Chen Tianjie d16b4ec1b9
Unshare object to avoid LRU/LFU being messed up (#250)
When LRU/LFU enabled, Valkey does not allow using shared objects, as
value objects may be shared among many different keys and they can't
share LRU/LFU information.

However `maxmemory-policy` is modifiable at runtime. If LRU/LFU is not
enabled at start, but then enabled when some shared objects are already
used, there could be some confusion in LRU/LFU information.

For `set` command it is OK since it is going to create a new object when
LRU/LFU enabled, but `get` command will not unshare the object and just
update LRU/LFU information.

So we may duplicate the object in this case. It is a one-time task for
each key using shared objects, unless this is the case for so many keys,
there should be no serious performance degradation.

Still, LRU will be updated anyway, no matter LRU/LFU is enabled or not,
because `OBJECT IDLETIME` needs it, unless `maxmemory-policy` is set to
LFU. So idle time of a key may still be messed up.

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Signed-off-by: chentianjie.ctj <chentianjie.ctj@alibaba-inc.com>
Signed-off-by: Chen Tianjie <TJ_Chen@outlook.com>
2024-06-01 10:09:20 +02:00
..
2024-04-15 14:25:33 +02:00
2024-04-16 21:17:38 +02:00
2024-05-17 13:35:31 +02:00