cache-control: add must-revalidate, proxy-revalidate, s-maxage

Author: zarqman

lib/protocol/http/header/cache_control.rb

@@ -14,11 +14,15 @@ class CacheControl < Split
 				NO_CACHE = 'no-cache'
 				NO_STORE = 'no-store'
 				MAX_AGE = 'max-age'
+				S_MAXAGE = 's-maxage'
 
 				STATIC = 'static'
 				DYNAMIC = 'dynamic'
 				STREAMING = 'streaming'
 
+				MUST_REVALIDATE = 'must-revalidate'
+				PROXY_REVALIDATE = 'proxy-revalidate'
+				
 				def initialize(value = nil)
 					super(value&.downcase)
 				end
@@ -55,11 +59,40 @@ def no_store?
 					self.include?(NO_STORE)
 				end
 
+				# Indicates that a response must not be used once it is stale.
+				# See https://www.rfc-editor.org/rfc/rfc9111.html#name-must-revalidate
+				def must_revalidate?
+					self.include?(MUST_REVALIDATE)
+				end
+				
+				# Like must-revalidate, but for shared caches only.
+				# See https://www.rfc-editor.org/rfc/rfc9111.html#name-proxy-revalidate
+				def proxy_revalidate?
+					self.include?(PROXY_REVALIDATE)
+				end
+				
+				# The maximum time, in seconds, a response should be considered fresh.
+				# See https://www.rfc-editor.org/rfc/rfc9111.html#name-max-age-2
 				def max_age
 					if value = self.find{|value| value.start_with?(MAX_AGE)}
 						_, age = value.split('=', 2)
 
-						return Integer(age)
+						if age =~ /^[0-9]+$/
+							return Integer(age)
+						end
+					end
+				end
+				
+				# Like max-age, but for shared caches only, which should use it before
+				# max-age when present.
+				# See https://www.rfc-editor.org/rfc/rfc9111.html#name-s-maxage
+				def s_maxage
+					if value = self.find{|value| value.start_with?(S_MAXAGE)}
+						_, age = value.split('=', 2)
+						
+						if age =~ /^[0-9]+$/
+							return Integer(age)
+						end
 					end
 				end
 			end

test/protocol/http/header/cache_control.rb

@@ -8,12 +8,22 @@
 describe Protocol::HTTP::Header::CacheControl do
 	let(:header) {subject.new(description)}
 
-	with "max-age=60, public" do
+	with "max-age=60, s-maxage=30, public" do
 		it "correctly parses cache header" do
 			expect(header).to have_attributes(
 				public?: be == true,
 				private?: be == false,
 				max_age: be == 60,
+				s_maxage: be == 30,
+			)
+		end
+	end
+	
+	with "max-age=-10, s-maxage=0x22" do
+		it "gracefully handles invalid values" do
+			expect(header).to have_attributes(
+				max_age: be == nil,
+				s_maxage: be == nil,
 			)
 		end
 	end
@@ -51,6 +61,22 @@
 		end
 	end
 
+	with "must-revalidate" do
+		it "correctly parses cache header" do
+			expect(header).to have_attributes(
+				must_revalidate?: be == true,
+			)
+		end
+	end
+	
+	with "proxy-revalidate" do
+		it "correctly parses cache header" do
+			expect(header).to have_attributes(
+				proxy_revalidate?: be == true,
+			)
+		end
+	end
+	
 	with "#<<" do
 		let(:header) {subject.new}