60 lines
1.5 KiB
Go
60 lines
1.5 KiB
Go
package utils
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import (
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"context"
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"fmt"
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"git.hlsq.asia/alex/service-common/db/redis"
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"git.hlsq.asia/alex/service-common/net/http/httpresp"
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"google.golang.org/grpc/metadata"
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"time"
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)
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const (
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replayTTL = 2 * time.Minute // 防重放缓存有效期
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lockTTL = 10 * time.Second // 分布式锁有效期
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)
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// WrapPreventReplay 防止重放请求
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func WrapPreventReplay[T any](ctx context.Context, usn int64, fun func() (T, error)) (T, error) {
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var zero T
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key := ""
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if md, ok := metadata.FromIncomingContext(ctx); ok {
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ridArr := md.Get("Request-Id")
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if len(ridArr) == 0 || ridArr[0] == "" {
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return fun()
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}
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key = fmt.Sprintf("cache:replay:%v:%v", usn, ridArr[0])
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} else {
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return fun()
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}
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// 先查缓存，命中直接返回
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if val := getReplayCache[T](ctx, key); val != nil {
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return *val, nil
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}
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// 尝试抢分布式锁，抢到就执行，没抢到报错
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lockKey := fmt.Sprintf("%s:lock", key)
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locked, err := redis.GetClient().SetNX(ctx, lockKey, "1", lockTTL).Result()
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if err == nil && locked {
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defer redis.GetClient().Del(ctx, lockKey)
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result, err := fun()
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// 这里报错了是没有缓存的
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if err != nil {
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return zero, err
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}
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redis.GetCacheClient().Set(ctx, key, result, replayTTL)
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return result, nil
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}
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return zero, httpresp.RequestTooFast
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}
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// getReplayCache 从 Redis 读取重放缓存
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func getReplayCache[T any](ctx context.Context, key string) *T {
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var dst T
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if redis.GetCacheClient().Get(ctx, key, &dst) {
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return &dst
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}
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return nil
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}
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