django-cacheops

import os import django from django.conf import settings from django.db import models # Minimal Django settings for a runnable example # In a real project, these would be in your settings.py if not settings.configured: settings.configure( INSTALLED_APPS=[ 'django.contrib.auth', 'django.contrib.contenttypes', 'cacheops', # Add cacheops to your installed apps 'myapp', # A dummy app for model definition ], CACHEOPS_REDIS=os.environ.get('CACHEOPS_REDIS', 'redis://localhost:6379/1'), # CACHEOPS_ENABLED defaults to True since v7.0 # CACHEOPS_TIMEOUT defaults to 3600 (1 hour) since v7.0 DATABASES={ 'default': { 'ENGINE': 'django.db.backends.sqlite3', 'NAME': ':memory:', } }, USE_TZ=True, TIME_ZONE='UTC', ) django.setup() # Define a simple Django model. For demonstration, we use 'myapp' as app_label. class Post(models.Model): title = models.CharField(max_length=200) body = models.TextField() created_at = models.DateTimeField(auto_now_add=True) class Meta: app_label = 'myapp' # Required when defining models outside an actual app directory def __str__(self): return self.title # Ensure the database schema is created for the model (for in-memory SQLite) from django.db import connection with connection.schema_editor() as schema_editor: schema_editor.create_model(Post) print(f"Using Redis connection string: {settings.CACHEOPS_REDIS}") # Create some sample data Post.objects.create(title="First Post", body="Content of the first post.") Post.objects.create(title="Second Article", body="More content here.") # --- Example 1: Caching a Queryset --- print("\n--- Example 1: Caching a Queryset ---") # The .cache() method makes the queryset result be cached. # First call will hit the database and store the result in cache. posts = Post.objects.filter(title__icontains='post').cache().all() print(f"Posts (first fetch, hits DB and caches): {[p.title for p in posts]}") # Subsequent calls with the same query parameters will hit the cache. posts_cached = Post.objects.filter(title__icontains='post').cache().all() print(f"Posts (second fetch, should hit cache): {[p.title for p in posts_cached]}") # --- Example 2: Invalidating Cache --- from cacheops import invalidate_model print("\n--- Example 2: Invalidating Cache ---") # Update an object (usually auto-invalidates if configured) post_to_update = Post.objects.get(title="First Post") post_to_update.title = "Updated First Post" post_to_update.save() # Explicitly invalidate all caches related to the Post model invalidate_model(Post) print("Post model cache explicitly invalidated.") # Fetching again will hit the DB to get the updated data and re-cache. updated_posts = Post.objects.filter(title__icontains='post').cache().all() print(f"Posts after update and invalidation: {[p.title for p in updated_posts]}") # --- Example 3: Using @cached_queryset decorator --- from cacheops import cached_queryset print("\n--- Example 3: Using @cached_queryset decorator ---") @cached_queryset def get_latest_articles(limit=1): print(" (Fetching from DB inside get_latest_articles)") return Post.objects.order_by('-created_at')[:limit] # First call of the decorated function latest1 = get_latest_articles() print(f"Latest article (first call): {[p.title for p in latest1]}") # Second call of the decorated function should hit the cache latest2 = get_latest_articles() print(f"Latest article (second call, should hit cache): {[p.title for p in latest2]}")