base/file_util.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 #include "base/file_util.h"
   6
   7 #if defined(OS_WIN)
   8 #include <io.h>
   9 #endif
  10 #include <stdio.h>
  11
  12 #include <fstream>
  13
  14 #include "base/files/file_enumerator.h"
  15 #include "base/files/file_path.h"
  16 #include "base/logging.h"
  17 #include "base/strings/string_piece.h"
  18 #include "base/strings/string_util.h"
  19 #include "base/strings/stringprintf.h"
  20 #include "base/strings/utf_string_conversions.h"
  21
  22 namespace base {
  23
  24 namespace {
  25
  26 // The maximum number of 'uniquified' files we will try to create.
  27 // This is used when the filename we're trying to download is already in use,
  28 // so we create a new unique filename by appending " (nnn)" before the
  29 // extension, where 1 <= nnn <= kMaxUniqueFiles.
  30 // Also used by code that cleans up said files.
  31 static const int kMaxUniqueFiles = 100;
  32
  33 }  // namespace
  34
  35 bool g_bug108724_debug = false;
  36
  37 int64 ComputeDirectorySize(const FilePath& root_path) {
  38   int64 running_size = 0;
  39   FileEnumerator file_iter(root_path, true, FileEnumerator::FILES);
  40   while (!file_iter.Next().empty())
  41     running_size += file_iter.GetInfo().GetSize();
  42   return running_size;
  43 }
  44
  45 bool Move(const FilePath& from_path, const FilePath& to_path) {
  46   if (from_path.ReferencesParent() || to_path.ReferencesParent())
  47     return false;
  48   return internal::MoveUnsafe(from_path, to_path);
  49 }
  50
  51 bool CopyFile(const FilePath& from_path, const FilePath& to_path) {
  52   if (from_path.ReferencesParent() || to_path.ReferencesParent())
  53     return false;
  54   return internal::CopyFileUnsafe(from_path, to_path);
  55 }
  56
  57 bool ContentsEqual(const FilePath& filename1, const FilePath& filename2) {
  58   // We open the file in binary format even if they are text files because
  59   // we are just comparing that bytes are exactly same in both files and not
  60   // doing anything smart with text formatting.
  61   std::ifstream file1(filename1.value().c_str(),
  62                       std::ios::in | std::ios::binary);
  63   std::ifstream file2(filename2.value().c_str(),
  64                       std::ios::in | std::ios::binary);
  65
  66   // Even if both files aren't openable (and thus, in some sense, "equal"),
  67   // any unusable file yields a result of "false".
  68   if (!file1.is_open() || !file2.is_open())
  69     return false;
  70
  71   const int BUFFER_SIZE = 2056;
  72   char buffer1[BUFFER_SIZE], buffer2[BUFFER_SIZE];
  73   do {
  74     file1.read(buffer1, BUFFER_SIZE);
  75     file2.read(buffer2, BUFFER_SIZE);
  76
  77     if ((file1.eof() != file2.eof()) ||
  78         (file1.gcount() != file2.gcount()) ||
  79         (memcmp(buffer1, buffer2, file1.gcount()))) {
  80       file1.close();
  81       file2.close();
  82       return false;
  83     }
  84   } while (!file1.eof() || !file2.eof());
  85
  86   file1.close();
  87   file2.close();
  88   return true;
  89 }
  90
  91 bool TextContentsEqual(const FilePath& filename1, const FilePath& filename2) {
  92   std::ifstream file1(filename1.value().c_str(), std::ios::in);
  93   std::ifstream file2(filename2.value().c_str(), std::ios::in);
  94
  95   // Even if both files aren't openable (and thus, in some sense, "equal"),
  96   // any unusable file yields a result of "false".
  97   if (!file1.is_open() || !file2.is_open())
  98     return false;
  99
 100   do {
 101     std::string line1, line2;
 102     getline(file1, line1);
 103     getline(file2, line2);
 104
 105     // Check for mismatched EOF states, or any error state.
 106     if ((file1.eof() != file2.eof()) ||
 107         file1.bad() || file2.bad()) {
 108       return false;
 109     }
 110
 111     // Trim all '\r' and '\n' characters from the end of the line.
 112     std::string::size_type end1 = line1.find_last_not_of("\r\n");
 113     if (end1 == std::string::npos)
 114       line1.clear();
 115     else if (end1 + 1 < line1.length())
 116       line1.erase(end1 + 1);
 117
 118     std::string::size_type end2 = line2.find_last_not_of("\r\n");
 119     if (end2 == std::string::npos)
 120       line2.clear();
 121     else if (end2 + 1 < line2.length())
 122       line2.erase(end2 + 1);
 123
 124     if (line1 != line2)
 125       return false;
 126   } while (!file1.eof() || !file2.eof());
 127
 128   return true;
 129 }
 130
 131 bool ReadFileToString(const FilePath& path, std::string* contents) {
 132   if (path.ReferencesParent())
 133     return false;
 134   FILE* file = file_util::OpenFile(path, "rb");
 135   if (!file) {
 136     return false;
 137   }
 138
 139   char buf[1 << 16];
 140   size_t len;
 141   while ((len = fread(buf, 1, sizeof(buf), file)) > 0) {
 142     if (contents)
 143       contents->append(buf, len);
 144   }
 145   file_util::CloseFile(file);
 146
 147   return true;
 148 }
 149
 150 }  // namespace base
 151
 152 // -----------------------------------------------------------------------------
 153
 154 namespace file_util {
 155
 156 using base::FileEnumerator;
 157 using base::FilePath;
 158 using base::kMaxUniqueFiles;
 159
 160 bool IsDirectoryEmpty(const FilePath& dir_path) {
 161   FileEnumerator files(dir_path, false,
 162       FileEnumerator::FILES | FileEnumerator::DIRECTORIES);
 163   if (files.Next().empty())
 164     return true;
 165   return false;
 166 }
 167
 168 FILE* CreateAndOpenTemporaryFile(FilePath* path) {
 169   FilePath directory;
 170   if (!GetTempDir(&directory))
 171     return NULL;
 172
 173   return CreateAndOpenTemporaryFileInDir(directory, path);
 174 }
 175
 176 bool CreateDirectory(const base::FilePath& full_path) {
 177   return CreateDirectoryAndGetError(full_path, NULL);
 178 }
 179
 180 bool GetFileSize(const FilePath& file_path, int64* file_size) {
 181   base::PlatformFileInfo info;
 182   if (!GetFileInfo(file_path, &info))
 183     return false;
 184   *file_size = info.size;
 185   return true;
 186 }
 187
 188 bool TouchFile(const FilePath& path,
 189                const base::Time& last_accessed,
 190                const base::Time& last_modified) {
 191   int flags = base::PLATFORM_FILE_OPEN | base::PLATFORM_FILE_WRITE_ATTRIBUTES;
 192
 193 #if defined(OS_WIN)
 194   // On Windows, FILE_FLAG_BACKUP_SEMANTICS is needed to open a directory.
 195   if (DirectoryExists(path))
 196     flags |= base::PLATFORM_FILE_BACKUP_SEMANTICS;
 197 #endif  // OS_WIN
 198
 199   const base::PlatformFile file =
 200       base::CreatePlatformFile(path, flags, NULL, NULL);
 201   if (file != base::kInvalidPlatformFileValue) {
 202     bool result = base::TouchPlatformFile(file, last_accessed, last_modified);
 203     base::ClosePlatformFile(file);
 204     return result;
 205   }
 206
 207   return false;
 208 }
 209
 210 bool SetLastModifiedTime(const FilePath& path,
 211                          const base::Time& last_modified) {
 212   return TouchFile(path, last_modified, last_modified);
 213 }
 214
 215 bool CloseFile(FILE* file) {
 216   if (file == NULL)
 217     return true;
 218   return fclose(file) == 0;
 219 }
 220
 221 bool TruncateFile(FILE* file) {
 222   if (file == NULL)
 223     return false;
 224   long current_offset = ftell(file);
 225   if (current_offset == -1)
 226     return false;
 227 #if defined(OS_WIN)
 228   int fd = _fileno(file);
 229   if (_chsize(fd, current_offset) != 0)
 230     return false;
 231 #else
 232   int fd = fileno(file);
 233   if (ftruncate(fd, current_offset) != 0)
 234     return false;
 235 #endif
 236   return true;
 237 }
 238
 239 int GetUniquePathNumber(
 240     const FilePath& path,
 241     const FilePath::StringType& suffix) {
 242   bool have_suffix = !suffix.empty();
 243   if (!PathExists(path) &&
 244       (!have_suffix || !PathExists(FilePath(path.value() + suffix)))) {
 245     return 0;
 246   }
 247
 248   FilePath new_path;
 249   for (int count = 1; count <= kMaxUniqueFiles; ++count) {
 250     new_path =
 251         path.InsertBeforeExtensionASCII(base::StringPrintf(" (%d)", count));
 252     if (!PathExists(new_path) &&
 253         (!have_suffix || !PathExists(FilePath(new_path.value() + suffix)))) {
 254       return count;
 255     }
 256   }
 257
 258   return -1;
 259 }
 260
 261 }  // namespace file_util