Merge pull request pandas-dev#154 from manahl/re-cache-the-library-quota-periodically

Re-cache the library quota periodically

Author: jamesblackburn

CHANGES.md

@@ -5,6 +5,7 @@
   * Bugfix: Faster TickStore querying for multiple symbols simultaneously
   * Bugfix: TickStore.read now respects `allow_secondary=True`
   * Bugfix: #147 Add get_info method to ChunkStore
+  * Bugfix: Periodically re-cache the library.quota to pick up any changes
 
 ### 1.25 (2016-05-23)
 

arctic/arctic.py

@@ -398,20 +398,17 @@ def check_quota(self):
         every write.  Will raise() if the library has exceeded its allotted
         quota.
         """
-        # Don't check on every write
-        if self.quota is None:
-            self.quota = self.get_library_metadata(ArcticLibraryBinding.QUOTA)
-            if self.quota is None:
-                self.quota = 0
-
-        if self.quota == 0:
-            return
-
         # Don't check on every write, that would be slow
         if self.quota_countdown > 0:
             self.quota_countdown -= 1
             return
 
+        # Re-cache the quota after the countdown
+        self.quota = self.get_library_metadata(ArcticLibraryBinding.QUOTA)
+        if self.quota is None or self.quota == 0:
+            self.quota = 0
+            return
+
         # Figure out whether the user has exceeded their quota
         library = self.arctic[self.get_name()]
         stats = library.stats()
@@ -439,6 +436,7 @@ def to_gigabytes(bytes_):
                                                               to_gigabytes(self.quota)))
 
         # Set-up a timer to prevent us for checking for a few writes.
+        # This will check every average half-life
         self.quota_countdown = int(max(remaining_count // 2, 1))
 
     def get_library_type(self):

tests/unit/test_arctic.py

@@ -162,13 +162,15 @@ def test_get_quota():
 
 def test_check_quota_Zero():
     self = create_autospec(ArcticLibraryBinding)
-    self.quota = 0
+    self.get_library_metadata.return_value = 0
+    self.quota_countdown = 0
     ArcticLibraryBinding.check_quota(self)
 
 
 def test_check_quota_None():
     m = Mock(spec=ArcticLibraryBinding)
     m.quota = None
+    m.quota_countdown = 0
     m.get_library_metadata.return_value = None
     ArcticLibraryBinding.check_quota(m)
     m.get_library_metadata.assert_called_once_with('QUOTA')
@@ -178,6 +180,7 @@ def test_check_quota_None():
 def test_check_quota_Zero2():
     m = Mock(spec=ArcticLibraryBinding)
     m.quota = None
+    m.quota_countdown = 0
     m.get_library_metadata.return_value = 0
     ArcticLibraryBinding.check_quota(m)
     m.get_library_metadata.assert_called_once_with('QUOTA')
@@ -186,7 +189,7 @@ def test_check_quota_Zero2():
 
 def test_check_quota_countdown():
     self = create_autospec(ArcticLibraryBinding)
-    self.quota = 10
+    self.get_library_metadata.return_value = 10
     self.quota_countdown = 10
     ArcticLibraryBinding.check_quota(self)
     assert self.quota_countdown == 9
@@ -195,7 +198,7 @@ def test_check_quota_countdown():
 def test_check_quota():
     self = create_autospec(ArcticLibraryBinding)
     self.arctic = create_autospec(Arctic)
-    self.quota = 1024 * 1024 * 1024
+    self.get_library_metadata.return_value = 1024 * 1024 * 1024
     self.quota_countdown = 0
     self.arctic.__getitem__.return_value = Mock(stats=Mock(return_value={'totals':
                                                                              {'size': 900 * 1024 * 1024,
@@ -212,7 +215,7 @@ def test_check_quota():
 def test_check_quota_info():
     self = create_autospec(ArcticLibraryBinding)
     self.arctic = create_autospec(Arctic)
-    self.quota = 1024 * 1024 * 1024
+    self.get_library_metadata.return_value = 1024 * 1024 * 1024
     self.quota_countdown = 0
     self.arctic.__getitem__.return_value = Mock(stats=Mock(return_value={'totals':
                                                                              {'size': 1 * 1024 * 1024,
@@ -229,7 +232,7 @@ def test_check_quota_info():
 def test_check_quota_exceeded():
     self = create_autospec(ArcticLibraryBinding)
     self.arctic = create_autospec(Arctic)
-    self.quota = 1024 * 1024 * 1024
+    self.get_library_metadata.return_value = 1024 * 1024 * 1024
     self.quota_countdown = 0
     self.arctic.__getitem__.return_value = Mock(stats=Mock(return_value={'totals':
                                                                              {'size': 1024 * 1024 * 1024,