Instantiate only one toolbar object on load.toolbar-refactor

Start of work on having one toolbar object and its panels handle multiple
requests, getting rid of the need to instantiate a toolbar and all panels per
request.  This will require much more work in panels to make sure everything is
thread-safe.

2 files changed, 28 insertions, 22 deletions

diff --git a/debug_toolbar/middleware.py b/debug_toolbar/middleware.py
index 4e4f69f..b0a0da1 100644
--- a/debug_toolbar/middleware.py
+++ b/debug_toolbar/middleware.py
@@ -32,7 +32,7 @@ class DebugToolbarMiddleware(object):
     on outgoing response.
     """
     def __init__(self):
-        self.debug_toolbars = {}
+        self.debug_toolbar = DebugToolbar()
         self.override_url = True
 
         # Set method to use to decide to show toolbar
@@ -66,6 +66,7 @@ class DebugToolbarMiddleware(object):
 
     def process_request(self, request):
         if self.show_toolbar(request):
+            self.debug_toolbar.process_request(request)
             if self.override_url:
                 original_urlconf = getattr(request, 'urlconf', settings.ROOT_URLCONF)
                 debug_toolbar.urls.urlpatterns += patterns('',
@@ -74,19 +75,18 @@ class DebugToolbarMiddleware(object):
                 self.override_url = False
             request.urlconf = 'debug_toolbar.urls'
 
-            self.debug_toolbars[request] = DebugToolbar(request)
-            for panel in self.debug_toolbars[request].panels:
+            for panel in self.debug_toolbar.panels:
                 panel.process_request(request)
 
     def process_view(self, request, view_func, view_args, view_kwargs):
-        if request in self.debug_toolbars:
-            for panel in self.debug_toolbars[request].panels:
+        if request in self.debug_toolbar.requests:
+            for panel in self.debug_toolbar.panels:
                 panel.process_view(request, view_func, view_args, view_kwargs)
 
     def process_response(self, request, response):
-        if request not in self.debug_toolbars:
+        if request not in self.debug_toolbar.requests:
             return response
-        if self.debug_toolbars[request].config['INTERCEPT_REDIRECTS']:
+        if self.debug_toolbar.config['INTERCEPT_REDIRECTS']:
             if isinstance(response, HttpResponseRedirect):
                 redirect_to = response.get('Location', None)
                 if redirect_to:
@@ -95,14 +95,14 @@ class DebugToolbarMiddleware(object):
                         {'redirect_to': redirect_to}
                     )
         if response.status_code == 200:
-            for panel in self.debug_toolbars[request].panels:
+            for panel in self.debug_toolbar.panels:
                 panel.process_response(request, response)
             if response['Content-Type'].split(';')[0] in _HTML_TYPES:
                 response.content = replace_insensitive(
                     smart_unicode(response.content), 
                     self.tag,
-                    smart_unicode(self.debug_toolbars[request].render_toolbar() + self.tag))
+                    smart_unicode(self.debug_toolbar.render_toolbar() + self.tag))
             if response.get('Content-Length', None):
                 response['Content-Length'] = len(response.content)
-        del self.debug_toolbars[request]
+        del self.debug_toolbar.requests[request]
         return response
diff --git a/debug_toolbar/toolbar/loader.py b/debug_toolbar/toolbar/loader.py
index 4b53d2f..9b468c5 100644
--- a/debug_toolbar/toolbar/loader.py
+++ b/debug_toolbar/toolbar/loader.py
@@ -6,20 +6,14 @@ from django.template.loader import render_to_string
 
 class DebugToolbar(object):
 
-    def __init__(self, request):
-        self.request = request
-        self.panels = []
-        base_url = self.request.META.get('SCRIPT_NAME', '')
-        self.config = {
-            'INTERCEPT_REDIRECTS': True,
-            'MEDIA_URL': u'%s/__debug__/m/' % base_url
-        }
+    config = {}
+    panels = []
+    requests = {}
+    template_context = {}
+
+    def __init__(self):
         # Check if settings has a DEBUG_TOOLBAR_CONFIG and updated config
         self.config.update(getattr(settings, 'DEBUG_TOOLBAR_CONFIG', {}))
-        self.template_context = {
-            'BASE_URL': base_url, # for backwards compatibility
-            'DEBUG_TOOLBAR_MEDIA_URL': self.config.get('MEDIA_URL'),
-        }
         # Override this tuple by copying to settings.py as `DEBUG_TOOLBAR_PANELS`
         self.default_panels = (
             'debug_toolbar.panels.version.VersionDebugPanel',
@@ -35,6 +29,18 @@ class DebugToolbar(object):
         )
         self.load_panels()
 
+    def process_request(self, request):
+        self.requests[request] = []
+        base_url = request.META.get('SCRIPT_NAME', '')
+        self.config.update({
+            'INTERCEPT_REDIRECTS': True,
+            'MEDIA_URL': u'%s/__debug__/m/' % (base_url,)
+        })
+        self.template_context.update({
+            'BASE_URL': base_url, # for backwards compatibility
+            'DEBUG_TOOLBAR_MEDIA_URL': self.config.get('MEDIA_URL'),
+        })
+
     def load_panels(self):
         """
         Populate debug panels