From: Charles Hixson <charleshixsn@...>
Date: 2004-09-13T13:48:10+09:00
Subject: Re: Problem with ensuring consistency .. Finalization??

Robert Klemme wrote:

>
> "Charles Hixson" <charleshixsn@earthlink.net> schrieb im Newsbeitrag 
> news:4142336A.4040005@earthlink.net...
>
>> Sort of.  The disk storage is permanent, it's the hash that's 
>> temporary. I certainly wouldn't want to eat up my ram by holding the 
>> entire database in ram, when at any one time it didn't need most of it.
>
>
> Ah, ok, that sounds as if you needed a cache.  An LRU cache is 
> relatively straightforward.  There might be one on RAA.  I remember I 
> did an experimental implementation once, if you're interested I can 
> check whether I still have it.

The cache seems to be working now... my current problem has to do with 
the db, which appears to be confusing variable name with variable 
value.  I may need to rename my db variables, which seems an altogether 
silly requirement, but that's what it looks like may be needed.

>>    at_exit    {  flush  }      #   this is run after the files are 
>> opened and the hash is initialized
>>  end  #  initializer
>> ..
>> end  #  class
>>
>> will solve the problem.   I've read the description of what it does 
>> three times, and I still can't be *sure* that the file and class 
>> variables will still be extant when I run it, but it looks like 
>> that's the intent.
>
> ..
>
> The only thing that at_exit can't help you with is a crash.  If for 
> some reason (e.g. buggy extension) Ruby crashes at_exit won't help you 
> here.  The best (i.e safest) is probably to directly store new data in 
> the DB and keep a cache of recent used data in mem.

If it's that corrupt, perhaps I'm better off not saving the cache.  (It 
should only cost me a few minutes work, and better stale data than corrupt.)

> Thanks for your assistance.
>
> You're welcome!
>
> Kind regards
>
>    robert

Thanks again,
Charles