common: move memcached exceptions to the base file.

Change-Id: I022404cd90d9755a09c20619c3a72588d3367467

swift/common/exceptions.py

@@ -243,6 +243,18 @@ class QuarantineRequest(SwiftException):
     pass
 
 
+class MemcacheConnectionError(Exception):
+    pass
+
+
+class MemcacheIncrNotFoundError(MemcacheConnectionError):
+    pass
+
+
+class MemcachePoolTimeout(Timeout):
+    pass
+
+
 class ClientException(Exception):
 
     def __init__(self, msg, http_scheme='', http_host='', http_port='',

swift/common/memcached.py

@@ -59,6 +59,8 @@ from eventlet import Timeout
 from six.moves import range
 from six.moves.configparser import ConfigParser, NoSectionError, NoOptionError
 from swift.common import utils
+from swift.common.exceptions import MemcacheConnectionError, \
+    MemcacheIncrNotFoundError, MemcachePoolTimeout
 from swift.common.utils import md5, human_readable, config_true_value, \
     memcached_timing_stats
 
@@ -122,18 +124,6 @@ def set_msg(key, flags, timeout, value):
     ]) + (b'\r\n' + value + b'\r\n')
 
 
-class MemcacheConnectionError(Exception):
-    pass
-
-
-class MemcacheIncrNotFoundError(MemcacheConnectionError):
-    pass
-
-
-class MemcachePoolTimeout(Timeout):
-    pass
-
-
 class MemcacheConnPool(Pool):
     """
     Connection pool for Memcache Connections