file_util_icu.cc revision 6e8cce623b6e4fe0c9e4af605d675dd9d0338c38 
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 base {
23namespace i18n {
24
25namespace {
26
27class IllegalCharacters {
28 public:
29  static IllegalCharacters* GetInstance() {
30    return Singleton<IllegalCharacters>::get();
31  }
32
33  bool contains(UChar32 ucs4) {
34    return !!set->contains(ucs4);
35  }
36
37  bool containsNone(const string16 &s) {
38    return !!set->containsNone(icu::UnicodeString(s.c_str(), s.size()));
39  }
40
41 private:
42  friend class Singleton<IllegalCharacters>;
43  friend struct DefaultSingletonTraits<IllegalCharacters>;
44
45  IllegalCharacters();
46  ~IllegalCharacters() { }
47
48  scoped_ptr<icu::UnicodeSet> set;
49
50  DISALLOW_COPY_AND_ASSIGN(IllegalCharacters);
51};
52
53IllegalCharacters::IllegalCharacters() {
54  UErrorCode status = U_ZERO_ERROR;
55  // Control characters, formatting characters, non-characters, and
56  // some printable ASCII characters regarded as dangerous ('"*/:<>?\\').
57  // See  http://blogs.msdn.com/michkap/archive/2006/11/03/941420.aspx
58  // and http://msdn2.microsoft.com/en-us/library/Aa365247.aspx
59  // TODO(jungshik): Revisit the set. ZWJ and ZWNJ are excluded because they
60  // are legitimate in Arabic and some S/SE Asian scripts. However, when used
61  // elsewhere, they can be confusing/problematic.
62  // Also, consider wrapping the set with our Singleton class to create and
63  // freeze it only once. Note that there's a trade-off between memory and
64  // speed.
65#if defined(WCHAR_T_IS_UTF16)
66  set.reset(new icu::UnicodeSet(icu::UnicodeString(
67      L"[[\"*/:<>?\\\\|][:Cc:][:Cf:] - [\u200c\u200d]]"), status));
68#else
69  set.reset(new icu::UnicodeSet(UNICODE_STRING_SIMPLE(
70      "[[\"*/:<>?\\\\|][:Cc:][:Cf:] - [\\u200c\\u200d]]").unescape(),
71      status));
72#endif
73  DCHECK(U_SUCCESS(status));
74  // Add non-characters. If this becomes a performance bottleneck by
75  // any chance, do not add these to |set| and change IsFilenameLegal()
76  // to check |ucs4 & 0xFFFEu == 0xFFFEu|, in addiition to calling
77  // containsNone().
78  set->add(0xFDD0, 0xFDEF);
79  for (int i = 0; i <= 0x10; ++i) {
80    int plane_base = 0x10000 * i;
81    set->add(plane_base + 0xFFFE, plane_base + 0xFFFF);
82  }
83  set->freeze();
84}
85
86}  // namespace
87
88bool IsFilenameLegal(const string16& file_name) {
89  return IllegalCharacters::GetInstance()->containsNone(file_name);
90}
91
92void ReplaceIllegalCharactersInPath(FilePath::StringType* file_name,
93                                    char replace_char) {
94  DCHECK(file_name);
95
96  DCHECK(!(IllegalCharacters::GetInstance()->contains(replace_char)));
97
98  // Remove leading and trailing whitespace.
99  TrimWhitespace(*file_name, TRIM_ALL, file_name);
100
101  IllegalCharacters* illegal = IllegalCharacters::GetInstance();
102  int cursor = 0;  // The ICU macros expect an int.
103  while (cursor < static_cast<int>(file_name->size())) {
104    int char_begin = cursor;
105    uint32 code_point;
106#if defined(OS_MACOSX)
107    // Mac uses UTF-8 encoding for filenames.
108    U8_NEXT(file_name->data(), cursor, static_cast<int>(file_name->length()),
109            code_point);
110#elif defined(OS_WIN)
111    // Windows uses UTF-16 encoding for filenames.
112    U16_NEXT(file_name->data(), cursor, static_cast<int>(file_name->length()),
113             code_point);
114#elif defined(OS_POSIX)
115    // Linux doesn't actually define an encoding. It basically allows anything
116    // except for a few special ASCII characters.
117    unsigned char cur_char = static_cast<unsigned char>((*file_name)[cursor++]);
118    if (cur_char >= 0x80)
119      continue;
120    code_point = cur_char;
121#else
122    NOTREACHED();
123#endif
124
125    if (illegal->contains(code_point)) {
126      file_name->replace(char_begin, cursor - char_begin, 1, replace_char);
127      // We just made the potentially multi-byte/word char into one that only
128      // takes one byte/word, so need to adjust the cursor to point to the next
129      // character again.
130      cursor = char_begin + 1;
131    }
132  }
133}
134
135bool LocaleAwareCompareFilenames(const FilePath& a, const 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 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 CompareString16WithCollator(
152      collator.get(),
153      WideToUTF16(SysNativeMBToWide(a.value().c_str())),
154      WideToUTF16(SysNativeMBToWide(b.value().c_str()))) == UCOL_LESS;
155#else
156  #error Not implemented on your system
157#endif
158}
159
160void NormalizeFileNameEncoding(FilePath* file_name) {
161#if defined(OS_CHROMEOS)
162  std::string normalized_str;
163  if (ConvertToUtf8AndNormalize(file_name->BaseName().value(),
164                                kCodepageUTF8,
165                                &normalized_str)) {
166    *file_name = file_name->DirName().Append(FilePath(normalized_str));
167  }
168#endif
169}
170
171}  // namespace i18n
172}  // namespace base
173