Move file and storage code to the storage app

The setting COMMON_TEMPORARY_DIRECTORY is now
STORAGE_TEMPORARY_DIRECTORY.

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

HISTORY.rst

@@ -227,6 +227,8 @@
 - Add a test mixin to generate random model primary keys.
 - Add support for checkout and check in multiple documents at
   the same time.
+- Move file and storage code to the storage app. The setting
+  COMMON_TEMPORARY_DIRECTORY is now STORAGE_TEMPORARY_DIRECTORY.
 
 3.1.9 (2018-11-01)
 ==================

mayan/apps/common/classes.py

@@ -72,16 +72,6 @@ class ErrorLogNamespace(object):
         return ErrorLogEntry.objects.filter(namespace=self.name)
 
 
-class FakeStorageSubclass(object):
-    """
-    Placeholder class to allow serializing the real storage subclass to
-    support migrations.
-    """
-
-    def __eq__(self, other):
-        return True
-
-
 class MissingItem(object):
     _registry = []
 

mayan/apps/common/management/commands/convertdb.py

@@ -11,8 +11,8 @@ from django.core.management.base import CommandError
 from django.utils.encoding import force_text
 from django.utils.translation import ugettext_lazy as _
 
-from mayan.apps.common.utils import fs_cleanup
 from mayan.apps.documents.models import DocumentType
+from mayan.apps.storage.utils import fs_cleanup
 
 CONVERTDB_FOLDER = 'convertdb'
 CONVERTDB_OUTPUT_FILENAME = 'migrate.json'

mayan/apps/common/migrations/0011_auto_20181229_0738.py

@@ -1,14 +1,13 @@
-# -*- coding: utf-8 -*-
-# Generated by Django 1.11.16 on 2018-12-29 07:38
 from __future__ import unicode_literals
 
 from django.db import migrations, models
+
 import mayan.apps.common.classes
 import mayan.apps.common.models
+import mayan.apps.storage.classes
 
 
 class Migration(migrations.Migration):
-
     dependencies = [
         ('common', '0010_auto_20180403_0702_squashed_0011_auto_20180429_0758'),
     ]
@@ -17,6 +16,10 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='shareduploadedfile',
             name='file',
-            field=models.FileField(storage=mayan.apps.common.classes.FakeStorageSubclass(), upload_to=mayan.apps.common.models.upload_to, verbose_name='File'),
+            field=models.FileField(
+                storage=mayan.apps.storage.classes.FakeStorageSubclass(),
+                upload_to=mayan.apps.common.models.upload_to,
+                verbose_name='File'
+            ),
         ),
     ]

mayan/apps/common/mixins.py

@@ -1,6 +1,5 @@
 from __future__ import unicode_literals
 
-from django.conf import settings
 from django.contrib import messages
 from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ImproperlyConfigured, PermissionDenied

mayan/apps/common/settings.py

@@ -1,7 +1,6 @@
 from __future__ import unicode_literals
 
 import os
-import tempfile
 
 from django.conf import settings
 from django.utils.translation import ugettext_lazy as _
@@ -76,13 +75,6 @@ setting_shared_storage_arguments = namespace.add_setting(
     global_name='COMMON_SHARED_STORAGE_ARGUMENTS',
     default={'location': os.path.join(settings.MEDIA_ROOT, 'shared_files')}
 )
-setting_temporary_directory = namespace.add_setting(
-    global_name='COMMON_TEMPORARY_DIRECTORY', default=tempfile.gettempdir(),
-    help_text=_(
-        'Temporary directory used site wide to store thumbnails, previews '
-        'and temporary files.'
-    )
-)
 
 namespace = Namespace(label=_('Django'), name='django')
 

mayan/apps/common/storages.py

@@ -1,7 +1,8 @@
 from __future__ import unicode_literals
 
+from mayan.apps.storage.utils import get_storage_subclass
+
 from .settings import setting_shared_storage, setting_shared_storage_arguments
-from .utils import get_storage_subclass
 
 storage_sharedupload = get_storage_subclass(
     dotted_path=setting_shared_storage.value

mayan/apps/common/tests/mixins.py

@@ -13,7 +13,7 @@ from django.template import Context, Template
 from django.test.utils import ContextList
 from django.urls import clear_url_caches, reverse
 
-from ..settings import setting_temporary_directory
+from mayan.apps.storage.settings import setting_temporary_directory
 
 from .literals import TEST_VIEW_NAME, TEST_VIEW_URL
 from .utils import mute_stdout

mayan/apps/common/tests/test_views.py

@@ -14,37 +14,33 @@ from .literals import TEST_ERROR_LOG_ENTRY_RESULT
 
 class CommonViewTestCase(GenericViewTestCase):
     def test_about_view(self):
-        self.login_user()
-
         response = self.get('common:about_view')
         self.assertContains(response, text='About', status_code=200)
 
     def _create_error_log_entry(self):
         ModelPermission.register(
-            model=get_user_model(), permission=permission_error_log_view
+            model=get_user_model(), permissions=(permission_error_log_view,)
         )
         ErrorLogEntry.objects.register(model=get_user_model())
 
-        self.error_log_entry = self.user.error_logs.create(
+        self.error_log_entry = self._test_case_user.error_logs.create(
             result=TEST_ERROR_LOG_ENTRY_RESULT
         )
 
     def _request_object_error_log_list(self):
-        content_type = ContentType.objects.get_for_model(model=self.user)
+        content_type = ContentType.objects.get_for_model(model=self._test_case_user)
 
         return self.get(
             'common:object_error_list', kwargs={
                 'app_label': content_type.app_label,
                 'model': content_type.model,
-                'object_id': self.user.pk
+                'object_id': self._test_case_user.pk
             }, follow=True
         )
 
     def test_object_error_list_view_no_permissions(self):
             self._create_error_log_entry()
 
-            self.login_user()
-
             response = self._request_object_error_log_list()
 
             self.assertNotContains(
@@ -55,9 +51,8 @@ class CommonViewTestCase(GenericViewTestCase):
     def test_object_error_list_view_with_access(self):
             self._create_error_log_entry()
 
-            self.login_user()
             self.grant_access(
-                obj=self.user, permission=permission_error_log_view
+                obj=self._test_case_user, permission=permission_error_log_view
             )
 
             response = self._request_object_error_log_list()

mayan/apps/common/utils.py

@@ -1,9 +1,6 @@
 from __future__ import unicode_literals
 
 import logging
-import os
-import shutil
-import tempfile
 
 from django.conf import settings
 from django.core.exceptions import FieldDoesNotExist
@@ -13,7 +10,6 @@ from django.urls.base import get_script_prefix
 from django.utils.datastructures import MultiValueDict
 from django.utils.http import urlencode as django_urlencode
 from django.utils.http import urlquote as django_urlquote
-from django.utils.module_loading import import_string
 from django.utils.six.moves import reduce as reduce_function
 from django.utils.six.moves import xmlrpc_client
 
@@ -21,7 +17,6 @@ import mayan
 
 from .exceptions import NotLatestVersion, UnknownLatestVersion
 from .literals import DJANGO_SQLITE_BACKEND, MAYAN_PYPI_NAME, PYPI_URL
-from .settings import setting_temporary_directory
 
 logger = logging.getLogger(__name__)
 
@@ -40,27 +35,6 @@ def check_version():
             raise NotLatestVersion(upstream_version=versions[0])
 
 
-# http://stackoverflow.com/questions/123198/how-do-i-copy-a-file-in-python
-def copyfile(source, destination, buffer_size=1024 * 1024):
-    """
-    Copy a file from source to dest. source and dest
-    can either be strings or any object with a read or
-    write method, like StringIO for example.
-    """
-    source_descriptor = get_descriptor(source)
-    destination_descriptor = get_descriptor(destination, read=False)
-
-    while True:
-        copy_buffer = source_descriptor.read(buffer_size)
-        if copy_buffer:
-            destination_descriptor.write(copy_buffer)
-        else:
-            break
-
-    source_descriptor.close()
-    destination_descriptor.close()
-
-
 def encapsulate(function):
     # Workaround Django ticket 15791
     # Changeset 16045
@@ -69,25 +43,6 @@ def encapsulate(function):
     return lambda: function
 
 
-def fs_cleanup(filename, file_descriptor=None, suppress_exceptions=True):
-    """
-    Tries to remove the given filename. Ignores non-existent files
-    """
-    if file_descriptor:
-        os.close(file_descriptor)
-
-    try:
-        os.remove(filename)
-    except OSError:
-        try:
-            shutil.rmtree(filename)
-        except OSError:
-            if suppress_exceptions:
-                pass
-            else:
-                raise
-
-
 def get_related_field(model, related_field_name):
     try:
         local_field_name, remaining_field_path = related_field_name.split(
@@ -108,41 +63,6 @@ def get_related_field(model, related_field_name):
     return related_field
 
 
-def get_descriptor(file_input, read=True):
-    try:
-        # Is it a file like object?
-        file_input.seek(0)
-    except AttributeError:
-        # If not, try open it.
-        if read:
-            return open(file_input, mode='rb')
-        else:
-            return open(file_input, mode='wb')
-    else:
-        return file_input
-
-
-def get_storage_subclass(dotted_path):
-    """
-    Import a storage class and return a subclass that will always return eq
-    True to avoid creating a new migration when for runtime storage class
-    changes.
-    """
-    imported_storage_class = import_string(dotted_path=dotted_path)
-
-    class StorageSubclass(imported_storage_class):
-        def __init__(self, *args, **kwargs):
-            return super(StorageSubclass, self).__init__(*args, **kwargs)
-
-        def __eq__(self, other):
-            return True
-
-        def deconstruct(self):
-            return ('mayan.apps.common.classes.FakeStorageSubclass', (), {})
-
-    return StorageSubclass
-
-
 def introspect_attribute(attribute_name, obj):
     try:
         # Try as a related field
@@ -168,21 +88,6 @@ def introspect_attribute(attribute_name, obj):
         return attribute_name, obj
 
 
-def TemporaryFile(*args, **kwargs):
-    kwargs.update({'dir': setting_temporary_directory.value})
-    return tempfile.TemporaryFile(*args, **kwargs)
-
-
-def mkdtemp(*args, **kwargs):
-    kwargs.update({'dir': setting_temporary_directory.value})
-    return tempfile.mkdtemp(*args, **kwargs)
-
-
-def mkstemp(*args, **kwargs):
-    kwargs.update({'dir': setting_temporary_directory.value})
-    return tempfile.mkstemp(*args, **kwargs)
-
-
 def resolve(path, urlconf=None):
     path = '/{}'.format(path.replace(get_script_prefix(), '', 1))
     return django_resolve(path=path, urlconf=urlconf)
@@ -275,24 +180,3 @@ def urlquote(link=None, get=None):
         return '%s%s' % (link, django_urlencode(get, doseq=True))
     else:
         return django_urlquote(link)
-
-
-def validate_path(path):
-    if not os.path.exists(path):
-        # If doesn't exist try to create it
-        try:
-            os.mkdir(path)
-        except Exception as exception:
-            logger.debug('unhandled exception: %s', exception)
-            return False
-
-    # Check if it is writable
-    try:
-        fd, test_filepath = tempfile.mkstemp(dir=path)
-        os.close(fd)
-        os.unlink(test_filepath)
-    except Exception as exception:
-        logger.debug('unhandled exception: %s', exception)
-        return False
-
-    return True

mayan/apps/converter/backends/python.py

@@ -11,7 +11,7 @@ import sh
 from django.utils.encoding import force_text
 from django.utils.translation import ugettext_lazy as _
 
-from mayan.apps.common.utils import fs_cleanup, mkstemp
+from mayan.apps.storage.utils import fs_cleanup, mkstemp
 
 from ..classes import ConverterBase
 from ..exceptions import PageCountError

mayan/apps/converter/classes.py

@@ -9,9 +9,9 @@ import sh
 
 from django.utils.translation import ugettext_lazy as _
 
-from mayan.apps.common.settings import setting_temporary_directory
-from mayan.apps.common.utils import fs_cleanup, mkdtemp, mkstemp
 from mayan.apps.mimetype.api import get_mimetype
+from mayan.apps.storage.settings import setting_temporary_directory
+from mayan.apps.storage.utils import fs_cleanup, mkdtemp, mkstemp
 
 from .exceptions import InvalidOfficeFormat, OfficeConversionError
 from .literals import (

mayan/apps/dependencies/javascript.py

@@ -15,7 +15,7 @@ from django.apps import apps
 from django.utils.encoding import force_bytes, force_text
 from django.utils.functional import cached_property
 
-from mayan.apps.common.utils import mkdtemp
+from mayan.apps.storage.utils import mkdtemp
 
 from .exceptions import DependenciesException
 

mayan/apps/django_gpg/classes.py

@@ -8,7 +8,7 @@ import gnupg
 
 from django.utils.translation import ugettext_lazy as _
 
-from mayan.apps.common.utils import mkdtemp
+from mayan.apps.storage.utils import mkdtemp
 
 
 class GPGBackend(object):

mayan/apps/django_gpg/managers.py

@@ -6,7 +6,7 @@ import os
 
 from django.db import models
 
-from mayan.apps.common.utils import mkstemp
+from mayan.apps.storage.utils import mkstemp
 
 from .classes import KeyStub, SignatureVerification
 from .exceptions import (

mayan/apps/django_gpg/tests/test_models.py

@@ -8,7 +8,7 @@ import mock
 from django.utils.encoding import force_bytes
 
 from mayan.apps.common.tests import BaseTestCase
-from mayan.apps.common.utils import TemporaryFile
+from mayan.apps.storage.utils import TemporaryFile
 
 from ..exceptions import (
     DecryptionError, KeyDoesNotExist, NeedPassphrase, PassphraseError,

mayan/apps/document_parsing/parsers.py

@@ -7,7 +7,7 @@ import subprocess
 from django.apps import apps
 from django.utils.translation import ugettext_lazy as _
 
-from mayan.apps.common.utils import copyfile, fs_cleanup, mkstemp
+from mayan.apps.storage.utils import copyfile, fs_cleanup, mkstemp
 
 from .exceptions import ParserError
 from .settings import setting_pdftotext_path

mayan/apps/document_signatures/managers.py

@@ -5,10 +5,10 @@ import os
 
 from django.db import models
 
-from mayan.apps.common.utils import mkstemp
 from mayan.apps.django_gpg.exceptions import DecryptionError
 from mayan.apps.django_gpg.models import Key
 from mayan.apps.documents.models import DocumentVersion
+from mayan.apps.storage.utils import mkstemp
 
 logger = logging.getLogger(__name__)
 

mayan/apps/document_signatures/migrations/0009_auto_20181229_0737.py

@@ -1,14 +1,13 @@
-# -*- coding: utf-8 -*-
-# Generated by Django 1.11.16 on 2018-12-29 07:37
 from __future__ import unicode_literals
 
 from django.db import migrations, models
+
 import mayan.apps.common.classes
 import mayan.apps.document_signatures.models
+import mayan.apps.storage.classes
 
 
 class Migration(migrations.Migration):
-
     dependencies = [
         ('document_signatures', '0008_auto_20180429_0759'),
     ]
@@ -17,6 +16,11 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='detachedsignature',
             name='signature_file',
-            field=models.FileField(blank=True, null=True, storage=mayan.apps.common.classes.FakeStorageSubclass(), upload_to=mayan.apps.document_signatures.models.upload_to, verbose_name='Signature file'),
+            field=models.FileField(
+                blank=True, null=True,
+                storage=mayan.apps.storage.classes.FakeStorageSubclass(),
+                upload_to=mayan.apps.document_signatures.models.upload_to,
+                verbose_name='Signature file'
+            ),
         ),
     ]

mayan/apps/document_signatures/storages.py

@@ -1,6 +1,6 @@
 from __future__ import unicode_literals
 
-from mayan.apps.common.utils import get_storage_subclass
+from mayan.apps.storage.utils import get_storage_subclass
 
 from .settings import (
     setting_storage_backend, setting_storage_backend_arguments

mayan/apps/document_signatures/views.py

@@ -15,9 +15,9 @@ from mayan.apps.common.generics import (
     SingleObjectDetailView, SingleObjectDownloadView, SingleObjectListView
 )
 from mayan.apps.common.mixins import ExternalObjectMixin
-from mayan.apps.common.utils import TemporaryFile
 from mayan.apps.django_gpg.exceptions import NeedPassphrase, PassphraseError
 from mayan.apps.documents.models import DocumentVersion
+from mayan.apps.storage.utils import TemporaryFile
 
 from .forms import (
     DocumentVersionSignatureCreateForm, DocumentVersionSignatureDetailForm

mayan/apps/documents/migrations/0051_auto_20181229_0745.py

@@ -1,10 +1,10 @@
-# -*- coding: utf-8 -*-
-# Generated by Django 1.11.16 on 2018-12-29 07:45
 from __future__ import unicode_literals
 
 from django.db import migrations, models
+
 import mayan.apps.common.classes
 import mayan.apps.documents.utils
+import mayan.apps.storage.classes
 
 
 class Migration(migrations.Migration):
@@ -17,6 +17,10 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='documentversion',
             name='file',
-            field=models.FileField(storage=mayan.apps.common.classes.FakeStorageSubclass(), upload_to=mayan.apps.documents.utils.document_uuid_function, verbose_name='File'),
+            field=models.FileField(
+                storage=mayan.apps.storage.classes.FakeStorageSubclass(),
+                upload_to=mayan.apps.documents.utils.document_uuid_function,
+                verbose_name='File'
+            ),
         ),
     ]

mayan/apps/documents/storages.py

@@ -2,7 +2,7 @@ from __future__ import unicode_literals
 
 from django.utils.module_loading import import_string
 
-from mayan.apps.common.utils import get_storage_subclass
+from mayan.apps.storage.utils import get_storage_subclass
 
 from .settings import (
     setting_documentimagecache_storage,

mayan/apps/file_metadata/drivers/exiftool.py

@@ -7,7 +7,7 @@ import sh
 
 from django.utils.translation import ugettext_lazy as _
 
-from mayan.apps.common.utils import fs_cleanup, mkstemp
+from mayan.apps.storage.utils import fs_cleanup, mkstemp
 
 from ..classes import FileMetadataDriver
 from ..settings import setting_drivers_arguments

mayan/apps/lock_manager/backends/file_lock.py

@@ -12,7 +12,7 @@ from django.conf import settings
 from django.core.files import locks
 from django.utils.encoding import force_bytes, force_text
 
-from mayan.apps.common.settings import setting_temporary_directory
+from mayan.apps.storage.settings import setting_temporary_directory
 
 from ..exceptions import LockError
 from ..settings import setting_default_lock_timeout

mayan/apps/smart_settings/tests/test_classes.py

@@ -8,7 +8,7 @@ from django.conf import settings
 
 from mayan.apps.common.settings import setting_paginate_by
 from mayan.apps.common.tests import BaseTestCase
-from mayan.apps.common.utils import fs_cleanup, mkstemp
+from mayan.apps.storage.utils import fs_cleanup, mkstemp
 
 from .literals import TEST_SETTING_NAME, TEST_SETTING_VALUE
 

mayan/apps/sources/models/scanner_sources.py

@@ -7,7 +7,7 @@ from django.db import models
 from django.utils.timezone import now
 from django.utils.translation import ugettext_lazy as _
 
-from mayan.apps.common.utils import TemporaryFile
+from mayan.apps.storage.utils import TemporaryFile
 
 from ..classes import PseudoFile, SourceUploadedFile
 from ..exceptions import SourceException

mayan/apps/sources/tests/test_classes.py

@@ -4,8 +4,8 @@ import os
 import shutil
 
 from mayan.apps.common.tests import BaseTestCase
-from mayan.apps.common.utils import mkdtemp
 from mayan.apps.documents.tests import TEST_NON_ASCII_DOCUMENT_PATH
+from mayan.apps.storage.utils import mkdtemp
 
 from ..classes import StagingFile
 

mayan/apps/sources/tests/test_models.py

@@ -9,7 +9,6 @@ from pathlib2 import Path
 from django.utils.encoding import force_text
 
 from mayan.apps.common.tests import BaseTestCase
-from mayan.apps.common.utils import mkdtemp
 from mayan.apps.documents.models import Document, DocumentType
 from mayan.apps.documents.tests import (
     TEST_COMPRESSED_DOCUMENT_PATH, TEST_DOCUMENT_TYPE_LABEL,
@@ -17,6 +16,7 @@ from mayan.apps.documents.tests import (
     TEST_NON_ASCII_DOCUMENT_PATH, DocumentTestMixin
 )
 from mayan.apps.metadata.models import MetadataType
+from mayan.apps.storage.utils import mkdtemp
 
 from ..literals import SOURCE_UNCOMPRESS_CHOICE_Y
 from ..models import POP3Email, WatchFolderSource, WebFormSource

mayan/apps/sources/tests/test_views.py

@@ -6,13 +6,13 @@ import shutil
 
 from mayan.apps.checkouts.models import NewVersionBlock
 from mayan.apps.common.tests import GenericViewTestCase
-from mayan.apps.common.utils import fs_cleanup, mkdtemp
 from mayan.apps.documents.models import Document
 from mayan.apps.documents.permissions import permission_document_create
 from mayan.apps.documents.tests import (
     TEST_DOCUMENT_DESCRIPTION, TEST_SMALL_DOCUMENT_CHECKSUM,
     TEST_SMALL_DOCUMENT_PATH, GenericDocumentViewTestCase
 )
+from mayan.apps.storage.utils import fs_cleanup, mkdtemp
 
 from ..links import link_upload_version
 from ..literals import SOURCE_CHOICE_WEB_FORM

mayan/apps/storage/classes.py

@@ -0,0 +1,10 @@
+from __future__ import unicode_literals
+
+
+class FakeStorageSubclass(object):
+    """
+    Placeholder class to allow serializing the real storage subclass to
+    support migrations.
+    """
+    def __eq__(self, other):
+        return True

mayan/apps/storage/settings.py

@@ -0,0 +1,17 @@
+from __future__ import unicode_literals
+
+import tempfile
+
+from django.utils.translation import ugettext_lazy as _
+
+from mayan.apps.smart_settings import Namespace
+
+namespace = Namespace(label=_('Storage'), name='storage')
+
+setting_temporary_directory = namespace.add_setting(
+    global_name='STORAGE_TEMPORARY_DIRECTORY', default=tempfile.gettempdir(),
+    help_text=_(
+        'Temporary directory used site wide to store thumbnails, previews '
+        'and temporary files.'
+    )
+)

mayan/apps/storage/utils.py

@@ -0,0 +1,123 @@
+from __future__ import unicode_literals
+
+import logging
+import os
+import shutil
+import tempfile
+
+from django.utils.module_loading import import_string
+
+from .settings import setting_temporary_directory
+
+logger = logging.getLogger(__name__)
+
+
+def TemporaryFile(*args, **kwargs):
+    kwargs.update({'dir': setting_temporary_directory.value})
+    return tempfile.TemporaryFile(*args, **kwargs)
+
+
+# http://stackoverflow.com/questions/123198/how-do-i-copy-a-file-in-python
+def copyfile(source, destination, buffer_size=1024 * 1024):
+    """
+    Copy a file from source to dest. source and dest
+    can either be strings or any object with a read or
+    write method, like StringIO for example.
+    """
+    source_descriptor = get_descriptor(source)
+    destination_descriptor = get_descriptor(destination, read=False)
+
+    while True:
+        copy_buffer = source_descriptor.read(buffer_size)
+        if copy_buffer:
+            destination_descriptor.write(copy_buffer)
+        else:
+            break
+
+    source_descriptor.close()
+    destination_descriptor.close()
+
+
+def fs_cleanup(filename, file_descriptor=None, suppress_exceptions=True):
+    """
+    Tries to remove the given filename. Ignores non-existent files
+    """
+    if file_descriptor:
+        os.close(file_descriptor)
+
+    try:
+        os.remove(filename)
+    except OSError:
+        try:
+            shutil.rmtree(filename)
+        except OSError:
+            if suppress_exceptions:
+                pass
+            else:
+                raise
+
+
+def get_descriptor(file_input, read=True):
+    try:
+        # Is it a file like object?
+        file_input.seek(0)
+    except AttributeError:
+        # If not, try open it.
+        if read:
+            return open(file_input, mode='rb')
+        else:
+            return open(file_input, mode='wb')
+    else:
+        return file_input
+
+
+def get_storage_subclass(dotted_path):
+    """
+    Import a storage class and return a subclass that will always return eq
+    True to avoid creating a new migration when for runtime storage class
+    changes.
+    """
+    imported_storage_class = import_string(dotted_path=dotted_path)
+
+    class StorageSubclass(imported_storage_class):
+        def __init__(self, *args, **kwargs):
+            return super(StorageSubclass, self).__init__(*args, **kwargs)
+
+        def __eq__(self, other):
+            return True
+
+        def deconstruct(self):
+            return ('mayan.apps.storage.classes.FakeStorageSubclass', (), {})
+
+    return StorageSubclass
+
+
+def mkdtemp(*args, **kwargs):
+    kwargs.update({'dir': setting_temporary_directory.value})
+    return tempfile.mkdtemp(*args, **kwargs)
+
+
+def mkstemp(*args, **kwargs):
+    kwargs.update({'dir': setting_temporary_directory.value})
+    return tempfile.mkstemp(*args, **kwargs)
+
+
+def validate_path(path):
+    if not os.path.exists(path):
+        # If doesn't exist try to create it
+        try:
+            os.mkdir(path)
+        except Exception as exception:
+            logger.debug('unhandled exception: %s', exception)
+            return False
+
+    # Check if it is writable
+    try:
+        fd, test_filepath = tempfile.mkstemp(dir=path)
+        os.close(fd)
+        os.unlink(test_filepath)
+    except Exception as exception:
+        logger.debug('unhandled exception: %s', exception)
+        return False
+
+    return True