Deletes Are Driving Me Crazy

[Matthew Glubb]

I think that you are on to something Skylos. I already use incr to  
provide a simple lock on cache objects. I guess I could just extend  
that lock to cover deletions as well.

Thanks for your Perlisms :)

On 11 Jan 2006, at 19:01, Skylos wrote:

> I dunno the architecture of your application...
>
> But were I doing this in a straightforward way... in a perlish sort  
> of way...
>
> $mc->delete($key,$val);
> unless ($mc->add($key,$val2)) {
>     $mc->replace($key, $val2);
> }
>
> But, if it was something on the order of
>
> Destroy objectinstanceA
> Create objectinstanceB
>
> where the destructor of A deletes, and the creator of B adds, it might
> be alot harder to do that.
>
> In that case, I could see a serious problem regarding this behavior.
>
> Then I start to be hacky.
>
> I'll do something like
>
> sub DESTROY {
>     $mc->add($key . "-okaytoreplace", 1) unless ($mc->incr($key .
> "-okaytoreplace"));
>     $mc->delete($key);
> }
>
> sub new {
>     unless ($mc->add($key, $value)) {
>         unless ($mc->decr($key . "-okaytoreplace")) {
>             $mc->replace($key, $value);
>         } else {
>             error("add failed no overwrite");
>         }
>     }
> }
>
> But... maybe that not work for you.  I dunno.
>
> Just a thought,
>
> Skylos
>
> PS - pardon my perlisms.



m a t t h e w   g l u b b

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