Cache rarely-changing allowance-related DB objects

coldfront/config/local_settings.py.sample

@@ -31,9 +31,9 @@ SESSION_COOKIE_SECURE = False
 # Sessions should last for one hour.
 SESSION_COOKIE_AGE = 60 * 60
 
-# ------------------------------------------------------------------------------
+#------------------------------------------------------------------------------
 # myBRC settings
-# ------------------------------------------------------------------------------
+#------------------------------------------------------------------------------
 
 # The ID of the Site object to use (probably 1).
 SITE_ID = 1

coldfront/core/allocation/forms.py

@@ -285,7 +285,11 @@ def __init__(self, *args, **kwargs):
                 not isinstance(self.computing_allowance, ComputingAllowance)):
             self.computing_allowance = ComputingAllowance(
                 self.computing_allowance)
-        self.interface = ComputingAllowanceInterface()
+        self.interface = (
+            # Short-circuit to avoid instantiating ComputingAllowanceInterface
+            # if possible.
+            kwargs.pop('computing_allowance_interface', None) or
+            ComputingAllowanceInterface())
         super().__init__(*args, **kwargs)
 
     def label_from_instance(self, obj):

coldfront/core/project/forms_/new_project_forms/request_forms.py

@@ -50,6 +50,11 @@ class SavioProjectAllocationPeriodForm(forms.Form):
 
     def __init__(self, *args, **kwargs):
         computing_allowance = kwargs.pop('computing_allowance', None)
+        computing_allowance_interface = (
+            # Short-circuit to avoid instantiating ComputingAllowanceInterface
+            # if possible.
+            kwargs.pop('computing_allowance_interface', None) or
+            ComputingAllowanceInterface())
         super().__init__(*args, **kwargs)
         if computing_allowance is not None:
             computing_allowance = ComputingAllowance(computing_allowance)
@@ -60,6 +65,7 @@ def __init__(self, *args, **kwargs):
             queryset = AllocationPeriod.objects.none()
         self.fields['allocation_period'] = AllocationPeriodChoiceField(
             computing_allowance=computing_allowance,
+            computing_allowance_interface=computing_allowance_interface,
             label='Allocation Period',
             queryset=queryset,
             required=True)
@@ -164,6 +170,11 @@ class SavioProjectExistingPIForm(forms.Form):
     def __init__(self, *args, **kwargs):
         self.computing_allowance = kwargs.pop('computing_allowance', None)
         self.allocation_period = kwargs.pop('allocation_period', None)
+        self.interface = (
+            # Short-circuit to avoid instantiating ComputingAllowanceInterface
+            # if possible.
+            kwargs.pop('computing_allowance_interface', None) or
+            ComputingAllowanceInterface())
         super().__init__(*args, **kwargs)
         if self.computing_allowance is not None:
             self.computing_allowance = ComputingAllowance(
@@ -196,7 +207,8 @@ def disable_pi_choices(self):
             disable_user_pks.update(
                 project_pi_pks(
                     computing_allowance=resource,
-                    project_status_names=project_status_names))
+                    project_status_names=project_status_names,
+                    computing_allowance_interface=self.interface))
             new_project_request_status_names = list(
                 non_denied_new_project_request_statuses().values_list(
                     'name', flat=True))
@@ -212,7 +224,8 @@ def disable_pi_choices(self):
                 pis_with_renewal_requests_pks(
                     self.allocation_period,
                     computing_allowance=resource,
-                    request_status_names=renewal_request_status_names))
+                    request_status_names=renewal_request_status_names,
+                    computing_allowance_interface=self.interface))
 
         if flag_enabled('LRC_ONLY'):
             # On LRC, PIs must be LBL employees.
@@ -528,7 +541,11 @@ class SavioProjectPooledProjectSelectionForm(forms.Form):
 
     def __init__(self, *args, **kwargs):
         self.computing_allowance = kwargs.pop('computing_allowance', None)
-        self.interface = ComputingAllowanceInterface()
+        self.interface = (
+            # Short-circuit to avoid instantiating ComputingAllowanceInterface
+            # if possible.
+            kwargs.pop('computing_allowance_interface', None) or
+            ComputingAllowanceInterface())
         super().__init__(*args, **kwargs)
 
         f = Q(status__name__in=['Pending - Add', 'New', 'Active'])
@@ -587,7 +604,11 @@ class SavioProjectDetailsForm(forms.Form):
 
     def __init__(self, *args, **kwargs):
         self.computing_allowance = kwargs.pop('computing_allowance', None)
-        self.interface = ComputingAllowanceInterface()
+        self.interface = (
+            # Short-circuit to avoid instantiating ComputingAllowanceInterface
+            # if possible.
+            kwargs.pop('computing_allowance_interface', None) or
+            ComputingAllowanceInterface())
         super().__init__(*args, **kwargs)
         if self.computing_allowance is not None:
             self.computing_allowance = ComputingAllowance(

coldfront/core/project/utils_/new_project_utils.py

@@ -82,7 +82,8 @@ def pis_with_new_project_requests_pks(allocation_period,
             f).values_list('pi__pk', flat=True))
 
 
-def project_pi_pks(computing_allowance=None, project_status_names=[]):
+def project_pi_pks(computing_allowance=None, project_status_names=[],
+                   computing_allowance_interface=None):
     """Return a list of primary keys of PI Users of Projects that match
     the given filters.
 
@@ -91,6 +92,9 @@ def project_pi_pks(computing_allowance=None, project_status_names=[]):
                                           allowance to filter with
         - project_status_names (list[str]): A list of names of Project
                                             statuses to filter with
+        - computing_allowance_interface (ComputingAllowanceInterface):
+              An optional ComputingAllowanceInterface instance to
+              perform lookups with
 
     Returns:
         - A list of integers representing primary keys of matching PIs.
@@ -101,9 +105,13 @@ def project_pi_pks(computing_allowance=None, project_status_names=[]):
           cannot be retrieved.
     """
     project_prefix = ''
+    if computing_allowance_interface is not None:
+        assert isinstance(
+            computing_allowance_interface, ComputingAllowanceInterface)
     if computing_allowance is not None:
         assert isinstance(computing_allowance, Resource)
-        interface = ComputingAllowanceInterface()
+        interface = (
+            computing_allowance_interface or ComputingAllowanceInterface())
         project_prefix = interface.code_from_name(computing_allowance.name)
     return set(
         ProjectUser.objects.filter(

coldfront/core/project/utils_/renewal_utils.py

@@ -232,7 +232,8 @@ def non_denied_renewal_request_statuses():
 
 
 def pis_with_renewal_requests_pks(allocation_period, computing_allowance=None,
-                                  request_status_names=[]):
+                                  request_status_names=[],
+                                  computing_allowance_interface=None):
     """Return a list of primary keys of PIs of allocation renewal
     requests for the given AllocationPeriod that match the given filters.
 
@@ -243,6 +244,9 @@ def pis_with_renewal_requests_pks(allocation_period, computing_allowance=None,
                                           allowance to filter with
         - request_status_names (list[str]): A list of names of request
                                             statuses to filter with
+        - computing_allowance_interface (ComputingAllowanceInterface):
+              An optional ComputingAllowanceInterface instance to
+              perform lookups with
 
     Returns:
         - A list of integers representing primary keys of matching PIs.
@@ -254,9 +258,13 @@ def pis_with_renewal_requests_pks(allocation_period, computing_allowance=None,
     """
     assert isinstance(allocation_period, AllocationPeriod)
     f = Q(allocation_period=allocation_period)
+    if computing_allowance_interface is not None:
+        assert isinstance(
+            computing_allowance_interface, ComputingAllowanceInterface)
     if computing_allowance is not None:
         assert isinstance(computing_allowance, Resource)
-        interface = ComputingAllowanceInterface()
+        interface = (
+            computing_allowance_interface or ComputingAllowanceInterface())
         project_prefix = interface.code_from_name(computing_allowance.name)
         f = f & Q(post_project__name__startswith=project_prefix)
     if request_status_names:

coldfront/core/project/views_/new_project_views/request_views.py

@@ -29,6 +29,7 @@
 from coldfront.core.resource.models import Resource
 from coldfront.core.resource.utils import get_primary_compute_resource
 from coldfront.core.resource.utils_.allowance_utils.computing_allowance import ComputingAllowance
+from coldfront.core.resource.utils_.allowance_utils.interface import cached_computing_allowance_interface
 from coldfront.core.resource.utils_.allowance_utils.interface import ComputingAllowanceInterface
 from coldfront.core.user.models import UserProfile
 from coldfront.core.user.utils import access_agreement_signed
@@ -178,6 +179,8 @@ def __init__(self, *args, **kwargs):
         # Define a lookup table from form name to step number.
         self.step_numbers_by_form_name = {
             name: i for i, (name, _) in enumerate(self.FORMS)}
+        self.computing_allowance_interface = \
+            cached_computing_allowance_interface()
 
     def test_func(self):
         if self.request.user.is_superuser:
@@ -223,6 +226,17 @@ def get_form_kwargs(self, step=None):
         step_name = step_names_by_step_number[step_number]
         for key in required_keys_by_step_name[step_name]:
             kwargs[key] = data.get(key, None)
+
+        step_names_requiring_computing_allowance_interface = {
+            'allocation_period',
+            'existing_pi',
+            'pooled_project_selection',
+            'details',
+        }
+        if step_name in step_names_requiring_computing_allowance_interface:
+            kwargs['computing_allowance_interface'] = \
+                self.computing_allowance_interface
+
         return kwargs
 
     def get_template_names(self):

coldfront/core/resource/utils_/allowance_utils/interface.py

@@ -1,7 +1,14 @@
+from base64 import b64decode
+from base64 import b64encode
+
+from django.core.cache import cache
+
 from coldfront.core.allocation.models import AllocationPeriod
 from coldfront.core.resource.models import Resource
 from coldfront.core.resource.models import ResourceType
 
+import pickle
+
 
 class ComputingAllowanceInterface(object):
     """A singleton that fetches computing allowances from the database
@@ -135,3 +142,20 @@ def service_units_from_name(self, name, is_timed=False,
 class ComputingAllowanceInterfaceError(Exception):
     """An exception to be raised by the ComputingAllowanceInterface."""
     pass
+
+
+def cached_computing_allowance_interface():
+    """Return an instance of ComputingAllowanceInterface. If one is
+    already in the cache, return it. Otherwise, create one, store it in
+    the cache, and return it."""
+    cache_key = 'computing_allowance_interface'
+    if cache_key in cache:
+        cache_value = cache.get(cache_key)
+        computing_allowance_interface = pickle.loads(
+            b64decode(cache_value.encode('utf-8')))
+    else:
+        computing_allowance_interface = ComputingAllowanceInterface()
+        cache_value = b64encode(
+            pickle.dumps(computing_allowance_interface)).decode('utf-8')
+        cache.set(cache_key, cache_value)
+    return computing_allowance_interface