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Merge pull request #622 from tseaver/move-thread_local_stack_up
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Move the 'thread-local stack' implementation up from datastore.
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tseaver committed Feb 12, 2015
2 parents 32e50eb + c6821d6 commit f73ad7e
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61 changes: 61 additions & 0 deletions gcloud/_localstack.py
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# Copyright 2014 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.
"""Thread-local resource stack.
This module is not part of the public API surface of `gcloud`.
"""

try:
from threading import local as Local
except ImportError: # pragma: NO COVER (who doesn't have it?)
class Local(object):
"""Placeholder for non-threaded applications."""


class _LocalStack(Local):
"""Manage a thread-local LIFO stack of resources.
Intended for use in :class:`gcloud.datastore.batch.Batch.__enter__`,
:class:`gcloud.storage.batch.Batch.__enter__`, etc.
"""
def __init__(self):
super(_LocalStack, self).__init__()
self._stack = []

def __iter__(self):
"""Iterate the stack in LIFO order.
"""
return iter(reversed(self._stack))

def push(self, resource):
"""Push a resource onto our stack.
"""
self._stack.append(resource)

def pop(self):
"""Pop a resource from our stack.
:raises: IndexError if the stack is empty.
:returns: the top-most resource, after removing it.
"""
return self._stack.pop()

@property
def top(self):
"""Get the top-most resource
:returns: the top-most item, or None if the stack is empty.
"""
if len(self._stack) > 0:
return self._stack[-1]
55 changes: 2 additions & 53 deletions gcloud/datastore/batch.py
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Expand Up @@ -13,66 +13,15 @@
# limitations under the License.

"""Create / interact with a batch of updates / deletes."""
try:
from threading import local as Local
except ImportError: # pragma: NO COVER (who doesn't have it?)
class Local(object):
"""Placeholder for non-threaded applications."""

from gcloud._localstack import _LocalStack
from gcloud.datastore import _implicit_environ
from gcloud.datastore import helpers
from gcloud.datastore.key import _dataset_ids_equal
from gcloud.datastore import _datastore_v1_pb2 as datastore_pb


class _Batches(Local):
"""Manage a thread-local LIFO stack of active batches / transactions.
Intended for use only in :class:`gcloud.datastore.batch.Batch.__enter__`
"""
def __init__(self):
super(_Batches, self).__init__()
self._stack = []

def __iter__(self):
"""Iterate the stack in LIFO order.
"""
return iter(reversed(self._stack))

def push(self, batch):
"""Push a batch / transaction onto our stack.
Intended for use only in :meth:`gcloud.datastore.batch.Batch.__enter__`
:type batch: :class:`gcloud.datastore.batch.Batch` or
:class:`gcloud.datastore.transaction.Transaction`
"""
self._stack.append(batch)

def pop(self):
"""Pop a batch / transaction from our stack.
Intended for use only in :meth:`gcloud.datastore.batch.Batch.__enter__`
:rtype: :class:`gcloud.datastore.batch.Batch` or
:class:`gcloud.datastore.transaction.Transaction`
:raises: IndexError if the stack is empty.
"""
return self._stack.pop()

@property
def top(self):
"""Get the top-most batch / transaction
:rtype: :class:`gcloud.datastore.batch.Batch` or
:class:`gcloud.datastore.transaction.Transaction` or None
:returns: the top-most item, or None if the stack is empty.
"""
if len(self._stack) > 0:
return self._stack[-1]


_BATCHES = _Batches()
_BATCHES = _LocalStack()


class Batch(object):
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28 changes: 0 additions & 28 deletions gcloud/datastore/test_batch.py
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Expand Up @@ -15,34 +15,6 @@
import unittest2


class Test_Batches(unittest2.TestCase):

def _getTargetClass(self):
from gcloud.datastore.batch import _Batches

return _Batches

def _makeOne(self):
return self._getTargetClass()()

def test_it(self):
batch1, batch2 = object(), object()
batches = self._makeOne()
self.assertEqual(list(batches), [])
self.assertTrue(batches.top is None)
batches.push(batch1)
self.assertTrue(batches.top is batch1)
batches.push(batch2)
self.assertTrue(batches.top is batch2)
popped = batches.pop()
self.assertTrue(popped is batch2)
self.assertTrue(batches.top is batch1)
self.assertEqual(list(batches), [batch1])
popped = batches.pop()
self.assertTrue(batches.top is None)
self.assertEqual(list(batches), [])


class TestBatch(unittest2.TestCase):

def _getTargetClass(self):
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43 changes: 43 additions & 0 deletions gcloud/test__localstack.py
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# Copyright 2014 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.

import unittest2


class Test__LocalStack(unittest2.TestCase):

def _getTargetClass(self):
from gcloud._localstack import _LocalStack

return _LocalStack

def _makeOne(self):
return self._getTargetClass()()

def test_it(self):
batch1, batch2 = object(), object()
batches = self._makeOne()
self.assertEqual(list(batches), [])
self.assertTrue(batches.top is None)
batches.push(batch1)
self.assertTrue(batches.top is batch1)
batches.push(batch2)
self.assertTrue(batches.top is batch2)
popped = batches.pop()
self.assertTrue(popped is batch2)
self.assertTrue(batches.top is batch1)
self.assertEqual(list(batches), [batch1])
popped = batches.pop()
self.assertTrue(batches.top is None)
self.assertEqual(list(batches), [])

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