Optimize the logs archiving worker to not issue extremely long queries

Fixes https://jira.coreos.com/browse/QUAY-1371

workers/test/test_logrotateworker.py

@@ -0,0 +1,60 @@
+from datetime import datetime, timedelta
+
+from data import model
+from data.database import LogEntry3
+from workers.logrotateworker import LogRotateWorker
+
+from test.fixtures import *
+
+
+def test_logrotateworker(initialized_db):
+  worker = LogRotateWorker()
+  logs = list(LogEntry3.select())
+
+  # Ensure there are logs.
+  assert logs
+
+  # Ensure we don't find any to archive that are new.
+  assert not worker._perform_archiving(LogEntry3, datetime.utcnow() - timedelta(weeks=6))
+  assert len(list(LogEntry3.select())) == len(logs)
+
+  # Archive all the logs.
+  assert worker._perform_archiving(LogEntry3, datetime.utcnow() + timedelta(days=1))
+
+  # Ensure all the logs were archived.
+  assert not list(LogEntry3.select())
+
+
+def test_logrotateworker_withcutoff(initialized_db):
+  # Delete all existing logs.
+  LogEntry3.delete().execute()
+
+  # Create a new set of logs.
+  start_timestamp = datetime.now()
+  for day in range(0, 100):
+    model.log.log_action('push_repo', 'devtable', timestamp=start_timestamp + timedelta(days=day))
+
+  logs = list(LogEntry3.select())
+
+  # Sort and find a midpoint in the logs.
+  logs.sort(key=lambda l: l.datetime)
+
+  midpoint = logs[0:len(logs)/2]
+  assert midpoint
+  assert len(midpoint) < len(logs)
+
+  # Archive the earlier logs.
+  worker = LogRotateWorker()
+  assert worker._perform_archiving(LogEntry3, midpoint[-1].datetime)
+
+  # Ensure the earlier logs were archived.
+  for log in midpoint:
+    try:
+      LogEntry3.get(id=log.id)
+      assert False, "Found unexpected log"
+    except LogEntry3.DoesNotExist:
+      pass
+
+  # Ensure the later logs were not.
+  for log in logs[len(logs)/2:]:
+    LogEntry3.get(id=log.id)