Add ceil method to utils.Timestamp

There are a few places where a last-modified value is calculated by
rounding a timestamp *up* to the nearest second. This patch refactors
to use a new Timestamp.ceil() method to do this rounding, along with a
clarifying docstring.

Change-Id: I9ef73e5183bdf21b22f5f19b8440ffef6988aec7

swift/common/utils.py

@@ -1350,6 +1350,18 @@ class Timestamp(object):
             isoformat += ".000000"
         return isoformat
 
+    def ceil(self):
+        """
+        Return the 'normal' part of the timestamp rounded up to the nearest
+        integer number of seconds.
+
+        This value should be used whenever the second-precision Last-Modified
+        time of a resource is required.
+
+        :return: a float value with second precision.
+        """
+        return math.ceil(float(self))
+
     def __eq__(self, other):
         if other is None:
             return False

swift/container/server.py

@@ -17,7 +17,6 @@ import json
 import os
 import time
 import traceback
-import math
 
 from eventlet import Timeout
 
@@ -598,7 +597,7 @@ class ContainerController(BaseStorageServer):
                                 is_sys_or_user_meta('container', key)))
         headers['Content-Type'] = out_content_type
         resp = HTTPNoContent(request=req, headers=headers, charset='utf-8')
-        resp.last_modified = math.ceil(float(headers['X-PUT-Timestamp']))
+        resp.last_modified = Timestamp(headers['X-PUT-Timestamp']).ceil()
         return resp
 
     def update_data_record(self, record):
@@ -804,7 +803,7 @@ class ContainerController(BaseStorageServer):
 
         ret = Response(request=req, headers=resp_headers, body=body,
                        content_type=out_content_type, charset='utf-8')
-        ret.last_modified = math.ceil(float(resp_headers['X-PUT-Timestamp']))
+        ret.last_modified = Timestamp(resp_headers['X-PUT-Timestamp']).ceil()
         if not ret.body:
             ret.status_int = HTTP_NO_CONTENT
         return ret

swift/obj/server.py

@@ -24,7 +24,6 @@ import multiprocessing
 import time
 import traceback
 import socket
-import math
 
 from eventlet import sleep, wsgi, Timeout, tpool
 from eventlet.greenthread import spawn
@@ -1113,7 +1112,7 @@ class ObjectController(BaseStorageServer):
                             key.lower() in self.allowed_headers):
                         response.headers[key] = value
                 response.etag = metadata['ETag']
-                response.last_modified = math.ceil(float(file_x_ts))
+                response.last_modified = file_x_ts.ceil()
                 response.content_length = obj_size
                 try:
                     response.content_encoding = metadata[
@@ -1181,7 +1180,7 @@ class ObjectController(BaseStorageServer):
                 response.headers[key] = value
         response.etag = metadata['ETag']
         ts = Timestamp(metadata['X-Timestamp'])
-        response.last_modified = math.ceil(float(ts))
+        response.last_modified = ts.ceil()
         # Needed for container sync feature
         response.headers['X-Timestamp'] = ts.normal
         response.headers['X-Backend-Timestamp'] = ts.internal

swift/proxy/controllers/container.py

@@ -14,7 +14,6 @@
 # limitations under the License.
 
 import json
-import math
 import random
 
 import six
@@ -170,8 +169,8 @@ class ContainerController(Controller):
                     # GETorHEAD_base does not, so don't set it here either
                     resp = Response(request=req, body=shard_range_body)
                     update_headers(resp, headers)
-                    resp.last_modified = math.ceil(
-                        float(headers['x-put-timestamp']))
+                    resp.last_modified = Timestamp(
+                        headers['x-put-timestamp']).ceil()
                     resp.environ['swift_x_timestamp'] = headers.get(
                         'x-timestamp')
                     resp.accept_ranges = 'bytes'

swift/proxy/controllers/obj.py

@@ -1009,8 +1009,7 @@ class ReplicatedObjectController(BaseObjectController):
         etag = etags.pop() if len(etags) else None
         resp = self.best_response(req, statuses, reasons, bodies,
                                   'Object PUT', etag=etag)
-        resp.last_modified = math.ceil(
-            float(Timestamp(req.headers['X-Timestamp'])))
+        resp.last_modified = Timestamp(req.headers['X-Timestamp']).ceil()
         return resp
 
 
@@ -3498,6 +3497,5 @@ class ECObjectController(BaseObjectController):
         resp = self.best_response(req, statuses, reasons, bodies,
                                   'Object PUT', etag=etag,
                                   quorum_size=min_conns)
-        resp.last_modified = math.ceil(
-            float(Timestamp(req.headers['X-Timestamp'])))
+        resp.last_modified = Timestamp(req.headers['X-Timestamp']).ceil()
         return resp

test/unit/common/test_utils.py

@@ -305,6 +305,13 @@ class TestTimestamp(unittest.TestCase):
         for value in test_values:
             self.assertEqual(utils.Timestamp(value).isoformat, expected)
 
+    def test_ceil(self):
+        self.assertEqual(0.0, utils.Timestamp(0).ceil())
+        self.assertEqual(1.0, utils.Timestamp(0.00001).ceil())
+        self.assertEqual(1.0, utils.Timestamp(0.000001).ceil())
+        self.assertEqual(12345678.0, utils.Timestamp(12345678.0).ceil())
+        self.assertEqual(12345679.0, utils.Timestamp(12345678.000001).ceil())
+
     def test_not_equal(self):
         ts = '1402436408.91203_0000000000000001'
         test_values = (