Add cache_page and simplify etag see HEA-872

Author: girumb

apps/baseline/viewsets.py

@@ -2,7 +2,10 @@
 from django.conf import settings
 from django.db import models
 from django.db.models import Q, Subquery
+from django.utils.decorators import method_decorator
 from django.utils.translation import override
+from django.views.decorators.cache import cache_page
+from django.views.decorators.http import etag
 from django_filters import rest_framework as filters
 from django_filters.filters import CharFilter
 from rest_framework.permissions import AllowAny
@@ -12,7 +15,7 @@
 
 from common.fields import translation_fields
 from common.filters import MultiFieldFilter, UpperCaseFilter
-from common.utils import etag_response
+from common.utils import get_etag_for_cachedrequest
 from common.viewsets import AggregatingViewSet, BaseModelViewSet
 
 from .models import (
@@ -265,7 +268,8 @@ def get_serializer_class(self):
             return LivelihoodZoneBaselineGeoSerializer  # Use GeoFeatureModelSerializer for GeoJSON
         return LivelihoodZoneBaselineSerializer
 
-    @etag_response()
+    @method_decorator(cache_page(60 * 60 * 24))  # Cache on server for 24 hours
+    @method_decorator(etag(get_etag_for_cachedrequest))
     def list(self, request, *args, **kwargs):
         return super().list(request, *args, **kwargs)
 

apps/common/utils.py

@@ -4,23 +4,19 @@
 import importlib
 import logging
 import re
-import time
 from copy import deepcopy
 from datetime import datetime, timedelta
-from functools import wraps
 from io import BytesIO, StringIO
 from pathlib import Path
 from urllib.parse import parse_qs, urlencode, urlparse
 
 import pandas as pd
 from django.apps import apps
-from django.db import connection, reset_queries
 from django.db.migrations.operations.base import Operation
 from django.forms.models import modelform_factory
 from django.utils.cache import set_response_etag
 from django.utils.timezone import now
 from openpyxl.utils import get_column_letter
-from rest_framework.response import Response
 from treebeard.mp_tree import MP_Node
 
 logger = logging.getLogger(__name__)
@@ -396,10 +392,6 @@ def timekeeper():
 def get_etag_for_cachedrequest(request, *args, **kwargs):
     """
     Generate an ETag for the request based on path and query parameters.
-
-    This is a simplified version that generates ETags without requiring a CachedRequest model
-    or permissions system. The ETag is deterministic based on the request URL.
-
     If the request includes a _refresh parameter, returns None to force a cache miss.
     """
     u = urlparse(request.get_full_path())
@@ -435,120 +427,3 @@ def set_etag_for_response(response):
         logger.info("Created etag header in %s seconds" % round(t.elapsed().total_seconds(), 2))
 
     return response
-
-
-def etag_response(etag_func=None, enable_etag=True):
-    """
-    Decorator that adds ETag support with 304 Not Modified responses for DRF viewsets.
-    """
-
-    if etag_func is None:
-        etag_func = get_etag_for_cachedrequest
-
-    def decorator(view_func):
-        @wraps(view_func)
-        def wrapped_view(self, request, *args, **kwargs):
-            start_time = time.time()
-
-            # Reset query count for accurate measurement
-            reset_queries()
-            initial_query_count = len(connection.queries)
-
-            # Generate ETag based on request using existing function
-            etag_start = time.time()
-            etag = etag_func(request, *args, **kwargs)
-            etag_time = time.time() - etag_start
-
-            # Check if ETag caching is enabled and client sent matching ETag
-            client_etag = request.META.get("HTTP_IF_NONE_MATCH")
-
-            # Normalize ETags for comparison (handle weak ETags with W/ prefix)
-            def normalize_etag(etag_value):
-                """Strip W/ prefix from weak ETags for comparison."""
-                if etag_value:
-                    return etag_value.replace("W/", "").strip()
-                return etag_value
-
-            normalized_client_etag = normalize_etag(client_etag)
-            normalized_server_etag = normalize_etag(etag)
-
-            # Log for debugging browser issues
-            if client_etag:
-                logger.debug(
-                    f"Client ETag: {client_etag} (normalized: {normalized_client_etag}), "
-                    f"Server ETag: {etag} (normalized: {normalized_server_etag})"
-                )
-
-            if enable_etag and etag and normalized_client_etag == normalized_server_etag:
-                # Cache HIT - return 304
-                response = Response(status=304)
-                response["ETag"] = etag
-                # Ensure Vary header is set for browser caching
-                response["Vary"] = "Accept, Accept-Language, Cookie"
-
-                elapsed_time = time.time() - start_time
-                query_count = len(connection.queries) - initial_query_count
-
-                logger.info(
-                    f"[ETAG HIT] "
-                    f"path={request.path} | "
-                    f"etag={etag[:12]}... | "
-                    f"time={elapsed_time:.3f}s | "
-                    f"etag_gen={etag_time:.3f}s | "
-                    f"queries={query_count} | "
-                    f"size=0 bytes | "
-                    f"status=304"
-                )
-                return response
-            elif enable_etag and client_etag and etag:
-                # Client sent ETag but it doesn't match
-                logger.debug(f"[ETAG MISMATCH] Client: {client_etag} vs Server: {etag}")
-
-            # Cache MISS or ETag disabled - render full response
-            render_start = time.time()
-            response = view_func(self, request, *args, **kwargs)
-            render_time = time.time() - render_start
-
-            if enable_etag and etag:
-                response["ETag"] = etag
-                response["Cache-Control"] = "public, max-age=2592000"  # 30 days
-                existing_vary = response.get("Vary", "")
-                if "Accept" not in existing_vary:
-                    response["Vary"] = "Accept, Accept-Language, Cookie"
-
-            # Calculate metrics
-            elapsed_time = time.time() - start_time
-            query_count = len(connection.queries) - initial_query_count
-
-            # Get response size safely
-            response_size = 0
-            try:
-                # Try to get size from data attribute first (DRF Response)
-                if hasattr(response, "data"):
-                    # Estimate size from data length
-                    response_size = len(str(response.data))
-                elif hasattr(response, "content"):
-                    response_size = len(response.content)
-            except (AssertionError, AttributeError):
-                # If we can't determine size, just log 0
-                response_size = 0
-
-            # Log with different prefix based on whether ETag is enabled
-            log_prefix = "[ETAG MISS]" if enable_etag else "[NO ETAG]"
-            logger.info(
-                f"{log_prefix} "
-                f"path={request.path} | "
-                f"etag={etag[:12] if etag else 'None'}... | "
-                f"time={elapsed_time:.3f}s | "
-                f"etag_gen={etag_time:.3f}s | "
-                f"render={render_time:.3f}s | "
-                f"queries={query_count} | "
-                f"size={response_size:,} bytes (estimated) | "
-                f"status={response.status_code}"
-            )
-
-            return response
-
-        return wrapped_view
-
-    return decorator