-# -*- coding: utf-8 -*-
-# This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
-# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
-#
-from __future__ import with_statement
-
-import random
-import time
-from base64 import urlsafe_b64encode
-
-from django.core.files.uploadedfile import UploadedFile
-from django.utils.hashcompat import sha_constructor
-from django.conf import settings
-from celery.task import task
-from os import mkdir, path, unlink
-from errno import EEXIST, ENOENT
-from fcntl import flock, LOCK_EX
-from zipfile import ZipFile
-
-from librarian import DocProvider
-
-
-# Use the system (hardware-based) random number generator if it exists.
-if hasattr(random, 'SystemRandom'):
- randrange = random.SystemRandom().randrange
-else:
- randrange = random.randrange
-MAX_SESSION_KEY = 18446744073709551616L # 2 << 63
-
-
-def get_random_hash(seed):
- sha_digest = sha_constructor('%s%s%s%s' %
- (randrange(0, MAX_SESSION_KEY), time.time(), unicode(seed).encode('utf-8', 'replace'),
- settings.SECRET_KEY)).digest()
- return urlsafe_b64encode(sha_digest).replace('=', '').replace('_', '-').lower()
-
-
-def split_tags(tags):
- result = {}
- for tag in tags:
- result.setdefault(tag.category, []).append(tag)
- return result
-
-
-class ExistingFile(UploadedFile):
-
- def __init__(self, path, *args, **kwargs):
- self.path = path
- return super(ExistingFile, self).__init__(*args, **kwargs)
-
- def temporary_file_path(self):
- return self.path
-
- def close(self):
- pass
-
-
-class ORMDocProvider(DocProvider):
- """Used for getting books' children."""
-
- def __init__(self, book):
- self.book = book
-
- def by_slug(self, slug):
- if slug == self.book.slug:
- return self.book.xml_file
- else:
- return type(self.book).objects.get(slug=slug).xml_file
-
-
-class LockFile(object):
- """
- A file lock monitor class; createas an ${objname}.lock
- file in directory dir, and locks it exclusively.
- To be used in 'with' construct.
- """
- def __init__(self, dir, objname):
- self.lockname = path.join(dir, objname + ".lock")
-
- def __enter__(self):
- self.lock = open(self.lockname, 'w')
- flock(self.lock, LOCK_EX)
-
- def __exit__(self, *err):
- try:
- unlink(self.lockname)
- except OSError as oe:
- if oe.errno != oe.EEXIST:
- raise oe
- self.lock.close()
-
-
-def create_zip(paths, zip_slug):
- """
- Creates a zip in MEDIA_ROOT/zip directory containing files from path.
- Resulting archive filename is ${zip_slug}.zip
- Returns it's path relative to MEDIA_ROOT (no initial slash)
- """
- # directory to store zip files
- zip_path = path.join(settings.MEDIA_ROOT, 'zip')
-
- try:
- mkdir(zip_path)
- except OSError as oe:
- if oe.errno != EEXIST:
- raise oe
- zip_filename = zip_slug + ".zip"
-
- with LockFile(zip_path, zip_slug):
- if not path.exists(path.join(zip_path, zip_filename)):
- zipf = ZipFile(path.join(zip_path, zip_filename), 'w')
- try:
- for p in paths:
- zipf.write(p, path.basename(p))
- finally:
- zipf.close()
-
- return 'zip/' + zip_filename
-
-
-def remove_zip(zip_slug):
- """
- removes the ${zip_slug}.zip file from zip store.
- """
- zip_file = path.join(settings.MEDIA_ROOT, 'zip', zip_slug + '.zip')
- try:
- unlink(zip_file)
- except OSError as oe:
- if oe.errno != ENOENT:
- raise oe
-
-
-@task
-def create_zip_task(*args):
- return create_zip(*args)