'Open as window' removed when --enable-new-bookmark-apps is disabled.
[chromium-blink-merge.git] / base / files / file_util_win.cc
blobe254232f66305910e0bd64d0f2c7ab71b5e3fac2
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.
5 #include "base/files/file_util.h"
7 #include <windows.h>
8 #include <io.h>
9 #include <psapi.h>
10 #include <shellapi.h>
11 #include <shlobj.h>
12 #include <time.h>
14 #include <algorithm>
15 #include <limits>
16 #include <string>
18 #include "base/files/file_enumerator.h"
19 #include "base/files/file_path.h"
20 #include "base/logging.h"
21 #include "base/metrics/histogram.h"
22 #include "base/process/process_handle.h"
23 #include "base/rand_util.h"
24 #include "base/strings/string_number_conversions.h"
25 #include "base/strings/string_util.h"
26 #include "base/strings/utf_string_conversions.h"
27 #include "base/threading/thread_restrictions.h"
28 #include "base/time/time.h"
29 #include "base/win/scoped_handle.h"
30 #include "base/win/windows_version.h"
32 namespace base {
34 namespace {
36 const DWORD kFileShareAll =
37 FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
39 } // namespace
41 FilePath MakeAbsoluteFilePath(const FilePath& input) {
42 ThreadRestrictions::AssertIOAllowed();
43 wchar_t file_path[MAX_PATH];
44 if (!_wfullpath(file_path, input.value().c_str(), MAX_PATH))
45 return FilePath();
46 return FilePath(file_path);
49 bool DeleteFile(const FilePath& path, bool recursive) {
50 ThreadRestrictions::AssertIOAllowed();
52 if (path.value().length() >= MAX_PATH)
53 return false;
55 // On XP SHFileOperation will return ERROR_ACCESS_DENIED instead of
56 // ERROR_FILE_NOT_FOUND, so just shortcut this here.
57 if (path.empty())
58 return true;
60 if (!recursive) {
61 // If not recursing, then first check to see if |path| is a directory.
62 // If it is, then remove it with RemoveDirectory.
63 File::Info file_info;
64 if (GetFileInfo(path, &file_info) && file_info.is_directory)
65 return RemoveDirectory(path.value().c_str()) != 0;
67 // Otherwise, it's a file, wildcard or non-existant. Try DeleteFile first
68 // because it should be faster. If DeleteFile fails, then we fall through
69 // to SHFileOperation, which will do the right thing.
70 if (::DeleteFile(path.value().c_str()) != 0)
71 return true;
74 // SHFILEOPSTRUCT wants the path to be terminated with two NULLs,
75 // so we have to use wcscpy because wcscpy_s writes non-NULLs
76 // into the rest of the buffer.
77 wchar_t double_terminated_path[MAX_PATH + 1] = {0};
78 #pragma warning(suppress:4996) // don't complain about wcscpy deprecation
79 wcscpy(double_terminated_path, path.value().c_str());
81 SHFILEOPSTRUCT file_operation = {0};
82 file_operation.wFunc = FO_DELETE;
83 file_operation.pFrom = double_terminated_path;
84 file_operation.fFlags = FOF_NOERRORUI | FOF_SILENT | FOF_NOCONFIRMATION;
85 if (!recursive)
86 file_operation.fFlags |= FOF_NORECURSION | FOF_FILESONLY;
87 int err = SHFileOperation(&file_operation);
89 // Since we're passing flags to the operation telling it to be silent,
90 // it's possible for the operation to be aborted/cancelled without err
91 // being set (although MSDN doesn't give any scenarios for how this can
92 // happen). See MSDN for SHFileOperation and SHFILEOPTSTRUCT.
93 if (file_operation.fAnyOperationsAborted)
94 return false;
96 // Some versions of Windows return ERROR_FILE_NOT_FOUND (0x2) when deleting
97 // an empty directory and some return 0x402 when they should be returning
98 // ERROR_FILE_NOT_FOUND. MSDN says Vista and up won't return 0x402. Windows 7
99 // can return DE_INVALIDFILES (0x7C) for nonexistent directories.
100 return (err == 0 || err == ERROR_FILE_NOT_FOUND || err == 0x402 ||
101 err == 0x7C);
104 bool DeleteFileAfterReboot(const FilePath& path) {
105 ThreadRestrictions::AssertIOAllowed();
107 if (path.value().length() >= MAX_PATH)
108 return false;
110 return MoveFileEx(path.value().c_str(), NULL,
111 MOVEFILE_DELAY_UNTIL_REBOOT |
112 MOVEFILE_REPLACE_EXISTING) != FALSE;
115 bool ReplaceFile(const FilePath& from_path,
116 const FilePath& to_path,
117 File::Error* error) {
118 ThreadRestrictions::AssertIOAllowed();
119 // Try a simple move first. It will only succeed when |to_path| doesn't
120 // already exist.
121 if (::MoveFile(from_path.value().c_str(), to_path.value().c_str()))
122 return true;
123 // Try the full-blown replace if the move fails, as ReplaceFile will only
124 // succeed when |to_path| does exist. When writing to a network share, we may
125 // not be able to change the ACLs. Ignore ACL errors then
126 // (REPLACEFILE_IGNORE_MERGE_ERRORS).
127 if (::ReplaceFile(to_path.value().c_str(), from_path.value().c_str(), NULL,
128 REPLACEFILE_IGNORE_MERGE_ERRORS, NULL, NULL)) {
129 return true;
131 if (error)
132 *error = File::OSErrorToFileError(GetLastError());
133 return false;
136 bool CopyDirectory(const FilePath& from_path, const FilePath& to_path,
137 bool recursive) {
138 // NOTE(maruel): Previous version of this function used to call
139 // SHFileOperation(). This used to copy the file attributes and extended
140 // attributes, OLE structured storage, NTFS file system alternate data
141 // streams, SECURITY_DESCRIPTOR. In practice, this is not what we want, we
142 // want the containing directory to propagate its SECURITY_DESCRIPTOR.
143 ThreadRestrictions::AssertIOAllowed();
145 // NOTE: I suspect we could support longer paths, but that would involve
146 // analyzing all our usage of files.
147 if (from_path.value().length() >= MAX_PATH ||
148 to_path.value().length() >= MAX_PATH) {
149 return false;
152 // This function does not properly handle destinations within the source.
153 FilePath real_to_path = to_path;
154 if (PathExists(real_to_path)) {
155 real_to_path = MakeAbsoluteFilePath(real_to_path);
156 if (real_to_path.empty())
157 return false;
158 } else {
159 real_to_path = MakeAbsoluteFilePath(real_to_path.DirName());
160 if (real_to_path.empty())
161 return false;
163 FilePath real_from_path = MakeAbsoluteFilePath(from_path);
164 if (real_from_path.empty())
165 return false;
166 if (real_to_path.value().size() >= real_from_path.value().size() &&
167 real_to_path.value().compare(0, real_from_path.value().size(),
168 real_from_path.value()) == 0) {
169 return false;
172 int traverse_type = FileEnumerator::FILES;
173 if (recursive)
174 traverse_type |= FileEnumerator::DIRECTORIES;
175 FileEnumerator traversal(from_path, recursive, traverse_type);
177 if (!PathExists(from_path)) {
178 DLOG(ERROR) << "CopyDirectory() couldn't stat source directory: "
179 << from_path.value().c_str();
180 return false;
182 // TODO(maruel): This is not necessary anymore.
183 DCHECK(recursive || DirectoryExists(from_path));
185 FilePath current = from_path;
186 bool from_is_dir = DirectoryExists(from_path);
187 bool success = true;
188 FilePath from_path_base = from_path;
189 if (recursive && DirectoryExists(to_path)) {
190 // If the destination already exists and is a directory, then the
191 // top level of source needs to be copied.
192 from_path_base = from_path.DirName();
195 while (success && !current.empty()) {
196 // current is the source path, including from_path, so append
197 // the suffix after from_path to to_path to create the target_path.
198 FilePath target_path(to_path);
199 if (from_path_base != current) {
200 if (!from_path_base.AppendRelativePath(current, &target_path)) {
201 success = false;
202 break;
206 if (from_is_dir) {
207 if (!DirectoryExists(target_path) &&
208 !::CreateDirectory(target_path.value().c_str(), NULL)) {
209 DLOG(ERROR) << "CopyDirectory() couldn't create directory: "
210 << target_path.value().c_str();
211 success = false;
213 } else if (!CopyFile(current, target_path)) {
214 DLOG(ERROR) << "CopyDirectory() couldn't create file: "
215 << target_path.value().c_str();
216 success = false;
219 current = traversal.Next();
220 if (!current.empty())
221 from_is_dir = traversal.GetInfo().IsDirectory();
224 return success;
227 bool PathExists(const FilePath& path) {
228 ThreadRestrictions::AssertIOAllowed();
229 return (GetFileAttributes(path.value().c_str()) != INVALID_FILE_ATTRIBUTES);
232 bool PathIsWritable(const FilePath& path) {
233 ThreadRestrictions::AssertIOAllowed();
234 HANDLE dir =
235 CreateFile(path.value().c_str(), FILE_ADD_FILE, kFileShareAll,
236 NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
238 if (dir == INVALID_HANDLE_VALUE)
239 return false;
241 CloseHandle(dir);
242 return true;
245 bool DirectoryExists(const FilePath& path) {
246 ThreadRestrictions::AssertIOAllowed();
247 DWORD fileattr = GetFileAttributes(path.value().c_str());
248 if (fileattr != INVALID_FILE_ATTRIBUTES)
249 return (fileattr & FILE_ATTRIBUTE_DIRECTORY) != 0;
250 return false;
253 bool GetTempDir(FilePath* path) {
254 wchar_t temp_path[MAX_PATH + 1];
255 DWORD path_len = ::GetTempPath(MAX_PATH, temp_path);
256 if (path_len >= MAX_PATH || path_len <= 0)
257 return false;
258 // TODO(evanm): the old behavior of this function was to always strip the
259 // trailing slash. We duplicate this here, but it shouldn't be necessary
260 // when everyone is using the appropriate FilePath APIs.
261 *path = FilePath(temp_path).StripTrailingSeparators();
262 return true;
265 FilePath GetHomeDir() {
266 char16 result[MAX_PATH];
267 if (SUCCEEDED(SHGetFolderPath(NULL, CSIDL_PROFILE, NULL, SHGFP_TYPE_CURRENT,
268 result)) &&
269 result[0]) {
270 return FilePath(result);
273 // Fall back to the temporary directory on failure.
274 FilePath temp;
275 if (GetTempDir(&temp))
276 return temp;
278 // Last resort.
279 return FilePath(L"C:\\");
282 bool CreateTemporaryFile(FilePath* path) {
283 ThreadRestrictions::AssertIOAllowed();
285 FilePath temp_file;
287 if (!GetTempDir(path))
288 return false;
290 if (CreateTemporaryFileInDir(*path, &temp_file)) {
291 *path = temp_file;
292 return true;
295 return false;
298 // On POSIX we have semantics to create and open a temporary file
299 // atomically.
300 // TODO(jrg): is there equivalent call to use on Windows instead of
301 // going 2-step?
302 FILE* CreateAndOpenTemporaryFileInDir(const FilePath& dir, FilePath* path) {
303 ThreadRestrictions::AssertIOAllowed();
304 if (!CreateTemporaryFileInDir(dir, path)) {
305 return NULL;
307 // Open file in binary mode, to avoid problems with fwrite. On Windows
308 // it replaces \n's with \r\n's, which may surprise you.
309 // Reference: http://msdn.microsoft.com/en-us/library/h9t88zwz(VS.71).aspx
310 return OpenFile(*path, "wb+");
313 bool CreateTemporaryFileInDir(const FilePath& dir, FilePath* temp_file) {
314 ThreadRestrictions::AssertIOAllowed();
316 wchar_t temp_name[MAX_PATH + 1];
318 if (!GetTempFileName(dir.value().c_str(), L"", 0, temp_name)) {
319 DPLOG(WARNING) << "Failed to get temporary file name in "
320 << UTF16ToUTF8(dir.value());
321 return false;
324 wchar_t long_temp_name[MAX_PATH + 1];
325 DWORD long_name_len = GetLongPathName(temp_name, long_temp_name, MAX_PATH);
326 if (long_name_len > MAX_PATH || long_name_len == 0) {
327 // GetLongPathName() failed, but we still have a temporary file.
328 *temp_file = FilePath(temp_name);
329 return true;
332 FilePath::StringType long_temp_name_str;
333 long_temp_name_str.assign(long_temp_name, long_name_len);
334 *temp_file = FilePath(long_temp_name_str);
335 return true;
338 bool CreateTemporaryDirInDir(const FilePath& base_dir,
339 const FilePath::StringType& prefix,
340 FilePath* new_dir) {
341 ThreadRestrictions::AssertIOAllowed();
343 FilePath path_to_create;
345 for (int count = 0; count < 50; ++count) {
346 // Try create a new temporary directory with random generated name. If
347 // the one exists, keep trying another path name until we reach some limit.
348 string16 new_dir_name;
349 new_dir_name.assign(prefix);
350 new_dir_name.append(IntToString16(GetCurrentProcId()));
351 new_dir_name.push_back('_');
352 new_dir_name.append(IntToString16(RandInt(0, kint16max)));
354 path_to_create = base_dir.Append(new_dir_name);
355 if (::CreateDirectory(path_to_create.value().c_str(), NULL)) {
356 *new_dir = path_to_create;
357 return true;
361 return false;
364 bool CreateNewTempDirectory(const FilePath::StringType& prefix,
365 FilePath* new_temp_path) {
366 ThreadRestrictions::AssertIOAllowed();
368 FilePath system_temp_dir;
369 if (!GetTempDir(&system_temp_dir))
370 return false;
372 return CreateTemporaryDirInDir(system_temp_dir, prefix, new_temp_path);
375 bool CreateDirectoryAndGetError(const FilePath& full_path,
376 File::Error* error) {
377 ThreadRestrictions::AssertIOAllowed();
379 // If the path exists, we've succeeded if it's a directory, failed otherwise.
380 const wchar_t* full_path_str = full_path.value().c_str();
381 DWORD fileattr = ::GetFileAttributes(full_path_str);
382 if (fileattr != INVALID_FILE_ATTRIBUTES) {
383 if ((fileattr & FILE_ATTRIBUTE_DIRECTORY) != 0) {
384 DVLOG(1) << "CreateDirectory(" << full_path_str << "), "
385 << "directory already exists.";
386 return true;
388 DLOG(WARNING) << "CreateDirectory(" << full_path_str << "), "
389 << "conflicts with existing file.";
390 if (error) {
391 *error = File::FILE_ERROR_NOT_A_DIRECTORY;
393 return false;
396 // Invariant: Path does not exist as file or directory.
398 // Attempt to create the parent recursively. This will immediately return
399 // true if it already exists, otherwise will create all required parent
400 // directories starting with the highest-level missing parent.
401 FilePath parent_path(full_path.DirName());
402 if (parent_path.value() == full_path.value()) {
403 if (error) {
404 *error = File::FILE_ERROR_NOT_FOUND;
406 return false;
408 if (!CreateDirectoryAndGetError(parent_path, error)) {
409 DLOG(WARNING) << "Failed to create one of the parent directories.";
410 if (error) {
411 DCHECK(*error != File::FILE_OK);
413 return false;
416 if (!::CreateDirectory(full_path_str, NULL)) {
417 DWORD error_code = ::GetLastError();
418 if (error_code == ERROR_ALREADY_EXISTS && DirectoryExists(full_path)) {
419 // This error code ERROR_ALREADY_EXISTS doesn't indicate whether we
420 // were racing with someone creating the same directory, or a file
421 // with the same path. If DirectoryExists() returns true, we lost the
422 // race to create the same directory.
423 return true;
424 } else {
425 if (error)
426 *error = File::OSErrorToFileError(error_code);
427 DLOG(WARNING) << "Failed to create directory " << full_path_str
428 << ", last error is " << error_code << ".";
429 return false;
431 } else {
432 return true;
436 bool NormalizeFilePath(const FilePath& path, FilePath* real_path) {
437 ThreadRestrictions::AssertIOAllowed();
438 FilePath mapped_file;
439 if (!NormalizeToNativeFilePath(path, &mapped_file))
440 return false;
441 // NormalizeToNativeFilePath() will return a path that starts with
442 // "\Device\Harddisk...". Helper DevicePathToDriveLetterPath()
443 // will find a drive letter which maps to the path's device, so
444 // that we return a path starting with a drive letter.
445 return DevicePathToDriveLetterPath(mapped_file, real_path);
448 bool DevicePathToDriveLetterPath(const FilePath& nt_device_path,
449 FilePath* out_drive_letter_path) {
450 ThreadRestrictions::AssertIOAllowed();
452 // Get the mapping of drive letters to device paths.
453 const int kDriveMappingSize = 1024;
454 wchar_t drive_mapping[kDriveMappingSize] = {'\0'};
455 if (!::GetLogicalDriveStrings(kDriveMappingSize - 1, drive_mapping)) {
456 DLOG(ERROR) << "Failed to get drive mapping.";
457 return false;
460 // The drive mapping is a sequence of null terminated strings.
461 // The last string is empty.
462 wchar_t* drive_map_ptr = drive_mapping;
463 wchar_t device_path_as_string[MAX_PATH];
464 wchar_t drive[] = L" :";
466 // For each string in the drive mapping, get the junction that links
467 // to it. If that junction is a prefix of |device_path|, then we
468 // know that |drive| is the real path prefix.
469 while (*drive_map_ptr) {
470 drive[0] = drive_map_ptr[0]; // Copy the drive letter.
472 if (QueryDosDevice(drive, device_path_as_string, MAX_PATH)) {
473 FilePath device_path(device_path_as_string);
474 if (device_path == nt_device_path ||
475 device_path.IsParent(nt_device_path)) {
476 *out_drive_letter_path = FilePath(drive +
477 nt_device_path.value().substr(wcslen(device_path_as_string)));
478 return true;
481 // Move to the next drive letter string, which starts one
482 // increment after the '\0' that terminates the current string.
483 while (*drive_map_ptr++) {}
486 // No drive matched. The path does not start with a device junction
487 // that is mounted as a drive letter. This means there is no drive
488 // letter path to the volume that holds |device_path|, so fail.
489 return false;
492 bool NormalizeToNativeFilePath(const FilePath& path, FilePath* nt_path) {
493 ThreadRestrictions::AssertIOAllowed();
494 // In Vista, GetFinalPathNameByHandle() would give us the real path
495 // from a file handle. If we ever deprecate XP, consider changing the
496 // code below to a call to GetFinalPathNameByHandle(). The method this
497 // function uses is explained in the following msdn article:
498 // http://msdn.microsoft.com/en-us/library/aa366789(VS.85).aspx
499 win::ScopedHandle file_handle(
500 ::CreateFile(path.value().c_str(),
501 GENERIC_READ,
502 kFileShareAll,
503 NULL,
504 OPEN_EXISTING,
505 FILE_ATTRIBUTE_NORMAL,
506 NULL));
507 if (!file_handle.IsValid())
508 return false;
510 // Create a file mapping object. Can't easily use MemoryMappedFile, because
511 // we only map the first byte, and need direct access to the handle. You can
512 // not map an empty file, this call fails in that case.
513 win::ScopedHandle file_map_handle(
514 ::CreateFileMapping(file_handle.Get(),
515 NULL,
516 PAGE_READONLY,
518 1, // Just one byte. No need to look at the data.
519 NULL));
520 if (!file_map_handle.IsValid())
521 return false;
523 // Use a view of the file to get the path to the file.
524 void* file_view = MapViewOfFile(file_map_handle.Get(),
525 FILE_MAP_READ, 0, 0, 1);
526 if (!file_view)
527 return false;
529 // The expansion of |path| into a full path may make it longer.
530 // GetMappedFileName() will fail if the result is longer than MAX_PATH.
531 // Pad a bit to be safe. If kMaxPathLength is ever changed to be less
532 // than MAX_PATH, it would be nessisary to test that GetMappedFileName()
533 // not return kMaxPathLength. This would mean that only part of the
534 // path fit in |mapped_file_path|.
535 const int kMaxPathLength = MAX_PATH + 10;
536 wchar_t mapped_file_path[kMaxPathLength];
537 bool success = false;
538 HANDLE cp = GetCurrentProcess();
539 if (::GetMappedFileNameW(cp, file_view, mapped_file_path, kMaxPathLength)) {
540 *nt_path = FilePath(mapped_file_path);
541 success = true;
543 ::UnmapViewOfFile(file_view);
544 return success;
547 // TODO(rkc): Work out if we want to handle NTFS junctions here or not, handle
548 // them if we do decide to.
549 bool IsLink(const FilePath& file_path) {
550 return false;
553 bool GetFileInfo(const FilePath& file_path, File::Info* results) {
554 ThreadRestrictions::AssertIOAllowed();
556 WIN32_FILE_ATTRIBUTE_DATA attr;
557 if (!GetFileAttributesEx(file_path.value().c_str(),
558 GetFileExInfoStandard, &attr)) {
559 return false;
562 ULARGE_INTEGER size;
563 size.HighPart = attr.nFileSizeHigh;
564 size.LowPart = attr.nFileSizeLow;
565 results->size = size.QuadPart;
567 results->is_directory =
568 (attr.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
569 results->last_modified = Time::FromFileTime(attr.ftLastWriteTime);
570 results->last_accessed = Time::FromFileTime(attr.ftLastAccessTime);
571 results->creation_time = Time::FromFileTime(attr.ftCreationTime);
573 return true;
576 FILE* OpenFile(const FilePath& filename, const char* mode) {
577 ThreadRestrictions::AssertIOAllowed();
578 string16 w_mode = ASCIIToUTF16(mode);
579 return _wfsopen(filename.value().c_str(), w_mode.c_str(), _SH_DENYNO);
582 FILE* FileToFILE(File file, const char* mode) {
583 if (!file.IsValid())
584 return NULL;
585 int fd =
586 _open_osfhandle(reinterpret_cast<intptr_t>(file.GetPlatformFile()), 0);
587 if (fd < 0)
588 return NULL;
589 file.TakePlatformFile();
590 FILE* stream = _fdopen(fd, mode);
591 if (!stream)
592 _close(fd);
593 return stream;
596 int ReadFile(const FilePath& filename, char* data, int max_size) {
597 ThreadRestrictions::AssertIOAllowed();
598 win::ScopedHandle file(CreateFile(filename.value().c_str(),
599 GENERIC_READ,
600 FILE_SHARE_READ | FILE_SHARE_WRITE,
601 NULL,
602 OPEN_EXISTING,
603 FILE_FLAG_SEQUENTIAL_SCAN,
604 NULL));
605 if (!file.IsValid())
606 return -1;
608 DWORD read;
609 if (::ReadFile(file.Get(), data, max_size, &read, NULL))
610 return read;
612 return -1;
615 int WriteFile(const FilePath& filename, const char* data, int size) {
616 ThreadRestrictions::AssertIOAllowed();
617 win::ScopedHandle file(CreateFile(filename.value().c_str(),
618 GENERIC_WRITE,
620 NULL,
621 CREATE_ALWAYS,
623 NULL));
624 if (!file.IsValid()) {
625 DPLOG(WARNING) << "CreateFile failed for path "
626 << UTF16ToUTF8(filename.value());
627 return -1;
630 DWORD written;
631 BOOL result = ::WriteFile(file.Get(), data, size, &written, NULL);
632 if (result && static_cast<int>(written) == size)
633 return written;
635 if (!result) {
636 // WriteFile failed.
637 DPLOG(WARNING) << "writing file " << UTF16ToUTF8(filename.value())
638 << " failed";
639 } else {
640 // Didn't write all the bytes.
641 DLOG(WARNING) << "wrote" << written << " bytes to "
642 << UTF16ToUTF8(filename.value()) << " expected " << size;
644 return -1;
647 bool AppendToFile(const FilePath& filename, const char* data, int size) {
648 ThreadRestrictions::AssertIOAllowed();
649 win::ScopedHandle file(CreateFile(filename.value().c_str(),
650 FILE_APPEND_DATA,
652 NULL,
653 OPEN_EXISTING,
655 NULL));
656 if (!file.IsValid()) {
657 VPLOG(1) << "CreateFile failed for path " << UTF16ToUTF8(filename.value());
658 return false;
661 DWORD written;
662 BOOL result = ::WriteFile(file.Get(), data, size, &written, NULL);
663 if (result && static_cast<int>(written) == size)
664 return true;
666 if (!result) {
667 // WriteFile failed.
668 VPLOG(1) << "Writing file " << UTF16ToUTF8(filename.value()) << " failed";
669 } else {
670 // Didn't write all the bytes.
671 VPLOG(1) << "Only wrote " << written << " out of " << size << " byte(s) to "
672 << UTF16ToUTF8(filename.value());
674 return false;
677 // Gets the current working directory for the process.
678 bool GetCurrentDirectory(FilePath* dir) {
679 ThreadRestrictions::AssertIOAllowed();
681 wchar_t system_buffer[MAX_PATH];
682 system_buffer[0] = 0;
683 DWORD len = ::GetCurrentDirectory(MAX_PATH, system_buffer);
684 if (len == 0 || len > MAX_PATH)
685 return false;
686 // TODO(evanm): the old behavior of this function was to always strip the
687 // trailing slash. We duplicate this here, but it shouldn't be necessary
688 // when everyone is using the appropriate FilePath APIs.
689 std::wstring dir_str(system_buffer);
690 *dir = FilePath(dir_str).StripTrailingSeparators();
691 return true;
694 // Sets the current working directory for the process.
695 bool SetCurrentDirectory(const FilePath& directory) {
696 ThreadRestrictions::AssertIOAllowed();
697 BOOL ret = ::SetCurrentDirectory(directory.value().c_str());
698 return ret != 0;
701 int GetMaximumPathComponentLength(const FilePath& path) {
702 ThreadRestrictions::AssertIOAllowed();
704 wchar_t volume_path[MAX_PATH];
705 if (!GetVolumePathNameW(path.NormalizePathSeparators().value().c_str(),
706 volume_path,
707 arraysize(volume_path))) {
708 return -1;
711 DWORD max_length = 0;
712 if (!GetVolumeInformationW(volume_path, NULL, 0, NULL, &max_length, NULL,
713 NULL, 0)) {
714 return -1;
717 // Length of |path| with path separator appended.
718 size_t prefix = path.StripTrailingSeparators().value().size() + 1;
719 // The whole path string must be shorter than MAX_PATH. That is, it must be
720 // prefix + component_length < MAX_PATH (or equivalently, <= MAX_PATH - 1).
721 int whole_path_limit = std::max(0, MAX_PATH - 1 - static_cast<int>(prefix));
722 return std::min(whole_path_limit, static_cast<int>(max_length));
725 bool CopyFile(const FilePath& from_path, const FilePath& to_path) {
726 ThreadRestrictions::AssertIOAllowed();
727 if (from_path.ReferencesParent() || to_path.ReferencesParent())
728 return false;
730 // NOTE: I suspect we could support longer paths, but that would involve
731 // analyzing all our usage of files.
732 if (from_path.value().length() >= MAX_PATH ||
733 to_path.value().length() >= MAX_PATH) {
734 return false;
737 // Unlike the posix implementation that copies the file manually and discards
738 // the ACL bits, CopyFile() copies the complete SECURITY_DESCRIPTOR and access
739 // bits, which is usually not what we want. We can't do much about the
740 // SECURITY_DESCRIPTOR but at least remove the read only bit.
741 const wchar_t* dest = to_path.value().c_str();
742 if (!::CopyFile(from_path.value().c_str(), dest, false)) {
743 // Copy failed.
744 return false;
746 DWORD attrs = GetFileAttributes(dest);
747 if (attrs == INVALID_FILE_ATTRIBUTES) {
748 return false;
750 if (attrs & FILE_ATTRIBUTE_READONLY) {
751 SetFileAttributes(dest, attrs & ~FILE_ATTRIBUTE_READONLY);
753 return true;
756 // -----------------------------------------------------------------------------
758 namespace internal {
760 bool MoveUnsafe(const FilePath& from_path, const FilePath& to_path) {
761 ThreadRestrictions::AssertIOAllowed();
763 // NOTE: I suspect we could support longer paths, but that would involve
764 // analyzing all our usage of files.
765 if (from_path.value().length() >= MAX_PATH ||
766 to_path.value().length() >= MAX_PATH) {
767 return false;
769 if (MoveFileEx(from_path.value().c_str(), to_path.value().c_str(),
770 MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING) != 0)
771 return true;
773 // Keep the last error value from MoveFileEx around in case the below
774 // fails.
775 bool ret = false;
776 DWORD last_error = ::GetLastError();
778 if (DirectoryExists(from_path)) {
779 // MoveFileEx fails if moving directory across volumes. We will simulate
780 // the move by using Copy and Delete. Ideally we could check whether
781 // from_path and to_path are indeed in different volumes.
782 ret = internal::CopyAndDeleteDirectory(from_path, to_path);
785 if (!ret) {
786 // Leave a clue about what went wrong so that it can be (at least) picked
787 // up by a PLOG entry.
788 ::SetLastError(last_error);
791 return ret;
794 bool CopyAndDeleteDirectory(const FilePath& from_path,
795 const FilePath& to_path) {
796 ThreadRestrictions::AssertIOAllowed();
797 if (CopyDirectory(from_path, to_path, true)) {
798 if (DeleteFile(from_path, true))
799 return true;
801 // Like Move, this function is not transactional, so we just
802 // leave the copied bits behind if deleting from_path fails.
803 // If to_path exists previously then we have already overwritten
804 // it by now, we don't get better off by deleting the new bits.
806 return false;
809 } // namespace internal
810 } // namespace base