Add PostgreSQL storage backend, add/get messages

project.clj

@@ -1,8 +1,10 @@
 (defproject de.viaboxx.flurfunk/flurfunk-server "0.1.0-SNAPSHOT" 
   :description "The Funk of the Flur"
   :dependencies [[org.clojure/clojure "1.3.0"]
+                 [org.clojure/java.jdbc "0.2.3"]
                  [compojure/compojure "0.6.5"]
                  [fleetdb-client "0.2.2"]
+                 [postgresql/postgresql "9.1-901.jdbc4"]
                  [ring/ring-jetty-adapter "0.3.11"]]
   :plugins [[lein-ring "0.6.3"]]
   :ring {:handler flurfunk.server.routes/app}

src/flurfunk/server/storage.clj

@@ -1,8 +1,9 @@
 (ns flurfunk.server.storage
   "Storage and retrieval of objects."
-  (:require [fleetdb.client :as db]
-            [clojure.string :as string]
-	    [clojure.walk :as walk]))
+  (:require [clojure.string :as string]
+            [clojure.java.jdbc :as sql]
+            [clojure.walk :as walk]
+            [fleetdb.client :as db]))
 
 (def message-limit 200)
 
@@ -80,14 +81,71 @@
    [this]
    (client ["delete", "messages"])))
 
+(def ^{:private true} postgresql-db
+     (or (System/getenv "DATABASE_URL")
+         "postgresql://flurfunk:flurfunk@localhost:5432/flurfunk"))
+
+(defn- postgresql-messages-table-exists?
+  []
+  (sql/with-query-results results
+    [(str "SELECT EXISTS(SELECT * FROM information_schema.tables"
+          " WHERE table_name = 'messages')")]
+    (boolean (Boolean. (:?column? (first results))))))
+
+(deftype PostgreSQLStorage [] Storage
+  (storage-get-messages
+   [this]
+   (try (sql/with-connection postgresql-db
+          (if (postgresql-messages-table-exists?)
+            (vec (sql/with-query-results results
+                   [(str "SELECT akeys(attributes), avals(attributes)"
+                         " FROM messages LIMIT " message-limit)]
+                   (map #(zipmap (map keyword (vec (.getArray (:akeys %))))
+                                 (vec (.getArray (:avals %))))
+                        (into [] results))))))
+        (catch Exception e (.printStackTrace e))))
+
+  (storage-get-messages
+   [this options]
+   ;; TODO: If db exists, query based on options
+   [])
+
+  (storage-add-message
+   [this message]
+   (sql/with-connection postgresql-db
+     (let [entries (map #(str \" (name (first %))\" " => \"" (second %) \")
+                        message)
+           value-string (string/join ",\n" entries)]
+       (sql/do-commands
+        (str "CREATE TABLE IF NOT EXISTS messages"
+             " (id serial PRIMARY KEY, attributes hstore)")
+        (str "INSERT INTO messages (attributes) VALUES ('"
+             value-string "')")))))
+
+  (storage-find-message
+   [this id]
+   ;; TODO: if db exists, query by id
+   )
+
+  (storage-clear-messages
+   [this]
+   (sql/with-connection postgresql-db
+     (sql/do-commands "drop table if exists messages"))))
+
 (defn- make-storage []
-  (if (= (System/getProperty "flurfunk.db") "fleetdb")
-    (FleetDBStorage. (db/connect {:host "127.0.0.1" :port 3400}))
-    (do
-      (println (string/trim "
-Using in-memory database. To use a persistent database, set the system property
-\"flurfunk.db\" to \"fleetdb\" or \"postgresql\"."))
-      (MemoryStorage. (atom [])))))
+  (case (System/getProperty "flurfunk.db")
+        "fleetdb" (do
+                    (println "Using FleetDB storage backend.")
+                    (FleetDBStorage. (db/connect {:host "127.0.0.1"
+                                                  :port 3400})))
+        "postgresql" (do
+                       (println "Using PostgreSQL storage backend.")
+                       (PostgreSQLStorage.))
+        (do
+          (println (string/trim "
+Using in-memory storage backend. To use a persistent backend, set the system
+property \"flurfunk.db\" to \"fleetdb\" or \"postgresql\"."))
+          (MemoryStorage. (atom [])))))
 
 (def ^{:private true} storage (make-storage))