apc_add() versus apc_store()
I know that apc_st开发者_运维问答ore() overwrites the key if it already exists, so I know the difference, my question is just: What's the better method/best practice?
The only difference between those two functions is that apc_add()
will not overwrite an existing entry.
apc_store()
, on the other hand, will overwrite an existing entry.
So, which one should your use, between apc_add()
and apc_store()
?
Well, it all depends on your needs : do you want an existing entry to be overwritten, or not ?
In addition to what @Pascal MARTIN writes, there is a major practical difference between them.
In a heavily concurrent environment, e.g. when using apc for user objects in apache, the use of apc_store might lead to apc time bomb (the link is from 2007 but still relevant!), while apc_add mitigates this issue.
See also: https://serverfault.com/questions/342295/apc-keeps-crashing
you need apc_add()
in case you like to implement an atomic counter in a concurrent environment. thats the main use-case IMO.
Really depends on the logic you need to apply: do you need to overwrite the key or not? It’s all up to you.
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