Move basic HTTP setup into a new module

We now subclass requests' Session to make further extensions of the HTTP
flow possible.

dosagelib/http.py

@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2019 Tobias Gruetzmacher
+
+from __future__ import absolute_import, division, print_function
+
+import requests
+from requests.adapters import HTTPAdapter
+from requests.packages.urllib3.util.retry import Retry
+
+from .configuration import UserAgent
+
+# Default number of retries
+MaxRetries = 3
+
+# Factor for retry backoff (see urllib3.util.retry, this default means
+# 2s, 4s, 8s)
+RetryBackoffFactor = 2
+
+# Default connection timeout
+ConnectionTimeoutSecs = 60
+
+
+class Session(requests.Session):
+    def __init__(self):
+        super(Session, self).__init__()
+
+        retry = Retry(MaxRetries, backoff_factor=RetryBackoffFactor)
+        self.mount('http://', HTTPAdapter(max_retries=retry))
+        self.mount('https://', HTTPAdapter(max_retries=retry))
+        self.headers.update({'User-Agent': UserAgent})
+
+    def send(self, request, **kwargs):
+        if 'timeout' not in kwargs:
+            kwargs['timeout'] = ConnectionTimeoutSecs
+        return super(Session, self).send(request, **kwargs)
+
+
+# A default session for cookie and connection sharing
+default_session = Session()

dosagelib/scraper.py

@@ -24,9 +24,9 @@ try:
 except ImportError:
     pycountry = None
 
-from . import loader, configuration, languages
+from . import configuration, http, languages, loader
 from .util import (get_page, makeSequence, get_system_uid, unescape, tagre,
-    normaliseURL, prettyMatcherList, requests_session, uniq)
+    normaliseURL, prettyMatcherList, uniq)
 from .comic import ComicStrip
 from .output import out
 from .events import getHandler
@@ -85,7 +85,7 @@ class Scraper(object):
     allow_errors = ()
 
     # HTTP session for configuration & cookies
-    session = requests_session()
+    session = http.default_session
 
     @classmethod
     def getmodules(cls):

dosagelib/updater.py

@@ -1,16 +1,18 @@
 # -*- coding: utf-8 -*-
 # Copyright (C) 2004-2008 Tristan Seligmann and Jonathan Jacobs
 # Copyright (C) 2012-2014 Bastian Kleineidam
-# Copyright (C) 2015-2017 Tobias Gruetzmacher
+# Copyright (C) 2015-2019 Tobias Gruetzmacher
 
 from __future__ import absolute_import, division, print_function
 
 import os
+
+from distutils.version import StrictVersion
+
 import dosagelib
 from dosagelib import configuration
-from .util import urlopen
+from . import http
-from distutils.version import StrictVersion
+
-import requests
 
 UPDATE_URL = "https://api.github.com/repos/webcomics/dosage/releases/latest"
 
@@ -38,13 +40,14 @@ def check_update():
 
 def get_online_version():
     """Download update info and parse it."""
-    session = requests.session()
+    page = http.default_session.get(UPDATE_URL).json()
-    page = urlopen(UPDATE_URL, session).json()
     version, url = None, None
     version = page['tag_name']
 
     if os.name == 'nt':
-        url = next((x['browser_download_url'] for x in page['assets'] if x['content_type'] == 'application/x-msdos-program'), configuration.Url)
+        url = next((x['browser_download_url'] for x in page['assets'] if
+            x['content_type'] == 'application/x-msdos-program'),
+            configuration.Url)
     else:
         url = page['tarball_url']
     return version, url

dosagelib/util.py

@@ -9,8 +9,6 @@ from six.moves.urllib.parse import (
     quote as url_quote, unquote as url_unquote, urlparse, urlunparse, urlsplit)
 from six.moves.urllib_robotparser import RobotFileParser
 import requests
-from requests.adapters import HTTPAdapter
-from requests.packages.urllib3.util.retry import Retry
 import sys
 import os
 import cgi
@@ -40,16 +38,6 @@ from . import AppName
 # Maximum content size for HTML pages
 MaxContentBytes = 1024 * 1024 * 3  # 3 MB
 
-# Default number of retries
-MaxRetries = 3
-
-# Factor for retry backoff (see urllib3.util.retry, this default means
-# 2s, 4s, 8s)
-RetryBackoffFactor = 2
-
-# Default connection timeout
-ConnectionTimeoutSecs = 60
-
 # The character set to encode non-ASCII characters in a URL. See also
 # http://tools.ietf.org/html/rfc2396#section-2.1
 # Note that the encoding is not really specified, but most browsers
@@ -59,15 +47,6 @@ ConnectionTimeoutSecs = 60
 UrlEncoding = "utf-8"
 
 
-def requests_session():
-    s = requests.Session()
-    retry = Retry(MaxRetries, backoff_factor=RetryBackoffFactor)
-    s.mount('http://', HTTPAdapter(max_retries=retry))
-    s.mount('https://', HTTPAdapter(max_retries=retry))
-    s.headers.update({'User-Agent': UserAgent})
-    return s
-
-
 def get_system_uid():
     """Get a (probably) unique ID to identify a system.
     Used to differentiate votes.
@@ -285,8 +264,6 @@ def urlopen(url, session, referrer=None, max_content_bytes=None,
         kwargs['headers']['Referer'] = referrer
     out.debug(u'Sending headers %s' % kwargs['headers'], level=3)
     out.debug(u'Sending cookies %s' % session.cookies)
-    if 'timeout' not in kwargs:
-        kwargs['timeout'] = ConnectionTimeoutSecs
     if 'data' not in kwargs:
         method = 'GET'
     else:

scripts/scriptutil.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # Copyright (C) 2004-2008 Tristan Seligmann and Jonathan Jacobs
 # Copyright (C) 2012-2014 Bastian Kleineidam
-# Copyright (C) 2015-2017 Tobias Gruetzmacher
+# Copyright (C) 2015-2019 Tobias Gruetzmacher
 
 from __future__ import absolute_import, division, print_function
 
@@ -17,13 +17,12 @@ try:
 except ImportError:
     from os import rename
 
-import requests
 from lxml import html
 
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))  # noqa
 
 from dosagelib.util import unescape, get_page
-from dosagelib import scraper
+from dosagelib import scraper, http
 
 
 def first_lower(x):
@@ -39,7 +38,7 @@ class ComicListUpdater(object):
 
     def __init__(self, name):
         self.json = name.replace(".py", ".json")
-        self.session = requests.Session()
+        self.session = http.default_session
         self.sleep = 0
 
     def get_url(self, url, expand=True):