Add a function to get cookie expiration time

netlib/http/cookies.py

@@ -269,6 +269,32 @@ def refresh_set_cookie_header(c, delta):
     return ret
 
 
+def get_expiration_ts(cookie_attrs):
+    """
+        Determines the time when the cookie will be expired.
+
+        Considering both 'expires' and 'max-age' parameters.
+
+        Returns: timestamp of when the cookie will expire.
+                 None, if no expiration time is set.
+    """
+    if 'expires' in cookie_attrs:
+        e = email.utils.parsedate_tz(cookie_attrs["expires"])
+        if e:
+            return email.utils.mktime_tz(e)
+
+    elif 'max-age' in cookie_attrs:
+        try:
+            max_age = int(cookie_attrs['Max-Age'])
+        except ValueError:
+            pass
+        else:
+            now_ts = time.time()
+            return now_ts + max_age
+
+    return None
+
+
 def is_expired(cookie_attrs):
     """
         Determines whether a cookie has expired.

test/netlib/http/test_cookies.py

@@ -1,6 +1,10 @@
+import time
+
 from netlib.http import cookies
 from netlib.tutils import raises
 
+import mock
+
 
 def test_read_token():
     tokens = [
@@ -247,6 +251,22 @@ def test_refresh_cookie():
     assert cookies.refresh_set_cookie_header(c, 0)
 
 
+@mock.patch('time.time')
+def test_get_expiration_ts(*args):
+    # Freeze time
+    now_ts = 17
+    time.time.return_value = now_ts
+
+    CA = cookies.CookieAttrs
+    F = cookies.get_expiration_ts
+
+    assert F(CA([("Expires", "Thu, 01-Jan-1970 00:00:00 GMT")])) == 0
+    assert F(CA([("Expires", "Thu, 24-Aug-2063 00:00:00 GMT")])) == 2955139200
+
+    assert F(CA([("Max-Age", "0")])) == now_ts
+    assert F(CA([("Max-Age", "31")])) == now_ts + 31
+
+
 def test_is_expired():
     CA = cookies.CookieAttrs