1 // Copyright (c) 2012 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 8 #include "base/md5.h" 9 #include "net/base/net_export.h" 10 11 class Pickle; 12 class PickleIterator; 13 14 namespace net { 15 16 struct HttpRequestInfo; 17 class HttpResponseHeaders; 18 19 // Used to implement the HTTP/1.1 Vary header. This class contains a MD5 hash 20 // over the request headers indicated by a Vary header. 21 // 22 // While RFC 2616 requires strict request header comparisons, it is much 23 // cheaper to store a MD5 sum, which should be sufficient. Storing a hash also 24 // avoids messy privacy issues as some of the request headers could hold 25 // sensitive data (e.g., cookies). 26 // 27 // NOTE: This class does not hold onto the contents of the Vary header. 28 // Instead, it relies on the consumer to store that and to supply it again to 29 // the MatchesRequest function for comparing against future HTTP requests. 30 // 31 class NET_EXPORT_PRIVATE HttpVaryData { 32 public: 33 HttpVaryData(); 34 35 bool is_valid() const { return is_valid_; } 36 37 // Initialize from a request and its corresponding response headers. 38 // 39 // Returns true if a Vary header was found in the response headers and that 40 // Vary header was not empty and did not contain the '*' value. Upon 41 // success, the object is also marked as valid such that is_valid() will 42 // return true. Otherwise, false is returned to indicate that this object 43 // is marked as invalid. 44 // 45 bool Init(const HttpRequestInfo& request_info, 46 const HttpResponseHeaders& response_headers); 47 48 // Initialize from a pickle that contains data generated by a call to the 49 // vary data's Persist method. 50 // 51 // Upon success, true is returned and the object is marked as valid such that 52 // is_valid() will return true. Otherwise, false is returned to indicate 53 // that this object is marked as invalid. 54 // 55 bool InitFromPickle(const Pickle& pickle, PickleIterator* pickle_iter); 56 57 // Call this method to persist the vary data. Illegal to call this on an 58 // invalid object. 59 void Persist(Pickle* pickle) const; 60 61 // Call this method to test if the given request matches the previous request 62 // with which this vary data corresponds. The |cached_response_headers| must 63 // be the same response headers used to generate this vary data. 64 bool MatchesRequest(const HttpRequestInfo& request_info, 65 const HttpResponseHeaders& cached_response_headers) const; 66 67 private: 68 // Returns the corresponding request header value. 69 static std::string GetRequestValue(const HttpRequestInfo& request_info, 70 const std::string& request_header); 71 72 // Append to the MD5 context for the given request header. 73 static void AddField(const HttpRequestInfo& request_info, 74 const std::string& request_header, 75 base::MD5Context* context); 76 77 // A digested version of the request headers corresponding to the Vary header. 78 base::MD5Digest request_digest_; 79 80 // True when request_digest_ contains meaningful data. 81 bool is_valid_; 82 }; 83 84 } // namespace net 85 86 #endif // NET_HTTP_HTTP_VARY_DATA_H_ 87
