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# -*- coding: utf-8 -*-
# _blobs.py
# Copyright (C) 2017 LEAP
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""
Blobs Server implementation.
This is a very simplistic implementation for the time being.
Clients should be able to opt-in util the feature is complete.
A more performant BlobsBackend can (and should) be implemented for production
environments.
"""
import os
from twisted.web import static
from twisted.web import resource
from twisted.web.client import FileBodyProducer
from twisted.web.server import NOT_DONE_YET
from zope.interface import Interface, implementer
from ._config import get_config
__all__ = ['BlobsResource', 'blobs_resource']
# TODO some error handling needed
# [ ] make path configurable
# [ ] sanitize path
# [ ] implement basic quota (and raise a QuotaExceeded if limit reached!)
# for the future:
# [ ] isolate user avatar in a safer way
# [ ] catch timeout in the server (and delete incomplete upload)
# p [ chunking (should we do it on the client or on the server?)
class BlobAlreadyExists(Exception):
pass
class IBlobsBackend(Interface):
"""
An interface for a BlobsBackend.
"""
def read_blob(user, blob_id, request):
"""
Read blob with a given blob_id, and write it to the passed request.
:returns: a deferred that fires upon finishing.
"""
def write_blob(user, blob_id, request):
"""
Write blob to the storage, reading it from the passed request.
:returns: a deferred that fires upon finishing.
"""
# other stuff for the API
def delete_blob(user, blob_id):
pass
def get_blob_size(user, blob_id):
pass
def get_total_storage(user):
pass
@implementer(IBlobsBackend)
class FilesystemBlobsBackend(object):
path = '/tmp/blobs/'
def read_blob(self, user, blob_id, request):
print "USER", user
print "BLOB_ID", blob_id
path = self.get_path(user, blob_id)
print "READ FROM", path
_file = static.File(path, defaultType='application/octet-stream')
return _file.render_GET(request)
def write_blob(self, user, blob_id, request):
path = self.get_path(user, blob_id)
if os.path.isfile(path):
raise BlobAlreadyExists()
try:
os.makedirs(os.path.split(path)[0])
except:
pass
print "WRITE TO", path
fbp = FileBodyProducer(request.content)
d = fbp.startProducing(open(path, 'wb'))
d.addCallback(lambda _: request.finish())
return NOT_DONE_YET
def get_path(self, user, blob_id):
parts = [user]
parts += [blob_id[0], blob_id[0:3], blob_id[0:6]]
parts += [blob_id]
return os.path.join(self.path, *parts)
class BlobsResource(resource.Resource):
isLeaf = True
# Allowed factory classes are defined here
blobsFactoryClass = FilesystemBlobsBackend
def __init__(self, blobs_path):
# TODO pass the backend as configurable option
"""
__init__(self, backend, opts={})
factorykls = getattr(self, backend + 'Class')(**opts)
self._handler = kls()
"""
resource.Resource.__init__(self)
self._blobs_path = blobs_path
self._handler = self.blobsFactoryClass()
assert IBlobsBackend.providedBy(self._handler)
# TODO double check credentials, we can have then
# under request.
def render_GET(self, request):
user, blob_id = self._split_path(request.path)
return self._handler.read_blob(user, blob_id, request)
def render_PUT(self, request):
user, blob_id = self._split_path(request.path)
return self._handler.write_blob(user, blob_id, request)
def _split_path(self, blob_id):
# FIXME catch errors here
parts = blob_id.split('/')
_, user, blobname = parts
return user, blobname
# provide a configured instance of the resource
_config = get_config()
_path = _config['blobs_path']
blobs_resource = BlobsResource(_path)
if __name__ == '__main__':
# A dummy blob server
# curl -X PUT --data-binary @/tmp/book.pdf localhost:9000/user/somerandomstring
# curl -X GET -o /dev/null localhost:9000/user/somerandomstring
from twisted.web.server import Site
from twisted.internet import reactor
# XXX pass the path here
root = BlobsResource()
# I picture somethink like
# BlobsResource(backend="filesystem", backend_opts={'path': '/tmp/blobs'})
factory = Site(root)
reactor.listenTCP(9000, factory)
reactor.run()
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