Escape job refresh

Author: walison17

cacheback/base.py

@@ -312,6 +312,21 @@ def refresh(self, *args, **kwargs):
         self.store(self.key(*args, **kwargs), self.expiry(*args, **kwargs), result)
         return result
 
+    def should_refresh(self, *args, **kwargs):
+        """
+        Verify if the cache should be refreshed
+        """
+        expiry, data = self.cache.get(self.key(*args, **kwargs), (None, None))
+
+        if data is None:
+            return True
+
+        delta = expiry - time.time()
+        if delta > 0:
+            return False
+
+        return True
+
     def async_refresh(self, *args, **kwargs):
         """
         Trigger an asynchronous job to refresh the cache
@@ -479,10 +494,16 @@ def perform_async_refresh(cls, klass_str, obj_args, obj_kwargs, call_args, call_
         logger.info(
             "Using %s with constructor args %r and kwargs %r", klass_str, obj_args, obj_kwargs
         )
+
+        job = klass(*obj_args, **obj_kwargs)
+        if not job.should_refresh(*call_args, **call_kwargs):
+            logger.info('Refresh escaped, cache is already fresh.')
+            return
+
         logger.info("Calling refresh with args %r and kwargs %r", call_args, call_kwargs)
         start = time.time()
         try:
-            klass(*obj_args, **obj_kwargs).refresh(*call_args, **call_kwargs)
+            job.refresh(*call_args, **call_kwargs)
         except Exception as e:
             logger.exception("Error running job: '%s'", e)
         else:

tests/test_base_job.py

@@ -291,3 +291,16 @@ def test_job_refresh_perform_error(self, logger_mock):
     def test_job_refresh(self):
         Job.perform_async_refresh('tests.test_base_job.EmptyDummyJob', (), {}, ('foo',), {})
         assert EmptyDummyJob().get('foo') is not None
+
+    @pytest.mark.redis_required
+    @mock.patch('tests.test_base_job.EmptyDummyJob.fetch', return_value='foo')
+    def test_escape_job_refresh(self, fetch_mock, rq_burst):
+        job = EmptyDummyJob()
+        job.task_options = {'is_async': False}
+
+        job.async_refresh('foo')
+        job.async_refresh('foo')
+
+        rq_burst()
+
+        assert fetch_mock.call_count == 1