file_util_icu.cc revision ca12bfac764ba476d6cd062bf1dde12cc64c3f40 
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// File utilities that use the ICU library go in this file.
6
7#include "base/i18n/file_util_icu.h"
8
9#include "base/files/file_path.h"
10#include "base/i18n/icu_string_conversions.h"
11#include "base/i18n/string_compare.h"
12#include "base/logging.h"
13#include "base/memory/scoped_ptr.h"
14#include "base/memory/singleton.h"
15#include "base/strings/string_util.h"
16#include "base/strings/sys_string_conversions.h"
17#include "base/strings/utf_string_conversions.h"
18#include "build/build_config.h"
19#include "third_party/icu/source/common/unicode/uniset.h"
20#include "third_party/icu/source/i18n/unicode/coll.h"
21
22namespace {
23
24class IllegalCharacters {
25 public:
26  static IllegalCharacters* GetInstance() {
27    return Singleton<IllegalCharacters>::get();
28  }
29
30  bool contains(UChar32 ucs4) {
31    return !!set->contains(ucs4);
32  }
33
34  bool containsNone(const string16 &s) {
35    return !!set->containsNone(icu::UnicodeString(s.c_str(), s.size()));
36  }
37
38 private:
39  friend class Singleton<IllegalCharacters>;
40  friend struct DefaultSingletonTraits<IllegalCharacters>;
41
42  IllegalCharacters();
43  ~IllegalCharacters() { }
44
45  scoped_ptr<icu::UnicodeSet> set;
46
47  DISALLOW_COPY_AND_ASSIGN(IllegalCharacters);
48};
49
50IllegalCharacters::IllegalCharacters() {
51  UErrorCode status = U_ZERO_ERROR;
52  // Control characters, formatting characters, non-characters, and
53  // some printable ASCII characters regarded as dangerous ('"*/:<>?\\').
54  // See  http://blogs.msdn.com/michkap/archive/2006/11/03/941420.aspx
55  // and http://msdn2.microsoft.com/en-us/library/Aa365247.aspx
56  // TODO(jungshik): Revisit the set. ZWJ and ZWNJ are excluded because they
57  // are legitimate in Arabic and some S/SE Asian scripts. However, when used
58  // elsewhere, they can be confusing/problematic.
59  // Also, consider wrapping the set with our Singleton class to create and
60  // freeze it only once. Note that there's a trade-off between memory and
61  // speed.
62#if defined(WCHAR_T_IS_UTF16)
63  set.reset(new icu::UnicodeSet(icu::UnicodeString(
64      L"[[\"*/:<>?\\\\|][:Cc:][:Cf:] - [\u200c\u200d]]"), status));
65#else
66  set.reset(new icu::UnicodeSet(UNICODE_STRING_SIMPLE(
67      "[[\"*/:<>?\\\\|][:Cc:][:Cf:] - [\\u200c\\u200d]]").unescape(),
68      status));
69#endif
70  DCHECK(U_SUCCESS(status));
71  // Add non-characters. If this becomes a performance bottleneck by
72  // any chance, do not add these to |set| and change IsFilenameLegal()
73  // to check |ucs4 & 0xFFFEu == 0xFFFEu|, in addiition to calling
74  // containsNone().
75  set->add(0xFDD0, 0xFDEF);
76  for (int i = 0; i <= 0x10; ++i) {
77    int plane_base = 0x10000 * i;
78    set->add(plane_base + 0xFFFE, plane_base + 0xFFFF);
79  }
80  set->freeze();
81}
82
83}  // namespace
84
85namespace file_util {
86
87bool IsFilenameLegal(const string16& file_name) {
88  return IllegalCharacters::GetInstance()->containsNone(file_name);
89}
90
91void ReplaceIllegalCharactersInPath(base::FilePath::StringType* file_name,
92                                    char replace_char) {
93  DCHECK(file_name);
94
95  DCHECK(!(IllegalCharacters::GetInstance()->contains(replace_char)));
96
97  // Remove leading and trailing whitespace.
98  TrimWhitespace(*file_name, TRIM_ALL, file_name);
99
100  IllegalCharacters* illegal = IllegalCharacters::GetInstance();
101  int cursor = 0;  // The ICU macros expect an int.
102  while (cursor < static_cast<int>(file_name->size())) {
103    int char_begin = cursor;
104    uint32 code_point;
105#if defined(OS_MACOSX)
106    // Mac uses UTF-8 encoding for filenames.
107    U8_NEXT(file_name->data(), cursor, static_cast<int>(file_name->length()),
108            code_point);
109#elif defined(OS_WIN)
110    // Windows uses UTF-16 encoding for filenames.
111    U16_NEXT(file_name->data(), cursor, static_cast<int>(file_name->length()),
112             code_point);
113#elif defined(OS_POSIX)
114    // Linux doesn't actually define an encoding. It basically allows anything
115    // except for a few special ASCII characters.
116    unsigned char cur_char = static_cast<unsigned char>((*file_name)[cursor++]);
117    if (cur_char >= 0x80)
118      continue;
119    code_point = cur_char;
120#else
121    NOTREACHED();
122#endif
123
124    if (illegal->contains(code_point)) {
125      file_name->replace(char_begin, cursor - char_begin, 1, replace_char);
126      // We just made the potentially multi-byte/word char into one that only
127      // takes one byte/word, so need to adjust the cursor to point to the next
128      // character again.
129      cursor = char_begin + 1;
130    }
131  }
132}
133
134bool LocaleAwareCompareFilenames(const base::FilePath& a,
135                                 const base::FilePath& b) {
136  UErrorCode error_code = U_ZERO_ERROR;
137  // Use the default collator. The default locale should have been properly
138  // set by the time this constructor is called.
139  scoped_ptr<icu::Collator> collator(icu::Collator::createInstance(error_code));
140  DCHECK(U_SUCCESS(error_code));
141  // Make it case-sensitive.
142  collator->setStrength(icu::Collator::TERTIARY);
143
144#if defined(OS_WIN)
145  return base::i18n::CompareString16WithCollator(collator.get(),
146      WideToUTF16(a.value()), WideToUTF16(b.value())) == UCOL_LESS;
147
148#elif defined(OS_POSIX)
149  // On linux, the file system encoding is not defined. We assume
150  // SysNativeMBToWide takes care of it.
151  return base::i18n::CompareString16WithCollator(collator.get(),
152      WideToUTF16(base::SysNativeMBToWide(a.value().c_str())),
153      WideToUTF16(base::SysNativeMBToWide(b.value().c_str()))) == UCOL_LESS;
154#else
155  #error Not implemented on your system
156#endif
157}
158
159void NormalizeFileNameEncoding(base::FilePath* file_name) {
160#if defined(OS_CHROMEOS)
161  std::string normalized_str;
162  if (base::ConvertToUtf8AndNormalize(file_name->BaseName().value(),
163                                      base::kCodepageUTF8,
164                                      &normalized_str)) {
165    *file_name = file_name->DirName().Append(base::FilePath(normalized_str));
166  }
167#endif
168}
169
170}  // namespace
171