1 files changed, 55 insertions, 5 deletions
diff --git a/src/user.clj b/src/user.clj
index 1d59944..7641bd8 100644
--- a/src/user.clj
+++ b/src/user.clj
@@ -16,12 +16,62 @@
    (> (count n) 16) "NICK_TOO_LONG"
    (not (re-matches *nick-regex* n)) "NICK_INVALID_CHARS"))
 
+;;; User info cache
+
+(def user-cache-size 500)
+(def user-nick-cache (ref {}))
+(def user-id-cache (ref {}))
+
+(defn update-cache! [uid attr val]
+  (dosync
+   (if-let [info (get @user-id-cache uid)]
+     (let [nick  (lower-case (:nick info))
+           new-info (assoc info attr val)]
+       (alter user-id-cache assoc uid new-info)
+       (alter user-nick-cache assoc nick new-info)))))
+     
+
 (defn fetch-nick [nick]
-  (let [q1 "SELECT * FROM users WHERE nick = ? LIMIT 1"
-        ; ORDER BY ensures consistent retrieval of ambiguious names
-        q2 "SELECT * FROM users WHERE lower(nick) = ? ORDER BY nick LIMIT 1"]
-    (or (first-or-nil (do-select [q1 nick]))
-        (first-or-nil (do-select [q2 (lower-case nick)])))))
+  (let [lcnick (lower-case nick)]
+    (if (contains? user-nick-cache lcnick)
+      (get user-nick-cache lcnick)
+      (let [info  (first
+                    (do-select ["SELECT * FROM users WHERE lower(nick) = ? LIMIT 1"
+                                lcnick]))
+          user-id (:user_id info)]
+        (dosync
+         (alter user-nick-cache assoc lcnick info)
+         (if (and info user-id)
+           (alter user-id-cache assoc user-id info)))
+        info))))
+
+(defn fetch-nicks [nicks]
+  (let [lcnicks       (map lower-case nicks)
+        cache         @user-nick-cache
+        to-fetch      (filter #(not (contains? cache %)) lcnicks)
+        fetched-info  (do-select ["SELECT * FROM users WHERE lower(nick) = ANY(?)"
+                                  (sql-array "text" to-fetch)])
+        info-map      (zipmap (map (comp lower-case :nick) fetched-info)
+                              fetched-info)]
+    (doseq [nick to-fetch]
+      (let [info (get info-map nick)]
+        (dosync
+         (alter user-nick-cache assoc nick info)
+         (if info
+           (alter user-id-cache assoc (:user_id info) info)))))
+    (filter
+     boolean
+     (for [nick lcnicks]
+       (get @user-nick-cache nick)))))
+
+(defn fetch-user-id [uid]
+  (if (contains? @user-id-cache uid)
+    (get @user-id-cache uid)
+    (if-let [info (first
+                   (do-select ["SELECT * FROM users WHERE user_id = ? LIMIT 1" uid]))]
+      (dosync
+       (alter user-nick-cache assoc (lower-case (:nick info)) info)
+       (alter user-id-cache assoc uid info)))))
 
 (defn authorize-nick-hash [nick hash]
   (let [db-user (fetch-nick nick)]