# -*- coding: utf-8 -*-
#
# This file is part of Invenio.
# Copyright (C) 2016 CERN.
#
# Invenio 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 2 of the
# License, or (at your option) any later version.
#
# Invenio 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 Invenio; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307, USA.
#
# In applying this license, CERN does not
# waive the privileges and immunities granted to it by virtue of its status
# as an Intergovernmental Organization or submit itself to any jurisdiction.
"""Storage related module."""
from __future__ import absolute_import, print_function
from flask import current_app
from fs.opener import opener
from fs.path import basename, dirname
from ..helpers import make_path
from .base import FileStorage
[docs]class PyFSFileStorage(FileStorage):
"""File system storage using PyFilesystem for access the file.
This storage class will store files according to the following pattern:
``<base_uri>/<file instance uuid>/data``.
.. warning::
File operations are not atomic. E.g. if errors happens during e.g.
updating part of a file it will leave the file in an inconsistent
state. The storage class tries as best as possible to handle errors
and leave the system in a consistent state.
"""
def __init__(self, fileurl, size=None, modified=None, clean_dir=True):
"""Storage initialization."""
self.fileurl = fileurl
self.clean_dir = clean_dir
super(PyFSFileStorage, self).__init__(size=size, modified=modified)
def _get_fs(self, create_dir=True):
"""Return tuple with filesystem and filename."""
filedir = dirname(self.fileurl)
filename = basename(self.fileurl)
return (
opener.opendir(filedir, writeable=True, create_dir=create_dir),
filename
)
[docs] def open(self, mode='rb'):
"""Open file.
The caller is responsible for closing the file.
"""
fs, path = self._get_fs()
return fs.open(path, mode=mode)
[docs] def delete(self):
"""Delete a file.
The base directory is also removed, as it is assumed that only one file
exists in the directory.
"""
fs, path = self._get_fs(create_dir=False)
if fs.exists(path):
fs.remove(path)
if self.clean_dir and fs.exists('.'):
fs.removedir('.')
return True
[docs] def initialize(self, size=0):
"""Initialize file on storage and truncate to given size."""
fs, path = self._get_fs()
# Required for reliably opening the file on certain file systems:
if fs.exists(path):
fp = fs.open(path, mode='r+b')
else:
fp = fs.open(path, mode='wb')
try:
fp.truncate(size)
except Exception:
fp.close()
self.delete()
raise
finally:
fp.close()
self._size = size
return self.fileurl, size, None
[docs] def save(self, incoming_stream, size_limit=None, size=None,
chunk_size=None, progress_callback=None):
"""Save file in the file system."""
fp = self.open(mode='wb')
try:
bytes_written, checksum = self._write_stream(
incoming_stream, fp, chunk_size=chunk_size,
progress_callback=progress_callback,
size_limit=size_limit, size=size)
except Exception:
fp.close()
self.delete()
raise
finally:
fp.close()
self._size = bytes_written
return self.fileurl, bytes_written, checksum
[docs] def update(self, incoming_stream, seek=0, size=None, chunk_size=None,
progress_callback=None):
"""Update a file in the file system."""
fp = self.open(mode='r+b')
try:
fp.seek(seek)
bytes_written, checksum = self._write_stream(
incoming_stream, fp, chunk_size=chunk_size,
size=size, progress_callback=progress_callback)
finally:
fp.close()
return bytes_written, checksum
[docs]def pyfs_storage_factory(fileinstance=None, default_location=None,
default_storage_class=None,
filestorage_class=PyFSFileStorage):
"""Get factory function for creating a PyFS file storage instance."""
assert fileinstance
fileurl = None
size = fileinstance.size
modified = fileinstance.updated
if fileinstance.uri:
# Use already existing URL.
fileurl = fileinstance.uri
else:
assert default_location
# Generate a new URL.
fileurl = make_path(
default_location,
str(fileinstance.id),
'data',
current_app.config['FILES_REST_STORAGE_PATH_DIMENSIONS'],
current_app.config['FILES_REST_STORAGE_PATH_SPLIT_LENGTH'],
)
return filestorage_class(
fileurl, size=size, modified=modified, clean_dir=True)
