Redundant DB queries eliminated. We're at about 5 hits per sequence w/o Askbot, and 10 with

courseware/models.py

@@ -45,15 +45,25 @@ class StudentModule(models.Model):
                     ('video','video'),
                     ('html','html'),
                     )
+    ## These three are the key for the object
     module_type = models.CharField(max_length=32, choices=MODULE_TYPES, default='problem')
     module_id = models.CharField(max_length=255) # Filename for homeworks, etc. 
     student = models.ForeignKey(User)
-
     class Meta:
         unique_together = (('student', 'module_id', 'module_type'),)
 
+    ## Internal state of the object
     state = models.TextField(null=True, blank=True)
+
+    ## Grade, and are we done? 
     grade = models.FloatField(null=True, blank=True)
+    #max_grade = models.FloatField(null=True, blank=True)
+    
+    # DONE_TYPES = (('done','DONE'),          # Finished
+    #               ('incomplete','NOTDONE'), # Not finished
+    #               ('na','NA'))              # Not applicable (e.g. vertical)
+    # done = models.CharField(max_length=16, choices=DONE_TYPES)
+
     created = models.DateTimeField(auto_now_add=True)
     modified = models.DateTimeField(auto_now=True)
 

courseware/module_render.py

@@ -4,6 +4,7 @@ from djangomako.shortcuts import render_to_response, render_to_string
 import json, os, sys
 from django.core.context_processors import csrf
 
+from django.db import connection
 from django.template import Context
 from django.contrib.auth.models import User
 from auth.models import UserProfile
@@ -44,6 +45,16 @@ modx_modules={'problem':courseware.modules.capa_module.LoncapaModule,
               'sequential':courseware.modules.seq_module.SequentialModule,
               'schematic':courseware.modules.schematic_module.SchematicModule}
 
+def object_cache(cache, user, module_type, module_id):
+    # We don't look up on user -- all queries include user
+    # Additional lookup would require a DB hit the way Django 
+    # is broken. 
+    for o in cache: 
+        if o.module_type == module_type and \
+                o.module_id == module_id:
+            return o
+    return None
+
 def make_track_function(request):
     def f(event_type, event):
         return track.views.server_track(request, event_type, event, page='x_module')
@@ -52,7 +63,6 @@ def make_track_function(request):
 def modx_dispatch(request, module=None, dispatch=None, id=None):
     ''' Generic view for extensions. '''
     # Grab the student information for the module from the database
-    print module, request.user, id
     s = StudentModule.objects.filter(module_type=module, 
                                      student=request.user, 
                                      module_id=id)
@@ -77,8 +87,7 @@ def modx_dispatch(request, module=None, dispatch=None, id=None):
                                   ajax_url=ajax_url, 
                                   state=s.state, 
                                   track_function = make_track_function(request), 
-                                  render_function = render_module, 
-                                  meta = request)
+                                  render_function = None)
     # Let the module handle the AJAX
     ajax_return=instance.handle_ajax(dispatch, request.POST)
     # Save the state back to the database
@@ -89,7 +98,7 @@ def modx_dispatch(request, module=None, dispatch=None, id=None):
     # Return whatever the module wanted to return to the client/caller
     return HttpResponse(ajax_return)
 
-def render_x_module(request, xml_module):
+def render_x_module(user, request, xml_module, module_object_preload):
     ''' Generic module for extensions. This renders to HTML. '''
     # Check if problem has an instance in DB
     module_type=xml_module.tag
@@ -97,13 +106,16 @@ def render_x_module(request, xml_module):
     module_id=xml_module.get('id') #module_class.id_attribute) or "" 
 
     # Grab state from database
-    s = StudentModule.objects.filter(student=request.user, 
-                                     module_id=module_id, 
-                                     module_type = module_type)
-    if len(s) == 0: # If nothing in the database...
+    s = object_cache(module_object_preload, 
+                     user, 
+                     module_type, 
+                     module_id)#student=request.user, 
+                     #module_id=module_id, 
+                     #module_type = module_type)
+    if s == None: # If nothing in the database...
         state=None
     else:
-        smod = s[0]
+        smod = s
         state = smod.state
 
     # Create a new instance
@@ -113,27 +125,25 @@ def render_x_module(request, xml_module):
                           ajax_url=ajax_url,
                           state=state, 
                           track_function = make_track_function(request), 
-                          render_function = render_module, 
-                          meta = request)
+                                  render_function = lambda x: render_module(user, request, x, module_object_preload))
     
     # If instance wasn't already in the database, create it
-    if len(s) == 0:
-        smod=StudentModule(student=request.user, 
+    if s == None:
+        smod=StudentModule(student=user, 
                            module_type = module_type,
                            module_id=module_id, 
                            state=instance.get_state())
+        smod.save() # This may be optional (at least in the case of no instance in the dB)
     # Grab content
     content = {'content':instance.get_html(), 
                "destroy_js":instance.get_destroy_js(),
                'init_js':instance.get_init_js(), 
                'type':module_type}
 
-    smod.save() # This may be optional (at least in the case of no instance in the dB)
-
     return content
 
-def render_module(request, module):
+def render_module(user, request, module, module_object_preload):
     ''' Generic dispatch for internal modules. '''
     if module==None :
         return {"content":""}
-    return render_x_module(request, module)
+    return render_x_module(user, request, module, module_object_preload)

courseware/modules/html_module.py

@@ -25,7 +25,7 @@ class HtmlModule(XModule):
             textlist=[i for i in textlist if type(i)==str]
             return "".join(textlist)
 
-    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, track_function=None, render_function = None, meta = None):
+    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, track_function=None, render_function = None):
         XModule.__init__(self, xml, item_id, ajax_url, track_url, state, track_function, render_function)
         xmltree=etree.fromstring(xml)
         self.filename = None

courseware/modules/schematic_module.py

@@ -18,6 +18,6 @@ class SchematicModule(XModule):
     def get_html(self):
         return '<input type="hidden" class="schematic" name="{item_id}" height="480" width="640">'.format(item_id=self.item_id)
 
-    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, render_function = None, meta = None):
+    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, render_function = None):
         XModule.__init__(self, xml, item_id, ajax_url, track_url, state, render_function)
 

courseware/modules/seq_module.py

@@ -36,7 +36,7 @@ class SequentialModule(XModule):
             return json.dumps({'success':True})
         raise Http404()
 
-    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, track_function=None, render_function = None, meta = None):
+    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, track_function=None, render_function = None):
         XModule.__init__(self, xml, item_id, ajax_url, track_url, state, track_function, render_function)
         xmltree=etree.fromstring(xml)
 
@@ -60,7 +60,7 @@ class SequentialModule(XModule):
                     'init_js':m['init_js'], 
                     'type':m['type']}
 
-        contents=[(e.get("name"),j(render_function(meta, e))) \
+        contents=[(e.get("name"),j(render_function(e))) \
                       for e in xmltree]
      
         js=""

courseware/modules/vertical_module.py

@@ -25,10 +25,10 @@ class VerticalModule(XModule):
     def get_destroy_js(self):
         return self.destroy_js_text
 
-    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, track_function=None, render_function = None, meta = None):
+    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, track_function=None, render_function = None):
         XModule.__init__(self, xml, item_id, ajax_url, track_url, state, track_function, render_function)
         xmltree=etree.fromstring(xml)
-        self.contents=[(e.get("name"),self.render_function(meta, e)) \
+        self.contents=[(e.get("name"),self.render_function(e)) \
                       for e in xmltree]
         self.init_js_text="".join([e[1]['init_js'] for e in self.contents if 'init_js' in e[1]])
         self.destroy_js_text="".join([e[1]['destroy_js'] for e in self.contents if 'destroy_js' in e[1]])

courseware/modules/video_module.py

@@ -51,7 +51,7 @@ class VideoModule(XModule):
     def get_destroy_js(self):
         return "videoDestroy(\""+self.item_id+"\");"
 
-    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, track_function=None, render_function = None, meta = None):
+    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, track_function=None, render_function = None):
         XModule.__init__(self, xml, item_id, ajax_url, track_url, state, track_function, render_function)
         self.youtube = etree.XML(xml).get('youtube')
         self.position = 0

courseware/modules/x_module.py

@@ -39,7 +39,7 @@ class XModule(object):
             get is a dictionary-like object ''' 
         return ""
 
-    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, track_function=None, render_function = None, meta = None):
+    def __init__(self, xml, item_id, ajax_url=None, track_url=None, state=None, track_function=None, render_function = None):
         ''' In most cases, you must pass state or xml'''
         self.xml = xml
         self.item_id = item_id
@@ -48,4 +48,4 @@ class XModule(object):
         self.state = state
         self.tracker = track_function
         self.render_function = render_function
-        self.meta = meta
+

courseware/views.py

@@ -13,6 +13,8 @@ from django.http import HttpResponse, Http404
 from django.shortcuts import redirect
 from django.template import Context, loader
 from djangomako.shortcuts import render_to_response, render_to_string
+from django.db import connection
+
 from lxml import etree
 
 from auth.models import UserProfile
@@ -105,7 +107,8 @@ def render_accordion(request,course,chapter,section):
 def index(request, course="6.002 Spring 2012", chapter="Using the System", section="Hints"): 
     ''' Displays courseware accordion, and any associated content. 
     ''' 
-    if not settings.COURSEWARE_ENABLED or not request.user.is_authenticated():
+    user = request.user
+    if not settings.COURSEWARE_ENABLED or not user.is_authenticated():
         return redirect('/')
 
     # Fixes URLs -- we don't get funny encoding characters from spaces
@@ -120,7 +123,7 @@ def index(request, course="6.002 Spring 2012", chapter="Using the System", secti
     if course!="6.002 Spring 2012":
         return redirect('/')
 
-    dom = content_parser.course_file(request.user)
+    dom = content_parser.course_file(user)
     dom_module = dom.xpath("//course[@name=$course]/chapter[@name=$chapter]//section[@name=$section]/*[1]", 
                            course=course, chapter=chapter, section=section)
     if len(dom_module) == 0:
@@ -130,17 +133,21 @@ def index(request, course="6.002 Spring 2012", chapter="Using the System", secti
 
     accordion=render_accordion(request, course, chapter, section)
 
-    module=render_module(request, module)
+    module_ids = dom.xpath("//course[@name=$course]/chapter[@name=$chapter]//section[@name=$section]//@id", 
+                           course=course, chapter=chapter, section=section)
 
-    if 'init_js' not in module:
-        module['init_js']=''
+    module_object_preload = StudentModule.objects.filter(student=user, 
+                                                         module_id__in=module_ids)
 
+    module=render_module(user, request, module, module_object_preload)
 
+    if 'init_js' not in module:
+        module['init_js']=''
 
     context={'init':accordion['init_js']+module['init_js'],
              'accordion':accordion['content'],
              'content':module['content'],
              'csrf':csrf(request)['csrf_token']}
-    return render_to_response('courseware.html', context)
-
 
+    result = render_to_response('courseware.html', context)
+    return result

settings_no_askbot.py

 ASKBOT_ENABLED = False
-execfile("settings.py")
+execfile("settings_old_askbot.py")