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#lang racket
(require (planet mordae/couchdb:1:11))
;(require (planet dherman/json:4:0))
(define (database-connection database-name)
(couchdb-db
(couchdb-connect
#:host "localhost"
#:port 5984
#:user "admin"
#:password "password")
database-name))
(define conn (database-connection "blipcache"))
(define (cached? id)
(with-handlers ([exn:couchdb:not-found?
(lambda (_)
#f)])
;(hash-ref (couchdb-get conn id) 'content)
(couchdb-get conn id)))
(define (user-cached? username page-num)
((compose
(λ (object)
(match object
[#f #f]
[(? (λ (obj) (not (hash-has-key? obj (string->symbol page-num))))) 'update]
[_ (hash-ref object (string->symbol page-num))]))
cached?) username))
(define category-cached?
(compose
(λ (obj)
(match obj
[#f #f]
[_ (hash-ref obj 'content)]))
cached?))
(define (cache-category info get-data)
(let* ([message (make-hash)]
[data (get-data)])
(hash-set! message '_id info)
(hash-set! message 'content data)
(hash-set! message 'last_updated (current-inexact-milliseconds))
(couchdb-put conn message)
data))
(define (cache-user message username page-num get-data)
(let ([data (get-data)])
(hash-set! message '_id username)
(hash-set! message (string->symbol page-num) data)
(hash-set! message 'last_updated (current-inexact-milliseconds))
(with-handlers ([exn:couchdb:conflict? (λ(x) data)])
(couchdb-put conn message)
data)))
;; Checks if a document needs updating
;; Info -> String
;; Data -> Hash
;; Updater -> (Hash -> Hash)
(define (update? key data updater)
(let* ([last-time (hash-ref data 'last_updated)]
[revision-id (hash-ref data '_rev)]
[current-time (current-inexact-milliseconds)]
[new-data (updater data)])
(match (> (- current-time last-time) 300000)
[#t (λ ()
(let ([message (hasheq '_rev revision-id
'last_updated current-time
key new-data
'_id (hash-ref data '_id))])
(couchdb-put conn message)
data))]
[_ #f])))
;((update? "foobar" (couchdb-get conn "foobar") (λ (h) (string-append "watwat" "foobarbaz"))))
(struct user-cache-params (username pagenum))
(define (immuthsh->muthsh hsh)
(make-hash (hash-map hsh cons)))
;;
(define (check-cache info get-data updater)
(match info
[(user-cache-params username pagenum)
(match (user-cached? username pagenum)
['update (let ([message (immuthsh->muthsh (couchdb-get conn username))])
(cache-user message username pagenum get-data))]
[#f (cache-user (make-hash) username pagenum get-data)]
[result result])]))
;(define (check-user-cache username page-number get-data)
; (match (
(provide check-cache user-cache-params)