Reverse read of multiple Redis Streams (imaginary XREVREAD command)

Question

With redis streams I can read multiple streams in a chronologically forward direction. Each stream is read from a point in time up to to newest point in that stream. I can get the oldest item multiple streams

XREAD COUNT 1 STREAMS streamA streamB streamC 0-0 0-0 0-0

and from there (noting the returned id's) move forward consuming all the items in a selection of streams. Limiting consumption to only 1 item per stream.

How can I easily consume multiple streams in reverse. Starting with the newest items on the tip on a stream and stepping backwards in time, whilst constraining consumption to only 1 item from each stream?

Answer 1

You can't, since Redis doesn't supply this XREVREAD command as of version 6.0.

The closest is XREVRANGE except it only takes one stream at a time. If you really want to, you might have to write a lua script so you can provide multiple streams, have the script loop the streams and call the XREVRANGE command, then result the results at once.