Files
mayan-edms/mayan/apps/documents/models.py
Roberto Rosario 48df3dcafa PEP8 cleanups
2015-06-24 17:11:24 -04:00

589 lines
19 KiB
Python

from __future__ import unicode_literals
import base64
import hashlib
import logging
import os
import uuid
from django.contrib.auth.models import User
from django.core.urlresolvers import reverse
from django.db import models, transaction
from django.utils.encoding import python_2_unicode_compatible
from django.utils.translation import ugettext_lazy as _
from acls.utils import apply_default_acls
from common.settings import setting_temporary_directory
from common.utils import fs_cleanup
from converter import (
converter_class, TransformationResize, TransformationRotate,
TransformationZoom
)
from converter.exceptions import InvalidOfficeFormat, UnknownFileFormat
from converter.literals import DEFAULT_ZOOM_LEVEL, DEFAULT_ROTATION
from converter.models import Transformation
from mimetype.api import get_mimetype
from .events import (
event_document_create, event_document_new_version,
event_document_version_revert
)
from .managers import (
DocumentManager, DocumentTypeManager, RecentDocumentManager
)
from .runtime import storage_backend
from .settings import (
setting_cache_path, setting_display_size, setting_language,
setting_language_choices, setting_zoom_max_level, setting_zoom_min_level
)
from .signals import post_version_upload, post_document_type_change
HASH_FUNCTION = lambda x: hashlib.sha256(x).hexdigest() # document image cache name hash function
logger = logging.getLogger(__name__)
def UUID_FUNCTION(*args, **kwargs):
return unicode(uuid.uuid4())
@python_2_unicode_compatible
class DocumentType(models.Model):
"""
Define document types or classes to which a specific set of
properties can be attached
"""
name = models.CharField(max_length=32, verbose_name=_('Name'), unique=True)
objects = DocumentTypeManager()
def __str__(self):
return self.name
def natural_key(self):
return (self.name,)
class Meta:
verbose_name = _('Document type')
verbose_name_plural = _('Documents types')
ordering = ('name',)
@python_2_unicode_compatible
class Document(models.Model):
"""
Defines a single document with it's fields and properties
"""
uuid = models.CharField(default=UUID_FUNCTION, max_length=48, editable=False)
document_type = models.ForeignKey(DocumentType, verbose_name=_('Document type'), related_name='documents')
label = models.CharField(max_length=255, default=_('Uninitialized document'), db_index=True, help_text=_('The name of the document'), verbose_name=_('Label'))
description = models.TextField(blank=True, null=True, verbose_name=_('Description'))
date_added = models.DateTimeField(verbose_name=_('Added'), auto_now_add=True)
language = models.CharField(choices=setting_language_choices.value, default=setting_language.value, max_length=8, verbose_name=_('Language'))
objects = DocumentManager()
class Meta:
verbose_name = _('Document')
verbose_name_plural = _('Documents')
ordering = ('-date_added',)
def set_document_type(self, document_type, force=False):
has_changed = self.document_type != document_type
self.document_type = document_type
self.save()
if has_changed or force:
post_document_type_change.send(sender=self.__class__, instance=self)
def invalidate_cache(self):
for document_version in self.versions.all():
document_version.invalidate_cache()
def __str__(self):
return self.label
def get_absolute_url(self):
return reverse('documents:document_preview', args=[self.pk])
def save(self, *args, **kwargs):
user = kwargs.pop('user', None)
new_document = not self.pk
super(Document, self).save(*args, **kwargs)
if new_document:
apply_default_acls(self, user)
if user:
self.add_as_recent_document_for_user(user)
event_document_create.commit(actor=user, target=self)
else:
event_document_create.commit(target=self)
def add_as_recent_document_for_user(self, user):
RecentDocument.objects.add_document_for_user(user, self)
def delete(self, *args, **kwargs):
for version in self.versions.all():
version.delete()
return super(Document, self).delete(*args, **kwargs)
@property
def size(self):
return self.latest_version.size
def new_version(self, file_object, user=None, comment=None):
logger.info('Creating a new document version for document: %s', self)
new_version = DocumentVersion.objects.create(
document=self,
file=file_object,
comment=comment or '',
)
logger.info('New document version created for document: %s', self)
event_document_new_version.commit(actor=user, target=self)
return new_version
# Proxy methods
def open(self, *args, **kwargs):
"""
Return a file descriptor to a document's file irrespective of
the storage backend
"""
return self.latest_version.open(*args, **kwargs)
def save_to_file(self, *args, **kwargs):
return self.latest_version.save_to_file(*args, **kwargs)
def exists(self):
"""
Returns a boolean value that indicates if the document's
latest version file exists in storage
"""
return self.latest_version.exists()
# Compatibility methods
@property
def file(self):
return self.latest_version.file
@property
def file_mimetype(self):
return self.latest_version.mimetype
# TODO: rename to file_encoding
@property
def file_mime_encoding(self):
return self.latest_version.encoding
@property
def date_updated(self):
return self.latest_version.timestamp
@property
def checksum(self):
return self.latest_version.checksum
@property
def signature_state(self):
return self.latest_version.signature_state
@property
def pages(self):
try:
return self.latest_version.pages
except AttributeError:
# Document has no version yet
return 0
@property
def page_count(self):
return self.latest_version.page_count
@property
def latest_version(self):
return self.versions.order_by('timestamp').last()
def document_save_to_temp_dir(self, filename, buffer_size=1024 * 1024):
temporary_path = os.path.join(setting_temporary_directory.value, filename)
return self.save_to_file(temporary_path, buffer_size)
@python_2_unicode_compatible
class DocumentVersion(models.Model):
"""
Model that describes a document version and its properties
"""
_pre_open_hooks = {}
_post_save_hooks = {}
@classmethod
def register_pre_open_hook(cls, order, func):
cls._pre_open_hooks[order] = func
@classmethod
def register_post_save_hook(cls, order, func):
cls._post_save_hooks[order] = func
document = models.ForeignKey(Document, verbose_name=_('Document'), related_name='versions')
timestamp = models.DateTimeField(verbose_name=_('Timestamp'), auto_now_add=True)
comment = models.TextField(blank=True, verbose_name=_('Comment'))
# File related fields
file = models.FileField(upload_to=UUID_FUNCTION, storage=storage_backend, verbose_name=_('File'))
mimetype = models.CharField(max_length=255, null=True, blank=True, editable=False)
encoding = models.CharField(max_length=64, null=True, blank=True, editable=False)
checksum = models.TextField(blank=True, null=True, verbose_name=_('Checksum'), editable=False)
class Meta:
verbose_name = _('Document version')
verbose_name_plural = _('Document version')
def __str__(self):
return '{0} - {1}'.format(self.document, self.timestamp)
def save(self, *args, **kwargs):
"""
Overloaded save method that updates the document version's checksum,
mimetype, and page count when created
"""
new_document_version = not self.pk
# Only do this for new documents
super(DocumentVersion, self).save(*args, **kwargs)
for key in sorted(DocumentVersion._post_save_hooks):
DocumentVersion._post_save_hooks[key](self)
if new_document_version:
# Only do this for new documents
self.update_checksum(save=False)
self.update_mimetype(save=False)
self.save()
self.update_page_count(save=False)
post_version_upload.send(sender=self.__class__, instance=self)
def invalidate_cache(self):
for page in self.pages.all():
page.invalidate_cache()
def update_checksum(self, save=True):
"""
Open a document version's file and update the checksum field using the
user provided checksum function
"""
if self.exists():
source = self.open()
self.checksum = unicode(HASH_FUNCTION(source.read()))
source.close()
if save:
self.save()
def update_page_count(self, save=True):
try:
with self.open() as file_object:
converter = converter_class(file_object=file_object, mime_type=self.mimetype)
detected_pages = converter.get_page_count()
except UnknownFileFormat:
# If converter backend doesn't understand the format,
# use 1 as the total page count
detected_pages = 1
with transaction.atomic():
self.pages.all().delete()
for page_number in range(detected_pages):
DocumentPage.objects.create(
document_version=self, page_number=page_number + 1
)
# TODO: is this needed anymore
if save:
self.save()
return detected_pages
def revert(self, user=None):
"""
Delete the subsequent versions after this one
"""
logger.info('Reverting to document document: %s to version: %s', self.document, self)
event_document_version_revert.commit(actor=user, target=self.document)
for version in self.document.versions.filter(timestamp__gt=self.timestamp):
version.delete()
def update_mimetype(self, save=True):
"""
Read a document verions's file and determine the mimetype by calling the
get_mimetype wrapper
"""
if self.exists():
try:
with self.open() as file_object:
self.mimetype, self.encoding = get_mimetype(file_object=file_object)
except:
self.mimetype = ''
self.encoding = ''
finally:
if save:
self.save()
def delete(self, *args, **kwargs):
for page in self.pages.all():
page.delete()
self.file.storage.delete(self.file.path)
return super(DocumentVersion, self).delete(*args, **kwargs)
def exists(self):
"""
Returns a boolean value that indicates if the document's file
exists in storage
"""
return self.file.storage.exists(self.file.path)
def open(self, raw=False):
"""
Return a file descriptor to a document version's file irrespective of
the storage backend
"""
if raw:
return self.file.storage.open(self.file.path)
else:
result = self.file.storage.open(self.file.path)
for key in sorted(DocumentVersion._pre_open_hooks):
result = DocumentVersion._pre_open_hooks[key](result, self)
return result
def save_to_file(self, filepath, buffer_size=1024 * 1024):
"""
Save a copy of the document from the document storage backend
to the local filesystem
"""
input_descriptor = self.open()
output_descriptor = open(filepath, 'wb')
while True:
copy_buffer = input_descriptor.read(buffer_size)
if copy_buffer:
output_descriptor.write(copy_buffer)
else:
break
output_descriptor.close()
input_descriptor.close()
return filepath
@property
def size(self):
if self.exists():
return self.file.storage.size(self.file.path)
else:
return None
@property
def page_count(self):
return self.pages.count()
@property
def uuid(self):
# Make cache UUID a mix of document UUID, version ID
return '{}-{}'.format(self.document.uuid, self.pk)
@property
def cache_filename(self):
return os.path.join(setting_cache_path.value, 'document-version-{}'.format(self.uuid))
def get_intermidiate_file(self):
cache_filename = self.cache_filename
logger.debug('Intermidiate filename: %s', cache_filename)
if os.path.exists(cache_filename):
logger.debug('Intermidiate file "%s" found.', cache_filename)
return open(cache_filename)
else:
logger.debug('Intermidiate file "%s" not found.', cache_filename)
try:
converter = converter_class(file_object=self.open())
pdf_file_object = converter.to_pdf()
with open(cache_filename, 'wb+') as file_object:
for chunk in pdf_file_object:
file_object.write(chunk)
return open(cache_filename)
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)
fs_cleanup(cache_filename)
raise
@python_2_unicode_compatible
class DocumentTypeFilename(models.Model):
"""
List of filenames available to a specific document type for the
quick rename functionality
"""
document_type = models.ForeignKey(DocumentType, related_name='filenames', verbose_name=_('Document type'))
filename = models.CharField(max_length=128, verbose_name=_('Filename'), db_index=True)
enabled = models.BooleanField(default=True, verbose_name=_('Enabled'))
def __str__(self):
return self.filename
class Meta:
ordering = ('filename',)
unique_together = ('document_type', 'filename')
verbose_name = _('Document type quick rename filename')
verbose_name_plural = _('Document types quick rename filenames')
@python_2_unicode_compatible
class DocumentPage(models.Model):
"""
Model that describes a document version page
"""
document_version = models.ForeignKey(DocumentVersion, verbose_name=_('Document version'), related_name='pages')
page_number = models.PositiveIntegerField(default=1, editable=False, verbose_name=_('Page number'), db_index=True)
def __str__(self):
return _('Page %(page_num)d out of %(total_pages)d of %(document)s') % {
'document': unicode(self.document),
'page_num': self.page_number,
'total_pages': self.document_version.pages.count()
}
class Meta:
ordering = ('page_number',)
verbose_name = _('Document page')
verbose_name_plural = _('Document pages')
def get_absolute_url(self):
return reverse('documents:document_page_view', args=[self.pk])
def delete(self, *args, **kwargs):
self.invalidate_cache()
super(DocumentPage, self).delete(*args, **kwargs)
@property
def siblings(self):
return DocumentPage.objects.filter(document_version=self.document_version)
# Compatibility methods
@property
def document(self):
return self.document_version.document
def invalidate_cache(self):
fs_cleanup(self.get_cache_filename())
@property
def uuid(self):
"""
Make cache UUID a mix of version ID and page ID to avoid using stale
images
"""
return '{}-{}'.format(self.document_version.uuid, self.pk)
@property
def cache_filename(self):
return os.path.join(setting_cache_path.value, 'page-cache-{}'.format(self.uuid))
def get_image(self, *args, **kwargs):
as_base64 = kwargs.pop('as_base64', False)
transformations = kwargs.pop('transformations', [])
size = kwargs.pop('size', setting_display_size.value)
rotation = kwargs.pop('rotation', DEFAULT_ROTATION)
zoom_level = kwargs.pop('zoom', DEFAULT_ZOOM_LEVEL)
if zoom_level < setting_zoom_min_level.value:
zoom_level = setting_zoom_min_level.value
if zoom_level > setting_zoom_max_level.value:
zoom_level = setting_zoom_max_level.value
rotation = rotation % 360
cache_filename = self.cache_filename
logger.debug('Page cache filename: %s', cache_filename)
if os.path.exists(cache_filename):
logger.debug('Page cache file "%s" found', cache_filename)
converter = converter_class(file_object=open(cache_filename))
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)
page_image = converter.get_page()
with 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)
fs_cleanup(cache_filename)
raise
# Stored transformations
for stored_transformation in Transformation.objects.get_for_model(self, as_classes=True):
converter.transform(transformation=stored_transformation)
# Interactive transformations
for transformation in transformations:
converter.transform(transformation=transformation)
if rotation:
converter.transform(transformation=TransformationRotate(degrees=rotation))
if size:
converter.transform(transformation=TransformationResize(**dict(zip(('width', 'height'), (size.split('x'))))))
if zoom_level:
converter.transform(transformation=TransformationZoom(percent=zoom_level))
page_image = converter.get_page()
if as_base64:
# TODO: don't prepend 'data:%s;base64,%s' part
return 'data:%s;base64,%s' % ('image/png', base64.b64encode(page_image.getvalue()))
else:
return page_image
@python_2_unicode_compatible
class RecentDocument(models.Model):
"""
Keeps a list of the n most recent accessed or created document for
a given user
"""
user = models.ForeignKey(User, verbose_name=_('User'), editable=False)
document = models.ForeignKey(Document, verbose_name=_('Document'), editable=False)
datetime_accessed = models.DateTimeField(verbose_name=_('Accessed'), auto_now=True, db_index=True)
objects = RecentDocumentManager()
def __str__(self):
return unicode(self.document)
class Meta:
ordering = ('-datetime_accessed',)
verbose_name = _('Recent document')
verbose_name_plural = _('Recent documents')