make_range function is fixed and properly tested

Fixes bug 1223293

Change-Id: I9c285be69cfa3e021cec418e5d794328b6066732

stackalytics/processor/runtime_storage.py

@@ -18,6 +18,7 @@ import re
 import memcache
 
 from stackalytics.openstack.common import log as logging
+from stackalytics.processor import utils
 
 LOG = logging.getLogger(__name__)
 
@@ -131,7 +132,7 @@ class MemcachedStorage(RuntimeStorage):
             for i in self.get_all_records():
                 yield i
         else:
-            for update_id_set in self._make_range(last_update, update_count,
+            for update_id_set in utils.make_range(last_update, update_count,
                                                   BULK_READ_SIZE):
                 update_set = self.memcached.get_multi(
                     update_id_set, UPDATE_ID_PREFIX).values()
@@ -156,7 +157,7 @@ class MemcachedStorage(RuntimeStorage):
                     min_update = n
 
         first_valid_update = self.memcached.get('first_valid_update') or 0
-        for delete_id_set in self._make_range(first_valid_update, min_update,
+        for delete_id_set in utils.make_range(first_valid_update, min_update,
                                               BULK_DELETE_SIZE):
             if not self.memcached.delete_multi(delete_id_set,
                                                key_prefix=UPDATE_ID_PREFIX):
@@ -182,15 +183,8 @@ class MemcachedStorage(RuntimeStorage):
     def _set_record_count(self, count):
         self.memcached.set('record:count', count)
 
-    def _make_range(self, start, stop, step):
-        i = start
-        for i in xrange(start, stop, step):
-            yield xrange(i, i + step)
-        if (stop - start) % step > 0:
-            yield xrange(i, stop)
-
     def get_all_records(self):
-        for record_id_set in self._make_range(0, self._get_record_count(),
+        for record_id_set in utils.make_range(0, self._get_record_count(),
                                               BULK_READ_SIZE):
             for i in self.memcached.get_multi(
                     record_id_set, RECORD_ID_PREFIX).values():

stackalytics/processor/utils.py

@@ -52,6 +52,14 @@ def read_json_from_uri(uri):
         LOG.warn('Error while reading uri: %s' % e)
 
 
+def make_range(start, stop, step):
+    last_full = stop - ((stop - start) % step)
+    for i in xrange(start, last_full, step):
+        yield xrange(i, i + step)
+    if stop > last_full:
+        yield xrange(last_full, stop)
+
+
 def store_user(runtime_storage_inst, user):
     runtime_storage_inst.set_by_key('user:%s' % user['user_id'], user)
 

tests/unit/test_utils.py

@@ -0,0 +1,44 @@
+# Copyright (c) 2013 Mirantis Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import testtools
+
+from stackalytics.processor import utils
+
+
+class TestUtils(testtools.TestCase):
+    def setUp(self):
+        super(TestUtils, self).setUp()
+
+    def _test_one_range(self, start, end, step):
+        elements = set()
+        for chunk in utils.make_range(start, end, step):
+            for item in chunk:
+                self.assertFalse(item in elements)
+                elements.add(item)
+
+        self.assertTrue(set(range(start, end)) == elements)
+
+    def test_make_range_0_10_1(self):
+        self._test_one_range(0, 10, 1)
+
+    def test_make_range_0_10_3(self):
+        self._test_one_range(0, 10, 3)
+
+    def test_make_range_3_5_4(self):
+        self._test_one_range(3, 5, 4)
+
+    def test_make_range_5_26_10(self):
+        self._test_one_range(5, 26, 10)