Merge pull request #9573 from bcoca/jsonfile_cache

a cache plugin that stores facts persistently in local json dumps
pull/9619/head
Brian Coca 10 years ago
commit 5e33db3b7e

@ -0,0 +1,137 @@
# (c) 2014, Brian Coca, Josh Drake, et al
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible. If not, see <http://www.gnu.org/licenses/>.
import os
import time
import json
import errno
from ansible import constants as C
from ansible import utils
from ansible.cache.base import BaseCacheModule
class CacheModule(BaseCacheModule):
"""
A caching module backed by json files.
"""
def __init__(self, *args, **kwargs):
self._timeout = float(C.CACHE_PLUGIN_TIMEOUT)
self._cache = {}
self._cache_dir = C.CACHE_PLUGIN_CONNECTION # expects a dir path
if not os.path.exists(self._cache_dir):
try:
os.makedirs(self._cache_dir)
except (OSError,IOError), e:
utils.warning("error while trying to create cache dir %s : %s" % (self._cache_dir, str(e)))
return None
def get(self, key):
if key in self._cache:
return self._cache.get(key)
if self.has_expired(key):
raise KeyError
cachefile = "%s/%s" % (self._cache_dir, key)
try:
f = open( cachefile, 'r')
except (OSError,IOError), e:
utils.warning("error while trying to write to %s : %s" % (cachefile, str(e)))
else:
value = json.load(f)
self._cache[key] = value
return value
finally:
f.close()
def set(self, key, value):
self._cache[key] = value
cachefile = "%s/%s" % (self._cache_dir, key)
try:
#TODO: check if valid keys can have invalid FS chars, base32?
f = open(cachefile, 'w')
except (OSError,IOError), e:
utils.warning("error while trying to read %s : %s" % (cachefile, str(e)))
else:
json.dump(value, f, ensure_ascii=False)
finally:
f.close()
def has_expired(self, key):
cachefile = "%s/%s" % (self._cache_dir, key)
try:
st = os.stat(cachefile)
except (OSError,IOError), e:
if e.errno == errno.ENOENT:
return False
else:
utils.warning("error while trying to stat %s : %s" % (cachefile, str(e)))
if time.time() - st.st_mtime <= self._timeout:
return False
if key in self._cache:
del self._cache[key]
return True
def keys(self):
keys = []
for k in os.listdir(self._cache_dir):
if not self.has_expired(k):
keys.append(k)
return keys
def contains(self, key):
if key in self._cache:
return True
if self.has_expired(key):
return False
try:
st = os.stat("%s/%s" % (self._cache_dir, key))
return True
except (OSError,IOError), e:
if e.errno == errno.ENOENT:
return False
else:
utils.warning("error while trying to stat %s : %s" % (cachefile, str(e)))
def delete(self, key):
del self._cache[key]
try:
os.remove("%s/%s" % (self._cache_dir, key))
except (OSError,IOError), e:
pass #TODO: only pass on non existing?
def flush(self):
self._cache = {}
for key in self.keys():
self.delete(key)
def copy(self):
ret = dict()
for key in self.keys():
ret[key] = self.get(key)
return ret
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