Reduced the number of queries Haystack has to perform in many cases (…

…pagination/facet_counts/spelling_suggestions). Thanks to acdha for the improvements!

haystack/backends/__init__.py

@@ -410,10 +410,10 @@ def get_count(self):
         the results.
         """
         if self._hit_count is None:
-            # Limit the slice to 10 so we get a count without consuming
+            # Limit the slice to 1 so we get a count without consuming
             # everything.
             if not self.end_offset:
-                self.end_offset = 10
+                self.end_offset = 1
 
             if self._more_like_this:
                 # Special case for MLT.

haystack/query.py

@@ -495,8 +495,11 @@ def facet_counts(self):
         This will cause the query to execute and should generally be used when
         presenting the data.
         """
-        clone = self._clone()
-        return clone.query.get_facet_counts()
+        if self.query.has_run():
+            return self.query.get_facet_counts()
+        else:
+            clone = self._clone()
+            return clone.query.get_facet_counts()
 
     def spelling_suggestion(self, preferred_query=None):
         """
@@ -508,8 +511,11 @@ def spelling_suggestion(self, preferred_query=None):
         This will cause the query to execute and should generally be used when
         presenting the data.
         """
-        clone = self._clone()
-        return clone.query.get_spelling_suggestion(preferred_query)
+        if self.query.has_run():
+            return self.query.get_spelling_suggestion(preferred_query)
+        else:
+            clone = self._clone()
+            return clone.query.get_spelling_suggestion(preferred_query)
 
 
     # Utility methods.

haystack/views.py

@@ -19,36 +19,36 @@ class SearchView(object):
     request = None
     form = None
     results_per_page = RESULTS_PER_PAGE
-    
+
     def __init__(self, template=None, load_all=True, form_class=None, searchqueryset=None, context_class=RequestContext, results_per_page=None):
         self.load_all = load_all
         self.form_class = form_class
         self.context_class = context_class
         self.searchqueryset = searchqueryset
-        
+
         if form_class is None:
             self.form_class = ModelSearchForm
-        
+
         if not results_per_page is None:
             self.results_per_page = results_per_page
-        
+
         if template:
             self.template = template
-    
+
     def __call__(self, request):
         """
         Generates the actual response to the search.
-        
+
         Relies on internal, overridable methods to construct the response.
         """
         self.request = request
-        
+
         self.form = self.build_form()
         self.query = self.get_query()
         self.results = self.get_results()
-        
+
         return self.create_response()
-    
+
     def build_form(self, form_kwargs=None):
         """
         Instantiates the form the class should use to process the search query.
@@ -59,76 +59,84 @@ def build_form(self, form_kwargs=None):
         }
         if form_kwargs:
             kwargs.update(form_kwargs)
-        
+
         if len(self.request.GET):
             data = self.request.GET
-        
+
         if self.searchqueryset is not None:
             kwargs['searchqueryset'] = self.searchqueryset
-        
+
         return self.form_class(data, **kwargs)
-    
+
     def get_query(self):
         """
         Returns the query provided by the user.
-        
+
         Returns an empty string if the query is invalid.
         """
         if self.form.is_valid():
             return self.form.cleaned_data['q']
-        
+
         return ''
-    
+
     def get_results(self):
         """
         Fetches the results via the form.
-        
+
         Returns an empty list if there's no query to search with.
         """
         return self.form.search()
-    
+
     def build_page(self):
         """
         Paginates the results appropriately.
-        
+
         In case someone does not want to use Django's built-in pagination, it
         should be a simple matter to override this method to do what they would
         like.
         """
+        try:
+            page_no = int(self.request.GET.get('page', 1))
+        except (TypeError, ValueError):
+            raise Http404
+
+        start_offset = (page_no - 1) * self.results_per_page
+        self.results[start_offset:start_offset + self.results_per_page]
+
         paginator = Paginator(self.results, self.results_per_page)
-        
+
         try:
-            page = paginator.page(self.request.GET.get('page', 1))
+            page = paginator.page(page_no)
         except InvalidPage:
             raise Http404
-        
+
         return (paginator, page)
-    
+
     def extra_context(self):
         """
         Allows the addition of more context variables as needed.
-        
+
         Must return a dictionary.
         """
         return {}
-    
+
     def create_response(self):
         """
         Generates the actual HttpResponse to send back to the user.
         """
         (paginator, page) = self.build_page()
-        
+
         context = {
             'query': self.query,
             'form': self.form,
             'page': page,
             'paginator': paginator,
             'suggestion': None,
         }
-        
+
         if self.results.query.backend.include_spelling:
             context['suggestion'] = self.form.get_suggestion()
-        
+
         context.update(self.extra_context())
         return render_to_response(self.template, context, context_instance=self.context_class(self.request))
 
@@ -141,24 +149,24 @@ def search_view(request):
 
 class FacetedSearchView(SearchView):
     __name__ = 'FacetedSearchView'
-    
+
     def __init__(self, *args, **kwargs):
         # Needed to switch out the default form class.
         if kwargs.get('form_class') is None:
             kwargs['form_class'] = FacetedSearchForm
-        
+
         super(FacetedSearchView, self).__init__(*args, **kwargs)
-    
+
     def build_form(self, form_kwargs=None):
         if form_kwargs is None:
             form_kwargs = {}
-        
+
         # This way the form can always receive a list containing zero or more
         # facet expressions:
         form_kwargs['selected_facets'] = self.request.GET.getlist("selected_facets")
-        
+
         return super(FacetedSearchView, self).build_form(form_kwargs)
-    
+
     def extra_context(self):
         extra = super(FacetedSearchView, self).extra_context()
         extra['request'] = self.request
@@ -170,12 +178,12 @@ def basic_search(request, template='search/search.html', load_all=True, form_cla
     """
     A more traditional view that also demonstrate an alternative
     way to use Haystack.
-    
+
     Useful as an example of for basing heavily custom views off of.
-    
+
     Also has the benefit of thread-safety, which the ``SearchView`` class may
     not be.
-    
+
     Template:: ``search/search.html``
     Context::
         * form
@@ -189,35 +197,35 @@ def basic_search(request, template='search/search.html', load_all=True, form_cla
     """
     query = ''
     results = EmptySearchQuerySet()
-    
+
     if request.GET.get('q'):
         form = form_class(request.GET, searchqueryset=searchqueryset, load_all=load_all)
-        
+
         if form.is_valid():
             query = form.cleaned_data['q']
             results = form.search()
     else:
         form = form_class(searchqueryset=searchqueryset, load_all=load_all)
-    
+
     paginator = Paginator(results, results_per_page or RESULTS_PER_PAGE)
-    
+
     try:
         page = paginator.page(int(request.GET.get('page', 1)))
     except InvalidPage:
         raise Http404("No such page of results!")
-    
+
     context = {
         'form': form,
         'page': page,
         'paginator': paginator,
         'query': query,
         'suggestion': None,
     }
-    
+
     if results.query.backend.include_spelling:
         context['suggestion'] = form.get_suggestion()
-    
+
     if extra_context:
         context.update(extra_context)
-    
+
     return render_to_response(template, context, context_instance=context_class(request))