You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

334 lines
8.6 KiB

# This program is free software; you can redistribute it and/or modify
# it under the terms of the (LGPL) GNU Lesser General Public License as
# published by the Free Software Foundation; either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Library Lesser General Public License for more details at
# ( http://www.gnu.org/licenses/lgpl.html ).
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
# written by: Jeff Ortel ( jortel@redhat.com )
"""
Contains basic caching classes.
"""
import os
import suds
from tempfile import gettempdir as tmp
from suds import log
from suds.sax.parser import Parser
from suds.sax.element import Element
from datetime import datetime as dt
from datetime import timedelta
try:
import cPickle as pickle
except:
import pickle
class Cache:
"""
An object object cache.
"""
def get(self, id):
"""
Get a object from the cache by ID.
@param id: The object ID.
@type id: str
@return: The object, else None
@rtype: any
"""
raise Exception('not-implemented')
def getf(self, id):
"""
Get a object from the cache by ID.
@param id: The object ID.
@type id: str
@return: The object, else None
@rtype: any
"""
raise Exception('not-implemented')
def put(self, id, object):
"""
Put a object into the cache.
@param id: The object ID.
@type id: str
@param object: The object to add.
@type object: any
"""
raise Exception('not-implemented')
def putf(self, id, fp):
"""
Write a fp into the cache.
@param id: The object ID.
@type id: str
@param fp: File pointer.
@type fp: file-like object.
"""
raise Exception('not-implemented')
def purge(self, id):
"""
Purge a object from the cache by id.
@param id: A object ID.
@type id: str
"""
raise Exception('not-implemented')
def clear(self):
"""
Clear all objects from the cache.
"""
raise Exception('not-implemented')
class NoCache(Cache):
"""
The passthru object cache.
"""
def get(self, id):
return None
def getf(self, id):
return None
def put(self, id, object):
pass
def putf(self, id, fp):
pass
class FileCache(Cache):
"""
A file-based URL cache.
@cvar fnprefix: The file name prefix.
@type fnsuffix: str
@ivar duration: The cached file duration which defines how
long the file will be cached.
@type duration: (unit, value)
@ivar location: The directory for the cached files.
@type location: str
"""
fnprefix = 'suds'
units = ('months', 'weeks', 'days', 'hours', 'minutes', 'seconds')
def __init__(self, location=None, **duration):
"""
@param location: The directory for the cached files.
@type location: str
@param duration: The cached file duration which defines how
long the file will be cached. A duration=0 means forever.
The duration may be: (months|weeks|days|hours|minutes|seconds).
@type duration: {unit:value}
"""
if location is None:
location = os.path.join(tmp(), 'suds')
self.location = location
self.duration = (None, 0)
self.setduration(**duration)
self.checkversion()
def fnsuffix(self):
"""
Get the file name suffix
@return: The suffix
@rtype: str
"""
return 'gcf'
def setduration(self, **duration):
"""
Set the caching duration which defines how long the
file will be cached.
@param duration: The cached file duration which defines how
long the file will be cached. A duration=0 means forever.
The duration may be: (months|weeks|days|hours|minutes|seconds).
@type duration: {unit:value}
"""
if len(duration) == 1:
arg = [x[0] for x in duration.items()]
if not arg[0] in self.units:
raise Exception('must be: %s' % str(self.units))
self.duration = arg
return self
def setlocation(self, location):
"""
Set the location (directory) for the cached files.
@param location: The directory for the cached files.
@type location: str
"""
self.location = location
def mktmp(self):
"""
Make the I{location} directory if it doesn't already exits.
"""
try:
if not os.path.isdir(self.location):
os.makedirs(self.location)
except:
log.debug(self.location, exc_info=1)
return self
def put(self, id, bfr):
try:
fn = self.__fn(id)
f = self.open(fn, 'wb')
f.write(bfr)
f.close()
return bfr
except:
log.debug(id, exc_info=1)
return bfr
def putf(self, id, fp):
try:
fn = self.__fn(id)
f = self.open(fn, 'w')
f.write(fp.read())
fp.close()
f.close()
return open(fn)
except:
log.debug(id, exc_info=1)
return fp
def get(self, id):
try:
f = self.getf(id)
bfr = f.read()
f.close()
return bfr
except:
pass
def getf(self, id):
try:
fn = self.__fn(id)
self.validate(fn)
return self.open(fn)
except:
pass
def validate(self, fn):
"""
Validate that the file has not expired based on the I{duration}.
@param fn: The file name.
@type fn: str
"""
if self.duration[1] < 1:
return
created = dt.fromtimestamp(os.path.getctime(fn))
d = {self.duration[0]: self.duration[1]}
expired = created+timedelta(**d)
if expired < dt.now():
log.debug('%s expired, deleted', fn)
os.remove(fn)
def clear(self):
for fn in os.listdir(self.location):
if os.path.isdir(fn):
continue
if fn.startswith(self.fnprefix):
log.debug('deleted: %s', fn)
os.remove(os.path.join(self.location, fn))
def purge(self, id):
fn = self.__fn(id)
try:
os.remove(fn)
except:
pass
def open(self, fn, *args):
"""
Open the cache file making sure the directory is created.
"""
self.mktmp()
return open(fn, *args)
def checkversion(self):
path = os.path.join(self.location, 'version')
try:
f = self.open(path)
version = f.read()
f.close()
if version != suds.__version__:
raise Exception()
except:
self.clear()
f = self.open(path, 'w')
f.write(suds.__version__)
f.close()
def __fn(self, id):
name = id
suffix = self.fnsuffix()
fn = '%s-%s.%s' % (self.fnprefix, name, suffix)
return os.path.join(self.location, fn)
class DocumentCache(FileCache):
"""
Provides xml document caching.
"""
def fnsuffix(self):
return 'xml'
def get(self, id):
try:
fp = FileCache.getf(self, id)
if fp is None:
return None
p = Parser()
return p.parse(fp)
except:
FileCache.purge(self, id)
def put(self, id, object):
if isinstance(object, Element):
FileCache.put(self, id, str(object))
return object
class ObjectCache(FileCache):
"""
Provides pickled object caching.
@cvar protocol: The pickling protocol.
@type protocol: int
"""
protocol = 2
def fnsuffix(self):
return 'px'
def get(self, id):
try:
fp = FileCache.getf(self, id)
if fp is None:
return None
else:
return pickle.load(fp)
except:
FileCache.purge(self, id)
def put(self, id, object):
bfr = pickle.dumps(object, self.protocol)
FileCache.put(self, id, bfr)
return object