From ac46013fcc5520b628631797b9d5f4db50174220 Mon Sep 17 00:00:00 2001
From: chris meyers <chris.meyers.fsu@gmail.com>
Date: Fri, 24 Apr 2020 14:22:46 -0400
Subject: [PATCH] fix sliding window per/minute calc

* Add tests to ensure correctness
---
 awx/main/analytics/broadcast_websocket.py     | 11 ++-
 .../analytics/test_broadcast_websocket.py     | 69 +++++++++++++++++++
 2 files changed, 74 insertions(+), 6 deletions(-)
 create mode 100644 awx/main/tests/unit/analytics/test_broadcast_websocket.py

diff --git a/awx/main/analytics/broadcast_websocket.py b/awx/main/analytics/broadcast_websocket.py
index 449726f3fe..5cfda529eb 100644
--- a/awx/main/analytics/broadcast_websocket.py
+++ b/awx/main/analytics/broadcast_websocket.py
@@ -44,8 +44,8 @@ class FixedSlidingWindow():
 
     def cleanup(self, now_bucket=None):
         now_bucket = now_bucket or now_seconds()
-        if self.start_time + 60 <= now_bucket:
-            self.start_time = now_bucket + 60 + 1
+        if self.start_time + 60 < now_bucket:
+            self.start_time = now_bucket - 60
 
             # Delete old entries
             for k in list(self.buckets.keys()):
@@ -53,16 +53,15 @@ class FixedSlidingWindow():
                     del self.buckets[k]
 
     def record(self, ts=None):
-        ts = ts or datetime.datetime.now()
-        now_bucket = int((ts - datetime.datetime(1970,1,1)).total_seconds())
+        now_bucket = ts or dt_to_seconds(datetime.datetime.now())
 
         val = self.buckets.get(now_bucket, 0)
         self.buckets[now_bucket] = val + 1
 
         self.cleanup(now_bucket)
 
-    def render(self):
-        self.cleanup()
+    def render(self, ts=None):
+        self.cleanup(now_bucket=ts)
         return sum(self.buckets.values()) or 0
 
 
diff --git a/awx/main/tests/unit/analytics/test_broadcast_websocket.py b/awx/main/tests/unit/analytics/test_broadcast_websocket.py
new file mode 100644
index 0000000000..6edfe51b92
--- /dev/null
+++ b/awx/main/tests/unit/analytics/test_broadcast_websocket.py
@@ -0,0 +1,69 @@
+import datetime
+
+from awx.main.analytics.broadcast_websocket import FixedSlidingWindow
+from awx.main.analytics.broadcast_websocket import dt_to_seconds
+
+
+class TestFixedSlidingWindow():
+
+    def ts(self, **kwargs):
+        e = {
+            'year': 1985,
+            'month': 1,
+            'day': 1,
+            'hour': 1,
+        }
+        return dt_to_seconds(datetime.datetime(**kwargs, **e))
+
+    def test_record_same_minute(self):
+        """
+        Legend:
+                - = record()
+                ^ = render()
+                |---| = 1 minute, 60 seconds
+
+         ....................
+        |------------------------------------------------------------|
+         ^^^^^^^^^^^^^^^^^^^^
+        """
+
+        fsw = FixedSlidingWindow(self.ts(minute=0, second=0, microsecond=0))
+        for i in range(20):
+            fsw.record(self.ts(minute=0, second=i, microsecond=0))
+            assert (i + 1) == fsw.render(self.ts(minute=0, second=i, microsecond=0))
+
+
+    def test_record_same_minute_render_diff_minute(self):
+        """
+        Legend:
+                - = record()
+                ^ = render()
+                |---| = 1 minute, 60 seconds
+
+         ....................
+        |------------------------------------------------------------|
+                            ^^                                      ^
+                            AB                                      C
+        |------------------------------------------------------------|
+         ^^^^^^^^^^^^^^^^^^^^^
+         DEEEEEEEEEEEEEEEEEEEF
+        """
+
+        fsw = FixedSlidingWindow(self.ts(minute=0, second=0, microsecond=0))
+        for i in range(20):
+            fsw.record(self.ts(minute=0, second=i, microsecond=0))
+
+        assert 20 == fsw.render(self.ts(minute=0, second=19, microsecond=0)), \
+            "A. The second of the last record() call"
+        assert 20 == fsw.render(self.ts(minute=0, second=20, microsecond=0)), \
+            "B. The second after the last record() call"
+        assert 20 == fsw.render(self.ts(minute=0, second=59, microsecond=0)), \
+            "C. Last second in the same minute that all record() called in"
+        assert 20 == fsw.render(self.ts(minute=1, second=0, microsecond=0)), \
+            "D. First second of the minute following the minute that all record() calls in"
+        for i in range(20):
+            assert 20 - i == fsw.render(self.ts(minute=1, second=i, microsecond=0)), \
+                "E. Sliding window where 1 record() should drop from the results each time"
+
+        assert 0 == fsw.render(self.ts(minute=1, second=20, microsecond=0)), \
+            "F. First second one minute after all record() calls"