b5eb3ea1cd
- New GridFSStorage storage backend - New FileDocument document for storing files in GridFS - Whitespace cleaned up in various files
113 lines
3.6 KiB
Python
113 lines
3.6 KiB
Python
import os
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import itertools
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import urlparse
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from mongoengine import *
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from django.conf import settings
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from django.core.files.storage import Storage
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from django.core.exceptions import ImproperlyConfigured
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class FileDocument(Document):
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"""A document used to store a single file in GridFS.
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"""
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file = FileField()
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class GridFSStorage(Storage):
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"""A custom storage backend to store files in GridFS
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"""
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def __init__(self, base_url=None):
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if base_url is None:
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base_url = settings.MEDIA_URL
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self.base_url = base_url
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self.document = FileDocument
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self.field = 'file'
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def delete(self, name):
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"""Deletes the specified file from the storage system.
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"""
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if self.exists(name):
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doc = self.document.objects.first()
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field = getattr(doc, self.field)
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self._get_doc_with_name(name).delete() # Delete the FileField
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field.delete() # Delete the FileDocument
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def exists(self, name):
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"""Returns True if a file referened by the given name already exists in the
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storage system, or False if the name is available for a new file.
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"""
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doc = self._get_doc_with_name(name)
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if doc:
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field = getattr(doc, self.field)
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return bool(field.name)
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else:
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return False
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def listdir(self, path=None):
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"""Lists the contents of the specified path, returning a 2-tuple of lists;
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the first item being directories, the second item being files.
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"""
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def name(doc):
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return getattr(doc, self.field).name
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docs = self.document.objects
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return [], [name(d) for d in docs if name(d)]
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def size(self, name):
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"""Returns the total size, in bytes, of the file specified by name.
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"""
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doc = self._get_doc_with_name(name)
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if doc:
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return getattr(doc, self.field).length
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else:
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raise ValueError("No such file or directory: '%s'" % name)
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def url(self, name):
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"""Returns an absolute URL where the file's contents can be accessed
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directly by a web browser.
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"""
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if self.base_url is None:
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raise ValueError("This file is not accessible via a URL.")
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return urlparse.urljoin(self.base_url, name).replace('\\', '/')
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def _get_doc_with_name(self, name):
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"""Find the documents in the store with the given name
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"""
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docs = self.document.objects
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doc = [d for d in docs if getattr(d, self.field).name == name]
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if doc:
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return doc[0]
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else:
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return None
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def _open(self, name, mode='rb'):
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doc = self._get_doc_with_name(name)
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if doc:
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return getattr(doc, self.field)
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else:
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raise ValueError("No file found with the name '%s'." % name)
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def get_available_name(self, name):
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"""Returns a filename that's free on the target storage system, and
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available for new content to be written to.
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"""
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file_root, file_ext = os.path.splitext(name)
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# If the filename already exists, add an underscore and a number (before
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# the file extension, if one exists) to the filename until the generated
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# filename doesn't exist.
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count = itertools.count(1)
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while self.exists(name):
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# file_ext includes the dot.
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name = os.path.join("%s_%s%s" % (file_root, count.next(), file_ext))
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return name
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def _save(self, name, content):
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doc = self.document()
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getattr(doc, self.field).put(content, filename=name)
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doc.save()
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return name
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