SP/web2py/gluon/contrib/appconfig.py
Saturneic 064f602b1a Add.
2018-10-25 23:33:13 +08:00

143 lines
4.5 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Read from configuration files easily without hurting performances
USAGE:
During development you can load a config file either in .ini or .json
format (by default app/private/appconfig.ini or app/private/appconfig.json)
The result is a dict holding the configured values. Passing reload=True
is meant only for development: in production, leave reload to False and all
values will be cached
from gluon.contrib.appconfig import AppConfig
myconfig = AppConfig(path_to_configfile, reload=False)
print myconfig['db']['uri']
The returned dict can walk with "dot notation" an arbitrarely nested dict
print myconfig.take('db.uri')
You can even pass a cast function, i.e.
print myconfig.take('auth.expiration', cast=int)
Once the value has been fetched (and casted) it won't change until the process
is restarted (or reload=True is passed).
"""
import os
import json
from gluon._compat import thread, configparser
from gluon.globals import current
locker = thread.allocate_lock()
def AppConfig(*args, **vars):
locker.acquire()
reload_ = vars.pop('reload', False)
try:
instance_name = 'AppConfig_' + current.request.application
if reload_ or not hasattr(AppConfig, instance_name):
setattr(AppConfig, instance_name, AppConfigLoader(*args, **vars))
return getattr(AppConfig, instance_name).settings
finally:
locker.release()
class AppConfigDict(dict):
"""
dict that has a .take() method to fetch nested values and puts
them into cache
"""
def __init__(self, *args, **kwargs):
dict.__init__(self, *args, **kwargs)
self.int_cache = {}
def get(self, path, default=None):
try:
value = self.take(path).strip()
if value.lower() in ('none','null',''):
return None
elif value.lower() == 'true':
return True
elif value.lower() == 'false':
return False
elif value.isdigit() or (value[0]=='-' and value[1:].isdigit()):
return int(value)
elif ',' in value:
return map(lambda x:x.strip(),value.split(','))
else:
try:
return float(value)
except:
return value
except:
return default
def take(self, path, cast=None):
parts = path.split('.')
if path in self.int_cache:
return self.int_cache[path]
value = self
walking = []
for part in parts:
if part not in value:
raise BaseException("%s not in config [%s]" %
(part, '-->'.join(walking)))
value = value[part]
walking.append(part)
if cast is None:
self.int_cache[path] = value
else:
try:
value = cast(value)
self.int_cache[path] = value
except (ValueError, TypeError):
raise BaseException("%s can't be converted to %s" %
(value, cast))
return value
class AppConfigLoader(object):
def __init__(self, configfile=None):
if not configfile:
priv_folder = os.path.join(current.request.folder, 'private')
configfile = os.path.join(priv_folder, 'appconfig.ini')
if not os.path.isfile(configfile):
configfile = os.path.join(priv_folder, 'appconfig.json')
if not os.path.isfile(configfile):
configfile = None
if not configfile or not os.path.isfile(configfile):
raise BaseException("Config file not found")
self.file = configfile
self.ctype = os.path.splitext(configfile)[1][1:]
self.settings = None
self.read_config()
def read_config_ini(self):
config = configparser.SafeConfigParser()
config.read(self.file)
settings = {}
for section in config.sections():
settings[section] = {}
for option in config.options(section):
settings[section][option] = config.get(section, option)
self.settings = AppConfigDict(settings)
def read_config_json(self):
with open(self.file, 'r') as c:
self.settings = AppConfigDict(json.load(c))
def read_config(self):
if self.settings is None:
try:
getattr(self, 'read_config_' + self.ctype)()
except AttributeError:
raise BaseException("Unsupported config file format")
return self.settings