116 lines
3.3 KiB
Python
116 lines
3.3 KiB
Python
"""Defines Falcon utility functions
|
|
|
|
Copyright 2013 by Rackspace Hosting, Inc.
|
|
|
|
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 datetime
|
|
import six
|
|
|
|
if six.PY3: # pragma nocover
|
|
from urllib.parse import quote as url_quote
|
|
else: # pragma nocover
|
|
from urllib import quote as url_quote
|
|
|
|
|
|
__all__ = ('dt_to_http', 'http_date_to_dt', 'to_query_str', 'percent_escape')
|
|
|
|
|
|
def dt_to_http(dt):
|
|
"""Converts a datetime instance to an HTTP date string.
|
|
|
|
Args:
|
|
dt: A datetime object, assumed to be UTC
|
|
|
|
Returns:
|
|
An HTTP date string, e.g., "Tue, 15 Nov 1994 12:45:26 GMT". See
|
|
also: http://goo.gl/R7So4
|
|
"""
|
|
|
|
# Tue, 15 Nov 1994 12:45:26 GMT
|
|
return dt.strftime('%a, %d %b %Y %H:%M:%S GMT')
|
|
|
|
|
|
def http_date_to_dt(http_date):
|
|
"""Converts an HTTP date string to a datetime instance.
|
|
|
|
Args:
|
|
http_date: An HTTP date string, e.g., "Tue, 15 Nov 1994 12:45:26 GMT".
|
|
|
|
Returns:
|
|
A UTC datetime instance corresponding to the given HTTP date.
|
|
"""
|
|
|
|
return datetime.datetime.strptime(
|
|
http_date, '%a, %d %b %Y %H:%M:%S %Z')
|
|
|
|
|
|
def to_query_str(params):
|
|
"""Converts a dict of params to afaln actual query string.
|
|
|
|
Args:
|
|
params: dict of simple key-value types, where key is a string and
|
|
value is a string or something that can be converted into a
|
|
string. If value is a list, it will be converted to a comma-
|
|
delimited string (e.g., thing=1,2,3)
|
|
|
|
Returns:
|
|
A URI query string starting with '?', or and empty string if there
|
|
are no params (the dict is empty).
|
|
"""
|
|
|
|
if not params:
|
|
return ''
|
|
|
|
# PERF: This is faster than a list comprehension and join, mainly
|
|
# because it allows us to inline the value transform.
|
|
query_str = '?'
|
|
for k, v in params.items():
|
|
if v is True:
|
|
v = 'true'
|
|
elif v is False:
|
|
v = 'false'
|
|
elif isinstance(v, list):
|
|
# PERF(kgriffs): map is faster than list comprehension in
|
|
# py26 and py33. No significant different in py27
|
|
v = ','.join(map(str, v))
|
|
else:
|
|
v = str(v)
|
|
|
|
query_str += k + '=' + v + '&'
|
|
|
|
return query_str[:-1]
|
|
|
|
|
|
def percent_escape(url):
|
|
"""Percent-escape reserved characters in the given url.
|
|
|
|
Args:
|
|
url: A full or relative URL.
|
|
|
|
Returns:
|
|
An escaped version of the URL, excluding '/', ',' and ':'
|
|
characters. In Python 2, unicode URL strings will be first
|
|
encoded to a UTF-8 byte string to work around a urllib
|
|
bug.
|
|
"""
|
|
|
|
# Convert the string so that urllib.quote does not complain
|
|
# if it actually has Unicode chars in it.
|
|
if not six.PY3 and isinstance(url, six.text_type): # pragma nocover
|
|
url = url.encode('utf-8')
|
|
|
|
return url_quote(url, safe='/:,=?&-_')
|