changed cacher and playlist server to use next/previous links for user playlists

cacher.rkt

@@ -8,21 +8,45 @@
    (couchdb-connect
    #:host "localhost"
    #:port 5984
-   #:user "wes"
+   #:user "admin"
    #:password "password")
    database-name))
 
+(define number->symbol (compose string->symbol number->string))
+
 (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 (number->symbol page-num))))) 'update]
+       [_ (hash-ref object (number->symbol page-num))]))
+     cached?) username))
+
+(define category-cached?
+  (compose
+   (λ (obj)
+     (match obj
+       [#f #f]
+       [_ (hash-ref obj 'content)]))
+   cached?))
+  
+
 ;; type is the type of data to cache
 ;; info is the actual name of the data to be cached
 ;; get-data is the proc that gets the data from the database
+
+
+
 (define (cache info type get-data)
   (match type
     ['user 
@@ -34,11 +58,19 @@
      (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 (number->symbol page-num) data)
+    (hash-set! message 'last_updated (current-inexact-milliseconds))
+    (couchdb-put conn message)
+    data))
+
 ;; Checks if a document needs updating
 ;; Info -> String
 ;; Data -> Hash
 ;; Updater -> (Hash -> Hash)
-(define (update? info data updater)
+(define (update? key data updater)
   (let* ([last-time (hash-ref data 'last_updated)]
          [revision-id (hash-ref data '_rev)]
          [current-time (current-inexact-milliseconds)]
@@ -47,21 +79,35 @@
     [#t (λ ()
           (let ([message (hasheq '_rev revision-id
                                  'last_updated current-time
-                                 'content new-data
+                                 key new-data
                                  '_id (hash-ref data '_id))])
-            (couchdb-put conn message)))]
+            (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 (λ (a b) (cons a b)))))
+
 ;; 
-(define (check-cache info type get-data)
-  (match (cached? info)
-    [#f (cache info type get-data)]
-    [result 
-     (match (update? info (couchdb-get conn info))
-       [#f result]
-       [updated (updated)])]))
+(define (check-cache info type get-data updater)
+  (match type
+    ['user (let* [(username (user-cache-params-username info))
+                  (pagenum (user-cache-params-pagenum info))]
+           (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]))]))
+     
        
-(provide check-cache)
+;(define (check-user-cache username page-number get-data)
+;  (match (
+
+
+
+(provide check-cache user-cache-params)

playlist_server.rkt

@@ -45,7 +45,11 @@
    (string->xexpr
     (let [(username (path/param-path (car (url-path (request-uri req)))))
           (page-n (hash-ref (list->hash (url-query (request-uri req))) 'p))]
-      (retrieve-videos username (string->number page-n))))))
+      (check-cache (user-cache-params username
+                                      (string->number page-n))
+                   'user
+                   (λ () (retrieve-videos username (string->number page-n)))
+                   identity)))))
 
 ;; Adds a new resource to the lazyplay queue
 (define (add-name req)