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import hashlib
import json
import os
import posixpath
import re
from collections import OrderedDict
from urllib.parse import unquote, urldefrag, urlsplit, urlunsplit
from django.conf import settings
from django.contrib.staticfiles.utils import check_settings, matches_patterns
from django.core.cache import (
InvalidCacheBackendError, cache as default_cache, caches,
)
from django.core.exceptions import ImproperlyConfigured
from django.core.files.base import ContentFile
from django.core.files.storage import FileSystemStorage, get_storage_class
from django.utils.encoding import force_bytes
from django.utils.functional import LazyObject
class StaticFilesStorage(FileSystemStorage):
"""
Standard file system storage for static files.
The defaults for ``location`` and ``base_url`` are
``STATIC_ROOT`` and ``STATIC_URL``.
"""
def __init__(self, location=None, base_url=None, *args, **kwargs):
if location is None:
location = settings.STATIC_ROOT
if base_url is None:
base_url = settings.STATIC_URL
check_settings(base_url)
super().__init__(location, base_url, *args, **kwargs)
# FileSystemStorage fallbacks to MEDIA_ROOT when location
# is empty, so we restore the empty value.
if not location:
self.base_location = None
self.location = None
def path(self, name):
if not self.location:
raise ImproperlyConfigured("You're using the staticfiles app "
"without having set the STATIC_ROOT "
"setting to a filesystem path.")
return super().path(name)
class HashedFilesMixin:
default_template = """url("%s")"""
max_post_process_passes = 5
patterns = (
("*.css", (
r"""(url\(['"]{0,1}\s*(.*?)["']{0,1}\))""",
(r"""(@import\s*["']\s*(.*?)["'])""", """@import url("%s")"""),
)),
)
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._patterns = OrderedDict()
self.hashed_files = {}
for extension, patterns in self.patterns:
for pattern in patterns:
if isinstance(pattern, (tuple, list)):
pattern, template = pattern
else:
template = self.default_template
compiled = re.compile(pattern, re.IGNORECASE)
self._patterns.setdefault(extension, []).append((compiled, template))
def file_hash(self, name, content=None):
"""
Return a hash of the file with the given name and optional content.
"""
if content is None:
return None
md5 = hashlib.md5()
for chunk in content.chunks():
md5.update(chunk)
return md5.hexdigest()[:12]
def hashed_name(self, name, content=None, filename=None):
# `filename` is the name of file to hash if `content` isn't given.
# `name` is the base name to construct the new hashed filename from.
parsed_name = urlsplit(unquote(name))
clean_name = parsed_name.path.strip()
if filename:
filename = urlsplit(unquote(filename)).path.strip()
filename = filename or clean_name
opened = False
if content is None:
if not self.exists(filename):
raise ValueError("The file '%s' could not be found with %r." % (filename, self))
try:
content = self.open(filename)
except IOError:
# Handle directory paths and fragments
return name
opened = True
try:
file_hash = self.file_hash(clean_name, content)
finally:
if opened:
content.close()
path, filename = os.path.split(clean_name)
root, ext = os.path.splitext(filename)
if file_hash is not None:
file_hash = ".%s" % file_hash
hashed_name = os.path.join(path, "%s%s%s" %
(root, file_hash, ext))
unparsed_name = list(parsed_name)
unparsed_name[2] = hashed_name
# Special casing for a @font-face hack, like url(myfont.eot?#iefix")
# http://www.fontspring.com/blog/the-new-bulletproof-font-face-syntax
if '?#' in name and not unparsed_name[3]:
unparsed_name[2] += '?'
return urlunsplit(unparsed_name)
def _url(self, hashed_name_func, name, force=False, hashed_files=None):
"""
Return the non-hashed URL in DEBUG mode.
"""
if settings.DEBUG and not force:
hashed_name, fragment = name, ''
else:
clean_name, fragment = urldefrag(name)
if urlsplit(clean_name).path.endswith('/'): # don't hash paths
hashed_name = name
else:
args = (clean_name,)
if hashed_files is not None:
args += (hashed_files,)
hashed_name = hashed_name_func(*args)
final_url = super().url(hashed_name)
# Special casing for a @font-face hack, like url(myfont.eot?#iefix")
# http://www.fontspring.com/blog/the-new-bulletproof-font-face-syntax
query_fragment = '?#' in name # [sic!]
if fragment or query_fragment:
urlparts = list(urlsplit(final_url))
if fragment and not urlparts[4]:
urlparts[4] = fragment
if query_fragment and not urlparts[3]:
urlparts[2] += '?'
final_url = urlunsplit(urlparts)
return unquote(final_url)
def url(self, name, force=False):
"""
Return the non-hashed URL in DEBUG mode.
"""
return self._url(self.stored_name, name, force)
def url_converter(self, name, hashed_files, template=None):
"""
Return the custom URL converter for the given file name.
"""
if template is None:
template = self.default_template
def converter(matchobj):
"""
Convert the matched URL to a normalized and hashed URL.
This requires figuring out which files the matched URL resolves
to and calling the url() method of the storage.
"""
matched, url = matchobj.groups()
# Ignore absolute/protocol-relative and data-uri URLs.
if re.match(r'^[a-z]+:', url):
return matched
# Ignore absolute URLs that don't point to a static file (dynamic
# CSS / JS?). Note that STATIC_URL cannot be empty.
if url.startswith('/') and not url.startswith(settings.STATIC_URL):
return matched
# Strip off the fragment so a path-like fragment won't interfere.
url_path, fragment = urldefrag(url)
if url_path.startswith('/'):
# Otherwise the condition above would have returned prematurely.
assert url_path.startswith(settings.STATIC_URL)
target_name = url_path[len(settings.STATIC_URL):]
else:
# We're using the posixpath module to mix paths and URLs conveniently.
source_name = name if os.sep == '/' else name.replace(os.sep, '/')
target_name = posixpath.join(posixpath.dirname(source_name), url_path)
# Determine the hashed name of the target file with the storage backend.
hashed_url = self._url(
self._stored_name, unquote(target_name),
force=True, hashed_files=hashed_files,
)
transformed_url = '/'.join(url_path.split('/')[:-1] + hashed_url.split('/')[-1:])
# Restore the fragment that was stripped off earlier.
if fragment:
transformed_url += ('?#' if '?#' in url else '#') + fragment
# Return the hashed version to the file
return template % unquote(transformed_url)
return converter
def post_process(self, paths, dry_run=False, **options):
"""
Post process the given OrderedDict of files (called from collectstatic).
Processing is actually two separate operations:
1. renaming files to include a hash of their content for cache-busting,
and copying those files to the target storage.
2. adjusting files which contain references to other files so they
refer to the cache-busting filenames.
If either of these are performed on a file, then that file is considered
post-processed.
"""
# don't even dare to process the files if we're in dry run mode
if dry_run:
return
# where to store the new paths
hashed_files = OrderedDict()
# build a list of adjustable files
adjustable_paths = [
path for path in paths
if matches_patterns(path, self._patterns)
]
# Do a single pass first. Post-process all files once, then repeat for
# adjustable files.
for name, hashed_name, processed, _ in self._post_process(paths, adjustable_paths, hashed_files):
yield name, hashed_name, processed
paths = {path: paths[path] for path in adjustable_paths}
for i in range(self.max_post_process_passes):
substitutions = False
for name, hashed_name, processed, subst in self._post_process(paths, adjustable_paths, hashed_files):
yield name, hashed_name, processed
substitutions = substitutions or subst
if not substitutions:
break
if substitutions:
yield 'All', None, RuntimeError('Max post-process passes exceeded.')
# Store the processed paths
self.hashed_files.update(hashed_files)
def _post_process(self, paths, adjustable_paths, hashed_files):
# Sort the files by directory level
def path_level(name):
return len(name.split(os.sep))
for name in sorted(paths, key=path_level, reverse=True):
substitutions = True
# use the original, local file, not the copied-but-unprocessed
# file, which might be somewhere far away, like S3
storage, path = paths[name]
with storage.open(path) as original_file:
cleaned_name = self.clean_name(name)
hash_key = self.hash_key(cleaned_name)
# generate the hash with the original content, even for
# adjustable files.
if hash_key not in hashed_files:
hashed_name = self.hashed_name(name, original_file)
else:
hashed_name = hashed_files[hash_key]
# then get the original's file content..
if hasattr(original_file, 'seek'):
original_file.seek(0)
hashed_file_exists = self.exists(hashed_name)
processed = False
# ..to apply each replacement pattern to the content
if name in adjustable_paths:
old_hashed_name = hashed_name
content = original_file.read().decode(settings.FILE_CHARSET)
for extension, patterns in self._patterns.items():
if matches_patterns(path, (extension,)):
for pattern, template in patterns:
converter = self.url_converter(name, hashed_files, template)
try:
content = pattern.sub(converter, content)
except ValueError as exc:
yield name, None, exc, False
if hashed_file_exists:
self.delete(hashed_name)
# then save the processed result
content_file = ContentFile(force_bytes(content))
# Save intermediate file for reference
saved_name = self._save(hashed_name, content_file)
hashed_name = self.hashed_name(name, content_file)
if self.exists(hashed_name):
self.delete(hashed_name)
saved_name = self._save(hashed_name, content_file)
hashed_name = self.clean_name(saved_name)
# If the file hash stayed the same, this file didn't change
if old_hashed_name == hashed_name:
substitutions = False
processed = True
if not processed:
# or handle the case in which neither processing nor
# a change to the original file happened
if not hashed_file_exists:
processed = True
saved_name = self._save(hashed_name, original_file)
hashed_name = self.clean_name(saved_name)
# and then set the cache accordingly
hashed_files[hash_key] = hashed_name
yield name, hashed_name, processed, substitutions
def clean_name(self, name):
return name.replace('\\', '/')
def hash_key(self, name):
return name
def _stored_name(self, name, hashed_files):
# Normalize the path to avoid multiple names for the same file like
# ../foo/bar.css and ../foo/../foo/bar.css which normalize to the same
# path.
name = posixpath.normpath(name)
cleaned_name = self.clean_name(name)
hash_key = self.hash_key(cleaned_name)
cache_name = hashed_files.get(hash_key)
if cache_name is None:
cache_name = self.clean_name(self.hashed_name(name))
return cache_name
def stored_name(self, name):
cleaned_name = self.clean_name(name)
hash_key = self.hash_key(cleaned_name)
cache_name = self.hashed_files.get(hash_key)
if cache_name:
return cache_name
# No cached name found, recalculate it from the files.
intermediate_name = name
for i in range(self.max_post_process_passes + 1):
cache_name = self.clean_name(
self.hashed_name(name, content=None, filename=intermediate_name)
)
if intermediate_name == cache_name:
# Store the hashed name if there was a miss.
self.hashed_files[hash_key] = cache_name
return cache_name
else:
# Move on to the next intermediate file.
intermediate_name = cache_name
# If the cache name can't be determined after the max number of passes,
# the intermediate files on disk may be corrupt; avoid an infinite loop.
raise ValueError("The name '%s' could not be hashed with %r." % (name, self))
class ManifestFilesMixin(HashedFilesMixin):
manifest_version = '1.0' # the manifest format standard
manifest_name = 'staticfiles.json'
manifest_strict = True
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.hashed_files = self.load_manifest()
def read_manifest(self):
try:
with self.open(self.manifest_name) as manifest:
return manifest.read().decode()
except IOError:
return None
def load_manifest(self):
content = self.read_manifest()
if content is None:
return OrderedDict()
try:
stored = json.loads(content, object_pairs_hook=OrderedDict)
except ValueError:
pass
else:
version = stored.get('version')
if version == '1.0':
return stored.get('paths', OrderedDict())
raise ValueError("Couldn't load manifest '%s' (version %s)" %
(self.manifest_name, self.manifest_version))
def post_process(self, *args, **kwargs):
self.hashed_files = OrderedDict()
yield from super().post_process(*args, **kwargs)
self.save_manifest()
def save_manifest(self):
payload = {'paths': self.hashed_files, 'version': self.manifest_version}
if self.exists(self.manifest_name):
self.delete(self.manifest_name)
contents = json.dumps(payload).encode()
self._save(self.manifest_name, ContentFile(contents))
def stored_name(self, name):
parsed_name = urlsplit(unquote(name))
clean_name = parsed_name.path.strip()
hash_key = self.hash_key(clean_name)
cache_name = self.hashed_files.get(hash_key)
if cache_name is None:
if self.manifest_strict:
raise ValueError("Missing staticfiles manifest entry for '%s'" % clean_name)
cache_name = self.clean_name(self.hashed_name(name))
unparsed_name = list(parsed_name)
unparsed_name[2] = cache_name
# Special casing for a @font-face hack, like url(myfont.eot?#iefix")
# http://www.fontspring.com/blog/the-new-bulletproof-font-face-syntax
if '?#' in name and not unparsed_name[3]:
unparsed_name[2] += '?'
return urlunsplit(unparsed_name)
class _MappingCache:
"""
A small dict-like wrapper for a given cache backend instance.
"""
def __init__(self, cache):
self.cache = cache
def __setitem__(self, key, value):
self.cache.set(key, value)
def __getitem__(self, key):
value = self.cache.get(key)
if value is None:
raise KeyError("Couldn't find a file name '%s'" % key)
return value
def clear(self):
self.cache.clear()
def update(self, data):
self.cache.set_many(data)
def get(self, key, default=None):
try:
return self[key]
except KeyError:
return default
class CachedFilesMixin(HashedFilesMixin):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
try:
self.hashed_files = _MappingCache(caches['staticfiles'])
except InvalidCacheBackendError:
# Use the default backend
self.hashed_files = _MappingCache(default_cache)
def hash_key(self, name):
key = hashlib.md5(force_bytes(self.clean_name(name))).hexdigest()
return 'staticfiles:%s' % key
class CachedStaticFilesStorage(CachedFilesMixin, StaticFilesStorage):
"""
A static file system storage backend which also saves
hashed copies of the files it saves.
"""
pass
class ManifestStaticFilesStorage(ManifestFilesMixin, StaticFilesStorage):
"""
A static file system storage backend which also saves
hashed copies of the files it saves.
"""
pass
class ConfiguredStorage(LazyObject):
def _setup(self):
self._wrapped = get_storage_class(settings.STATICFILES_STORAGE)()
staticfiles_storage = ConfiguredStorage()