matthias/mayan-edms
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Caching: MVP stage

Browse Source 
Working implementation with three levels of organization per cache.
Cache -> Partition -> File.

Current non blocking lock for the intermediate file generation needs
to be replaced to a blocking lock.

Needs tests.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>
This commit is contained in:
Roberto Rosario
2018-12-02 05:00:35 -04:00
parent a414b8df92
commit 77fc9b5831
6 changed files with 262 additions and 143 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
mayan/apps/common/migrations/0012_auto_20181130_2348.py → mayan/apps/common/migrations/0012_auto_20181202_0803.py
View File

@@ -1,9 +1,7 @@
# -*- coding: utf-8 -*-
# Generated by Django 1.11.16 on 2018-11-30 23:48
# Generated by Django 1.11.16 on 2018-12-02 08:03
from __future__ import unicode_literals
import common.models
import django.core.files.storage
from django.db import migrations, models
import django.db.models.deletion
@@ -11,7 +9,6 @@ import django.db.models.deletion
class Migration(migrations.Migration):
dependencies = [
('contenttypes', '0002_remove_content_type_name'),
('common', '0011_auto_20180429_0758'),
]
@@ -20,12 +17,10 @@ class Migration(migrations.Migration):
name='Cache',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('name', models.CharField(max_length=128, verbose_name='Name')),
('name', models.CharField(max_length=128, unique=True, verbose_name='Name')),
('label', models.CharField(max_length=128, verbose_name='Label')),
('maximum_size', models.PositiveIntegerField(verbose_name='Maximum size')),
('object_id', models.PositiveIntegerField()),
('storage_instance_path', models.CharField(max_length=255, verbose_name='Storage instance path')),
('content_type', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='contenttypes.ContentType')),
('storage_instance_path', models.CharField(max_length=255, unique=True, verbose_name='Storage instance path')),
],
options={
'verbose_name': 'Cache',
@@ -33,23 +28,38 @@ class Migration(migrations.Migration):
},
),
migrations.CreateModel(
name='CacheFile',
name='CachePartition',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('name', models.CharField(max_length=128, verbose_name='Name')),
('cache', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='partitions', to='common.Cache', verbose_name='Cache')),
],
options={
'verbose_name': 'Cache partition',
'verbose_name_plural': 'Cache partitions',
},
),
migrations.CreateModel(
name='CachePartitionFile',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('datetime', models.DateTimeField(auto_now_add=True, db_index=True, verbose_name='Date time')),
('filename', models.CharField(max_length=128, verbose_name='Filename')),
('filename', models.CharField(max_length=255, verbose_name='Filename')),
('file_size', models.PositiveIntegerField(db_index=True, default=0, verbose_name='File size')),
('cache', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='files', to='common.Cache', verbose_name='Cache')),
('partition', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='files', to='common.CachePartition', verbose_name='Cache partition')),
],
options={
'get_latest_by': 'datetime',
'verbose_name': 'Cache file',
'verbose_name_plural': 'Cache files',
'verbose_name': 'Cache partition file',
'verbose_name_plural': 'Cache partition files',
},
),
migrations.AlterField(
model_name='shareduploadedfile',
name='file',
field=models.FileField(storage=django.core.files.storage.FileSystemStorage(location='/usr/local/development/mayan-edms/mayan/media/shared_files'), upload_to=common.models.upload_to, verbose_name='File'),
migrations.AlterUniqueTogether(
name='cachepartitionfile',
unique_together=set([('partition', 'filename')]),
),
migrations.AlterUniqueTogether(
name='cachepartition',
unique_together=set([('cache', 'name')]),
),
]

146
mayan/apps/common/models.py
View File

@@ -1,5 +1,7 @@
from __future__ import unicode_literals
from contextlib import contextmanager
import logging
import uuid
from pytz import common_timezones
@@ -7,16 +9,22 @@ from pytz import common_timezones
from django.conf import settings
from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType
from django.db import models
from django.core.files.base import ContentFile
from django.db import models, transaction, OperationalError
from django.db.models import Sum
from django.utils.encoding import force_text, python_2_unicode_compatible
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
from django.utils.translation import ugettext_lazy as _
from lock_manager import LockError
from lock_manager.runtime import locking_backend
from .managers import ErrorLogEntryManager, UserLocaleProfileManager
from .storages import storage_sharedupload
logger = logging.getLogger(__name__)
def upload_to(instance, filename):
return 'shared-file-{}'.format(uuid.uuid4().hex)
@@ -24,14 +32,13 @@ def upload_to(instance, filename):
@python_2_unicode_compatible
class Cache(models.Model):
name = models.CharField(max_length=128, verbose_name=_('Name'))
name = models.CharField(
max_length=128, unique=True, verbose_name=_('Name')
)
label = models.CharField(max_length=128, verbose_name=_('Label'))
maximum_size = models.PositiveIntegerField(verbose_name=_('Maximum size'))
content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
object_id = models.PositiveIntegerField()
content_object = GenericForeignKey('content_type', 'object_id')
storage_instance_path = models.CharField(
max_length=255, verbose_name=_('Storage instance path')
max_length=255, unique=True, verbose_name=_('Storage instance path')
)
class Meta:
@@ -41,46 +48,143 @@ class Cache(models.Model):
def __str__(self):
return self.label
def get_files(self):
return CachePartitionFile.objects.filter(partition__cache__id=self.pk)
def get_total_size(self):
return self.files.aggregate(
return self.get_files().aggregate(
file_size__sum=Sum('file_size')
)['file_size__sum']
)['file_size__sum'] or 0
def prune(self):
while self.get_total_size() > self.maximum_size:
self.files.earliest().delete()
self.get_files().earliest().delete()
def purge(self):
for partition in self.partitions.all():
partition.purge()
@cached_property
def storage_instance(self):
def storage(self):
return import_string(self.storage_instance_path)
class CacheFile(models.Model):
class CachePartition(models.Model):
cache = models.ForeignKey(
on_delete=models.CASCADE, related_name='files',
on_delete=models.CASCADE, related_name='partitions',
to=Cache, verbose_name=_('Cache')
)
name = models.CharField(
max_length=128, verbose_name=_('Name')
)
class Meta:
unique_together = ('cache', 'name')
verbose_name = _('Cache partition')
verbose_name_plural = _('Cache partitions')
@staticmethod
def get_combined_filename(parent, filename):
return '{}-{}'.format(parent, filename)
@contextmanager
def create_file(self, filename):
lock_id = 'cache_partition-create_file-{}-{}'.format(self.pk, filename)
try:
logger.debug('trying to acquire lock: %s', lock_id)
lock = locking_backend.acquire_lock(lock_id)#, LOCK_EXPIRE)
logger.debug('acquired lock: %s', lock_id)
try:
self.cache.prune()
# Since open "wb+" doesn't create files force the creation of an
# empty file.
self.cache.storage.save(
name=self.get_full_filename(filename=filename),
content=ContentFile(content='')
)
try:
with transaction.atomic():
partition_file = self.files.create(filename=filename)
yield partition_file.open(mode='wb')
partition_file.update_size()
except Exception as exception:
logger.error(
'Unexpected exception while trying to save new '
'cache file.'
)
self.cache.storage.delete(
name=self.get_full_filename(filename=filename)
)
raise
finally:
lock.release()
except LockError:
logger.debug('unable to obtain lock: %s' % lock_id)
raise
def get_file(self, filename):
try:
return self.files.get(filename=filename)
except self.files.model.DoesNotExist:
return None
def get_full_filename(self, filename):
return CachePartition.get_combined_filename(
parent=self.name, filename=filename
)
def purge(self):
for parition_file in self.files.all():
parition_file.delete()
class CachePartitionFile(models.Model):
partition = models.ForeignKey(
on_delete=models.CASCADE, related_name='files',
to=CachePartition, verbose_name=_('Cache partition')
)
datetime = models.DateTimeField(
auto_now_add=True, db_index=True, verbose_name=_('Date time')
)
filename = models.CharField(max_length=128, verbose_name=_('Filename'))
filename = models.CharField(max_length=255, verbose_name=_('Filename'))
file_size = models.PositiveIntegerField(
db_index=True, default=0, verbose_name=_('File size')
)
class Meta:
get_latest_by = 'datetime'
verbose_name = _('Cache file')
verbose_name_plural = _('Cache files')
unique_together = ('partition', 'filename')
verbose_name = _('Cache partition file')
verbose_name_plural = _('Cache partition files')
def delete(self, *args, **kwargs):
self.cache.storage_instance.delete(self.filename)
return super(CacheFile, self).delete(*args, **kwargs)
self.partition.cache.storage.delete(name=self.full_filename)
return super(CachePartitionFile, self).delete(*args, **kwargs)
def save(self, *args, **kwargs):
self.cache.prune()
self.file_size = self.cache.storage_instance.size(self.filename)
return super(CacheFile, self).save(*args, **kwargs)
@cached_property
def full_filename(self):
return CachePartition.get_combined_filename(
parent=self.partition.name, filename=self.filename
)
def open(self, mode='rb'):
try:
return self.partition.cache.storage.open(
name=self.full_filename, mode=mode
)
except Exception as exception:
logger.error(
'Unexpected exception opening the cache file; %s', exception
)
raise
def update_size(self):
self.file_size = self.partition.cache.storage.size(
name=self.full_filename
)
self.save()
class ErrorLogEntry(models.Model):

3
mayan/apps/documents/api_views.py
View File

@@ -234,7 +234,8 @@ class APIDocumentPageImageView(generics.RetrieveAPIView):
)
cache_filename = task.get(timeout=DOCUMENT_IMAGE_TASK_TIMEOUT)
with storage_documentimagecache.open(cache_filename) as file_object:
#with storage_documentimagecache.open(cache_filename) as file_object:
with self.get_object().cache_partition.get_file(filename=cache_filename).open() as file_object:
response = HttpResponse(file_object.read(), content_type='image')
if '_hash' in request.GET:
patch_cache_control(

15
mayan/apps/documents/handlers.py
View File

@@ -3,7 +3,11 @@ from __future__ import unicode_literals
from django.apps import apps
from django.utils.translation import ugettext_lazy as _
from .literals import DEFAULT_DOCUMENT_TYPE_LABEL
from .literals import (
DEFAULT_DOCUMENT_TYPE_LABEL, DOCUMENT_CACHE_STORAGE_INSTANCE_PATH,
DOCUMENT_IMAGES_CACHE_NAME
)
from .settings import setting_document_cache_maximum_size
from .signals import post_initial_document_type
from .tasks import task_clean_empty_duplicate_lists, task_scan_duplicates_for
@@ -24,9 +28,12 @@ def create_default_document_type(sender, **kwargs):
def handler_create_document_cache(sender, **kwargs):
Cache = apps.get_model(app_label='common', model_name='Cache')
Cache.objects.get_or_create(
name='document_images', label=_('Document images'),
storage_instance_path='documents.storages.storage_documentimagecache'
Cache.objects.update_or_create(
defaults={
'label': _('Document images'),
'storage_instance_path': DOCUMENT_CACHE_STORAGE_INSTANCE_PATH,
'maximum_size': setting_document_cache_maximum_size.value,
}, name=DOCUMENT_IMAGES_CACHE_NAME,
)

4
mayan/apps/documents/literals.py
View File

@@ -9,7 +9,7 @@ CHECK_TRASH_PERIOD_INTERVAL = 60
DELETE_STALE_STUBS_INTERVAL = 60 * 10 # 10 minutes
DEFAULT_DELETE_PERIOD = 30
DEFAULT_DELETE_TIME_UNIT = TIME_DELTA_UNIT_DAYS
DEFAULT_DOCUMENTS_CACHE_MAXIMUM_SIZE = 50 * 2 ** 20 # 50 Megabytes
DEFAULT_DOCUMENTS_CACHE_MAXIMUM_SIZE = 100 * 2 ** 20 # 100 Megabytes
DEFAULT_LANGUAGE = 'eng'
DEFAULT_LANGUAGE_CODES = (
'ilo', 'run', 'uig', 'hin', 'pan', 'pnb', 'wuu', 'msa', 'kxd', 'ind',
@@ -30,6 +30,8 @@ DEFAULT_LANGUAGE_CODES = (
DEFAULT_ZIP_FILENAME = 'document_bundle.zip'
DEFAULT_DOCUMENT_TYPE_LABEL = _('Default')
DOCUMENT_IMAGE_TASK_TIMEOUT = 120
DOCUMENT_IMAGES_CACHE_NAME = 'document_images'
DOCUMENT_CACHE_STORAGE_INSTANCE_PATH = 'documents.storages.storage_documentimagecache'
STUB_EXPIRATION_INTERVAL = 60 * 60 * 24 # 24 hours
UPDATE_PAGE_COUNT_RETRY_DELAY = 10
UPLOAD_NEW_VERSION_RETRY_DELAY = 10

193
mayan/apps/documents/models.py
View File

@@ -7,6 +7,7 @@ import uuid
from furl import furl
from django.apps import apps
from django.conf import settings
from django.core.files import File
from django.core.files.base import ContentFile
@@ -14,6 +15,7 @@ from django.db import models, transaction
from django.template import Template, Context
from django.urls import reverse
from django.utils.encoding import force_text, python_2_unicode_compatible
from django.utils.functional import cached_property
from django.utils.timezone import now
from django.utils.translation import ugettext, ugettext_lazy as _
@@ -26,6 +28,7 @@ from converter import (
from converter.exceptions import InvalidOfficeFormat, PageCountError
from converter.literals import DEFAULT_ZOOM_LEVEL, DEFAULT_ROTATION
from converter.models import Transformation
from lock_manager import LockError
from mimetype.api import get_mimetype
from .events import (
@@ -34,7 +37,9 @@ from .events import (
event_document_type_created, event_document_type_edited,
event_document_version_revert
)
from .literals import DEFAULT_DELETE_PERIOD, DEFAULT_DELETE_TIME_UNIT
from .literals import (
DEFAULT_DELETE_PERIOD, DEFAULT_DELETE_TIME_UNIT, DOCUMENT_IMAGES_CACHE_NAME
)
from .managers import (
DocumentManager, DocumentPageCachedImage, DocumentPageManager,
DocumentVersionManager, DocumentTypeManager, DuplicatedDocumentManager,
@@ -50,7 +55,7 @@ from .settings import (
from .signals import (
post_document_created, post_document_type_change, post_version_upload
)
from .storages import storage_documentversion, storage_documentimagecache
from .storages import storage_documentversion
logger = logging.getLogger(__name__)
@@ -472,9 +477,17 @@ class DocumentVersion(models.Model):
def __str__(self):
return self.get_rendered_string()
@property
def cache_filename(self):
return 'document-version-{}'.format(self.uuid)
@cached_property
def cache(self):
Cache = apps.get_model(app_label='common', model_name='Cache')
return Cache.objects.get(name=DOCUMENT_IMAGES_CACHE_NAME)
@cached_property
def cache_partition(self):
partition, created = self.cache.partitions.get_or_create(
name='version-{}'.format(self.uuid)
)
return partition
def delete(self, *args, **kwargs):
for page in self.pages.all():
@@ -511,34 +524,34 @@ class DocumentVersion(models.Model):
return first_page.get_api_image_url(*args, **kwargs)
def get_intermidiate_file(self):
cache_filename = self.cache_filename
logger.debug('Intermidiate filename: %s', cache_filename)
import time
if storage_documentimagecache.exists(cache_filename):
logger.debug('Intermidiate file "%s" found.', cache_filename)
return storage_documentimagecache.open(cache_filename)
cache_file = self.cache_partition.get_file(filename='intermediate_file')
if cache_file:
logger.debug('Intermidiate file found.')
return cache_file.open()
else:
logger.debug('Intermidiate file "%s" not found.', cache_filename)
logger.debug('Intermidiate file not found.')
try:
converter = converter_class(file_object=self.open())
pdf_file_object = converter.to_pdf()
with storage_documentimagecache.open(cache_filename, mode='wb+') as file_object:
for chunk in pdf_file_object:
file_object.write(chunk)
try:
with self.cache_partition.create_file(filename='intermediate_file') as file_object:
for chunk in pdf_file_object:
file_object.write(chunk)
except LockError:
time.sleep(0.1)
return self.get_intermidiate_file()
return storage_documentimagecache.open(cache_filename)
return self.cache_partition.get_file(filename='intermediate_file').open()
except InvalidOfficeFormat:
return self.open()
except Exception as exception:
# Cleanup in case of error
logger.error(
'Error creating intermediate file "%s"; %s.',
cache_filename, exception
'Error creating intermediate file; %s.', exception
)
storage_documentimagecache.delete(cache_filename)
raise
def get_rendered_string(self, preserve_extension=False):
@@ -562,7 +575,7 @@ class DocumentVersion(models.Model):
natural_key.dependencies = ['documents.Document']
def invalidate_cache(self):
storage_documentimagecache.delete(self.cache_filename)
self.cache_partition.purge()
for page in self.pages.all():
page.invalidate_cache()
@@ -743,37 +756,12 @@ class DocumentVersion(models.Model):
return detected_pages
@property
@cached_property
def uuid(self):
# Make cache UUID a mix of document UUID, version ID
return '{}-{}'.format(self.document.uuid, self.pk)
@python_2_unicode_compatible
class DocumentTypeFilename(models.Model):
"""
List of labels available to a specific document type for the
quick rename functionality
"""
document_type = models.ForeignKey(
on_delete=models.CASCADE, related_name='filenames', to=DocumentType,
verbose_name=_('Document type')
)
filename = models.CharField(
db_index=True, max_length=128, verbose_name=_('Label')
)
enabled = models.BooleanField(default=True, verbose_name=_('Enabled'))
class Meta:
ordering = ('filename',)
unique_together = ('document_type', 'filename')
verbose_name = _('Quick label')
verbose_name_plural = _('Quick labels')
def __str__(self):
return self.filename
@python_2_unicode_compatible
class DocumentPage(models.Model):
"""
@@ -804,9 +792,12 @@ class DocumentPage(models.Model):
'total_pages': self.document_version.pages.count()
}
@property
def cache_filename(self):
return 'page-cache-{}'.format(self.uuid)
@cached_property
def cache_partition(self):
partition, created = self.document_version.cache.partitions.get_or_create(
name=self.uuid
)
return partition
def delete(self, *args, **kwargs):
self.invalidate_cache()
@@ -822,35 +813,30 @@ class DocumentPage(models.Model):
page_number=self.page_number
)
@property
@cached_property
def document(self):
return self.document_version.document
def generate_image(self, *args, **kwargs):
transformation_list = self.get_combined_transformation_list(*args, **kwargs)
cache_filename = '{}-{}'.format(
self.cache_filename, BaseTransformation.combine(transformation_list)
)
combined_cache_filename = BaseTransformation.combine(transformation_list)
# Check is transformed image is available
logger.debug('transformations cache filename: %s', cache_filename)
logger.debug('transformations cache filename: %s', combined_cache_filename)
if not setting_disable_transformed_image_cache.value and storage_documentimagecache.exists(cache_filename):
if not setting_disable_transformed_image_cache.value and self.cache_partition.get_file(filename=combined_cache_filename):
logger.debug(
'transformations cache file "%s" found', cache_filename
'transformations cache file "%s" found', combined_cache_filename
)
else:
logger.debug(
'transformations cache file "%s" not found', cache_filename
'transformations cache file "%s" not found', combined_cache_filename
)
image = self.get_image(transformations=transformation_list)
with storage_documentimagecache.open(cache_filename, 'wb+') as file_object:
with self.cache_partition.create_file(filename=combined_cache_filename) as file_object:
file_object.write(image.getvalue())
self.cached_images.create(filename=cache_filename)
return cache_filename
return combined_cache_filename
def get_absolute_url(self):
return reverse('documents:document_page_view', args=(self.pk,))
@@ -913,7 +899,6 @@ class DocumentPage(models.Model):
zoom_level = setting_zoom_max_level.value
# Generate transformation hash
transformation_list = []
# Stored transformations first
@@ -940,42 +925,29 @@ class DocumentPage(models.Model):
return transformation_list
def get_image(self, transformations=None):
cache_filename = self.cache_filename
cache_filename = 'base_image'
logger.debug('Page cache filename: %s', cache_filename)
if not setting_disable_base_image_cache.value and storage_documentimagecache.exists(cache_filename):
cache_file = self.cache_partition.get_file(filename=cache_filename)
if not setting_disable_base_image_cache.value and cache_file:
logger.debug('Page cache file "%s" found', cache_filename)
converter = converter_class(
file_object=storage_documentimagecache.open(cache_filename)
file_object=cache_file.open()
)
converter.seek(0)
else:
logger.debug('Page cache file "%s" not found', cache_filename)
try:
converter = converter_class(
file_object=self.document_version.get_intermidiate_file()
)
converter.seek(page_number=self.page_number - 1)
converter = converter_class(
file_object=self.document_version.get_intermidiate_file()
)
converter.seek(page_number=self.page_number - 1)
page_image = converter.get_page()
page_image = converter.get_page()
# Since open "wb+" doesn't create files, check if the file
# exists, if not then create it
if not storage_documentimagecache.exists(cache_filename):
storage_documentimagecache.save(name=cache_filename, content=ContentFile(content=''))
with storage_documentimagecache.open(cache_filename, 'wb+') as file_object:
file_object.write(page_image.getvalue())
except Exception as exception:
# Cleanup in case of error
logger.error(
'Error creating page cache file "%s"; %s',
cache_filename, exception
)
storage_documentimagecache.delete(cache_filename)
raise
with self.cache_partition.create_file(filename=cache_filename) as file_object:
file_object.write(page_image.getvalue())
for transformation in transformations:
converter.transform(transformation=transformation)
@@ -983,9 +955,7 @@ class DocumentPage(models.Model):
return converter.get_page()
def invalidate_cache(self):
storage_documentimagecache.delete(self.cache_filename)
for cached_image in self.cached_images.all():
cached_image.delete()
self.cache_partition.purge()
@property
def is_in_trash(self):
@@ -1001,10 +971,10 @@ class DocumentPage(models.Model):
document_version=self.document_version
)
@property
@cached_property
def uuid(self):
"""
Make cache UUID a mix of version ID and page ID to avoid using stale
Make cache UUID a mix of version UUID and page ID to avoid using stale
images
"""
return '{}-{}'.format(self.document_version.uuid, self.pk)
@@ -1029,17 +999,17 @@ class DocumentPageCachedImage(models.Model):
verbose_name = _('Document page cached image')
verbose_name_plural = _('Document page cached images')
def delete(self, *args, **kwargs):
storage_documentimagecache.delete(self.filename)
return super(DocumentPageCachedImage, self).delete(*args, **kwargs)
#def delete(self, *args, **kwargs):
# storage_documentimagecache.delete(self.filename)
# return super(DocumentPageCachedImage, self).delete(*args, **kwargs)
def natural_key(self):
return (self.filename, self.document_page.natural_key())
natural_key.dependencies = ['documents.DocumentPage']
def save(self, *args, **kwargs):
self.file_size = storage_documentimagecache.size(self.filename)
return super(DocumentPageCachedImage, self).save(*args, **kwargs)
#def save(self, *args, **kwargs):
# self.file_size = storage_documentimagecache.size(self.filename)
# return super(DocumentPageCachedImage, self).save(*args, **kwargs)
class DocumentPageResult(DocumentPage):
@@ -1050,6 +1020,31 @@ class DocumentPageResult(DocumentPage):
verbose_name_plural = _('Document pages')
@python_2_unicode_compatible
class DocumentTypeFilename(models.Model):
"""
List of labels available to a specific document type for the
quick rename functionality
"""
document_type = models.ForeignKey(
on_delete=models.CASCADE, related_name='filenames', to=DocumentType,
verbose_name=_('Document type')
)
filename = models.CharField(
db_index=True, max_length=128, verbose_name=_('Label')
)
enabled = models.BooleanField(default=True, verbose_name=_('Enabled'))
class Meta:
ordering = ('filename',)
unique_together = ('document_type', 'filename')
verbose_name = _('Quick label')
verbose_name_plural = _('Quick labels')
def __str__(self):
return self.filename
@python_2_unicode_compatible
class DuplicatedDocument(models.Model):
document = models.ForeignKey(