQL 链接
+func Init() error {
+	var (
+		db         *gorm.DB
+		err        error
+		confDBType string = conf.DatabaseConfig.Type
+	)
+
+	// 兼容已有配置中的 "sqlite3" 配置项
+	if confDBType == "sqlite3" {
+		confDBType = "sqlite"
+	}
+
+	switch confDBType {
+	case "UNSET", "sqlite":
+		// 未指定数据库或者明确指定为 sqlite 时，使用 SQLite 数据库
+		db, err = gorm.Open("sqlite3", util.RelativePath(conf.DatabaseConfig.DBFile))
+	case "postgres":
+		db, err = gorm.Open(confDBType, fmt.Sprintf("host=%s user=%s password=%s dbname=%s port=%d sslmode=disable",
+			conf.DatabaseConfig.Host,
+			conf.DatabaseConfig.User,
+			conf.DatabaseConfig.Password,
+			conf.DatabaseConfig.Name,
+			conf.DatabaseConfig.Port))
+	case "mysql", "mssql":
+		var host string
+		if conf.DatabaseConfig.UnixSocket {
+			host = fmt.Sprintf("unix(%s)",
+				conf.DatabaseConfig.Host)
+		} else {
+			host = fmt.Sprintf("(%s:%d)",
+				conf.DatabaseConfig.Host,
+				conf.DatabaseConfig.Port)
+		}
+
+		db, err = gorm.Open(confDBType, fmt.Sprintf("%s:%s@%s/%s?charset=%s&parseTime=True&loc=Local",
+			conf.DatabaseConfig.User,
+			conf.DatabaseConfig.Password,
+			host,
+			conf.DatabaseConfig.Name,
+			conf.DatabaseConfig.Charset))
+	default:
+		return fmt.Errorf("unsupported database type %q", confDBType)
+	}
+
+	//db.SetLogger(util.Log())
+	if err != nil {
+		return fmt.Errorf("failed to connect to database: %w", err)
+	}
+
+	// 处理表前缀
+	gorm.DefaultTableNameHandler = func(db *gorm.DB, defaultTableName string) string {
+		return conf.DatabaseConfig.TablePrefix + defaultTableName
+	}
+
+	// Debug模式下，输出所有 SQL 日志
+	db.LogMode(true)
+
+	//设置连接池
+	db.DB().SetMaxIdleConns(50)
+	if confDBType == "sqlite" || confDBType == "UNSET" {
+		db.DB().SetMaxOpenConns(1)
+	} else {
+		db.DB().SetMaxOpenConns(100)
+	}
+
+	//超时
+	db.DB().SetConnMaxLifetime(time.Second * 30)
+
+	DB = db
+
+	return nil
+}