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
14namespace net {
15
16class 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
62