Update checked in version of gsutil to version 4.6

gslib/parallelism_framework_util.py

+# -*- coding: utf-8 -*-
 # Copyright 2013 Google Inc. All Rights Reserved.
 #
 # 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.
+"""Utility classes for the parallelism framework."""
 
-"""Utility classes for the parallelism framework."""
+from __future__ import absolute_import
 
 import multiprocessing
 import threading
 
+
 class BasicIncrementDict(object):
+  """Dictionary meant for storing values for which increment is defined.
+
+  This handles any values for which the "+" operation is defined (e.g., floats,
+  lists, etc.). This class is neither thread- nor process-safe.
   """
-  Dictionary meant for storing any values for which the "+" operation is
-  defined (e.g., floats, lists, etc.). This class is neither thread- nor
-  process-safe.
-  """
+
   def __init__(self):
     self.dict = {}
 
-  def get(self, key, default_value=None):
+  def Get(self, key, default_value=None):
     return self.dict.get(key, default_value)
 
-  def put(self, key, value):
+  def Put(self, key, value):
     self.dict[key] = value
 
-  def update(self, key, inc, default_value=0):
-    """
-    Update the stored value associated with the given key (or the default_value,
-    if there is no existing value for the key) by performing the equivalent of
+  def Update(self, key, inc, default_value=0):
+    """Update the stored value associated with the given key.
+
+    Performs the equivalent of
     self.put(key, self.get(key, default_value) + inc).
+
+    Args:
+      key: lookup key for the value of the first operand of the "+" operation.
+      inc: Second operand of the "+" operation.
+      default_value: Default value if there is no existing value for the key.
+
+    Returns:
+      Incremented value.
     """
     val = self.dict.get(key, default_value) + inc
     self.dict[key] = val
     return val
 
 
 class AtomicIncrementDict(BasicIncrementDict):
+  """Dictionary meant for storing values for which increment is defined.
+
+  This handles any values for which the "+" operation is defined (e.g., floats,
+  lists, etc.) in a thread- and process-safe way that allows for atomic get,
+  put, and update.
   """
-  Dictionary meant for storing any values for which the "+" operation is
-  defined (e.g., floats, lists, etc.) in a way that allows for atomic get, put,
-  and update in a thread- and process-safe way.
-  """
-  def __init__(self, manager):
+
+  def __init__(self, manager):  # pylint: disable=super-init-not-called
     self.dict = ThreadAndProcessSafeDict(manager)
     self.lock = multiprocessing.Lock()
 
-  def update(self, key, inc, default_value=0):
-    """
-    Update the stored value associated with the given key (or the default_value,
-    if there is no existing value for the key) by performing the equivalent of
-    self.put(key, self.get(key, default_value) + inc) atomically.
+  def Update(self, key, inc, default_value=0):
+    """Atomically update the stored value associated with the given key.
+
+    Performs the atomic equivalent of
+    self.put(key, self.get(key, default_value) + inc).
+
+    Args:
+      key: lookup key for the value of the first operand of the "+" operation.
+      inc: Second operand of the "+" operation.
+      default_value: Default value if there is no existing value for the key.
+
+    Returns:
+      Incremented value.
     """
     with self.lock:
-      return super(AtomicIncrementDict, self).update(key, inc, default_value)
+      return super(AtomicIncrementDict, self).Update(key, inc, default_value)
 
 
 class ThreadAndProcessSafeDict(object):
+  """Wraps a multiprocessing.Manager's proxy objects for thread-safety.
+
+  The proxy objects returned by a manager are process-safe but not necessarily
+  thread-safe, so this class simply wraps their access with a lock for ease of
+  use. Since the objects are process-safe, we can use the more efficient
+  threading Lock.
   """
-  The proxy objects returned by a manager are not necessarily thread-safe, so
-  this class simply wraps their access with a lock for ease of use. They are,
-  however, process-safe, so we can use the more efficient threading Lock.
-  """
+
   def __init__(self, manager):
+    """Initializes the thread and process safe dict.
+
+    Args:
+      manager: Multiprocessing.manager object.
+    """
     self.dict = manager.dict()
     self.lock = threading.Lock()
-    
+
   def __getitem__(self, key):
     with self.lock:
       return self.dict[key]
-    
+
   def __setitem__(self, key, value):
     with self.lock:
       self.dict[key] = value
-      
+
+  # pylint: disable=invalid-name
   def get(self, key, default_value=None):
     with self.lock:
-      return self.dict.get(key, default_value)
+      return self.dict.get(key, default_value)