CC-3464: Playout forward cache should be configurable

-Done

airtime_mvc/application/configs/conf.php

@@ -62,6 +62,8 @@ class Config {
         $CC_CONFIG['baseUrl'] = $values['general']['base_url'];
         $CC_CONFIG['basePort'] = $values['general']['base_port'];
         
+        $CC_CONFIG['cache_ahead_hours'] = $values['general']['cache_ahead_hours'];
+        
 	    // Database config
         $CC_CONFIG['dsn']['username'] = $values['database']['dbuser'];
         $CC_CONFIG['dsn']['password'] = $values['database']['dbpass'];

airtime_mvc/application/models/Schedule.php

@@ -609,7 +609,17 @@ class Application_Model_Schedule {
         }
         if (is_null($p_fromDateTime)) {
             $t2 = new DateTime("@".time());
-            $t2->add(new DateInterval("PT30M"));
+            
+            $cache_ahead_hours = $CC_CONFIG["cache_ahead_hours"];
+            
+            if (is_numeric($cache_ahead_hours)){
+                //make sure we are not dealing with a float
+                $cache_ahead_hours = intval($cache_ahead_hours);
+            } else {
+                $cache_ahead_hours = 1;
+            }
+                        
+            $t2->add(new DateInterval("PT".$cache_ahead_hours."H"));
             $range_end = $t2->format("Y-m-d H:i:s");
         } else {
             $range_end = Application_Model_Schedule::PypoTimeToAirtimeTime($p_toDateTime);

airtime_mvc/build/airtime.conf

@@ -18,6 +18,10 @@ airtime_dir = x
 base_url = localhost
 base_port = 80
 
+#How many hours ahead of time should Airtime playout engine (PYPO)
+#cache scheduled media files.
+cache_ahead_hours = 1
+
 [soundcloud]
 connection_retries = 3
 time_between_retries = 60