base/i18n/file_util_icu.cc

   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
  22 namespace base {
  23 namespace i18n {
  24
  25 namespace {
  26
  27 class 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
  53 IllegalCharacters::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
  88 bool IsFilenameLegal(const string16& file_name) {
  89   return IllegalCharacters::GetInstance()->containsNone(file_name);
  90 }
  91
  92 void 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
 135 bool 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
 160 void 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