net/tools/balsa/balsa_headers_token_utils.h

   1 // Copyright 2013 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 // Utility class that performs basic operations on header value tokens: parsing
   6 // them out, checking for presense of certain tokens, and removing them.
   7
   8 #ifndef NET_TOOLS_BALSA_BALSA_HEADERS_TOKEN_UTILS_H_
   9 #define NET_TOOLS_BALSA_BALSA_HEADERS_TOKEN_UTILS_H_
  10
  11 #include "base/strings/string_piece.h"
  12 #include "net/tools/balsa/balsa_headers.h"
  13
  14 namespace net {
  15
  16 class BalsaHeadersTokenUtils {
  17  public:
  18   // All the functions below respect multiple header lines with the same key.
  19
  20   // Checks whether the last header token matches a given value. Useful to
  21   // check the outer-most content or transfer-encoding, for example. In the
  22   // presence of multiple header lines with given key, the last token of the
  23   // last line is compared.
  24   static bool CheckHeaderForLastToken(const BalsaHeaders& headers,
  25                                       const base::StringPiece& key,
  26                                       const base::StringPiece& token);
  27
  28   // Tokenizes header value for a given key. In the presence of multiple lines
  29   // with that key, all of them will be tokenized and tokens will be added to
  30   // the list in the order in which they are encountered.
  31   static void TokenizeHeaderValue(const BalsaHeaders& headers,
  32                                   const base::StringPiece& key,
  33                                   BalsaHeaders::HeaderTokenList* tokens);
  34
  35   // Removes the last token from the header value. In the presence of multiple
  36   // header lines with given key, will remove the last token of the last line.
  37   // Can be useful if the last encoding has to be removed.
  38   static void RemoveLastTokenFromHeaderValue(const base::StringPiece& key,
  39                                              BalsaHeaders* headers);
  40
  41   // Given a pointer to the beginning and the end of the header value
  42   // in some buffer, populates tokens list with beginning and end indices
  43   // of all tokens present in the value string.
  44   static void ParseTokenList(const char* start,
  45                              const char* end,
  46                              BalsaHeaders::HeaderTokenList* tokens);
  47
  48  private:
  49   // Helper function to tokenize a header line once we have its description.
  50   static void TokenizeHeaderLine(
  51       const BalsaHeaders& headers,
  52       const BalsaHeaders::HeaderLineDescription& line,
  53       BalsaHeaders::HeaderTokenList* tokens);
  54
  55   BalsaHeadersTokenUtils();  // Prohibit instantiation
  56 };
  57
  58 }  // namespace net
  59
  60 #endif  // NET_TOOLS_BALSA_BALSA_HEADERS_TOKEN_UTILS_H_
  61