1 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef NET_HTTP_HTTP_VARY_DATA_H__ 6 #define NET_HTTP_HTTP_VARY_DATA_H__ 7 #pragma once 8 9 #include "base/md5.h" 10 11 class Pickle; 12 13 namespace net { 14 15 struct HttpRequestInfo; 16 class HttpResponseHeaders; 17 18 // Used to implement the HTTP/1.1 Vary header. This class contains a MD5 hash 19 // over the request headers indicated by a Vary header. 20 // 21 // While RFC 2616 requires strict request header comparisons, it is much 22 // cheaper to store a MD5 sum, which should be sufficient. Storing a hash also 23 // avoids messy privacy issues as some of the request headers could hold 24 // sensitive data (e.g., cookies). 25 // 26 // NOTE: This class does not hold onto the contents of the Vary header. 27 // Instead, it relies on the consumer to store that and to supply it again to 28 // the MatchesRequest function for comparing against future HTTP requests. 29 // 30 class HttpVaryData { 31 public: 32 HttpVaryData(); 33 is_valid()34 bool is_valid() const { return is_valid_; } 35 36 // Initialize from a request and its corresponding response headers. 37 // 38 // Returns true if a Vary header was found in the response headers and that 39 // Vary header was not empty and did not contain the '*' value. Upon 40 // success, the object is also marked as valid such that is_valid() will 41 // return true. Otherwise, false is returned to indicate that this object 42 // is marked as invalid. 43 // 44 bool Init(const HttpRequestInfo& request_info, 45 const HttpResponseHeaders& response_headers); 46 47 // Initialize from a pickle that contains data generated by a call to the 48 // vary data's Persist method. 49 // 50 // Upon success, true is returned and the object is marked as valid such that 51 // is_valid() will return true. Otherwise, false is returned to indicate 52 // that this object is marked as invalid. 53 // 54 bool InitFromPickle(const Pickle& pickle, void** pickle_iter); 55 56 // Call this method to persist the vary data. Illegal to call this on an 57 // invalid object. 58 void Persist(Pickle* pickle) const; 59 60 // Call this method to test if the given request matches the previous request 61 // with which this vary data corresponds. The |cached_response_headers| must 62 // be the same response headers used to generate this vary data. 63 bool MatchesRequest(const HttpRequestInfo& request_info, 64 const HttpResponseHeaders& cached_response_headers) const; 65 66 private: 67 // Returns the corresponding request header value. 68 static std::string GetRequestValue(const HttpRequestInfo& request_info, 69 const std::string& request_header); 70 71 // Append to the MD5 context for the given request header. 72 static void AddField(const HttpRequestInfo& request_info, 73 const std::string& request_header, 74 MD5Context* context); 75 76 // A digested version of the request headers corresponding to the Vary header. 77 MD5Digest request_digest_; 78 79 // True when request_digest_ contains meaningful data. 80 bool is_valid_; 81 }; 82 83 } // namespace net 84 85 #endif // NET_HTTP_HTTP_VARY_DATA_H__ 86