magic_server/commons/core/redisclient/getDataFromCacheOrDb.go

package redisclient

import (
	"context"
	"encoding/json"
	"fmt"
	"reflect"
	"time"
)

// GetFromCacheOrDB 通用缓存获取方法
// cacheKey: 缓存键
// cacheTime: 缓存时间
// target: 目标结构体指针(需要传入指针)
// dbFunc: 数据库查询函数，当缓存不存在时调用

func GetBytesFromCacheOrDB(cacheKey string, cacheTime time.Duration, target interface{}, dbFunc func() (interface{}, error)) error {
	// 1. 尝试从缓存获取
	cacheDataStr, err := DefaultClient().Get(context.Background(), cacheKey).Result()
	if err == nil {
		if err := json.Unmarshal([]byte(cacheDataStr), target); err == nil {
			return nil
		}
	}
	// 2. 缓存未命中，从数据库获取
	data, err := dbFunc()
	if err != nil {
		return err
	}

	// 3. 序列化数据并存入缓存(异步)
	go func() {
		cacheData, err := json.Marshal(data)
		if err != nil {
			return
		}
		if err := DefaultClient().Set(context.Background(), cacheKey, cacheData, cacheTime).Err(); err != nil {
			fmt.Println(fmt.Sprintf("failed to set cache for key %s: %v", cacheKey, err))
		}
	}()

	// 4. 将数据赋值给target
	val := reflect.ValueOf(target)
	if val.Kind() != reflect.Ptr || val.IsNil() {
		return fmt.Errorf("target must be a non-nil pointer")
	}

	dataVal := reflect.ValueOf(data)
	if dataVal.Type().AssignableTo(val.Elem().Type()) {
		val.Elem().Set(dataVal)
		return nil
	}

	// 如果类型不匹配，尝试通过JSON转换
	dataBytes, err := json.Marshal(data)
	if err != nil {
		return fmt.Errorf("failed to marshal data: %v", err)
	}
	return json.Unmarshal(dataBytes, target)
}

// 适用于保存json数据

func GetJsonDataFromCacheOrDB(cacheKey string, cacheTime time.Duration, target interface{}, dbFunc func() (interface{}, error)) error {
	// 1. 尝试从缓存获取
	cacheDataStr, err := DefaultClient().Get(context.Background(), cacheKey).Result()
	if err == nil {
		if err := json.Unmarshal([]byte(cacheDataStr), target); err == nil {
			return nil
		}
	}
	// 2. 缓存未命中，从数据库获取
	data, err := dbFunc()
	if err != nil {
		return err
	}

	// 3. 序列化数据并存入缓存(异步)
	go func() {
		cacheData, err := json.Marshal(data)
		if err != nil {
			return
		}
		if err := DefaultClient().Set(context.Background(), cacheKey, cacheData, cacheTime).Err(); err != nil {
			fmt.Println(fmt.Sprintf("failed to set cache for key %s: %v", cacheKey, err))
		}
	}()

	// 4. 将数据赋值给target
	val := reflect.ValueOf(target)
	if val.Kind() != reflect.Ptr || val.IsNil() {
		return fmt.Errorf("target must be a non-nil pointer")
	}

	dataVal := reflect.ValueOf(data)
	if dataVal.Type().AssignableTo(val.Elem().Type()) {
		val.Elem().Set(dataVal)
		return nil
	}

	// 如果类型不匹配，尝试通过JSON转换
	dataBytes, err := json.Marshal(data)
	if err != nil {
		return fmt.Errorf("failed to marshal data: %v", err)
	}
	return json.Unmarshal(dataBytes, target)
}