use the new key resolution algorithm

[pmlopes]

Signed-off-by: Paulo Lopes pmlopes@gmail.com

Motivation:

Redis 7 introduced a new way to perform key resolution. This PR removes the wrong way we were using and follows the requirements by redis itself.

[pmlopes]

@pendula95 redis 7 introduced metadata for the commands with an algorithm on how to extract the right keys from a command in order to compute the right cluster slot.

Before we had some basic heuristics and some ad-hoc key extractor that worked mostly.

This PR tries to remove the non-standard ways of finding if a cluster command is read only, keys and splitting.

All reviews are welcome :)

[liuchong]

Hi, what is the needGetKeys for? @pmlopes Thanks!

[liuchong]

Another question, look at the below commands, are they readOnly or not?

Command CONFIG = new CommandImpl("config", -2, null, false, false);
Command SAVE = new CommandImpl("save", 1, null, false, false);

They are having a null readOnly argument by with no keyLocators, and they should by default got a readOnly true.

[pmlopes]

That information is extracted from the COMMANDS command. If a command has a flag read or write then it's clear if the command is read only or not, but some cases like these don't include any flag, so nothing can be said. Redis states that for these we should rely on the server to decide.

It's not a bug, it's what the metadata tells us. Before we were assuming all commands were either read only or not but it seems our assumption was wrong.

Do not you don't need this metadata unless you want to use a cluster connection. For most cases all you need is the regular command name.