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xlgo-core/database/dialect.go
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2026-07-08 18:48:41 +08:00

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package database
import (
"fmt"
"strings"
"sync"
"github.com/EthanCodeCraft/xlgo-core/config"
"github.com/EthanCodeCraft/xlgo-core/logger"
"gorm.io/driver/mysql"
"gorm.io/driver/postgres"
"gorm.io/gorm"
)
// 内置驱动常量(更多驱动可通过 RegisterDialect 扩展)
const (
DriverMySQL = config.DriverMySQL
DriverPostgres = config.DriverPostgres
)
// DialectorFactory 根据 DSN 返回 GORM Dialector
type DialectorFactory func(dsn string) gorm.Dialector
// DialectSpec 描述一种数据库方言:如何建立连接 + 如何拼接 DSN
type DialectSpec struct {
// Name 驱动主名称(如 "mysql"、"postgres"、"sqlite"),大小写不敏感
Name string
// Aliases 驱动别名(如 postgres 的 "postgresql"、"pg"
Aliases []string
// Dialector 由 DSN 构造 GORM Dialector
Dialector DialectorFactory
// DSN 由 DatabaseConfig 拼接连接字符串。可选——
// 不提供时使用 cfg.MySQLDSN() 兜底(适合自定义驱动通过 CustomDSN 指定连接串的场景)
DSN config.DSNBuilder
}
var (
dialectsMu sync.RWMutex
dialects = map[string]DialectorFactory{}
)
// RegisterDialect 注册一种数据库方言。
// 同时把 DSN 构建器登记到 config 包,使 cfg.Database.DSN() 也能识别新驱动。
// 已注册的同名驱动会被覆盖。
//
// 用法示例(接入 SQLite):
//
// import "gorm.io/driver/sqlite"
//
// database.RegisterDialect(database.DialectSpec{
// Name: "sqlite",
// Dialector: func(dsn string) gorm.Dialector { return sqlite.Open(dsn) },
// DSN: func(c *config.DatabaseConfig) string { return c.Name }, // 文件路径
// })
func RegisterDialect(spec DialectSpec) {
if spec.Dialector == nil || strings.TrimSpace(spec.Name) == "" {
return
}
dialectsMu.Lock()
for _, n := range append([]string{spec.Name}, spec.Aliases...) {
key := normalizeDriver(n)
if key != "" {
dialects[key] = spec.Dialector
}
}
dialectsMu.Unlock()
if spec.DSN != nil {
config.RegisterDSNBuilder(spec.Name, spec.DSN, spec.Aliases...)
}
}
// LookupDialect 查找已注册的 Dialector 工厂
func LookupDialect(driver string) (DialectorFactory, bool) {
key := normalizeDriver(driver)
dialectsMu.RLock()
defer dialectsMu.RUnlock()
f, ok := dialects[key]
return f, ok
}
// RegisteredDialects 返回所有已注册的驱动名(用于诊断)
func RegisteredDialects() []string {
dialectsMu.RLock()
defer dialectsMu.RUnlock()
names := make([]string, 0, len(dialects))
for k := range dialects {
names = append(names, k)
}
return names
}
// Dialector 根据配置返回 GORM Dialector。
// 驱动由 cfg.Database.Driver 决定,未指定或未注册时按 MySQL 兜底(向后兼容)。
func Dialector(cfg *config.Config) gorm.Dialector {
if cfg == nil {
logger.Warn("database: 配置为空,回退到 MySQL 空 DSN")
return mysql.Open("")
}
return dialectorForDSN(cfg.Database.Driver, cfg.Database.DSN())
}
// dialectorForDSN 根据驱动名和 DSN 返回 Dialector
func dialectorForDSN(driver, dsn string) gorm.Dialector {
if f, ok := LookupDialect(driver); ok {
return f(dsn)
}
// 未注册时回退到 MySQL,与 config.DSN() 的回退保持一致。
// 拼写错误的驱动名(如 "mysq"/"postgrs")会静默回退 MySQL,导致连接错误难排查(M10),
// 故在此告警一次,提示用户驱动名未注册。
logger.Warnf("database: 驱动 %q 未注册,回退到 MySQL(已注册: %s);若是拼写错误请在配置中修正 driver",
normalizeDriver(driver), strings.Join(RegisteredDialects(), ", "))
return mysql.Open(dsn)
}
// normalizeDriver 规范化驱动名(小写、去空白)
func normalizeDriver(name string) string {
return strings.ToLower(strings.TrimSpace(name))
}
// driverDescription 返回带别名提示的驱动描述(用于错误信息和日志)
func driverDescription(driver string) string {
key := normalizeDriver(driver)
if key == "" {
return DriverMySQL + " (default)"
}
if _, ok := LookupDialect(key); ok {
return key
}
return fmt.Sprintf("%s (unregistered, fallback=%s)", key, DriverMySQL)
}
func init() {
// 内置 MySQL
RegisterDialect(DialectSpec{
Name: DriverMySQL,
Dialector: func(dsn string) gorm.Dialector { return mysql.Open(dsn) },
DSN: func(c *config.DatabaseConfig) string { return c.MySQLDSN() },
})
// 内置 PostgreSQL
RegisterDialect(DialectSpec{
Name: DriverPostgres,
Aliases: []string{"postgresql", "pg"},
Dialector: func(dsn string) gorm.Dialector { return postgres.Open(dsn) },
DSN: func(c *config.DatabaseConfig) string { return c.PostgresDSN() },
})
}