[WIP] Implement Xreadgroup

[LiuYuHui]

This PR is still in a very early stage, it is not ready for review.

[Yangsx-1]

Hi @LiuYuHui , how's it going now? Feel free to ask question if you have any problems. :)

[LiuYuHui]

Hi @LiuYuHui , how's it going now? Feel free to ask question if you have any problems. :)

Hi @Yangsx-1, thanks for asking, I was a bit busy in previous weeks, but recently I found some time, and will continue to work on this PR :D

[LiuYuHui]

Hi @Yangsx-1, currently I only record min_entry_id/max_entry_id in stream consumer metadata, because If put every every entry in metadata, it will make the metadata very big. But I am not sure the current design is efficient when I want to read entries in PEL, I have to iterate the elements range from min_entry_id and max_entry_id, maybe it will be too slow. Do you have any suggestions about this?

[Yangsx-1]

Yes, it is a little inefficient. But only XPENDING and XINFO commands need to iterate the whole elements, and XACK, XCLAIM will only have o(1) complexity in this design, I think it's ok for now. @LiuYuHui

[Yangsx-1]

Hi @LiuYuHui , is there any progress?

[LiuYuHui]

Hi @LiuYuHui , is there any progress?

Hi @Yangsx-1 Apologies for the delayed response. I am currently occupied with other commitments, and unfortunately, I won't be able to continue with this PR at the moment. Please ingore this PR, I apologize for any inconvenience this may cause.