Feature request: Support TTL command

[me0den]

Hi guys,

In my scenario, I have set a TTL value for the redis key and reuse it for next time. Can we support this command for more flexible TTL values?

ttl, _ := redis.TTL(ctx, key).Result()
redis.Set(ctx, key, val, ttl).Result()

[knadh]

Can we support this command for more flexible TTL values?

Could you explain what you mean by this?

[me0den]

For each key in Redis, We have set a TTL value for it. I want to get this TTL value and reuse it for the next time set. Sorry if my eng is bad.

For code example:

// Set ttl 3 mins for key
ttl := 3 * time.Minute
redis.Set(ctx, key, val, ttl).Result()

// after a momemt
ttl, _ := redis.TTL(ctx, key).Result()

// re-set ttl to key
redis.Set(ctx, key, val, ttl).Result()

[knadh]

Your example is the right way of doing this (you should handle those errors though). If you are doing this in many places, you could just wrap it in a helper function SetWithOldTTL(key, val, cache ...). Don't think such a function in the main lib would be ideal.

[tausten]

Heads-up -- in recent versions of https://github.com/go-redis/redis , there is a redis.KeepTTL value (i.e. -1) which maps to the REDIS keepttl option for write operations, but the latest version of cache takes anything < 0 and remaps it to 0, so this doesn't flow through to the underlying redis client, and ultimately doesn't turn into keepttl on the Redis server.