Merge pull request #26737 from blaggacao/feat/cache-control

feat: add cache control

frappe/app.py

@@ -8,6 +8,7 @@ import os
 import re
 
 from werkzeug.exceptions import HTTPException, NotFound
+from werkzeug.http import generate_etag, is_resource_modified, quote_etag
 from werkzeug.middleware.profiler import ProfilerMiddleware
 from werkzeug.middleware.proxy_fix import ProxyFix
 from werkzeug.middleware.shared_data import SharedDataMiddleware
@@ -148,8 +149,13 @@ def application(request: Request):
 			# We can not handle exceptions safely here.
 			frappe.logger().error("Failed to run after request hook", exc_info=True)
 
-		log_request(request, response)
-		process_response(response)
+	log_request(request, response)
+	# return 304 if unmodified
+	if not response.direct_passthrough:
+		etag = generate_etag(response.data)
+		if not is_resource_modified(request.environ, etag):
+			return Response(status=304, headers={"ETag": quote_etag(etag)})
+	process_response(response)
 
 	return response
 
@@ -237,8 +243,26 @@ def process_response(response):
 	if not response:
 		return
 
-	# set cookies
-	if hasattr(frappe.local, "cookie_manager"):
+	# cache control
+	# read: https://simonhearne.com/2022/caching-header-best-practices/
+	if frappe.local.response.can_cache:
+		response.headers.extend(
+			{
+				# default: 5m (proxy), 5m (client), 3h (allow stale resources for this long if upstream is down)
+				"Cache-Control": "public,s-maxage=300,max-age=300,stale-while-revalidate=10800",
+				# for revalidation of a stale resource
+				"ETag": quote_etag(generate_etag(response.data)),
+			}
+		)
+	else:
+		response.headers.extend(
+			{
+				"Cache-Control": "no-store,no-cache,must-revalidate,max-age=0",
+			}
+		)
+
+	# Set cookies, only if response is non-cacheable to avoid proxy cache invalidation
+	if hasattr(frappe.local, "cookie_manager") and not frappe.local.response.can_cache:
 		frappe.local.cookie_manager.flush_cookies(response=response)
 
 	# rate limiter headers

frappe/auth.py

@@ -98,7 +98,7 @@ class HTTPRequest:
 
 
 class LoginManager:
-	__slots__ = ("user", "info", "full_name", "user_type", "resume")
+	__slots__ = ("user", "info", "full_name", "user_type", "user_lang", "resume")
 
 	def __init__(self):
 		self.user = None
@@ -161,7 +161,7 @@ class LoginManager:
 		self.info = frappe.get_cached_value(
 			"User", self.user, ["user_type", "first_name", "last_name", "user_image"], as_dict=1
 		)
-
+		self.user_lang = frappe.translate.get_user_lang()
 		self.user_type = self.info.user_type
 
 	def setup_boot_cache(self):
@@ -198,6 +198,8 @@ class LoginManager:
 		frappe.local.cookie_manager.set_cookie("full_name", self.full_name)
 		frappe.local.cookie_manager.set_cookie("user_id", self.user)
 		frappe.local.cookie_manager.set_cookie("user_image", self.info.user_image or "")
+		# cache control: round trip the effectively delivered language
+		frappe.local.cookie_manager.set_cookie("user_lang", self.user_lang)
 
 	def clear_preferred_language(self):
 		frappe.local.cookie_manager.delete_cookie("preferred_language")
@@ -418,7 +420,9 @@ def get_logged_user():
 def clear_cookies():
 	if hasattr(frappe.local, "session"):
 		frappe.session.sid = ""
-	frappe.local.cookie_manager.delete_cookie(["full_name", "user_id", "sid", "user_image", "system_user"])
+	frappe.local.cookie_manager.delete_cookie(
+		["full_name", "user_id", "sid", "user_image", "user_lang", "system_user"]
+	)
 
 
 def validate_ip_address(user):

frappe/public/js/frappe/request.js

@@ -267,7 +267,7 @@ frappe.request.call = function (opts) {
 			},
 			opts.headers
 		),
-		cache: true,
+		cache: window.dev_server ? false : true,
 	};
 
 	if (opts.args && opts.args.doctype) {

frappe/website/page_renderers/redirect_page.py

@@ -17,6 +17,5 @@ class RedirectPage:
 			self.http_status_code,
 			{
 				"Location": frappe.flags.redirect_location or (frappe.local.response or {}).get("location"),
-				"Cache-Control": "no-store, no-cache, must-revalidate",
 			},
 		)

frappe/website/utils.py

@@ -523,6 +523,7 @@ def cache_html(func):
 				html = page_cache[frappe.local.lang]
 			if html:
 				frappe.local.response.from_cache = True
+				frappe.local.response.can_cache = True
 				return html
 		html = func(*args, **kwargs)
 		context = args[0].context
@@ -530,6 +531,7 @@ def cache_html(func):
 			page_cache = frappe.cache.hget("website_page", args[0].path) or {}
 			page_cache[frappe.local.lang] = html
 			frappe.cache.hset("website_page", args[0].path, page_cache)
+			frappe.local.response.can_cache = True
 
 		return html