Richer expiration time(in v9)

[monkey92t]

Many commands have expiration time parameters:

• EX (second)
• PX (millisecond)
• EXAT (timestamp)
• PXAT (milliseconds-timestamp)
• KEEPTTL
• PERSIST

I have two thoughts:

// TTL related parameters, not all commands support all ttl attributes.
// priority: Expire > ExpireAt > KeepTTL > Persist
type SetTTL struct {
	// set the specified expire time.
	// Expire > time.Second AND Expire % time.Second == 0: set key EX Expire/time.Second
	// Expire < time.Second OR Expire % time.Second != 0: set key PX Expire/time.Millisecond
	Expire time.Duration

	// set the specified Unix time at which the key will expire.
	// Example: set key EXAT ExpireAt.Unix()
	// Don't consider milliseconds for now(PXAT)
	ExpireAt time.Time

	// Retain the time to live associated with the key.
	KeepTTL bool

	// Remove the time to live associated with the key, Change to never expire
	Persist bool
}
func (c cmdable) Set(ctx context.Context, key string, value interface{}, ttl SetTTL) *StatusCmd

//client.Set(ctx, "key", "value", redis.SetTTL{Expire: 10 * time.Second})

OR:

type SetTTL struct {
	expireSecond, expireMill time.Duration
	expireAT time.Time
	...
}
func WithTTLEX(expire time.Duration) SetTTL {
	return SetTTL{expireSecond: expire}
}
func (c cmdable) Set(ctx context.Context, key string, value interface{}, ttl SetTTL) *StatusCmd

//client.Set(ctx, "key", "value", redis.WithExTTL(10 * time.Second))
//client.Set(ctx, "key", "value", redis.WithPxTTL(500 * time.Millisecond))
//client.Set(ctx, "key", "value", redis.WithKeepTTL())
//client.Set(ctx, "key", "value", redis.WithKPersistTTL())

have a better idea?

[vmihailenco]

I think that the current behavior of Set should not change

Set(key, value, 0) // persist
Set(key, value, -1) // keep ttl
Set(key, value, time.Minute) // ttl

It is as simple as it can be and that is good. It does not support EXAT|PXAT, but it is fine.

---

As an idea we can also consider the following

rdb := redis.NewClient(...)
rdb.SetCmd(key, value).TTL(time.Minute).Exec()
rdb.SetCmd(key, value).KeepTTL().Exec()
rdb.SetCmd(key, value).ExpireAt(time.Now()).Exec()

type SetCmd struct {
    key         string
    value      string
    ttl            time.Duration
    expireAt  time.Time
}

---

But TBH I think we should continue doing what we currently do by providing Set for simple/popular cases + SetArgs for all supported options.