1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
#
# Copyright 2015 Rackspace, Inc
# All Rights Reserved
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import logging
import os
import dogpile.cache
import platformdirs
LOG = logging.getLogger(__name__)
AUTHOR = 'openstack'
PROGNAME = 'python-ironicclient'
CACHE = None
CACHE_DIR = platformdirs.user_cache_dir(PROGNAME, AUTHOR)
CACHE_EXPIRY_ENV_VAR = 'IRONICCLIENT_CACHE_EXPIRY' # environment variable
CACHE_FILENAME = os.path.join(CACHE_DIR, 'ironic-api-version.dbm')
DEFAULT_EXPIRY = 300 # seconds
def _get_cache():
"""Configure file caching."""
global CACHE
if CACHE is None:
# Ensure cache directory present
if not os.path.exists(CACHE_DIR):
os.makedirs(CACHE_DIR)
# Use the cache expiry if specified in an env var
expiry_time = os.environ.get(CACHE_EXPIRY_ENV_VAR, DEFAULT_EXPIRY)
try:
expiry_time = int(expiry_time)
except ValueError:
LOG.warning("Environment variable %(env_var)s should be an "
"integer (not '%(curr_val)s'). Using default "
"expiry of %(default)s seconds instead.",
{'env_var': CACHE_EXPIRY_ENV_VAR,
'curr_val': expiry_time,
'default': DEFAULT_EXPIRY})
expiry_time = DEFAULT_EXPIRY
CACHE = dogpile.cache.make_region(key_mangler=str).configure(
'dogpile.cache.dbm',
expiration_time=expiry_time,
arguments={
"filename": CACHE_FILENAME,
}
)
return CACHE
def _build_key(host, port):
"""Build a key based upon the hostname or address supplied."""
return "%s:%s" % (host, port)
def save_data(host, port, data):
"""Save 'data' for a particular 'host' in the appropriate cache dir.
param host: The host that we need to save data for
param port: The port on the host that we need to save data for
param data: The data we want saved
"""
key = _build_key(host, port)
_get_cache().set(key, data)
def retrieve_data(host, port, expiry=None):
"""Retrieve the version stored for an ironic 'host', if it's not stale.
Check to see if there is valid cached data for the host/port
combination and return that if it isn't stale.
param host: The host that we need to retrieve data for
param port: The port on the host that we need to retrieve data for
param expiry: The age in seconds before cached data is deemed invalid
"""
# Ensure that a cache file exists first
if not os.path.isfile(CACHE_FILENAME):
return None
key = _build_key(host, port)
data = _get_cache().get(key, expiration_time=expiry)
if data == dogpile.cache.api.NO_VALUE:
return None
return data
|
