Create basic memory store for toolbar to reproduce existing functionality.

Author: tim-schilling

debug_toolbar/panels/history/panel.py

@@ -12,6 +12,7 @@
 from debug_toolbar.panels import Panel
 from debug_toolbar.panels.history import views
 from debug_toolbar.panels.history.forms import HistoryStoreForm
+from debug_toolbar.store import store
 
 
 class HistoryPanel(Panel):
@@ -81,7 +82,7 @@ def content(self):
         Fetch every store for the toolbar and include it in the template.
         """
         stores = OrderedDict()
-        for id, toolbar in reversed(self.toolbar._store.items()):
+        for id, toolbar in reversed(store.all()):
             stores[id] = {
                 "toolbar": toolbar,
                 "form": SignedDataForm(

debug_toolbar/panels/history/views.py

@@ -4,7 +4,7 @@
 from debug_toolbar.decorators import require_show_toolbar, signed_data_view
 from debug_toolbar.forms import SignedDataForm
 from debug_toolbar.panels.history.forms import HistoryStoreForm
-from debug_toolbar.toolbar import DebugToolbar
+from debug_toolbar.store import store
 
 
 @require_show_toolbar
@@ -15,7 +15,7 @@ def history_sidebar(request, verified_data):
 
     if form.is_valid():
         store_id = form.cleaned_data["store_id"]
-        toolbar = DebugToolbar.fetch(store_id)
+        toolbar = store.get(store_id)
         context = {}
         if toolbar is None:
             # When the store_id has been popped already due to
@@ -45,8 +45,7 @@ def history_refresh(request, verified_data):
 
     if form.is_valid():
         requests = []
-        # Convert to list to handle mutations happenening in parallel
-        for id, toolbar in list(DebugToolbar._store.items())[::-1]:
+        for id, toolbar in list(reversed(store.all())):
             requests.append(
                 {
                     "id": id,

debug_toolbar/settings.py

@@ -21,6 +21,7 @@
     "ROOT_TAG_EXTRA_ATTRS": "",
     "SHOW_COLLAPSED": False,
     "SHOW_TOOLBAR_CALLBACK": "debug_toolbar.middleware.show_toolbar",
+    "TOOLBAR_STORE_CLASS": "debug_toolbar.store.MemoryStore",
     # Panel options
     "EXTRA_SIGNALS": [],
     "ENABLE_STACKTRACES": True,

debug_toolbar/store.py

@@ -0,0 +1,50 @@
+from collections import OrderedDict
+
+from django.utils.module_loading import import_string
+
+from debug_toolbar import settings as dt_settings
+
+
+class BaseStore:
+    config = dt_settings.get_config().copy()
+
+    @classmethod
+    def get(cls, store_id):
+        raise NotImplementedError
+
+    @classmethod
+    def all(cls):
+        raise NotImplementedError
+
+    @classmethod
+    def set(cls, store_id, toolbar):
+        raise NotImplementedError
+
+    @classmethod
+    def delete(cls, store_id):
+        raise NotImplementedError
+
+
+class MemoryStore(BaseStore):
+    _store = OrderedDict()
+
+    @classmethod
+    def get(cls, store_id):
+        return cls._store.get(store_id)
+
+    @classmethod
+    def all(cls):
+        return cls._store.items()
+
+    @classmethod
+    def set(cls, store_id, toolbar):
+        cls._store[store_id] = toolbar
+        for _ in range(cls.config["RESULTS_CACHE_SIZE"], len(cls._store)):
+            cls._store.popitem(last=False)
+
+    @classmethod
+    def delete(cls, store_id):
+        del cls._store[store_id]
+
+
+store = import_string(dt_settings.get_config()["TOOLBAR_STORE_CLASS"])

debug_toolbar/toolbar.py

@@ -14,6 +14,7 @@
 from django.utils.module_loading import import_string
 
 from debug_toolbar import settings as dt_settings
+from debug_toolbar.store import store
 
 
 class DebugToolbar:
@@ -88,22 +89,12 @@ def should_render_panels(self):
             render_panels = self.request.META["wsgi.multiprocess"]
         return render_panels
 
-    # Handle storing toolbars in memory and fetching them later on
-
-    _store = OrderedDict()
-
     def store(self):
         # Store already exists.
         if self.store_id:
             return
         self.store_id = uuid.uuid4().hex
-        self._store[self.store_id] = self
-        for _ in range(self.config["RESULTS_CACHE_SIZE"], len(self._store)):
-            self._store.popitem(last=False)
-
-    @classmethod
-    def fetch(cls, store_id):
-        return cls._store.get(store_id)
+        store.set(self.store_id, self)
 
     # Manually implement class-level caching of panel classes and url patterns
     # because it's more obvious than going through an abstraction.

debug_toolbar/views.py

@@ -3,13 +3,13 @@
 from django.utils.translation import gettext as _
 
 from debug_toolbar.decorators import require_show_toolbar
-from debug_toolbar.toolbar import DebugToolbar
+from debug_toolbar.store import store
 
 
 @require_show_toolbar
 def render_panel(request):
     """Render the contents of a panel"""
-    toolbar = DebugToolbar.fetch(request.GET["store_id"])
+    toolbar = store.get(request.GET["store_id"])
     if toolbar is None:
         content = _(
             "Data for this panel isn't available anymore. "

tests/base.py

@@ -2,6 +2,7 @@
 from django.http import HttpResponse
 from django.test import RequestFactory, TestCase
 
+from debug_toolbar.store import store
 from debug_toolbar.toolbar import DebugToolbar
 
 rf = RequestFactory()
@@ -52,6 +53,6 @@ def setUp(self):
         # The HistoryPanel keeps track of previous stores in memory.
         # This bleeds into other tests and violates their idempotency.
         # Clear the store before each test.
-        for key in list(DebugToolbar._store.keys()):
-            del DebugToolbar._store[key]
+        for key, _ in list(store.all()):
+            store.delete(key)
         super().setUp()

tests/panels/test_history.py

@@ -4,7 +4,7 @@
 from django.urls import resolve, reverse
 
 from debug_toolbar.forms import SignedDataForm
-from debug_toolbar.toolbar import DebugToolbar
+from debug_toolbar.store import store
 
 from ..base import BaseTestCase, IntegrationTestCase
 
@@ -83,29 +83,31 @@ class HistoryViewsTestCase(IntegrationTestCase):
 
     def test_history_panel_integration_content(self):
         """Verify the history panel's content renders properly.."""
-        self.assertEqual(len(DebugToolbar._store), 0)
+        self.assertEqual(len(store.all()), 0)
 
         data = {"foo": "bar"}
         self.client.get("/json_view/", data, content_type="application/json")
 
         # Check the history panel's stats to verify the toolbar rendered properly.
-        self.assertEqual(len(DebugToolbar._store), 1)
-        toolbar = list(DebugToolbar._store.values())[0]
+        self.assertEqual(len(store.all()), 1)
+        toolbar = list(store.all())[0][1]
         content = toolbar.get_panel_by_id("HistoryPanel").content
         self.assertIn("bar", content)
 
     def test_history_sidebar_invalid(self):
         response = self.client.get(reverse("djdt:history_sidebar"))
         self.assertEqual(response.status_code, 400)
 
-        data = {"signed": SignedDataForm.sign({"store_id": "foo"}) + "invalid"}
+        self.client.get("/json_view/")
+        store_id = list(store.all())[0][0]
+        data = {"signed": SignedDataForm.sign({"store_id": store_id}) + "invalid"}
         response = self.client.get(reverse("djdt:history_sidebar"), data=data)
         self.assertEqual(response.status_code, 400)
 
-    def test_history_sidebar(self):
-        """Validate the history sidebar view."""
+    def test_history_sidebar_hash(self):
+        """Validate the hashing mechanism."""
         self.client.get("/json_view/")
-        store_id = list(DebugToolbar._store)[0]
+        store_id = list(store.all())[0][0]
         data = {"signed": SignedDataForm.sign({"store_id": store_id})}
         response = self.client.get(reverse("djdt:history_sidebar"), data=data)
         self.assertEqual(response.status_code, 200)
@@ -120,7 +122,7 @@ def test_history_sidebar(self):
     def test_history_sidebar_expired_store_id(self):
         """Validate the history sidebar view."""
         self.client.get("/json_view/")
-        store_id = list(DebugToolbar._store)[0]
+        store_id = list(store.all())[0][0]
         data = {"signed": SignedDataForm.sign({"store_id": store_id})}
         response = self.client.get(reverse("djdt:history_sidebar"), data=data)
         self.assertEqual(response.status_code, 200)
@@ -130,14 +132,18 @@ def test_history_sidebar_expired_store_id(self):
         )
         self.client.get("/json_view/")
 
-        # Querying old store_id should return in empty response
+        # Querying previous store_id should still work
         data = {"signed": SignedDataForm.sign({"store_id": store_id})}
         response = self.client.get(reverse("djdt:history_sidebar"), data=data)
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json(), {})
+        self.assertEqual(
+            set(response.json()),
+            self.PANEL_KEYS,
+        )
 
         # Querying with latest store_id
-        latest_store_id = list(DebugToolbar._store)[0]
+        latest_store_id = list(store.all())[-1][0]
+        self.assertNotEqual(latest_store_id, store_id)
         data = {"signed": SignedDataForm.sign({"store_id": latest_store_id})}
         response = self.client.get(reverse("djdt:history_sidebar"), data=data)
         self.assertEqual(response.status_code, 200)
@@ -157,15 +163,14 @@ def test_history_refresh_invalid_signature(self):
 
     def test_history_refresh(self):
         """Verify refresh history response has request variables."""
-        data = {"foo": "bar"}
-        self.client.get("/json_view/", data, content_type="application/json")
+        self.client.get("/json_view/", {"foo": "bar"}, content_type="application/json")
         data = {"signed": SignedDataForm.sign({"store_id": "foo"})}
         response = self.client.get(reverse("djdt:history_refresh"), data=data)
         self.assertEqual(response.status_code, 200)
         data = response.json()
         self.assertEqual(len(data["requests"]), 1)
 
-        store_id = list(DebugToolbar._store)[0]
+        store_id = list(store.all())[0][0]
         signature = SignedDataForm.sign({"store_id": store_id})
         self.assertIn(html.escape(signature), data["requests"][0]["content"])
 

tests/test_integration.py

@@ -16,6 +16,7 @@
 from debug_toolbar.forms import SignedDataForm
 from debug_toolbar.middleware import DebugToolbarMiddleware, show_toolbar
 from debug_toolbar.panels import Panel
+from debug_toolbar.store import store
 from debug_toolbar.toolbar import DebugToolbar
 
 from .base import BaseTestCase, IntegrationTestCase
@@ -207,15 +208,15 @@ def get_response(request):
 
     def test_middleware_render_toolbar_json(self):
         """Verify the toolbar is rendered and data is stored for a json request."""
-        self.assertEqual(len(DebugToolbar._store), 0)
+        self.assertEqual(len(store.all()), 0)
 
         data = {"foo": "bar"}
         response = self.client.get("/json_view/", data, content_type="application/json")
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.content.decode("utf-8"), '{"foo": "bar"}')
         # Check the history panel's stats to verify the toolbar rendered properly.
-        self.assertEqual(len(DebugToolbar._store), 1)
-        toolbar = list(DebugToolbar._store.values())[0]
+        self.assertEqual(len(store.all()), 1)
+        toolbar = list(store.all())[0][1]
         self.assertEqual(
             toolbar.get_panel_by_id("HistoryPanel").get_stats()["data"],
             {"foo": ["bar"]},
@@ -523,6 +524,8 @@ def test_rerender_on_history_switch(self):
 
     @override_settings(DEBUG_TOOLBAR_CONFIG={"RESULTS_CACHE_SIZE": 0})
     def test_expired_store(self):
+        original_value = store.config["RESULTS_CACHE_SIZE"]
+        store.config["RESULTS_CACHE_SIZE"] = 0
         self.get("/regular/basic/")
         version_panel = self.selenium.find_element_by_id("VersionsPanel")
 
@@ -534,6 +537,7 @@ def test_expired_store(self):
             lambda selenium: version_panel.find_element_by_tag_name("p")
         )
         self.assertIn("Data for this panel isn't available anymore.", error.text)
+        store.config["RESULTS_CACHE_SIZE"] = original_value
 
     @override_settings(
         TEMPLATES=[