X-Git-Url: https://git.mdrn.pl/wolnelektury.git/blobdiff_plain/0cae17bec6d31806615fae59a5b3945016285fbe..7d92d059f03572fe9119db1e6fe8363cbe0d2d90:/apps/catalogue/utils.py diff --git a/apps/catalogue/utils.py b/apps/catalogue/utils.py index d1cee5045..29f40d16b 100644 --- a/apps/catalogue/utils.py +++ b/apps/catalogue/utils.py @@ -1,4 +1,40 @@ # -*- 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 re +import time +from base64 import urlsafe_b64encode + +from django.http import HttpResponse +from django.core.files.uploadedfile import UploadedFile +from django.core.files.storage import DefaultStorage +from django.utils.encoding import force_unicode +from django.utils.hashcompat import sha_constructor +from django.conf import settings +from os import mkdir, path, unlink +from errno import EEXIST, ENOENT +from fcntl import flock, LOCK_EX +from zipfile import ZipFile + +from reporting.utils import read_chunks + +# 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): @@ -7,3 +43,217 @@ def split_tags(tags): result.setdefault(tag.category, []).append(tag) return result + +class ExistingFile(UploadedFile): + + def __init__(self, path, *args, **kwargs): + self.path = path + super(ExistingFile, self).__init__(*args, **kwargs) + + def temporary_file_path(self): + return self.path + + def close(self): + pass + + +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 != EEXIST: + raise oe + self.lock.close() + + +#@task +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 arcname, p in paths: + if arcname is None: + arcname = path.basename(p) + zipf.write(p, arcname) + 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 + + +class AttachmentHttpResponse(HttpResponse): + """Response serving a file to be downloaded. + """ + def __init__ (self, file_path, file_name, mimetype): + super(AttachmentHttpResponse, self).__init__(mimetype=mimetype) + self['Content-Disposition'] = 'attachment; filename=%s' % file_name + self.file_path = file_path + self.file_name = file_name + + with open(DefaultStorage().path(self.file_path)) as f: + for chunk in read_chunks(f): + self.write(chunk) + +class MultiQuerySet(object): + def __init__(self, *args, **kwargs): + self.querysets = args + self._count = None + + def count(self): + if not self._count: + self._count = sum(len(qs) for qs in self.querysets) + return self._count + + def __len__(self): + return self.count() + + def __getitem__(self, item): + try: + indices = (offset, stop, step) = item.indices(self.count()) + except AttributeError: + # it's not a slice - make it one + return self[item : item + 1][0] + items = [] + total_len = stop - offset + for qs in self.querysets: + if len(qs) < offset: + offset -= len(qs) + else: + items += list(qs[offset:stop]) + if len(items) >= total_len: + return items + else: + offset = 0 + stop = total_len - len(items) + continue + + +def truncate_html_words(s, num, end_text='...'): + """Truncates HTML to a certain number of words (not counting tags and + comments). Closes opened tags if they were correctly closed in the given + html. Takes an optional argument of what should be used to notify that the + string has been truncated, defaulting to ellipsis (...). + + Newlines in the HTML are preserved. + + This is just a version of django.utils.text.truncate_html_words with no space before the end_text. + """ + s = force_unicode(s) + length = int(num) + if length <= 0: + return u'' + html4_singlets = ('br', 'col', 'link', 'base', 'img', 'param', 'area', 'hr', 'input') + # Set up regular expressions + re_words = re.compile(r'&.*?;|<.*?>|(\w[\w-]*)', re.U) + re_tag = re.compile(r'<(/)?([^ ]+?)(?: (/)| .*?)?>') + # Count non-HTML words and keep note of open tags + pos = 0 + end_text_pos = 0 + words = 0 + open_tags = [] + while words <= length: + m = re_words.search(s, pos) + if not m: + # Checked through whole string + break + pos = m.end(0) + if m.group(1): + # It's an actual non-HTML word + words += 1 + if words == length: + end_text_pos = pos + continue + # Check for tag + tag = re_tag.match(m.group(0)) + if not tag or end_text_pos: + # Don't worry about non tags or tags after our truncate point + continue + closing_tag, tagname, self_closing = tag.groups() + tagname = tagname.lower() # Element names are always case-insensitive + if self_closing or tagname in html4_singlets: + pass + elif closing_tag: + # Check for match in open tags list + try: + i = open_tags.index(tagname) + except ValueError: + pass + else: + # SGML: An end tag closes, back to the matching start tag, all unclosed intervening start tags with omitted end tags + open_tags = open_tags[i+1:] + else: + # Add it to the start of the open tags list + open_tags.insert(0, tagname) + if words <= length: + # Don't try to close tags if we don't need to truncate + return s + out = s[:end_text_pos] + if end_text: + out += end_text + # Close any tags still open + for tag in open_tags: + out += '' % tag + # Return string + return out + + +def customizations_hash(customizations): + customizations.sort() + return hash(tuple(customizations)) + + +def get_customized_pdf_path(book, customizations): + """ + Returns a MEDIA_ROOT relative path for a customized pdf. The name will contain a hash of customization options. + """ + h = customizations_hash(customizations) + return 'book/%s/%s-custom-%s.pdf' % (book.slug, book.slug, h) + + +def clear_custom_pdf(book): + """ + Returns a list of paths to generated customized pdf of a book + """ + from waiter.utils import clear_cache + clear_cache('book/%s' % book.slug)