Adds django cache as monitor cache

Not the best solution yet, but it solves monitoring problems with brokers that don't have a pattern getter for cluster stats.

django_q/brokers/__init__.py

@@ -1,10 +1,12 @@
 from django_q.conf import Conf
+from django.core.cache import caches, InvalidCacheBackendError
 
 
 class Broker(object):
     def __init__(self, list_key=Conf.Q_LIST):
         self.connection = self.get_connection()
         self.list_key = list_key
+        self.cache=self.get_cache()
 
     def enqueue(self, task):
         pass
@@ -24,14 +26,36 @@ class Broker(object):
     def ping(self):
         pass
 
-    def set(self, key, value, timeout):
+    def set_stat(self, key, value, timeout):
-        pass
+        key_list=self.cache.get(Conf.Q_STAT, [])
+        if key not in key_list:
+            key_list.append(key)
+        self.cache.set(Conf.Q_STAT, key_list)
+        return self.cache.set(key, value, timeout)
 
-    def get(self, key):
+    def get_stat(self, key):
-        pass
+        return self.cache.get(key)
 
-    def get_pattern(self, pattern):
+    def get_stats(self, pattern):
-        pass
+        key_list = self.cache.get(Conf.Q_STAT)
+        if not key_list or len(key_list) == 0:
+            return []
+        stats = []
+        for key in key_list:
+            stat = self.cache.get(key)
+            if stat:
+                stats.append(stat)
+            else:
+                key_list.remove(key)
+        self.cache.set(Conf.Q_STAT,key_list)
+        return stats
+
+    @staticmethod
+    def get_cache():
+        try:
+            return caches[Conf.CACHE]
+        except InvalidCacheBackendError:
+            return None
 
     @staticmethod
     def get_connection():

django_q/brokers/redis.py

@@ -26,14 +26,14 @@ class Redis(Broker):
             logger.error('Can not connect to Redis server.')
             raise e
 
-    def set(self, key, value, timeout):
+    def set_stat(self, key, value, timeout):
         self.connection.set(key, value, timeout)
 
-    def get(self, key):
+    def get_stat(self, key):
         if self.connection.exists(key):
             return self.connection.get(key)
 
-    def get_pattern(self, pattern):
+    def get_stats(self, pattern):
         keys = self.connection.keys(pattern=pattern)
         if keys:
             return self.connection.mget(keys)

django_q/conf.py

@@ -85,6 +85,9 @@ class Conf(object):
     # Global sync option to for debugging
     SYNC = conf.get('sync', False)
 
+    # The Django cache to use
+    CACHE = conf.get('cache', 'default')
+
     # If set to False the scheduler won't execute tasks in the past.
     # Instead it will run once and reschedule the next run in the future. Defaults to True.
     CATCH_UP = conf.get('catch_up', True)

django_q/status.py

@@ -64,7 +64,7 @@ class Stat(Status):
 
     def save(self):
         try:
-            self.broker.set(self.key, signing.SignedPackage.dumps(self, True), 3)
+            self.broker.set_stat(self.key, signing.SignedPackage.dumps(self, True), 3)
         except Exception as e:
             logger.error(e)
 
@@ -78,7 +78,7 @@ class Stat(Status):
         :param cluster_id: id of the cluster
         :return: Stat or Status
         """
-        pack = broker.get(Stat.get_key(cluster_id))
+        pack = broker.get_stat(Stat.get_key(cluster_id))
         if pack:
             try:
                 return signing.SignedPackage.loads(pack)
@@ -94,7 +94,7 @@ class Stat(Status):
         :return: list of type Stat
         """
         stats = []
-        packs = broker.get_pattern('{}:*'.format(Conf.Q_STAT)) or []
+        packs = broker.get_stats('{}:*'.format(Conf.Q_STAT)) or []
         for pack in packs:
             try:
                 stats.append(signing.SignedPackage.loads(pack))