1869: Course program api performance improvements (#1872)

* This works but is just POC

* Add department serializer and prefetch

* improvement for courses API

* program improvements

* Fix course run serializer, migration, enrollment api

* Add live filter to front end API call

* Fix tests, format, add filtering to front end query

* select related course on course_run API

* Javascript formatting

* Fix serializers

* Fix Course serializer

* Format

* py test passing

* Format and repair tests

* Clean up department serializer

* Add class doc

* Cleanup department serializer

cms/models.py

@@ -12,6 +12,7 @@
 from django.core.exceptions import ValidationError
 from django.core.serializers.json import DjangoJSONEncoder
 from django.db import models
+from django.utils.functional import cached_property
 from django.forms import ChoiceField, DecimalField
 from django.http import Http404
 from django.template.response import TemplateResponse
@@ -1084,7 +1085,7 @@ class CoursePage(ProductPage):
         )
     ]
 
-    @property
+    @cached_property
     def product(self):
         """Gets the product associated with this page"""
         return self.course

cms/serializers.py

@@ -20,7 +20,6 @@ class CoursePageSerializer(serializers.ModelSerializer):
     description = serializers.SerializerMethodField()
     current_price = serializers.SerializerMethodField()
     instructors = serializers.SerializerMethodField()
-    live = serializers.SerializerMethodField()
     effort = serializers.SerializerMethodField()
     length = serializers.SerializerMethodField()
 
@@ -76,28 +75,14 @@ def get_financial_assistance_form_url(self, instance):
             else ""
         )
 
-    def get_next_run_id(self, instance):
-        """Get next run id"""
-        run = instance.course.first_unexpired_run
-        return run.id if run is not None else None
-
     def get_description(self, instance):
         return bleach.clean(instance.description, tags=[], strip=True)
 
     def get_current_price(self, instance):
-        next_run = self.get_next_run_id(instance)
-
-        if next_run is None:
-            return None
-
-        course_ct = ContentType.objects.get(app_label="courses", model="courserun")
-
         relevant_product = (
-            Product.objects.filter(
-                content_type=course_ct, object_id=next_run, is_active=True
-            )
-            .order_by("-price")
-            .first()
+            instance.product.active_products.filter().order_by("-price").first()
+            if instance.product.active_products
+            else None
         )
         return relevant_product.price if relevant_product else None
 
@@ -120,9 +105,6 @@ def get_instructors(self, instance):
 
         return returnable_members
 
-    def get_live(self, instance):
-        return instance.live
-
     def get_effort(self, instance):
         return (
             bleach.clean(instance.effort, tags=[], strip=True)

courses/api.py

@@ -31,11 +31,9 @@
     CourseRunCertificate,
     CourseRunEnrollment,
     CourseRunGrade,
-    Program,
     ProgramCertificate,
     ProgramEnrollment,
     ProgramRequirement,
-    ProgramRequirementNodeType,
 )
 from courses.tasks import subscribe_edx_course_emails
 from courses.utils import (

courses/migrations/0043_course_program_live_index.py

@@ -0,0 +1,22 @@
+# Generated by Django 3.2.20 on 2023-09-10 11:40
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("courses", "0042_add_ordering_to_course_and_program"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="course",
+            name="live",
+            field=models.BooleanField(db_index=True, default=False),
+        ),
+        migrations.AlterField(
+            model_name="program",
+            name="live",
+            field=models.BooleanField(db_index=True, default=False),
+        ),
+    ]

courses/models.py

@@ -125,7 +125,7 @@ class Meta:
     readable_id = models.CharField(
         max_length=255, unique=True, validators=[validate_url_path_field]
     )
-    live = models.BooleanField(default=False)
+    live = models.BooleanField(default=False, db_index=True)
     program_type = models.CharField(
         max_length=255,
         default="Series",
@@ -295,7 +295,7 @@ def save(self, *args, **kwargs):
                 program=self, node_type=ProgramRequirementNodeType.PROGRAM_ROOT.value
             )
 
-    @property
+    @cached_property
     def courses(self):
         """
         Returns the courses associated with this program via the requirements
@@ -315,7 +315,7 @@ def courses(self):
                     path__startswith=op.path,
                     node_type=ProgramRequirementNodeType.COURSE,
                 )
-                .select_related("course", "course__page")
+                .select_related("course")
                 .all()
             )
 
@@ -436,7 +436,7 @@ class Meta:
     readable_id = models.CharField(
         max_length=255, unique=True, validators=[validate_url_path_field]
     )
-    live = models.BooleanField(default=False)
+    live = models.BooleanField(default=False, db_index=True)
     departments = models.ManyToManyField(Department, blank=True)
     flexible_prices = GenericRelation(
         "flexiblepricing.FlexiblePrice",
@@ -449,7 +449,7 @@ class Meta:
         content_type_field="courseware_content_type",
     )
 
-    @property
+    @cached_property
     def course_number(self):
         """
         Returns:
@@ -523,6 +523,7 @@ def programs(self):
             ProgramRequirement.objects.filter(
                 node_type=ProgramRequirementNodeType.COURSE, course=self
             )
+            .all()
             .distinct("program_id")
             .order_by("program_id")
             .values_list("program_id", flat=True)
@@ -575,7 +576,7 @@ class CourseRun(TimestampedModel):
 
     objects = CourseRunQuerySet.as_manager()
     course = models.ForeignKey(
-        Course, on_delete=models.CASCADE, related_name="courseruns"
+        Course, on_delete=models.CASCADE, related_name="courseruns", db_index=True
     )
     # product = GenericRelation(Product, related_query_name="course_run")
     title = models.CharField(
@@ -633,7 +634,9 @@ class CourseRun(TimestampedModel):
 
     live = models.BooleanField(default=False)
     is_self_paced = models.BooleanField(default=False)
-    products = GenericRelation("ecommerce.Product", related_query_name="courseruns")
+    products = GenericRelation(
+        "ecommerce.Product", related_query_name="courserunproducts"
+    )
 
     class Meta:
         unique_together = ("course", "run_tag")