Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

284 lines (224 sloc) 9.474 kb
# -*- encoding: utf-8 -*-
#
# Copyright 2012 Martin Zimmermann <info@posativ.org>. All rights reserved.
# License: BSD Style, 2 clauses -- see LICENSE.
#
# This provide some basic functionality of Acrylamid: caching and re-validating.
import os
import io
import zlib
import types
import pickle
import shutil
import tempfile
from os.path import join, exists, getmtime, getsize, dirname, basename
from acrylamid import log, defaults
from acrylamid.errors import AcrylamidException
from acrylamid.compat import PY2K, iteritems, iterkeys
from acrylamid.utils import (
classproperty, cached_property, Struct, hash, HashableList, find, execfile,
lchop, force_unicode as u
)
if PY2K:
import cPickle as pickle
__all__ = ['Memory', 'cache', 'Environment', 'Configuration']
class Memory(dict):
"""A callable dictionary object described at
:func:`acrylamid.helpers.memoize`."""
def __call__(self, key, value=None):
if value is None:
return self.get(key)
rv = self.get(key)
self[key] = value
return rv != value
class cache(object):
"""A cache that stores all intermediates of an entry zlib-compressed on
file system. Inspired from ``werkzeug.contrib.cache``, but heavily modified
to fit our needs.
Terminology: A cache object is a pickled dictionary into a single file. An
intermediate (object) is a key/value pair that we store into a cache object.
An intermediate is the content of an entry that is the same for a chain of
filters used in different views.
:class:`cache` is designed as global singleton and should not be constructed.
.. attribute:: cache_dir
Location where all cache objects are being stored, defaults to `.cache/`.
The :class:`cache` does no longer maintain used/unused intermediates and cache
objects due performance reasons (and an edge case described in #67)."""
_fs_transaction_suffix = '.__ac_cache'
cache_dir = '.cache/'
mode = 0o600
memoize = Memory()
@classmethod
def init(self, cache_dir=None):
"""Initialize cache object by creating the cache_dir if non-existent,
read all available cache objects and restore memoized key/values.
:param cache_dir: the directory where cache files are stored.
:param mode: the file mode wanted for the cache files, default 0600
"""
if cache_dir:
self.cache_dir = cache_dir
if not exists(self.cache_dir):
try:
os.mkdir(self.cache_dir, 0o700)
except OSError:
raise AcrylamidException("could not create directory '%s'" % self.cache_dir)
# load memorized items
try:
with io.open(join(self.cache_dir, 'info'), 'rb') as fp:
self.memoize.update(pickle.load(fp))
except (IOError, pickle.PickleError):
self.emptyrun = True
else:
self.emptyrun = False
@classmethod
def shutdown(self):
"""Write memoized key-value pairs to disk."""
try:
with io.open(join(self.cache_dir, 'info'), 'wb') as fp:
pickle.dump(self.memoize, fp, pickle.HIGHEST_PROTOCOL)
except (IOError, pickle.PickleError) as e:
log.warn('%s: %s' % (e.__class__.__name__, e))
@classmethod
def remove(self, path):
"""Remove a cache object completely from disk and `objects`."""
try:
os.remove(join(self.cache_dir, path))
except OSError as e:
log.debug('OSError: %s' % e)
@classmethod
def clear(self, directory=None):
"""Wipe current cache objects and reset all stored informations.
:param directory: directory to clean (defaults to `.cache/`"""
if directory is not None:
self.cache_dir = directory
self.memoize = Memory()
shutil.rmtree(self.cache_dir, ignore_errors=True)
@classmethod
def get(self, path, key, default=None):
"""Restore value from obj[key] if mtime has not changed or return
default.
:param path: path of this cache object
:param key: key of this value
:param default: default return value
"""
try:
with io.open(join(self.cache_dir, path), 'rb') as fp:
return zlib.decompress(pickle.load(fp)[key]).decode('utf-8')
except KeyError:
pass
except (IOError, pickle.PickleError, zlib.error):
self.remove(join(self.cache_dir, path))
return default
@classmethod
def set(self, path, key, value):
"""Save a key, value pair into a blob using pickle and moderate zlib
compression (level 6). We simply save a dictionary containing all
different intermediates (from every view) of an entry.
:param path: path of this cache object
:param key: dictionary key where we store the value
:param value: a string we compress with zlib and afterwards save
"""
path = join(self.cache_dir, path)
if exists(path):
try:
with io.open(path, 'rb') as fp:
rv = pickle.load(fp)
except (pickle.PickleError, IOError):
self.remove(path)
rv = {}
try:
with io.open(path, 'wb') as fp:
rv[key] = zlib.compress(value.encode('utf-8'), 6)
pickle.dump(rv, fp, pickle.HIGHEST_PROTOCOL)
except (IOError, pickle.PickleError) as e:
log.warn('%s: %s' % (e.__class__.__name__, e))
else:
try:
fd, tmp = tempfile.mkstemp(suffix=self._fs_transaction_suffix,
dir=self.cache_dir)
with io.open(fd, 'wb') as fp:
pickle.dump({key: zlib.compress(value.encode('utf-8'), 6)}, fp,
pickle.HIGHEST_PROTOCOL)
os.rename(tmp, path)
os.chmod(path, self.mode)
except (IOError, OSError, pickle.PickleError, zlib.error) as e:
log.warn('%s: %s' % (e.__class__.__name__, e))
return value
@classmethod
def getmtime(self, path, default=0.0):
"""Get last modification timestamp from cache object but store it over
the whole compilation process so we have the same value for different
views.
:param path: valid cache object
:param default: default value if an :class:`OSError` occurs
"""
try:
return getmtime(join(self.cache_dir, path))
except OSError:
return default
@classproperty
@classmethod
def size(self):
"""return size of all cacheobjects in bytes"""
try:
res = getsize(join(self.cache_dir, 'info'))
except OSError:
res = 0
for (path, dirs, files) in os.walk(self.cache_dir):
for file in files:
filename = os.path.join(path, file)
res += getsize(filename)
return res
def load(path):
"""Load default configuration, prepare namespace and update configuration
with `conf.py`'s uppercase values and normalizes ambiguous values.
"""
conf = Configuration(defaults.conf)
ns = dict([(k.upper(), v) for k, v in iteritems(defaults.conf)])
os.chdir(dirname(find(basename(path), u(dirname(path) or os.getcwd()))))
if PY2K:
execfile(path, ns)
else:
exec(compile(open(path).read(), path, 'exec'), ns)
conf.update(dict([(k.lower(), ns[k]) for k in ns if k.upper() == k]))
# append trailing slash to *_dir and place certain values into an array
return defaults.normalize(conf)
class Environment(Struct):
"""Use *only* for the environment container. This class hides un-hashable
keys from :class:`Struct` hash function.
.. attribute:: modified
Return whether the Environment has changed between two runs. This
attribute must only be accessed after all modifications to the environment!
"""
blacklist = set(['engine', 'translationsfor', 'options', 'archives', 'webassets'])
@classmethod
def new(self, env):
return Environment({'author': env.author, 'url': env.url,
'options': env.options, 'globals': Struct()})
def keys(self):
return sorted(list(set(super(Environment, self).keys()) - self.blacklist))
def values(self):
for key in self.keys():
yield self[key]
@cached_property
def modified(self):
return hash(self) != cache.memoize(self.__class__.__name__)
class Configuration(Environment):
"""Similar to :class:`Environment` but allows hashing of a literarily
defined dictionary (that's the conf.py)."""
blacklist = set(['if', 'hooks'])
def fetch(self, ns):
return Configuration((lchop(k, ns), v)
for k, v in iteritems(self) if k.startswith(ns))
def values(self):
for key in self.keys():
if isinstance(self[key], types.FunctionType):
continue
if isinstance(self[key], list):
yield HashableList(self[key])
elif isinstance(self[key], dict):
yield Configuration(self[key])
elif isinstance(self[key], type(None)):
yield -1
else:
yield self[key]
Jump to Line
Something went wrong with that request. Please try again.