102 lines
3.1 KiB
Python
102 lines
3.1 KiB
Python
from django.core.files.storage import Storage, get_storage_class
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from django.utils.deconstruct import deconstructible
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from django.conf import settings
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from hashlib import sha1
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import os.path
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import shutil
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import tempfile
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import time
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import logging
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logger = logging.getLogger(__name__)
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@deconstructible
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class CachedStorage(Storage):
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def __init__(self, remote=None, cachedir=None, expires=600):
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if not remote:
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remote = getattr(settings, 'CACHED_STORAGE_REMOTE')
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if not cachedir:
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cachedir = getattr(settings, 'CACHED_STORAGE_DIR', 'cache')
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self.remote = get_storage_class(remote)()
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self.cachedir = cachedir
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self.expires = expires
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os.makedirs(self.cachedir, exist_ok=True)
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self.clean()
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def _filepath(self, name):
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base, ext = os.path.splitext(name)
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filename = sha1(base.encode('utf8')).hexdigest() + ext
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return os.path.join(self.cachedir, filename)
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def _cached(self, name):
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p = self._filepath(name)
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if not os.path.exists(p):
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logger.debug("Caching %s to %s", name, p)
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source = self.remote.open(name, 'rb')
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dest = tempfile.NamedTemporaryFile(dir=self.cachedir, delete=False, prefix="_")
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shutil.copyfileobj(source, dest)
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source.close()
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dest.close()
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os.rename(dest.name, p)
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now = time.time()
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os.utime(p, (now, now))
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if now > self.next_check:
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self.clean() # wont get this file as we just touched it
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return p
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def _open(self, name, mode='rb'):
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assert 'r' in mode, "Can only open for reading"
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p = self._cached(name)
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return open(p, mode)
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def path(self, name):
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return self._cached(name)
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def save(self, name, content, max_length=None):
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p = self._filepath(name)
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if os.path.exists(p):
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os.unlink(p)
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return self.remote.save(name, content, max_length)
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def delete(self, name):
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return self.remote.delete(name)
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def exists(self, name):
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return self.remote.exists(name)
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def listdir(self, name):
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return self.remote.listdir(name)
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def size(self, name):
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return self.remote.size(name)
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def url(self, name):
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return self.remote.url(name)
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def get_valid_name(self, name):
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return self.remote.get_valid_name(name)
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def get_available_name(self, name, max_length=None):
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return self.remote.get_available_name(name, max_length)
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def get_alternative_name(self, file_root, file_ext):
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return self.remote.get_alternative_name(file_root, file_ext)
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def clean(self):
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now = time.time()
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threshold = now - self.expires
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logger.info("Removing cached files older than %d seconds", self.expires)
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for f in os.listdir(self.cachedir):
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f = os.path.join(self.cachedir, f)
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s = os.stat(f)
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if s.st_atime < threshold:
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logger.debug("Removing %s", f)
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os.unlink(f)
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self.next_check = now + 300 # wait at least 5 minutes before running again
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