LRU cache for note pages added

src/notehub/api.clj

@@ -87,6 +87,7 @@
 (defn get-note [{:keys [noteID]}]
   (if (storage/note-exists? noteID)
     (let [note (storage/get-note noteID)]
+      (storage/increment-note-view noteID)
       {:note note
        :title (derive-title note)
        :longURL (get-path noteID)

src/notehub/handler.clj

@@ -6,6 +6,7 @@
     [clojure.string :rename {replace sreplace} :only [replace]]
     [clojure.core.incubator :only [-?>]])
   (:require 
+    [clojure.core.cache :as cache]
     [hiccup.util :as util]
     [compojure.handler :as handler]
     [compojure.route :as route]
@@ -13,6 +14,9 @@
     [notehub.storage :as storage]
     [cheshire.core :refer :all]))
 
+; note page cache
+(def C (atom (cache/lru-cache-factory {})))
+
 ; TODO: make sure the status is really set to the response!!!!
 (defn- response
   "Sets a custom message for each needed HTTP status.
@@ -56,7 +60,10 @@
          (return-content-type "text/plain; charset=utf-8" md-text)))
 
   (GET "/:year/:month/:day/:title/stats" [year month day title]
-       (when-let [resp (api/get-note {:noteID (api/build-key year month day title)})]
+       (let [note-id (api/build-key year month day title)
+             resp {:statistics (storage/get-note-statistics note-id)
+                   :note (storage/get-note note-id)
+                   :noteID note-id}]
          (statistics-page resp)))
 
   (GET "/:year/:month/:day/:title/edit" [year month day title]
@@ -69,7 +76,13 @@
                            :year year :month month :day day :title title)
              note-id (api/build-key year month day title)]
          (when (storage/note-exists? note-id)
-           (note-page note-id (storage/create-short-url note-id params)))))
+           (if (cache/has? @C note-id)
+             (do
+               (swap! C cache/hit note-id)
+               (storage/increment-note-view note-id))
+             (swap! C cache/miss note-id
+                    (note-page note-id (storage/create-short-url note-id params))))
+           (cache/lookup @C note-id))))
 
   (GET "/:short-url" [short-url]
        (when-let [params (storage/resolve-url short-url)]
@@ -103,7 +116,9 @@
                                                :signature
                                                (storage/sign pid psk noteID note password)))]
               (if (get-in resp [:status :success])
-                (redirect (:longURL resp))
+                (do
+                  (swap! C cache/evict noteID)
+                  (redirect (:longURL resp)))
                 (response 403)))
             (response 500))))
 

src/notehub/storage.clj

@@ -80,9 +80,10 @@
 
 (defn get-note [noteID]
   (when (note-exists? noteID)
-    (do
-      (redis :hincrby :views noteID 1)
-      (unzip (redis :hget :note noteID)))))
+    (unzip (redis :hget :note noteID))))
+
+(defn increment-note-view [noteID]
+  (redis :hincrby :views noteID 1))
 
 (defn short-url-exists? [url]
   (= 1 (redis :hexists :short-url url)))

src/notehub/views.clj

@@ -8,7 +8,8 @@
     [hiccup.element]
     [hiccup.util :only [escape-html]]
     [hiccup.page :only [include-js html5]])
-  (:require [notehub.api :as api]))
+  (:require
+    [notehub.api :as api]))
 
 (def get-message (get-map "messages"))