Refactor the util directory to use subpackages.

util/saas/queuemetrics.py

@@ -0,0 +1,56 @@
+import logging
+
+from util.saas.cloudwatch import get_queue
+
+
+logger = logging.getLogger(__name__)
+
+
+class NullReporter(object):
+  def report(self, *args):
+    pass
+
+
+class CloudWatchReporter(object):
+  """ CloudWatchReporter reports work queue metrics to CloudWatch """
+  def __init__(self, request_queue, namespace, need_capacity_name, build_percent_name):
+    self._namespace = namespace
+    self._need_capacity_name = need_capacity_name
+    self._build_percent_name = build_percent_name
+    self._put_metrics_queue = request_queue
+
+  def _send_to_queue(self, *args, **kwargs):
+    self._put_metrics_queue.put((args, kwargs))
+
+  def report(self, currently_processing, running_count, total_count):
+    logger.debug('Worker indicated %s running count and %s total count', running_count,
+                 total_count)
+
+    need_capacity_count = total_count - running_count
+    self._send_to_queue(self._namespace, self._need_capacity_name, need_capacity_count,
+                        unit='Count')
+
+    building_percent = 100 if currently_processing else 0
+    self._send_to_queue(self._namespace, self._build_percent_name, building_percent,
+                        unit='Percent')
+
+class QueueMetrics(object):
+  """
+  QueueMetrics initializes a reporter for recording metrics of work queues.
+  """
+  def __init__(self, app=None):
+    self._app = app
+    self._reporter = NullReporter()
+    if app is not None:
+      reporter_type = app.config.get('QUEUE_METRICS_TYPE', 'Null')
+      if reporter_type == 'CloudWatch':
+        namespace = app.config['QUEUE_METRICS_NAMESPACE']
+        req_capacity_name = app.config['QUEUE_METRICS_CAPACITY_SHORTAGE_NAME']
+        build_percent_name = app.config['QUEUE_METRICS_BUILD_PERCENT_NAME']
+
+        request_queue = get_queue(app)
+        self._reporter = CloudWatchReporter(request_queue, namespace, req_capacity_name,
+                                        build_percent_name)
+
+  def __getattr__(self, name):
+    return getattr(self._reporter, name, None)