Add Redis persistence.

source/app.d

@@ -18,18 +18,25 @@ Then get the apt key, and install the things:
 import vibe.d;
 
 final class Room {
-    string[] messages;
+    RedisDatabase db;
+    string room;
+    RedisList!string messages;
     ManualEvent messageEvent;
 
-    this() {
+    this(RedisDatabase db, string room) {
+        this.db = db;
+        this.room = room;
+        this.messages = db.getAsList!string("webchat_" ~ room);
         messageEvent = createManualEvent();
     }
 
     void addMessage(string nick, string message) {
-        messages ~= nick ~ ": " ~ message;
+        messages.insertBack(nick ~ ": " ~ message);
+        messageEvent.emit();
+        //messages ~= nick ~ ": " ~ message;
     }
 
-    void waitForMessage(size_t next_message) {
+    void waitForMessage(long next_message) {
         while (messages.length <= next_message) {
             messageEvent.wait();
         }
@@ -37,7 +44,14 @@ final class Room {
 }
 
 final class WebChat {
-    private Room[string] rooms;
+    private {
+        Room[string] rooms;
+        RedisDatabase db;
+    }
+
+    this() {
+        db = connectRedis("127.0.0.1").getDatabase(0);
+    }
 
     // Uses vibe.d magic method names - in this case, GET /
     void get() {
@@ -87,7 +101,7 @@ final class WebChat {
 
     private Room getOrCreateRoom(string room) {
         if (auto pr = room in rooms) return *pr;
-        return rooms[room] = new Room;
+        return rooms[room] = new Room(db, room);
     }
 }