core: Invert request priority meaning, a higher request.priority value means more priority

docs/ref/settings.rst

@@ -702,7 +702,7 @@ restrict automatic redirection to a maximum delay (in seconds)
 REDIRECT_PRIORITY_ADJUST
 ------------------------------
 
-Default: ``-2``
+Default: ``+2``
 
 Adjust redirect request priority relative to original request.
 A negative priority adjust means more priority.

scrapy/conf/default_settings.py

@@ -141,7 +141,7 @@ NEWSPIDER_MODULE = ''
 
 REDIRECT_MAX_METAREFRESH_DELAY = 100
 REDIRECT_MAX_TIMES = 20 # uses Firefox default setting
-REDIRECT_PRIORITY_ADJUST = -2
+REDIRECT_PRIORITY_ADJUST = +2
 
 REQUESTS_QUEUE_SIZE = 0
 REQUESTS_PER_DOMAIN = 8     # max simultaneous requests per domain
@@ -149,7 +149,7 @@ REQUESTS_PER_DOMAIN = 8     # max simultaneous requests per domain
 # contrib.middleware.retry.RetryMiddleware default settings
 RETRY_TIMES = 2 # initial response + 2 retries = 3 requests
 RETRY_HTTP_CODES = ['500', '503', '504', '400', '408']
-RETRY_PRIORITY_ADJUST = +1
+RETRY_PRIORITY_ADJUST = -1
 
 ROBOTSTXT_OBEY = False
 

scrapy/core/scheduler/schedulers.py

@@ -54,7 +54,7 @@ class Scheduler(object):
 
     def _enqueue_request(self, domain, request):
         dfd = defer.Deferred()
-        self.pending_requests[domain].push((request, dfd), request.priority)
+        self.pending_requests[domain].push((request, dfd), -request.priority)
         return dfd
 
     def next_request(self, domain):

scrapy/tests/test_downloadermiddleware_redirect.py

@@ -16,7 +16,7 @@ class RedirectMiddlewareTest(unittest.TestCase):
         req = Request('http://a.com')
         rsp = Response('http://a.com', headers={'Location': 'http://a.com/redirected'}, status=301)
         req2 = self.mw.process_response(req, rsp, self.spider)
-        assert req2.priority < req.priority
+        assert req2.priority > req.priority
 
     def test_redirect_301(self):
         url = 'http://www.example.com/301'

scrapy/tests/test_downloadermiddleware_retry.py

@@ -20,7 +20,7 @@ class RetryTest(unittest.TestCase):
         req = Request('http://www.scrapytest.org/503')
         rsp = Response('http://www.scrapytest.org/503', body='', status=503)
         req2 = self.mw.process_response(req, rsp, self.spider)
-        assert req2.priority > req.priority
+        assert req2.priority < req.priority
 
     def test_404(self):
         req = Request('http://www.scrapytest.org/404')