general.rb in async-http-cache-0.4.3

- old
+ new

@@ -1,27 +1,28 @@
 # frozen_string_literal: true
 
 # Copyright, 2020, by Samuel G. D. Williams. <http://www.codeotaku.com>
-# 
+#
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
 # in the Software without restriction, including without limitation the rights
 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 # copies of the Software, and to permit persons to whom the Software is
 # furnished to do so, subject to the following conditions:
-# 
+#
 # The above copyright notice and this permission notice shall be included in
 # all copies or substantial portions of the Software.
-# 
+#
 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 
+require 'set'
 require 'protocol/http/middleware'
 
 require_relative 'body'
 require_relative 'response'
 require_relative 'store'
@@ -29,105 +30,125 @@
 module Async
 	module HTTP
 		module Cache
 			class General < ::Protocol::HTTP::Middleware
 				CACHE_CONTROL  = 'cache-control'
-				
+
 				CONTENT_TYPE = 'content-type'
 				AUTHORIZATION = 'authorization'
 				COOKIE = 'cookie'
-				
+
+				# Status codes of responses that MAY be stored by a cache or used in reply
+				# to a subsequent request.
+				#
+				# http://tools.ietf.org/html/rfc2616#section-13.4
+				CACHEABLE_RESPONSE_CODES = {
+					200 => true, # OK
+					203 => true, # Non-Authoritative Information
+					300 => true, # Multiple Choices
+					301 => true, # Moved Permanently
+					302 => true, # Found
+					404 => true, # Not Found
+					410 => true  # Gone
+				}.freeze
+
 				def initialize(app, store: Store.default)
 					super(app)
-					
+
 					@count = 0
-					
+
 					@store = store
 				end
-				
+
 				attr :count
 				attr :store
-				
+
 				def close
 					@store.close
 				ensure
 					super
 				end
-				
+
 				def key(request)
 					@store.normalize(request)
-					
+
 					[request.authority, request.method, request.path]
 				end
-				
+
 				def cacheable?(request)
-					# We don't support caching requests which have a body:
+					# We don't support caching requests which have a request body:
 					if request.body
 						return false
 					end
-					
+
 					# We can't cache upgraded requests:
 					if request.protocol
 						return false
 					end
-					
+
 					# We only support caching GET and HEAD requests:
 					unless request.method == 'GET' || request.method == 'HEAD'
 						return false
 					end
-					
+
 					if request.headers[AUTHORIZATION]
 						return false
 					end
-					
+
 					if request.headers[COOKIE]
 						return false
 					end
-					
+
 					# Otherwise, we can cache it:
 					return true
 				end
-				
+
 				def wrap(key, request, response)
-					if response.status != 200
+					unless CACHEABLE_RESPONSE_CODES.include?(response.status)
 						return response
 					end
-					
+
+					response_cache_control = response.headers[CACHE_CONTROL]
+
+					if response_cache_control&.no_store? || response_cache_control&.private?
+						return response
+					end
+
 					if request.head? and body = response.body
 						unless body.empty?
 							Console.logger.warn(self) {"HEAD request resulted in non-empty body!"}
-							
+
 							return response
 						end
 					end
-					
+
 					return Body.wrap(response) do |response, body|
 						Console.logger.debug(self) {"Updating cache for #{key}..."}
 						@store.insert(key, request, Response.new(response, body))
 					end
 				end
-				
+
 				def call(request)
 					key = self.key(request)
-					
+
 					cache_control = request.headers[CACHE_CONTROL]
-					
+
 					unless cache_control&.no_cache?
 						if response = @store.lookup(key, request)
 							Console.logger.debug(self) {"Cache hit for #{key}..."}
 							@count += 1
-							
+
 							# Return the cached response:
 							return response
 						end
 					end
-					
+
 					unless cache_control&.no_store?
 						if cacheable?(request)
 							return wrap(key, request, super)
 						end
 					end
-					
+
 					return super
 				end
 			end
 		end
 	end