net/http/http_request_headers.h

   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 // HttpRequestHeaders manages the request headers.
   6 // It maintains these in a vector of header key/value pairs, thereby maintaining
   7 // the order of the headers.  This means that any lookups are linear time
   8 // operations.
   9
  10 #ifndef NET_HTTP_HTTP_REQUEST_HEADERS_H_
  11 #define NET_HTTP_HTTP_REQUEST_HEADERS_H_
  12
  13 #include <string>
  14 #include <vector>
  15
  16 #include "base/basictypes.h"
  17 #include "base/strings/string_piece.h"
  18 #include "net/base/net_export.h"
  19 #include "net/base/net_log.h"
  20
  21 namespace net {
  22
  23 class NET_EXPORT HttpRequestHeaders {
  24  public:
  25   struct HeaderKeyValuePair {
  26     HeaderKeyValuePair();
  27     HeaderKeyValuePair(const base::StringPiece& key,
  28                        const base::StringPiece& value);
  29
  30     std::string key;
  31     std::string value;
  32   };
  33
  34   typedef std::vector<HeaderKeyValuePair> HeaderVector;
  35
  36   class NET_EXPORT Iterator {
  37    public:
  38     explicit Iterator(const HttpRequestHeaders& headers);
  39     ~Iterator();
  40
  41     // Advances the iterator to the next header, if any.  Returns true if there
  42     // is a next header.  Use name() and value() methods to access the resultant
  43     // header name and value.
  44     bool GetNext();
  45
  46     // These two accessors are only valid if GetNext() returned true.
  47     const std::string& name() const { return curr_->key; }
  48     const std::string& value() const { return curr_->value; }
  49
  50    private:
  51     bool started_;
  52     HttpRequestHeaders::HeaderVector::const_iterator curr_;
  53     const HttpRequestHeaders::HeaderVector::const_iterator end_;
  54
  55     DISALLOW_COPY_AND_ASSIGN(Iterator);
  56   };
  57
  58   static const char kGetMethod[];
  59
  60   static const char kAcceptCharset[];
  61   static const char kAcceptEncoding[];
  62   static const char kAcceptLanguage[];
  63   static const char kAuthorization[];
  64   static const char kCacheControl[];
  65   static const char kConnection[];
  66   static const char kContentType[];
  67   static const char kCookie[];
  68   static const char kContentLength[];
  69   static const char kHost[];
  70   static const char kIfModifiedSince[];
  71   static const char kIfNoneMatch[];
  72   static const char kIfRange[];
  73   static const char kOrigin[];
  74   static const char kPragma[];
  75   static const char kProxyAuthorization[];
  76   static const char kProxyConnection[];
  77   static const char kRange[];
  78   static const char kReferer[];
  79   static const char kUserAgent[];
  80   static const char kTransferEncoding[];
  81
  82   HttpRequestHeaders();
  83   ~HttpRequestHeaders();
  84
  85   bool IsEmpty() const { return headers_.empty(); }
  86
  87   bool HasHeader(const base::StringPiece& key) const {
  88     return FindHeader(key) != headers_.end();
  89   }
  90
  91   // Gets the first header that matches |key|.  If found, returns true and
  92   // writes the value to |out|.
  93   bool GetHeader(const base::StringPiece& key, std::string* out) const;
  94
  95   // Clears all the headers.
  96   void Clear();
  97
  98   // Sets the header value pair for |key| and |value|.  If |key| already exists,
  99   // then the header value is modified, but the key is untouched, and the order
 100   // in the vector remains the same.  When comparing |key|, case is ignored.
 101   void SetHeader(const base::StringPiece& key, const base::StringPiece& value);
 102
 103   // Sets the header value pair for |key| and |value|, if |key| does not exist.
 104   // If |key| already exists, the call is a no-op.
 105   // When comparing |key|, case is ignored.
 106   void SetHeaderIfMissing(const base::StringPiece& key,
 107                           const base::StringPiece& value);
 108
 109   // Removes the first header that matches (case insensitive) |key|.
 110   void RemoveHeader(const base::StringPiece& key);
 111
 112   // Parses the header from a string and calls SetHeader() with it.  This string
 113   // should not contain any CRLF.  As per RFC2616, the format is:
 114   //
 115   // message-header = field-name ":" [ field-value ]
 116   // field-name     = token
 117   // field-value    = *( field-content | LWS )
 118   // field-content  = <the OCTETs making up the field-value
 119   //                  and consisting of either *TEXT or combinations
 120   //                  of token, separators, and quoted-string>
 121   //
 122   // AddHeaderFromString() will trim any LWS surrounding the
 123   // field-content.
 124   void AddHeaderFromString(const base::StringPiece& header_line);
 125
 126   // Same thing as AddHeaderFromString() except that |headers| is a "\r\n"
 127   // delimited string of header lines.  It will split up the string by "\r\n"
 128   // and call AddHeaderFromString() on each.
 129   void AddHeadersFromString(const base::StringPiece& headers);
 130
 131   // Calls SetHeader() on each header from |other|, maintaining order.
 132   void MergeFrom(const HttpRequestHeaders& other);
 133
 134   // Copies from |other| to |this|.
 135   void CopyFrom(const HttpRequestHeaders& other) {
 136     *this = other;
 137   }
 138
 139   void Swap(HttpRequestHeaders* other) {
 140     headers_.swap(other->headers_);
 141   }
 142
 143   // Serializes HttpRequestHeaders to a string representation.  Joins all the
 144   // header keys and values with ": ", and inserts "\r\n" between each header
 145   // line, and adds the trailing "\r\n".
 146   std::string ToString() const;
 147
 148   // Takes in the request line and returns a Value for use with the NetLog
 149   // containing both the request line and all headers fields.
 150   base::Value* NetLogCallback(const std::string* request_line,
 151                               NetLog::LogLevel log_level) const;
 152
 153   // Takes in a Value created by the above function, and attempts to extract the
 154   // request line and create a copy of the original headers.  Returns true on
 155   // success.  On failure, clears |headers| and |request_line|.
 156   // TODO(mmenke):  Long term, we want to remove this, and migrate external
 157   //                consumers to be NetworkDelegates.
 158   static bool FromNetLogParam(const base::Value* event_param,
 159                               HttpRequestHeaders* headers,
 160                               std::string* request_line);
 161
 162  private:
 163   HeaderVector::iterator FindHeader(const base::StringPiece& key);
 164   HeaderVector::const_iterator FindHeader(const base::StringPiece& key) const;
 165
 166   HeaderVector headers_;
 167
 168   // Allow the copy construction and operator= to facilitate copying in
 169   // HttpRequestHeaders.
 170   // TODO(willchan): Investigate to see if we can remove the need to copy
 171   // HttpRequestHeaders.
 172   // DISALLOW_COPY_AND_ASSIGN(HttpRequestHeaders);
 173 };
 174
 175 }  // namespace net
 176
 177 #endif  // NET_HTTP_HTTP_REQUEST_HEADERS_H_