Re: [Chicken-users] memcached

[Alaric Snell-Pym]

On 20 Jun 2007, at 10:19 am, Dan Muresan wrote:

> > Ok, so that's one vote for separate 'memcached' and 'cache' eggs.
>
> I would vote against a generically-named cache egg... There are
> many types of caches (depending on storage medium, indexing, time
> complexities of caching/retrieval, expiration strategies etc)

That's why my generic cache interface is intended to be a front-end
to different cache implementations, with a common interface, and some
tools built on top of that interface (such as memoizing functions).

I've not settled on an API yet, but I can imagine something like:

(require-extension cache)

;; for production:

(require-extension memcached)
(define my-cache (make-memcached-cache
  '(("cache1.example.com" 11211 1)   ; hostname, port, weighting
    ("cache2.example.com" 11211 1)
    ("cache3.example.com" 11211 1))

;; for development:

; Store up to 256 objects, maximum 64Kb, in memory, LRU
; (define my-cache (make-lru-memory-cache 256 65536))

;; From here on, we are independent of the cache implementation

(cache-set! my-cache foo bar) ; store bar under key foo
(cache-get my-cache foo) ; and get it back again

(define (factor x) (...split x into prime factors...))
(define memoized-factor (memoize-with-cache my-cache factor))

(memoized-factor
205872349782348907340789347890213478900784578923402379023478902390783480
79458079213407891234890)
; should be quick the second time!
(memoized-factor
205872349782348907340789347890213478900784578923402379023478902390783480
79458079213407891234890)

> Best,
> Dan

ABS

--
Alaric Snell-Pym
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