Add support for stream XTRIM MINID command

[WeihanLi]

From the redis command document, I learned about that we could use XTRIM mystream MINID 649085820 to implement all entries that have an ID lower than 649085820-0 will be evicted, so I'm wondering if we could add support for MINID subcommand for stream XTRIM.

Besides, I noticed that it seemed we could use MINID subcommand when we try to XADD new entry to a stream, maybe we could have it implemented?

• https://redis.io/commands/xadd
• https://redis.io/commands/xtrim

[WeihanLi]

I think maybe it's better to add a new method to avoid breaking changes, for example:

For XTRIM:

StreamTrimWithMinId(RedisKey key, RedisValue minId, bool useApproximateMaxLength = false, CommandFlags flags = CommandFlags.None);

For XADD:

RedisValue StreamAddWithMinId(RedisKey key, RedisValue streamField, RedisValue streamValue, RedisValue minMessageId, RedisValue? messageId = null, bool useApproximateMaxLength = false, CommandFlags flags = CommandFlags.None);

RedisValue StreamAddWithMinId(RedisKey key, NameValueEntry[] streamPairs, RedisValue minMessageId, RedisValue? messageId = null, bool useApproximateMaxLength = false, CommandFlags flags = CommandFlags.None);

[WeihanLi]

Hi @NickCraver, @mgravell, any thoughts on this?

If we could accept breaking changes, I think maybe it's better to add support for a trim policy, maybe something like follows:

public enum StreamTrimPolicy
{
  MaxLength = 0,
  MinID = 1,
}

RedisValue StreamAdd(RedisKey key, RedisValue streamField, RedisValue streamValue, StreamTrimPolicy trimPolicy = StreamTrimPolicy.MaxLength , RedisValue? minMessageIdOrStreamLength = null, RedisValue? messageId = null, bool useApproximateMaxLength = false, CommandFlags flags = CommandFlags.None);

long StreamTrim(RedisKey key, StreamTrimPolicy trimPolicy = StreamTrimPolicy.MaxLength , RedisValue minMessageIdOrStreamLength, bool useApproximateMaxLength = false, CommandFlags flags = CommandFlags.None);

[mgravell]

We try very very hard to avoid MME problems, so unless we already have a necessary "major" (break), it is preferred to do this in a way that doesn't break compatibility. Adding overloads is fine, though. The usual approach is to remove the optional parameters from the old method (making them mandatory parameters), which means new builds prefer the new methods (except for exact matches)

[WeihanLi]

Thanks @mgravell , so it's suggested to add new methods to implement this, right? If so, how about the new method signature above.
If it's fine, maybe I could contribute to this.

[morinow]

Any update on this so far? Would be awesome to have this.

[WeihanLi]

Any more thoughts on this @NickCraver @mgravell

[qrli]

I find myself in need of this feature. Before it is added, is there any workaround?

[WeihanLi]

Hi @qrli , you can use the Execute/ExecuteAsync method to execute a command not supported by a specific API.
For example:

// https://redis.io/commands/xadd, https://redis.io/commands/xtrim
var redis = ConnectionMultiplexer.Connect("").GetDatabase();
var result = redis.Execute("XADD", "stream-key", "MINID", "=",
     DateTimeOffset.UtcNow.Subtract(Expiry).ToUnixTimeMilliseconds(), "*", "message", "stream-message");
var msgId = result.ToString();

[kijanawoodard]

Is anyone working on this one? I might pick it up over the holiday.

[kijanawoodard]

I didn't get to it over the holidays, but I got the PR in.
Have a few question, but maybe it's reasonably close?

#2842

[kijanawoodard]

@NickCraver @mgravell I believe this one can be closed with the release of 2.8.58.

In particular, #2912.