base/file_util_win.cc

   1 // Copyright (c) 2011 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 #include <windows.h>
   8 #include <propvarutil.h>
   9 #include <psapi.h>
  10 #include <shellapi.h>
  11 #include <shlobj.h>
  12 #include <time.h>
  13 #include <string>
  14
  15 #include "base/file_path.h"
  16 #include "base/logging.h"
  17 #include "base/metrics/histogram.h"
  18 #include "base/win/pe_image.h"
  19 #include "base/win/scoped_handle.h"
  20 #include "base/string_number_conversions.h"
  21 #include "base/string_util.h"
  22 #include "base/threading/thread_restrictions.h"
  23 #include "base/time.h"
  24 #include "base/utf_string_conversions.h"
  25 #include "base/win/scoped_comptr.h"
  26 #include "base/win/win_util.h"
  27 #include "base/win/windows_version.h"
  28
  29 namespace file_util {
  30
  31 namespace {
  32
  33 const DWORD kFileShareAll =
  34     FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
  35
  36 // Helper for NormalizeFilePath(), defined below.
  37 bool DevicePathToDriveLetterPath(const FilePath& device_path,
  38                                  FilePath* drive_letter_path) {
  39   base::ThreadRestrictions::AssertIOAllowed();
  40
  41   // Get the mapping of drive letters to device paths.
  42   const int kDriveMappingSize = 1024;
  43   wchar_t drive_mapping[kDriveMappingSize] = {'\0'};
  44   if (!::GetLogicalDriveStrings(kDriveMappingSize - 1, drive_mapping)) {
  45     LOG(ERROR) << "Failed to get drive mapping.";
  46     return false;
  47   }
  48
  49   // The drive mapping is a sequence of null terminated strings.
  50   // The last string is empty.
  51   wchar_t* drive_map_ptr = drive_mapping;
  52   wchar_t device_name[MAX_PATH];
  53   wchar_t drive[] = L" :";
  54
  55   // For each string in the drive mapping, get the junction that links
  56   // to it.  If that junction is a prefix of |device_path|, then we
  57   // know that |drive| is the real path prefix.
  58   while (*drive_map_ptr) {
  59     drive[0] = drive_map_ptr[0];  // Copy the drive letter.
  60
  61     if (QueryDosDevice(drive, device_name, MAX_PATH) &&
  62         StartsWith(device_path.value(), device_name, true)) {
  63       *drive_letter_path = FilePath(drive +
  64           device_path.value().substr(wcslen(device_name)));
  65       return true;
  66     }
  67     // Move to the next drive letter string, which starts one
  68     // increment after the '\0' that terminates the current string.
  69     while (*drive_map_ptr++);
  70   }
  71
  72   // No drive matched.  The path does not start with a device junction
  73   // that is mounted as a drive letter.  This means there is no drive
  74   // letter path to the volume that holds |device_path|, so fail.
  75   return false;
  76 }
  77
  78 }  // namespace
  79
  80 bool AbsolutePath(FilePath* path) {
  81   base::ThreadRestrictions::AssertIOAllowed();
  82   wchar_t file_path_buf[MAX_PATH];
  83   if (!_wfullpath(file_path_buf, path->value().c_str(), MAX_PATH))
  84     return false;
  85   *path = FilePath(file_path_buf);
  86   return true;
  87 }
  88
  89 int CountFilesCreatedAfter(const FilePath& path,
  90                            const base::Time& comparison_time) {
  91   base::ThreadRestrictions::AssertIOAllowed();
  92
  93   int file_count = 0;
  94   FILETIME comparison_filetime(comparison_time.ToFileTime());
  95
  96   WIN32_FIND_DATA find_file_data;
  97   // All files in given dir
  98   std::wstring filename_spec = path.Append(L"*").value();
  99   HANDLE find_handle = FindFirstFile(filename_spec.c_str(), &find_file_data);
 100   if (find_handle != INVALID_HANDLE_VALUE) {
 101     do {
 102       // Don't count current or parent directories.
 103       if ((wcscmp(find_file_data.cFileName, L"..") == 0) ||
 104           (wcscmp(find_file_data.cFileName, L".") == 0))
 105         continue;
 106
 107       long result = CompareFileTime(&find_file_data.ftCreationTime,  // NOLINT
 108                                     &comparison_filetime);
 109       // File was created after or on comparison time
 110       if ((result == 1) || (result == 0))
 111         ++file_count;
 112     } while (FindNextFile(find_handle,  &find_file_data));
 113     FindClose(find_handle);
 114   }
 115
 116   return file_count;
 117 }
 118
 119 bool Delete(const FilePath& path, bool recursive) {
 120   base::ThreadRestrictions::AssertIOAllowed();
 121
 122   if (path.value().length() >= MAX_PATH)
 123     return false;
 124
 125   if (!recursive) {
 126     // If not recursing, then first check to see if |path| is a directory.
 127     // If it is, then remove it with RemoveDirectory.
 128     base::PlatformFileInfo file_info;
 129     if (GetFileInfo(path, &file_info) && file_info.is_directory)
 130       return RemoveDirectory(path.value().c_str()) != 0;
 131
 132     // Otherwise, it's a file, wildcard or non-existant. Try DeleteFile first
 133     // because it should be faster. If DeleteFile fails, then we fall through
 134     // to SHFileOperation, which will do the right thing.
 135     if (DeleteFile(path.value().c_str()) != 0)
 136       return true;
 137   }
 138
 139   // SHFILEOPSTRUCT wants the path to be terminated with two NULLs,
 140   // so we have to use wcscpy because wcscpy_s writes non-NULLs
 141   // into the rest of the buffer.
 142   wchar_t double_terminated_path[MAX_PATH + 1] = {0};
 143 #pragma warning(suppress:4996)  // don't complain about wcscpy deprecation
 144   wcscpy(double_terminated_path, path.value().c_str());
 145
 146   SHFILEOPSTRUCT file_operation = {0};
 147   file_operation.wFunc = FO_DELETE;
 148   file_operation.pFrom = double_terminated_path;
 149   file_operation.fFlags = FOF_NOERRORUI | FOF_SILENT | FOF_NOCONFIRMATION;
 150   if (!recursive)
 151     file_operation.fFlags |= FOF_NORECURSION | FOF_FILESONLY;
 152   int err = SHFileOperation(&file_operation);
 153
 154   // Since we're passing flags to the operation telling it to be silent,
 155   // it's possible for the operation to be aborted/cancelled without err
 156   // being set (although MSDN doesn't give any scenarios for how this can
 157   // happen).  See MSDN for SHFileOperation and SHFILEOPTSTRUCT.
 158   if (file_operation.fAnyOperationsAborted)
 159     return false;
 160
 161   // Some versions of Windows return ERROR_FILE_NOT_FOUND (0x2) when deleting
 162   // an empty directory and some return 0x402 when they should be returning
 163   // ERROR_FILE_NOT_FOUND. MSDN says Vista and up won't return 0x402.
 164   return (err == 0 || err == ERROR_FILE_NOT_FOUND || err == 0x402);
 165 }
 166
 167 bool DeleteAfterReboot(const FilePath& path) {
 168   base::ThreadRestrictions::AssertIOAllowed();
 169
 170   if (path.value().length() >= MAX_PATH)
 171     return false;
 172
 173   return MoveFileEx(path.value().c_str(), NULL,
 174                     MOVEFILE_DELAY_UNTIL_REBOOT |
 175                         MOVEFILE_REPLACE_EXISTING) != FALSE;
 176 }
 177
 178 bool Move(const FilePath& from_path, const FilePath& to_path) {
 179   base::ThreadRestrictions::AssertIOAllowed();
 180
 181   // NOTE: I suspect we could support longer paths, but that would involve
 182   // analyzing all our usage of files.
 183   if (from_path.value().length() >= MAX_PATH ||
 184       to_path.value().length() >= MAX_PATH) {
 185     return false;
 186   }
 187   if (MoveFileEx(from_path.value().c_str(), to_path.value().c_str(),
 188                  MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING) != 0)
 189     return true;
 190
 191   // Keep the last error value from MoveFileEx around in case the below
 192   // fails.
 193   bool ret = false;
 194   DWORD last_error = ::GetLastError();
 195
 196   if (DirectoryExists(from_path)) {
 197     // MoveFileEx fails if moving directory across volumes. We will simulate
 198     // the move by using Copy and Delete. Ideally we could check whether
 199     // from_path and to_path are indeed in different volumes.
 200     ret = CopyAndDeleteDirectory(from_path, to_path);
 201   }
 202
 203   if (!ret) {
 204     // Leave a clue about what went wrong so that it can be (at least) picked
 205     // up by a PLOG entry.
 206     ::SetLastError(last_error);
 207   }
 208
 209   return ret;
 210 }
 211
 212 bool ReplaceFile(const FilePath& from_path, const FilePath& to_path) {
 213   base::ThreadRestrictions::AssertIOAllowed();
 214
 215   // Make sure that the target file exists.
 216   HANDLE target_file = ::CreateFile(
 217       to_path.value().c_str(),
 218       0,
 219       FILE_SHARE_READ | FILE_SHARE_WRITE,
 220       NULL,
 221       CREATE_NEW,
 222       FILE_ATTRIBUTE_NORMAL,
 223       NULL);
 224   if (target_file != INVALID_HANDLE_VALUE)
 225     ::CloseHandle(target_file);
 226   // When writing to a network share, we may not be able to change the ACLs.
 227   // Ignore ACL errors then (REPLACEFILE_IGNORE_MERGE_ERRORS).
 228   return ::ReplaceFile(to_path.value().c_str(),
 229       from_path.value().c_str(), NULL,
 230       REPLACEFILE_IGNORE_MERGE_ERRORS, NULL, NULL) ? true : false;
 231 }
 232
 233 bool CopyFile(const FilePath& from_path, const FilePath& to_path) {
 234   base::ThreadRestrictions::AssertIOAllowed();
 235
 236   // NOTE: I suspect we could support longer paths, but that would involve
 237   // analyzing all our usage of files.
 238   if (from_path.value().length() >= MAX_PATH ||
 239       to_path.value().length() >= MAX_PATH) {
 240     return false;
 241   }
 242   return (::CopyFile(from_path.value().c_str(), to_path.value().c_str(),
 243                      false) != 0);
 244 }
 245
 246 bool ShellCopy(const FilePath& from_path, const FilePath& to_path,
 247                bool recursive) {
 248   base::ThreadRestrictions::AssertIOAllowed();
 249
 250   // NOTE: I suspect we could support longer paths, but that would involve
 251   // analyzing all our usage of files.
 252   if (from_path.value().length() >= MAX_PATH ||
 253       to_path.value().length() >= MAX_PATH) {
 254     return false;
 255   }
 256
 257   // SHFILEOPSTRUCT wants the path to be terminated with two NULLs,
 258   // so we have to use wcscpy because wcscpy_s writes non-NULLs
 259   // into the rest of the buffer.
 260   wchar_t double_terminated_path_from[MAX_PATH + 1] = {0};
 261   wchar_t double_terminated_path_to[MAX_PATH + 1] = {0};
 262 #pragma warning(suppress:4996)  // don't complain about wcscpy deprecation
 263   wcscpy(double_terminated_path_from, from_path.value().c_str());
 264 #pragma warning(suppress:4996)  // don't complain about wcscpy deprecation
 265   wcscpy(double_terminated_path_to, to_path.value().c_str());
 266
 267   SHFILEOPSTRUCT file_operation = {0};
 268   file_operation.wFunc = FO_COPY;
 269   file_operation.pFrom = double_terminated_path_from;
 270   file_operation.pTo = double_terminated_path_to;
 271   file_operation.fFlags = FOF_NOERRORUI | FOF_SILENT | FOF_NOCONFIRMATION |
 272                           FOF_NOCONFIRMMKDIR;
 273   if (!recursive)
 274     file_operation.fFlags |= FOF_NORECURSION | FOF_FILESONLY;
 275
 276   return (SHFileOperation(&file_operation) == 0);
 277 }
 278
 279 bool CopyDirectory(const FilePath& from_path, const FilePath& to_path,
 280                    bool recursive) {
 281   base::ThreadRestrictions::AssertIOAllowed();
 282
 283   if (recursive)
 284     return ShellCopy(from_path, to_path, true);
 285
 286   // The following code assumes that from path is a directory.
 287   DCHECK(DirectoryExists(from_path));
 288
 289   // Instead of creating a new directory, we copy the old one to include the
 290   // security information of the folder as part of the copy.
 291   if (!PathExists(to_path)) {
 292     // Except that Vista fails to do that, and instead do a recursive copy if
 293     // the target directory doesn't exist.
 294     if (base::win::GetVersion() >= base::win::VERSION_VISTA)
 295       CreateDirectory(to_path);
 296     else
 297       ShellCopy(from_path, to_path, false);
 298   }
 299
 300   FilePath directory = from_path.Append(L"*.*");
 301   return ShellCopy(directory, to_path, false);
 302 }
 303
 304 bool CopyAndDeleteDirectory(const FilePath& from_path,
 305                             const FilePath& to_path) {
 306   base::ThreadRestrictions::AssertIOAllowed();
 307   if (CopyDirectory(from_path, to_path, true)) {
 308     if (Delete(from_path, true)) {
 309       return true;
 310     }
 311     // Like Move, this function is not transactional, so we just
 312     // leave the copied bits behind if deleting from_path fails.
 313     // If to_path exists previously then we have already overwritten
 314     // it by now, we don't get better off by deleting the new bits.
 315   }
 316   return false;
 317 }
 318
 319
 320 bool PathExists(const FilePath& path) {
 321   base::ThreadRestrictions::AssertIOAllowed();
 322   return (GetFileAttributes(path.value().c_str()) != INVALID_FILE_ATTRIBUTES);
 323 }
 324
 325 bool PathIsWritable(const FilePath& path) {
 326   base::ThreadRestrictions::AssertIOAllowed();
 327   HANDLE dir =
 328       CreateFile(path.value().c_str(), FILE_ADD_FILE, kFileShareAll,
 329                  NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
 330
 331   if (dir == INVALID_HANDLE_VALUE)
 332     return false;
 333
 334   CloseHandle(dir);
 335   return true;
 336 }
 337
 338 bool DirectoryExists(const FilePath& path) {
 339   base::ThreadRestrictions::AssertIOAllowed();
 340   DWORD fileattr = GetFileAttributes(path.value().c_str());
 341   if (fileattr != INVALID_FILE_ATTRIBUTES)
 342     return (fileattr & FILE_ATTRIBUTE_DIRECTORY) != 0;
 343   return false;
 344 }
 345
 346 bool GetFileCreationLocalTimeFromHandle(HANDLE file_handle,
 347                                         LPSYSTEMTIME creation_time) {
 348   base::ThreadRestrictions::AssertIOAllowed();
 349   if (!file_handle)
 350     return false;
 351
 352   FILETIME utc_filetime;
 353   if (!GetFileTime(file_handle, &utc_filetime, NULL, NULL))
 354     return false;
 355
 356   FILETIME local_filetime;
 357   if (!FileTimeToLocalFileTime(&utc_filetime, &local_filetime))
 358     return false;
 359
 360   return !!FileTimeToSystemTime(&local_filetime, creation_time);
 361 }
 362
 363 bool GetFileCreationLocalTime(const std::wstring& filename,
 364                               LPSYSTEMTIME creation_time) {
 365   base::ThreadRestrictions::AssertIOAllowed();
 366   base::win::ScopedHandle file_handle(
 367       CreateFile(filename.c_str(), GENERIC_READ, kFileShareAll, NULL,
 368                  OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL));
 369   return GetFileCreationLocalTimeFromHandle(file_handle.Get(), creation_time);
 370 }
 371
 372 bool ResolveShortcut(FilePath* path) {
 373   base::ThreadRestrictions::AssertIOAllowed();
 374
 375   HRESULT result;
 376   base::win::ScopedComPtr<IShellLink> i_shell_link;
 377   bool is_resolved = false;
 378
 379   // Get pointer to the IShellLink interface
 380   result = i_shell_link.CreateInstance(CLSID_ShellLink, NULL,
 381                                        CLSCTX_INPROC_SERVER);
 382   if (SUCCEEDED(result)) {
 383     base::win::ScopedComPtr<IPersistFile> persist;
 384     // Query IShellLink for the IPersistFile interface
 385     result = persist.QueryFrom(i_shell_link);
 386     if (SUCCEEDED(result)) {
 387       WCHAR temp_path[MAX_PATH];
 388       // Load the shell link
 389       result = persist->Load(path->value().c_str(), STGM_READ);
 390       if (SUCCEEDED(result)) {
 391         // Try to find the target of a shortcut
 392         result = i_shell_link->Resolve(0, SLR_NO_UI);
 393         if (SUCCEEDED(result)) {
 394           result = i_shell_link->GetPath(temp_path, MAX_PATH,
 395                                   NULL, SLGP_UNCPRIORITY);
 396           *path = FilePath(temp_path);
 397           is_resolved = true;
 398         }
 399       }
 400     }
 401   }
 402
 403   return is_resolved;
 404 }
 405
 406 bool CreateShortcutLink(const wchar_t *source, const wchar_t *destination,
 407                         const wchar_t *working_dir, const wchar_t *arguments,
 408                         const wchar_t *description, const wchar_t *icon,
 409                         int icon_index, const wchar_t* app_id) {
 410   base::ThreadRestrictions::AssertIOAllowed();
 411
 412   // Length of arguments and description must be less than MAX_PATH.
 413   DCHECK(lstrlen(arguments) < MAX_PATH);
 414   DCHECK(lstrlen(description) < MAX_PATH);
 415
 416   base::win::ScopedComPtr<IShellLink> i_shell_link;
 417   base::win::ScopedComPtr<IPersistFile> i_persist_file;
 418
 419   // Get pointer to the IShellLink interface
 420   HRESULT result = i_shell_link.CreateInstance(CLSID_ShellLink, NULL,
 421                                                CLSCTX_INPROC_SERVER);
 422   if (FAILED(result))
 423     return false;
 424
 425   // Query IShellLink for the IPersistFile interface
 426   result = i_persist_file.QueryFrom(i_shell_link);
 427   if (FAILED(result))
 428     return false;
 429
 430   if (FAILED(i_shell_link->SetPath(source)))
 431     return false;
 432
 433   if (working_dir && FAILED(i_shell_link->SetWorkingDirectory(working_dir)))
 434     return false;
 435
 436   if (arguments && FAILED(i_shell_link->SetArguments(arguments)))
 437     return false;
 438
 439   if (description && FAILED(i_shell_link->SetDescription(description)))
 440     return false;
 441
 442   if (icon && FAILED(i_shell_link->SetIconLocation(icon, icon_index)))
 443     return false;
 444
 445   if (app_id && (base::win::GetVersion() >= base::win::VERSION_WIN7)) {
 446     base::win::ScopedComPtr<IPropertyStore> property_store;
 447     if (FAILED(property_store.QueryFrom(i_shell_link)))
 448       return false;
 449
 450     if (!base::win::SetAppIdForPropertyStore(property_store, app_id))
 451       return false;
 452   }
 453
 454   result = i_persist_file->Save(destination, TRUE);
 455   return SUCCEEDED(result);
 456 }
 457
 458 bool UpdateShortcutLink(const wchar_t *source, const wchar_t *destination,
 459                         const wchar_t *working_dir, const wchar_t *arguments,
 460                         const wchar_t *description, const wchar_t *icon,
 461                         int icon_index, const wchar_t* app_id) {
 462   base::ThreadRestrictions::AssertIOAllowed();
 463
 464   // Length of arguments and description must be less than MAX_PATH.
 465   DCHECK(lstrlen(arguments) < MAX_PATH);
 466   DCHECK(lstrlen(description) < MAX_PATH);
 467
 468   // Get pointer to the IPersistFile interface and load existing link
 469   base::win::ScopedComPtr<IShellLink> i_shell_link;
 470   if (FAILED(i_shell_link.CreateInstance(CLSID_ShellLink, NULL,
 471                                          CLSCTX_INPROC_SERVER)))
 472     return false;
 473
 474   base::win::ScopedComPtr<IPersistFile> i_persist_file;
 475   if (FAILED(i_persist_file.QueryFrom(i_shell_link)))
 476     return false;
 477
 478   if (FAILED(i_persist_file->Load(destination, STGM_READWRITE)))
 479     return false;
 480
 481   if (source && FAILED(i_shell_link->SetPath(source)))
 482     return false;
 483
 484   if (working_dir && FAILED(i_shell_link->SetWorkingDirectory(working_dir)))
 485     return false;
 486
 487   if (arguments && FAILED(i_shell_link->SetArguments(arguments)))
 488     return false;
 489
 490   if (description && FAILED(i_shell_link->SetDescription(description)))
 491     return false;
 492
 493   if (icon && FAILED(i_shell_link->SetIconLocation(icon, icon_index)))
 494     return false;
 495
 496   if (app_id && base::win::GetVersion() >= base::win::VERSION_WIN7) {
 497     base::win::ScopedComPtr<IPropertyStore> property_store;
 498     if (FAILED(property_store.QueryFrom(i_shell_link)))
 499       return false;
 500
 501     if (!base::win::SetAppIdForPropertyStore(property_store, app_id))
 502       return false;
 503   }
 504
 505   HRESULT result = i_persist_file->Save(destination, TRUE);
 506
 507   i_persist_file.Release();
 508   i_shell_link.Release();
 509
 510   // If we successfully updated the icon, notify the shell that we have done so.
 511   if (SUCCEEDED(result)) {
 512     SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST | SHCNF_FLUSHNOWAIT,
 513                    NULL, NULL);
 514   }
 515
 516   return SUCCEEDED(result);
 517 }
 518
 519 bool TaskbarPinShortcutLink(const wchar_t* shortcut) {
 520   base::ThreadRestrictions::AssertIOAllowed();
 521
 522   // "Pin to taskbar" is only supported after Win7.
 523   if (base::win::GetVersion() < base::win::VERSION_WIN7)
 524     return false;
 525
 526   int result = reinterpret_cast<int>(ShellExecute(NULL, L"taskbarpin", shortcut,
 527       NULL, NULL, 0));
 528   return result > 32;
 529 }
 530
 531 bool TaskbarUnpinShortcutLink(const wchar_t* shortcut) {
 532   base::ThreadRestrictions::AssertIOAllowed();
 533
 534   // "Unpin from taskbar" is only supported after Win7.
 535   if (base::win::GetVersion() < base::win::VERSION_WIN7)
 536     return false;
 537
 538   int result = reinterpret_cast<int>(ShellExecute(NULL, L"taskbarunpin",
 539       shortcut, NULL, NULL, 0));
 540   return result > 32;
 541 }
 542
 543 bool GetTempDir(FilePath* path) {
 544   base::ThreadRestrictions::AssertIOAllowed();
 545
 546   wchar_t temp_path[MAX_PATH + 1];
 547   DWORD path_len = ::GetTempPath(MAX_PATH, temp_path);
 548   if (path_len >= MAX_PATH || path_len <= 0)
 549     return false;
 550   // TODO(evanm): the old behavior of this function was to always strip the
 551   // trailing slash.  We duplicate this here, but it shouldn't be necessary
 552   // when everyone is using the appropriate FilePath APIs.
 553   *path = FilePath(temp_path).StripTrailingSeparators();
 554   return true;
 555 }
 556
 557 bool GetShmemTempDir(FilePath* path) {
 558   return GetTempDir(path);
 559 }
 560
 561 bool CreateTemporaryFile(FilePath* path) {
 562   base::ThreadRestrictions::AssertIOAllowed();
 563
 564   FilePath temp_file;
 565
 566   if (!GetTempDir(path))
 567     return false;
 568
 569   if (CreateTemporaryFileInDir(*path, &temp_file)) {
 570     *path = temp_file;
 571     return true;
 572   }
 573
 574   return false;
 575 }
 576
 577 FILE* CreateAndOpenTemporaryShmemFile(FilePath* path) {
 578   base::ThreadRestrictions::AssertIOAllowed();
 579   return CreateAndOpenTemporaryFile(path);
 580 }
 581
 582 // On POSIX we have semantics to create and open a temporary file
 583 // atomically.
 584 // TODO(jrg): is there equivalent call to use on Windows instead of
 585 // going 2-step?
 586 FILE* CreateAndOpenTemporaryFileInDir(const FilePath& dir, FilePath* path) {
 587   base::ThreadRestrictions::AssertIOAllowed();
 588   if (!CreateTemporaryFileInDir(dir, path)) {
 589     return NULL;
 590   }
 591   // Open file in binary mode, to avoid problems with fwrite. On Windows
 592   // it replaces \n's with \r\n's, which may surprise you.
 593   // Reference: http://msdn.microsoft.com/en-us/library/h9t88zwz(VS.71).aspx
 594   return OpenFile(*path, "wb+");
 595 }
 596
 597 bool CreateTemporaryFileInDir(const FilePath& dir,
 598                               FilePath* temp_file) {
 599   base::ThreadRestrictions::AssertIOAllowed();
 600
 601   wchar_t temp_name[MAX_PATH + 1];
 602
 603   if (!GetTempFileName(dir.value().c_str(), L"", 0, temp_name)) {
 604     PLOG(WARNING) << "Failed to get temporary file name in " << dir.value();
 605     return false;
 606   }
 607
 608   DWORD path_len = GetLongPathName(temp_name, temp_name, MAX_PATH);
 609   if (path_len > MAX_PATH + 1 || path_len == 0) {
 610     PLOG(WARNING) << "Failed to get long path name for " << temp_name;
 611     return false;
 612   }
 613
 614   std::wstring temp_file_str;
 615   temp_file_str.assign(temp_name, path_len);
 616   *temp_file = FilePath(temp_file_str);
 617   return true;
 618 }
 619
 620 bool CreateTemporaryDirInDir(const FilePath& base_dir,
 621                              const FilePath::StringType& prefix,
 622                              FilePath* new_dir) {
 623   base::ThreadRestrictions::AssertIOAllowed();
 624
 625   FilePath path_to_create;
 626   srand(static_cast<uint32>(time(NULL)));
 627
 628   for (int count = 0; count < 50; ++count) {
 629     // Try create a new temporary directory with random generated name. If
 630     // the one exists, keep trying another path name until we reach some limit.
 631     string16 new_dir_name;
 632     new_dir_name.assign(prefix);
 633     new_dir_name.append(base::IntToString16(rand() % kint16max));
 634
 635     path_to_create = base_dir.Append(new_dir_name);
 636     if (::CreateDirectory(path_to_create.value().c_str(), NULL)) {
 637       *new_dir = path_to_create;
 638       return true;
 639     }
 640   }
 641
 642   return false;
 643 }
 644
 645 bool CreateNewTempDirectory(const FilePath::StringType& prefix,
 646                             FilePath* new_temp_path) {
 647   base::ThreadRestrictions::AssertIOAllowed();
 648
 649   FilePath system_temp_dir;
 650   if (!GetTempDir(&system_temp_dir))
 651     return false;
 652
 653   return CreateTemporaryDirInDir(system_temp_dir, prefix, new_temp_path);
 654 }
 655
 656 bool CreateDirectory(const FilePath& full_path) {
 657   base::ThreadRestrictions::AssertIOAllowed();
 658
 659   // If the path exists, we've succeeded if it's a directory, failed otherwise.
 660   const wchar_t* full_path_str = full_path.value().c_str();
 661   DWORD fileattr = ::GetFileAttributes(full_path_str);
 662   if (fileattr != INVALID_FILE_ATTRIBUTES) {
 663     if ((fileattr & FILE_ATTRIBUTE_DIRECTORY) != 0) {
 664       DVLOG(1) << "CreateDirectory(" << full_path_str << "), "
 665                << "directory already exists.";
 666       return true;
 667     }
 668     LOG(WARNING) << "CreateDirectory(" << full_path_str << "), "
 669                  << "conflicts with existing file.";
 670     return false;
 671   }
 672
 673   // Invariant:  Path does not exist as file or directory.
 674
 675   // Attempt to create the parent recursively.  This will immediately return
 676   // true if it already exists, otherwise will create all required parent
 677   // directories starting with the highest-level missing parent.
 678   FilePath parent_path(full_path.DirName());
 679   if (parent_path.value() == full_path.value()) {
 680     return false;
 681   }
 682   if (!CreateDirectory(parent_path)) {
 683     DLOG(WARNING) << "Failed to create one of the parent directories.";
 684     return false;
 685   }
 686
 687   if (!::CreateDirectory(full_path_str, NULL)) {
 688     DWORD error_code = ::GetLastError();
 689     if (error_code == ERROR_ALREADY_EXISTS && DirectoryExists(full_path)) {
 690       // This error code ERROR_ALREADY_EXISTS doesn't indicate whether we
 691       // were racing with someone creating the same directory, or a file
 692       // with the same path.  If DirectoryExists() returns true, we lost the
 693       // race to create the same directory.
 694       return true;
 695     } else {
 696       LOG(WARNING) << "Failed to create directory " << full_path_str
 697                    << ", last error is " << error_code << ".";
 698       return false;
 699     }
 700   } else {
 701     return true;
 702   }
 703 }
 704
 705 // TODO(rkc): Work out if we want to handle NTFS junctions here or not, handle
 706 // them if we do decide to.
 707 bool IsLink(const FilePath& file_path) {
 708   return false;
 709 }
 710
 711 bool GetFileInfo(const FilePath& file_path, base::PlatformFileInfo* results) {
 712   base::ThreadRestrictions::AssertIOAllowed();
 713
 714   WIN32_FILE_ATTRIBUTE_DATA attr;
 715   if (!GetFileAttributesEx(file_path.value().c_str(),
 716                            GetFileExInfoStandard, &attr)) {
 717     return false;
 718   }
 719
 720   ULARGE_INTEGER size;
 721   size.HighPart = attr.nFileSizeHigh;
 722   size.LowPart = attr.nFileSizeLow;
 723   results->size = size.QuadPart;
 724
 725   results->is_directory =
 726       (attr.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
 727   results->last_modified = base::Time::FromFileTime(attr.ftLastWriteTime);
 728   results->last_accessed = base::Time::FromFileTime(attr.ftLastAccessTime);
 729   results->creation_time = base::Time::FromFileTime(attr.ftCreationTime);
 730
 731   return true;
 732 }
 733
 734 FILE* OpenFile(const FilePath& filename, const char* mode) {
 735   base::ThreadRestrictions::AssertIOAllowed();
 736   std::wstring w_mode = ASCIIToWide(std::string(mode));
 737   return _wfsopen(filename.value().c_str(), w_mode.c_str(), _SH_DENYNO);
 738 }
 739
 740 FILE* OpenFile(const std::string& filename, const char* mode) {
 741   base::ThreadRestrictions::AssertIOAllowed();
 742   return _fsopen(filename.c_str(), mode, _SH_DENYNO);
 743 }
 744
 745 int ReadFile(const FilePath& filename, char* data, int size) {
 746   base::ThreadRestrictions::AssertIOAllowed();
 747   base::win::ScopedHandle file(CreateFile(filename.value().c_str(),
 748                                           GENERIC_READ,
 749                                           FILE_SHARE_READ | FILE_SHARE_WRITE,
 750                                           NULL,
 751                                           OPEN_EXISTING,
 752                                           FILE_FLAG_SEQUENTIAL_SCAN,
 753                                           NULL));
 754   if (!file)
 755     return -1;
 756
 757   DWORD read;
 758   if (::ReadFile(file, data, size, &read, NULL) &&
 759       static_cast<int>(read) == size)
 760     return read;
 761   return -1;
 762 }
 763
 764 int WriteFile(const FilePath& filename, const char* data, int size) {
 765   base::ThreadRestrictions::AssertIOAllowed();
 766   base::win::ScopedHandle file(CreateFile(filename.value().c_str(),
 767                                           GENERIC_WRITE,
 768                                           0,
 769                                           NULL,
 770                                           CREATE_ALWAYS,
 771                                           0,
 772                                           NULL));
 773   if (!file) {
 774     LOG(WARNING) << "CreateFile failed for path " << filename.value()
 775                  << " error code=" << GetLastError();
 776     return -1;
 777   }
 778
 779   DWORD written;
 780   BOOL result = ::WriteFile(file, data, size, &written, NULL);
 781   if (result && static_cast<int>(written) == size)
 782     return written;
 783
 784   if (!result) {
 785     // WriteFile failed.
 786     LOG(WARNING) << "writing file " << filename.value()
 787                  << " failed, error code=" << GetLastError();
 788   } else {
 789     // Didn't write all the bytes.
 790     LOG(WARNING) << "wrote" << written << " bytes to " <<
 791         filename.value() << " expected " << size;
 792   }
 793   return -1;
 794 }
 795
 796 bool RenameFileAndResetSecurityDescriptor(const FilePath& source_file_path,
 797                                           const FilePath& target_file_path) {
 798   base::ThreadRestrictions::AssertIOAllowed();
 799
 800   // The parameters to SHFileOperation must be terminated with 2 NULL chars.
 801   std::wstring source = source_file_path.value();
 802   std::wstring target = target_file_path.value();
 803
 804   source.append(1, L'\0');
 805   target.append(1, L'\0');
 806
 807   SHFILEOPSTRUCT move_info = {0};
 808   move_info.wFunc = FO_MOVE;
 809   move_info.pFrom = source.c_str();
 810   move_info.pTo = target.c_str();
 811   move_info.fFlags = FOF_SILENT | FOF_NOCONFIRMATION | FOF_NOERRORUI |
 812                      FOF_NOCONFIRMMKDIR | FOF_NOCOPYSECURITYATTRIBS;
 813
 814   if (0 != SHFileOperation(&move_info))
 815     return false;
 816
 817   return true;
 818 }
 819
 820 // Gets the current working directory for the process.
 821 bool GetCurrentDirectory(FilePath* dir) {
 822   base::ThreadRestrictions::AssertIOAllowed();
 823
 824   wchar_t system_buffer[MAX_PATH];
 825   system_buffer[0] = 0;
 826   DWORD len = ::GetCurrentDirectory(MAX_PATH, system_buffer);
 827   if (len == 0 || len > MAX_PATH)
 828     return false;
 829   // TODO(evanm): the old behavior of this function was to always strip the
 830   // trailing slash.  We duplicate this here, but it shouldn't be necessary
 831   // when everyone is using the appropriate FilePath APIs.
 832   std::wstring dir_str(system_buffer);
 833   *dir = FilePath(dir_str).StripTrailingSeparators();
 834   return true;
 835 }
 836
 837 // Sets the current working directory for the process.
 838 bool SetCurrentDirectory(const FilePath& directory) {
 839   base::ThreadRestrictions::AssertIOAllowed();
 840   BOOL ret = ::SetCurrentDirectory(directory.value().c_str());
 841   return ret != 0;
 842 }
 843
 844 ///////////////////////////////////////////////
 845 // FileEnumerator
 846
 847 FileEnumerator::FileEnumerator(const FilePath& root_path,
 848                                bool recursive,
 849                                FileEnumerator::FILE_TYPE file_type)
 850     : recursive_(recursive),
 851       file_type_(file_type),
 852       has_find_data_(false),
 853       find_handle_(INVALID_HANDLE_VALUE) {
 854   // INCLUDE_DOT_DOT must not be specified if recursive.
 855   DCHECK(!(recursive && (INCLUDE_DOT_DOT & file_type_)));
 856   pending_paths_.push(root_path);
 857 }
 858
 859 FileEnumerator::FileEnumerator(const FilePath& root_path,
 860                                bool recursive,
 861                                FileEnumerator::FILE_TYPE file_type,
 862                                const FilePath::StringType& pattern)
 863     : recursive_(recursive),
 864       file_type_(file_type),
 865       has_find_data_(false),
 866       pattern_(pattern),
 867       find_handle_(INVALID_HANDLE_VALUE) {
 868   // INCLUDE_DOT_DOT must not be specified if recursive.
 869   DCHECK(!(recursive && (INCLUDE_DOT_DOT & file_type_)));
 870   pending_paths_.push(root_path);
 871 }
 872
 873 FileEnumerator::~FileEnumerator() {
 874   if (find_handle_ != INVALID_HANDLE_VALUE)
 875     FindClose(find_handle_);
 876 }
 877
 878 void FileEnumerator::GetFindInfo(FindInfo* info) {
 879   DCHECK(info);
 880
 881   if (!has_find_data_)
 882     return;
 883
 884   memcpy(info, &find_data_, sizeof(*info));
 885 }
 886
 887 bool FileEnumerator::IsDirectory(const FindInfo& info) {
 888   return (info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
 889 }
 890
 891 // static
 892 FilePath FileEnumerator::GetFilename(const FindInfo& find_info) {
 893   return FilePath(find_info.cFileName);
 894 }
 895
 896 FilePath FileEnumerator::Next() {
 897   base::ThreadRestrictions::AssertIOAllowed();
 898
 899   while (has_find_data_ || !pending_paths_.empty()) {
 900     if (!has_find_data_) {
 901       // The last find FindFirstFile operation is done, prepare a new one.
 902       root_path_ = pending_paths_.top();
 903       pending_paths_.pop();
 904
 905       // Start a new find operation.
 906       FilePath src = root_path_;
 907
 908       if (pattern_.empty())
 909         src = src.Append(L"*");  // No pattern = match everything.
 910       else
 911         src = src.Append(pattern_);
 912
 913       find_handle_ = FindFirstFile(src.value().c_str(), &find_data_);
 914       has_find_data_ = true;
 915     } else {
 916       // Search for the next file/directory.
 917       if (!FindNextFile(find_handle_, &find_data_)) {
 918         FindClose(find_handle_);
 919         find_handle_ = INVALID_HANDLE_VALUE;
 920       }
 921     }
 922
 923     if (INVALID_HANDLE_VALUE == find_handle_) {
 924       has_find_data_ = false;
 925
 926       // This is reached when we have finished a directory and are advancing to
 927       // the next one in the queue. We applied the pattern (if any) to the files
 928       // in the root search directory, but for those directories which were
 929       // matched, we want to enumerate all files inside them. This will happen
 930       // when the handle is empty.
 931       pattern_ = FilePath::StringType();
 932
 933       continue;
 934     }
 935
 936     FilePath cur_file(find_data_.cFileName);
 937     if (ShouldSkip(cur_file))
 938       continue;
 939
 940     // Construct the absolute filename.
 941     cur_file = root_path_.Append(find_data_.cFileName);
 942
 943     if (find_data_.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
 944       if (recursive_) {
 945         // If |cur_file| is a directory, and we are doing recursive searching,
 946         // add it to pending_paths_ so we scan it after we finish scanning this
 947         // directory.
 948         pending_paths_.push(cur_file);
 949       }
 950       if (file_type_ & FileEnumerator::DIRECTORIES)
 951         return cur_file;
 952     } else if (file_type_ & FileEnumerator::FILES) {
 953       return cur_file;
 954     }
 955   }
 956
 957   return FilePath();
 958 }
 959
 960 ///////////////////////////////////////////////
 961 // MemoryMappedFile
 962
 963 MemoryMappedFile::MemoryMappedFile()
 964     : file_(INVALID_HANDLE_VALUE),
 965       file_mapping_(INVALID_HANDLE_VALUE),
 966       data_(NULL),
 967       length_(INVALID_FILE_SIZE) {
 968 }
 969
 970 bool MemoryMappedFile::InitializeAsImageSection(const FilePath& file_name) {
 971   if (IsValid())
 972     return false;
 973   file_ = base::CreatePlatformFile(
 974       file_name, base::PLATFORM_FILE_OPEN | base::PLATFORM_FILE_READ,
 975       NULL, NULL);
 976
 977   if (file_ == base::kInvalidPlatformFileValue) {
 978     LOG(ERROR) << "Couldn't open " << file_name.value();
 979     return false;
 980   }
 981
 982   if (!MapFileToMemoryInternalEx(SEC_IMAGE)) {
 983     CloseHandles();
 984     return false;
 985   }
 986
 987   return true;
 988 }
 989
 990 bool MemoryMappedFile::MapFileToMemoryInternal() {
 991   return MapFileToMemoryInternalEx(0);
 992 }
 993
 994 bool MemoryMappedFile::MapFileToMemoryInternalEx(int flags) {
 995   base::ThreadRestrictions::AssertIOAllowed();
 996
 997   if (file_ == INVALID_HANDLE_VALUE)
 998     return false;
 999
1000   length_ = ::GetFileSize(file_, NULL);
1001   if (length_ == INVALID_FILE_SIZE)
1002     return false;
1003
1004   file_mapping_ = ::CreateFileMapping(file_, NULL, PAGE_READONLY | flags,
1005                                       0, 0, NULL);
1006   if (!file_mapping_) {
1007     // According to msdn, system error codes are only reserved up to 15999.
1008     // http://msdn.microsoft.com/en-us/library/ms681381(v=VS.85).aspx.
1009     UMA_HISTOGRAM_ENUMERATION("MemoryMappedFile.CreateFileMapping",
1010                               logging::GetLastSystemErrorCode(), 16000);
1011     return false;
1012   }
1013
1014   data_ = static_cast<uint8*>(
1015       ::MapViewOfFile(file_mapping_, FILE_MAP_READ, 0, 0, 0));
1016   if (!data_) {
1017     UMA_HISTOGRAM_ENUMERATION("MemoryMappedFile.MapViewOfFile",
1018                               logging::GetLastSystemErrorCode(), 16000);
1019   }
1020   return data_ != NULL;
1021 }
1022
1023 void MemoryMappedFile::CloseHandles() {
1024   if (data_)
1025     ::UnmapViewOfFile(data_);
1026   if (file_mapping_ != INVALID_HANDLE_VALUE)
1027     ::CloseHandle(file_mapping_);
1028   if (file_ != INVALID_HANDLE_VALUE)
1029     ::CloseHandle(file_);
1030
1031   data_ = NULL;
1032   file_mapping_ = file_ = INVALID_HANDLE_VALUE;
1033   length_ = INVALID_FILE_SIZE;
1034 }
1035
1036 bool HasFileBeenModifiedSince(const FileEnumerator::FindInfo& find_info,
1037                               const base::Time& cutoff_time) {
1038   base::ThreadRestrictions::AssertIOAllowed();
1039   long result = CompareFileTime(&find_info.ftLastWriteTime,  // NOLINT
1040                                 &cutoff_time.ToFileTime());
1041   return result == 1 || result == 0;
1042 }
1043
1044 bool NormalizeFilePath(const FilePath& path, FilePath* real_path) {
1045   base::ThreadRestrictions::AssertIOAllowed();
1046   FilePath mapped_file;
1047   if (!NormalizeToNativeFilePath(path, &mapped_file))
1048     return false;
1049   // NormalizeToNativeFilePath() will return a path that starts with
1050   // "\Device\Harddisk...".  Helper DevicePathToDriveLetterPath()
1051   // will find a drive letter which maps to the path's device, so
1052   // that we return a path starting with a drive letter.
1053   return DevicePathToDriveLetterPath(mapped_file, real_path);
1054 }
1055
1056 bool NormalizeToNativeFilePath(const FilePath& path, FilePath* nt_path) {
1057   base::ThreadRestrictions::AssertIOAllowed();
1058   // In Vista, GetFinalPathNameByHandle() would give us the real path
1059   // from a file handle.  If we ever deprecate XP, consider changing the
1060   // code below to a call to GetFinalPathNameByHandle().  The method this
1061   // function uses is explained in the following msdn article:
1062   // http://msdn.microsoft.com/en-us/library/aa366789(VS.85).aspx
1063   base::win::ScopedHandle file_handle(
1064       ::CreateFile(path.value().c_str(),
1065                    GENERIC_READ,
1066                    kFileShareAll,
1067                    NULL,
1068                    OPEN_EXISTING,
1069                    FILE_ATTRIBUTE_NORMAL,
1070                    NULL));
1071   if (!file_handle)
1072     return false;
1073
1074   // Create a file mapping object.  Can't easily use MemoryMappedFile, because
1075   // we only map the first byte, and need direct access to the handle. You can
1076   // not map an empty file, this call fails in that case.
1077   base::win::ScopedHandle file_map_handle(
1078       ::CreateFileMapping(file_handle.Get(),
1079                           NULL,
1080                           PAGE_READONLY,
1081                           0,
1082                           1,  // Just one byte.  No need to look at the data.
1083                           NULL));
1084   if (!file_map_handle)
1085     return false;
1086
1087   // Use a view of the file to get the path to the file.
1088   void* file_view = MapViewOfFile(file_map_handle.Get(),
1089                                   FILE_MAP_READ, 0, 0, 1);
1090   if (!file_view)
1091     return false;
1092
1093   // The expansion of |path| into a full path may make it longer.
1094   // GetMappedFileName() will fail if the result is longer than MAX_PATH.
1095   // Pad a bit to be safe.  If kMaxPathLength is ever changed to be less
1096   // than MAX_PATH, it would be nessisary to test that GetMappedFileName()
1097   // not return kMaxPathLength.  This would mean that only part of the
1098   // path fit in |mapped_file_path|.
1099   const int kMaxPathLength = MAX_PATH + 10;
1100   wchar_t mapped_file_path[kMaxPathLength];
1101   bool success = false;
1102   HANDLE cp = GetCurrentProcess();
1103   if (::GetMappedFileNameW(cp, file_view, mapped_file_path, kMaxPathLength)) {
1104     *nt_path = FilePath(mapped_file_path);
1105     success = true;
1106   }
1107   ::UnmapViewOfFile(file_view);
1108   return success;
1109 }
1110
1111 bool PreReadImage(const wchar_t* file_path, size_t size_to_read,
1112                   size_t step_size) {
1113   base::ThreadRestrictions::AssertIOAllowed();
1114   if (base::win::GetVersion() > base::win::VERSION_XP) {
1115     // Vista+ branch. On these OSes, the forced reads through the DLL actually
1116     // slows warm starts. The solution is to sequentially read file contents
1117     // with an optional cap on total amount to read.
1118     base::win::ScopedHandle file(
1119         CreateFile(file_path,
1120                    GENERIC_READ,
1121                    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
1122                    NULL,
1123                    OPEN_EXISTING,
1124                    FILE_FLAG_SEQUENTIAL_SCAN,
1125                    NULL));
1126
1127     if (!file.IsValid())
1128       return false;
1129
1130     // Default to 1MB sequential reads.
1131     const DWORD actual_step_size = std::max(static_cast<DWORD>(step_size),
1132                                             static_cast<DWORD>(1024*1024));
1133     LPVOID buffer = ::VirtualAlloc(NULL,
1134                                    actual_step_size,
1135                                    MEM_COMMIT,
1136                                    PAGE_READWRITE);
1137
1138     if (buffer == NULL)
1139       return false;
1140
1141     DWORD len;
1142     size_t total_read = 0;
1143     while (::ReadFile(file, buffer, actual_step_size, &len, NULL) &&
1144            len > 0 &&
1145            (size_to_read ? total_read < size_to_read : true)) {
1146       total_read += static_cast<size_t>(len);
1147     }
1148     ::VirtualFree(buffer, 0, MEM_RELEASE);
1149   } else {
1150     // WinXP branch. Here, reading the DLL from disk doesn't do
1151     // what we want so instead we pull the pages into memory by loading
1152     // the DLL and touching pages at a stride.
1153     HMODULE dll_module = ::LoadLibraryExW(
1154         file_path,
1155         NULL,
1156         LOAD_WITH_ALTERED_SEARCH_PATH | DONT_RESOLVE_DLL_REFERENCES);
1157
1158     if (!dll_module)
1159       return false;
1160
1161     base::win::PEImage pe_image(dll_module);
1162     PIMAGE_NT_HEADERS nt_headers = pe_image.GetNTHeaders();
1163     size_t actual_size_to_read = size_to_read ? size_to_read :
1164                                  nt_headers->OptionalHeader.SizeOfImage;
1165     volatile uint8* touch = reinterpret_cast<uint8*>(dll_module);
1166     size_t offset = 0;
1167     while (offset < actual_size_to_read) {
1168       uint8 unused = *(touch + offset);
1169       offset += step_size;
1170     }
1171     FreeLibrary(dll_module);
1172   }
1173
1174   return true;
1175 }
1176
1177 }  // namespace file_util