[PEAK] The path of model and storage

Phillip J. Eby pje at telecommunity.com
Wed Jul 28 14:17:54 EDT 2004

At 11:00 AM 7/28/04 -0700, Robert Brewer wrote:
>And if, in the process, you decided to make a cache container which:
>1. Accepts any Python object (i.e. - don't have to subclass from
>2. Is thread-safe: avoiding "dict mutated while iterating" (probably
>with a page-locking btree),
>3. Indexes on arbitrary keys, which are simple attributes of the cached
>objects (both unique and non-), and
>4. Is no more than 4 times as slow as a native dict,

#2 just ain't gonna happen.  Workspaces will not be shareable across 
threads.  (Or more precisely, workspaces and the objects provided by them 
will not include any protection against simultaneous access by multiple 
threads.)  #4 is also impossible, if I understand it correctly, since 
accessing just *one* attribute will in the typical case require *two* 
dictionary lookups.  So, unless you're not counting the time needed to 
*generate* the keys, that's clearly a non-starter.

>..I'd (wash your car | walk your dog | do your taxes) for a year. :)

And based on those requirements, you'd be getting the better half of the 
deal by far!

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