| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/file_util.h" |
| |
| #include <windows.h> |
| #include <psapi.h> |
| #include <shellapi.h> |
| #include <shlobj.h> |
| #include <time.h> |
| |
| #include <algorithm> |
| #include <limits> |
| #include <string> |
| |
| #include "base/files/file_path.h" |
| #include "base/logging.h" |
| #include "base/metrics/histogram.h" |
| #include "base/process_util.h" |
| #include "base/rand_util.h" |
| #include "base/strings/string_number_conversions.h" |
| #include "base/strings/string_util.h" |
| #include "base/strings/utf_string_conversions.h" |
| #include "base/threading/thread_restrictions.h" |
| #include "base/time/time.h" |
| #include "base/win/scoped_handle.h" |
| #include "base/win/windows_version.h" |
| |
| namespace base { |
| |
| namespace { |
| |
| const DWORD kFileShareAll = |
| FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE; |
| |
| bool ShellCopy(const FilePath& from_path, |
| const FilePath& to_path, |
| bool recursive) { |
| // WinXP SHFileOperation doesn't like trailing separators. |
| FilePath stripped_from = from_path.StripTrailingSeparators(); |
| FilePath stripped_to = to_path.StripTrailingSeparators(); |
| |
| ThreadRestrictions::AssertIOAllowed(); |
| |
| // NOTE: I suspect we could support longer paths, but that would involve |
| // analyzing all our usage of files. |
| if (stripped_from.value().length() >= MAX_PATH || |
| stripped_to.value().length() >= MAX_PATH) { |
| return false; |
| } |
| |
| // SHFILEOPSTRUCT wants the path to be terminated with two NULLs, |
| // so we have to use wcscpy because wcscpy_s writes non-NULLs |
| // into the rest of the buffer. |
| wchar_t double_terminated_path_from[MAX_PATH + 1] = {0}; |
| wchar_t double_terminated_path_to[MAX_PATH + 1] = {0}; |
| #pragma warning(suppress:4996) // don't complain about wcscpy deprecation |
| wcscpy(double_terminated_path_from, stripped_from.value().c_str()); |
| #pragma warning(suppress:4996) // don't complain about wcscpy deprecation |
| wcscpy(double_terminated_path_to, stripped_to.value().c_str()); |
| |
| SHFILEOPSTRUCT file_operation = {0}; |
| file_operation.wFunc = FO_COPY; |
| file_operation.pFrom = double_terminated_path_from; |
| file_operation.pTo = double_terminated_path_to; |
| file_operation.fFlags = FOF_NOERRORUI | FOF_SILENT | FOF_NOCONFIRMATION | |
| FOF_NOCONFIRMMKDIR; |
| if (!recursive) |
| file_operation.fFlags |= FOF_NORECURSION | FOF_FILESONLY; |
| |
| return (SHFileOperation(&file_operation) == 0); |
| } |
| |
| } // namespace |
| |
| FilePath MakeAbsoluteFilePath(const FilePath& input) { |
| ThreadRestrictions::AssertIOAllowed(); |
| wchar_t file_path[MAX_PATH]; |
| if (!_wfullpath(file_path, input.value().c_str(), MAX_PATH)) |
| return FilePath(); |
| return FilePath(file_path); |
| } |
| |
| bool Delete(const FilePath& path, bool recursive) { |
| ThreadRestrictions::AssertIOAllowed(); |
| |
| if (path.value().length() >= MAX_PATH) |
| return false; |
| |
| if (!recursive) { |
| // If not recursing, then first check to see if |path| is a directory. |
| // If it is, then remove it with RemoveDirectory. |
| PlatformFileInfo file_info; |
| if (file_util::GetFileInfo(path, &file_info) && file_info.is_directory) |
| return RemoveDirectory(path.value().c_str()) != 0; |
| |
| // Otherwise, it's a file, wildcard or non-existant. Try DeleteFile first |
| // because it should be faster. If DeleteFile fails, then we fall through |
| // to SHFileOperation, which will do the right thing. |
| if (DeleteFile(path.value().c_str()) != 0) |
| return true; |
| } |
| |
| // SHFILEOPSTRUCT wants the path to be terminated with two NULLs, |
| // so we have to use wcscpy because wcscpy_s writes non-NULLs |
| // into the rest of the buffer. |
| wchar_t double_terminated_path[MAX_PATH + 1] = {0}; |
| #pragma warning(suppress:4996) // don't complain about wcscpy deprecation |
| if (g_bug108724_debug) |
| LOG(WARNING) << "copying "; |
| wcscpy(double_terminated_path, path.value().c_str()); |
| |
| SHFILEOPSTRUCT file_operation = {0}; |
| file_operation.wFunc = FO_DELETE; |
| file_operation.pFrom = double_terminated_path; |
| file_operation.fFlags = FOF_NOERRORUI | FOF_SILENT | FOF_NOCONFIRMATION; |
| if (!recursive) |
| file_operation.fFlags |= FOF_NORECURSION | FOF_FILESONLY; |
| if (g_bug108724_debug) |
| LOG(WARNING) << "Performing shell operation"; |
| int err = SHFileOperation(&file_operation); |
| if (g_bug108724_debug) |
| LOG(WARNING) << "Done: " << err; |
| |
| // Since we're passing flags to the operation telling it to be silent, |
| // it's possible for the operation to be aborted/cancelled without err |
| // being set (although MSDN doesn't give any scenarios for how this can |
| // happen). See MSDN for SHFileOperation and SHFILEOPTSTRUCT. |
| if (file_operation.fAnyOperationsAborted) |
| return false; |
| |
| // Some versions of Windows return ERROR_FILE_NOT_FOUND (0x2) when deleting |
| // an empty directory and some return 0x402 when they should be returning |
| // ERROR_FILE_NOT_FOUND. MSDN says Vista and up won't return 0x402. |
| return (err == 0 || err == ERROR_FILE_NOT_FOUND || err == 0x402); |
| } |
| |
| bool DeleteAfterReboot(const FilePath& path) { |
| ThreadRestrictions::AssertIOAllowed(); |
| |
| if (path.value().length() >= MAX_PATH) |
| return false; |
| |
| return MoveFileEx(path.value().c_str(), NULL, |
| MOVEFILE_DELAY_UNTIL_REBOOT | |
| MOVEFILE_REPLACE_EXISTING) != FALSE; |
| } |
| |
| bool ReplaceFile(const FilePath& from_path, |
| const FilePath& to_path, |
| PlatformFileError* error) { |
| ThreadRestrictions::AssertIOAllowed(); |
| // Try a simple move first. It will only succeed when |to_path| doesn't |
| // already exist. |
| if (::MoveFile(from_path.value().c_str(), to_path.value().c_str())) |
| return true; |
| // Try the full-blown replace if the move fails, as ReplaceFile will only |
| // succeed when |to_path| does exist. When writing to a network share, we may |
| // not be able to change the ACLs. Ignore ACL errors then |
| // (REPLACEFILE_IGNORE_MERGE_ERRORS). |
| if (::ReplaceFile(to_path.value().c_str(), from_path.value().c_str(), NULL, |
| REPLACEFILE_IGNORE_MERGE_ERRORS, NULL, NULL)) { |
| return true; |
| } |
| if (error) |
| *error = LastErrorToPlatformFileError(GetLastError()); |
| return false; |
| } |
| |
| bool CopyDirectory(const FilePath& from_path, const FilePath& to_path, |
| bool recursive) { |
| ThreadRestrictions::AssertIOAllowed(); |
| |
| if (recursive) |
| return ShellCopy(from_path, to_path, true); |
| |
| // The following code assumes that from path is a directory. |
| DCHECK(file_util::DirectoryExists(from_path)); |
| |
| // Instead of creating a new directory, we copy the old one to include the |
| // security information of the folder as part of the copy. |
| if (!PathExists(to_path)) { |
| // Except that Vista fails to do that, and instead do a recursive copy if |
| // the target directory doesn't exist. |
| if (base::win::GetVersion() >= base::win::VERSION_VISTA) |
| file_util::CreateDirectory(to_path); |
| else |
| ShellCopy(from_path, to_path, false); |
| } |
| |
| FilePath directory = from_path.Append(L"*.*"); |
| return ShellCopy(directory, to_path, false); |
| } |
| |
| bool PathExists(const FilePath& path) { |
| ThreadRestrictions::AssertIOAllowed(); |
| return (GetFileAttributes(path.value().c_str()) != INVALID_FILE_ATTRIBUTES); |
| } |
| |
| } // namespace base |
| |
| // ----------------------------------------------------------------------------- |
| |
| namespace file_util { |
| |
| using base::FilePath; |
| using base::kFileShareAll; |
| |
| bool PathIsWritable(const FilePath& path) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| HANDLE dir = |
| CreateFile(path.value().c_str(), FILE_ADD_FILE, kFileShareAll, |
| NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL); |
| |
| if (dir == INVALID_HANDLE_VALUE) |
| return false; |
| |
| CloseHandle(dir); |
| return true; |
| } |
| |
| bool DirectoryExists(const FilePath& path) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| DWORD fileattr = GetFileAttributes(path.value().c_str()); |
| if (fileattr != INVALID_FILE_ATTRIBUTES) |
| return (fileattr & FILE_ATTRIBUTE_DIRECTORY) != 0; |
| return false; |
| } |
| |
| bool GetTempDir(FilePath* path) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| |
| wchar_t temp_path[MAX_PATH + 1]; |
| DWORD path_len = ::GetTempPath(MAX_PATH, temp_path); |
| if (path_len >= MAX_PATH || path_len <= 0) |
| return false; |
| // TODO(evanm): the old behavior of this function was to always strip the |
| // trailing slash. We duplicate this here, but it shouldn't be necessary |
| // when everyone is using the appropriate FilePath APIs. |
| *path = FilePath(temp_path).StripTrailingSeparators(); |
| return true; |
| } |
| |
| bool GetShmemTempDir(FilePath* path, bool executable) { |
| return GetTempDir(path); |
| } |
| |
| bool CreateTemporaryFile(FilePath* path) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| |
| FilePath temp_file; |
| |
| if (!GetTempDir(path)) |
| return false; |
| |
| if (CreateTemporaryFileInDir(*path, &temp_file)) { |
| *path = temp_file; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| FILE* CreateAndOpenTemporaryShmemFile(FilePath* path, bool executable) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| return CreateAndOpenTemporaryFile(path); |
| } |
| |
| // On POSIX we have semantics to create and open a temporary file |
| // atomically. |
| // TODO(jrg): is there equivalent call to use on Windows instead of |
| // going 2-step? |
| FILE* CreateAndOpenTemporaryFileInDir(const FilePath& dir, FilePath* path) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| if (!CreateTemporaryFileInDir(dir, path)) { |
| return NULL; |
| } |
| // Open file in binary mode, to avoid problems with fwrite. On Windows |
| // it replaces \n's with \r\n's, which may surprise you. |
| // Reference: http://msdn.microsoft.com/en-us/library/h9t88zwz(VS.71).aspx |
| return OpenFile(*path, "wb+"); |
| } |
| |
| bool CreateTemporaryFileInDir(const FilePath& dir, |
| FilePath* temp_file) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| |
| wchar_t temp_name[MAX_PATH + 1]; |
| |
| if (!GetTempFileName(dir.value().c_str(), L"", 0, temp_name)) { |
| DPLOG(WARNING) << "Failed to get temporary file name in " << dir.value(); |
| return false; |
| } |
| |
| wchar_t long_temp_name[MAX_PATH + 1]; |
| DWORD long_name_len = GetLongPathName(temp_name, long_temp_name, MAX_PATH); |
| if (long_name_len > MAX_PATH || long_name_len == 0) { |
| // GetLongPathName() failed, but we still have a temporary file. |
| *temp_file = FilePath(temp_name); |
| return true; |
| } |
| |
| FilePath::StringType long_temp_name_str; |
| long_temp_name_str.assign(long_temp_name, long_name_len); |
| *temp_file = FilePath(long_temp_name_str); |
| return true; |
| } |
| |
| bool CreateTemporaryDirInDir(const FilePath& base_dir, |
| const FilePath::StringType& prefix, |
| FilePath* new_dir) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| |
| FilePath path_to_create; |
| |
| for (int count = 0; count < 50; ++count) { |
| // Try create a new temporary directory with random generated name. If |
| // the one exists, keep trying another path name until we reach some limit. |
| string16 new_dir_name; |
| new_dir_name.assign(prefix); |
| new_dir_name.append(base::IntToString16(::base::GetCurrentProcId())); |
| new_dir_name.push_back('_'); |
| new_dir_name.append(base::IntToString16(base::RandInt(0, kint16max))); |
| |
| path_to_create = base_dir.Append(new_dir_name); |
| if (::CreateDirectory(path_to_create.value().c_str(), NULL)) { |
| *new_dir = path_to_create; |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| bool CreateNewTempDirectory(const FilePath::StringType& prefix, |
| FilePath* new_temp_path) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| |
| FilePath system_temp_dir; |
| if (!GetTempDir(&system_temp_dir)) |
| return false; |
| |
| return CreateTemporaryDirInDir(system_temp_dir, prefix, new_temp_path); |
| } |
| |
| bool CreateDirectoryAndGetError(const FilePath& full_path, |
| base::PlatformFileError* error) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| |
| // If the path exists, we've succeeded if it's a directory, failed otherwise. |
| const wchar_t* full_path_str = full_path.value().c_str(); |
| DWORD fileattr = ::GetFileAttributes(full_path_str); |
| if (fileattr != INVALID_FILE_ATTRIBUTES) { |
| if ((fileattr & FILE_ATTRIBUTE_DIRECTORY) != 0) { |
| DVLOG(1) << "CreateDirectory(" << full_path_str << "), " |
| << "directory already exists."; |
| return true; |
| } |
| DLOG(WARNING) << "CreateDirectory(" << full_path_str << "), " |
| << "conflicts with existing file."; |
| if (error) { |
| *error = base::PLATFORM_FILE_ERROR_NOT_A_DIRECTORY; |
| } |
| return false; |
| } |
| |
| // Invariant: Path does not exist as file or directory. |
| |
| // Attempt to create the parent recursively. This will immediately return |
| // true if it already exists, otherwise will create all required parent |
| // directories starting with the highest-level missing parent. |
| FilePath parent_path(full_path.DirName()); |
| if (parent_path.value() == full_path.value()) { |
| if (error) { |
| *error = base::PLATFORM_FILE_ERROR_NOT_FOUND; |
| } |
| return false; |
| } |
| if (!CreateDirectoryAndGetError(parent_path, error)) { |
| DLOG(WARNING) << "Failed to create one of the parent directories."; |
| if (error) { |
| DCHECK(*error != base::PLATFORM_FILE_OK); |
| } |
| return false; |
| } |
| |
| if (!::CreateDirectory(full_path_str, NULL)) { |
| DWORD error_code = ::GetLastError(); |
| if (error_code == ERROR_ALREADY_EXISTS && DirectoryExists(full_path)) { |
| // This error code ERROR_ALREADY_EXISTS doesn't indicate whether we |
| // were racing with someone creating the same directory, or a file |
| // with the same path. If DirectoryExists() returns true, we lost the |
| // race to create the same directory. |
| return true; |
| } else { |
| if (error) |
| *error = base::LastErrorToPlatformFileError(error_code); |
| DLOG(WARNING) << "Failed to create directory " << full_path_str |
| << ", last error is " << error_code << "."; |
| return false; |
| } |
| } else { |
| return true; |
| } |
| } |
| |
| // TODO(rkc): Work out if we want to handle NTFS junctions here or not, handle |
| // them if we do decide to. |
| bool IsLink(const FilePath& file_path) { |
| return false; |
| } |
| |
| bool GetFileInfo(const FilePath& file_path, base::PlatformFileInfo* results) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| |
| WIN32_FILE_ATTRIBUTE_DATA attr; |
| if (!GetFileAttributesEx(file_path.value().c_str(), |
| GetFileExInfoStandard, &attr)) { |
| return false; |
| } |
| |
| ULARGE_INTEGER size; |
| size.HighPart = attr.nFileSizeHigh; |
| size.LowPart = attr.nFileSizeLow; |
| results->size = size.QuadPart; |
| |
| results->is_directory = |
| (attr.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0; |
| results->last_modified = base::Time::FromFileTime(attr.ftLastWriteTime); |
| results->last_accessed = base::Time::FromFileTime(attr.ftLastAccessTime); |
| results->creation_time = base::Time::FromFileTime(attr.ftCreationTime); |
| |
| return true; |
| } |
| |
| FILE* OpenFile(const FilePath& filename, const char* mode) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| std::wstring w_mode = ASCIIToWide(std::string(mode)); |
| return _wfsopen(filename.value().c_str(), w_mode.c_str(), _SH_DENYNO); |
| } |
| |
| FILE* OpenFile(const std::string& filename, const char* mode) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| return _fsopen(filename.c_str(), mode, _SH_DENYNO); |
| } |
| |
| int ReadFile(const FilePath& filename, char* data, int size) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| base::win::ScopedHandle file(CreateFile(filename.value().c_str(), |
| GENERIC_READ, |
| FILE_SHARE_READ | FILE_SHARE_WRITE, |
| NULL, |
| OPEN_EXISTING, |
| FILE_FLAG_SEQUENTIAL_SCAN, |
| NULL)); |
| if (!file) |
| return -1; |
| |
| DWORD read; |
| if (::ReadFile(file, data, size, &read, NULL) && |
| static_cast<int>(read) == size) |
| return read; |
| return -1; |
| } |
| |
| int WriteFile(const FilePath& filename, const char* data, int size) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| base::win::ScopedHandle file(CreateFile(filename.value().c_str(), |
| GENERIC_WRITE, |
| 0, |
| NULL, |
| CREATE_ALWAYS, |
| 0, |
| NULL)); |
| if (!file) { |
| DLOG_GETLASTERROR(WARNING) << "CreateFile failed for path " |
| << filename.value(); |
| return -1; |
| } |
| |
| DWORD written; |
| BOOL result = ::WriteFile(file, data, size, &written, NULL); |
| if (result && static_cast<int>(written) == size) |
| return written; |
| |
| if (!result) { |
| // WriteFile failed. |
| DLOG_GETLASTERROR(WARNING) << "writing file " << filename.value() |
| << " failed"; |
| } else { |
| // Didn't write all the bytes. |
| DLOG(WARNING) << "wrote" << written << " bytes to " |
| << filename.value() << " expected " << size; |
| } |
| return -1; |
| } |
| |
| int AppendToFile(const FilePath& filename, const char* data, int size) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| base::win::ScopedHandle file(CreateFile(filename.value().c_str(), |
| FILE_APPEND_DATA, |
| 0, |
| NULL, |
| OPEN_EXISTING, |
| 0, |
| NULL)); |
| if (!file) { |
| DLOG_GETLASTERROR(WARNING) << "CreateFile failed for path " |
| << filename.value(); |
| return -1; |
| } |
| |
| DWORD written; |
| BOOL result = ::WriteFile(file, data, size, &written, NULL); |
| if (result && static_cast<int>(written) == size) |
| return written; |
| |
| if (!result) { |
| // WriteFile failed. |
| DLOG_GETLASTERROR(WARNING) << "writing file " << filename.value() |
| << " failed"; |
| } else { |
| // Didn't write all the bytes. |
| DLOG(WARNING) << "wrote" << written << " bytes to " |
| << filename.value() << " expected " << size; |
| } |
| return -1; |
| } |
| |
| // Gets the current working directory for the process. |
| bool GetCurrentDirectory(FilePath* dir) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| |
| wchar_t system_buffer[MAX_PATH]; |
| system_buffer[0] = 0; |
| DWORD len = ::GetCurrentDirectory(MAX_PATH, system_buffer); |
| if (len == 0 || len > MAX_PATH) |
| return false; |
| // TODO(evanm): the old behavior of this function was to always strip the |
| // trailing slash. We duplicate this here, but it shouldn't be necessary |
| // when everyone is using the appropriate FilePath APIs. |
| std::wstring dir_str(system_buffer); |
| *dir = FilePath(dir_str).StripTrailingSeparators(); |
| return true; |
| } |
| |
| // Sets the current working directory for the process. |
| bool SetCurrentDirectory(const FilePath& directory) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| BOOL ret = ::SetCurrentDirectory(directory.value().c_str()); |
| return ret != 0; |
| } |
| |
| bool NormalizeFilePath(const FilePath& path, FilePath* real_path) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| FilePath mapped_file; |
| if (!NormalizeToNativeFilePath(path, &mapped_file)) |
| return false; |
| // NormalizeToNativeFilePath() will return a path that starts with |
| // "\Device\Harddisk...". Helper DevicePathToDriveLetterPath() |
| // will find a drive letter which maps to the path's device, so |
| // that we return a path starting with a drive letter. |
| return DevicePathToDriveLetterPath(mapped_file, real_path); |
| } |
| |
| bool DevicePathToDriveLetterPath(const FilePath& nt_device_path, |
| FilePath* out_drive_letter_path) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| |
| // Get the mapping of drive letters to device paths. |
| const int kDriveMappingSize = 1024; |
| wchar_t drive_mapping[kDriveMappingSize] = {'\0'}; |
| if (!::GetLogicalDriveStrings(kDriveMappingSize - 1, drive_mapping)) { |
| DLOG(ERROR) << "Failed to get drive mapping."; |
| return false; |
| } |
| |
| // The drive mapping is a sequence of null terminated strings. |
| // The last string is empty. |
| wchar_t* drive_map_ptr = drive_mapping; |
| wchar_t device_path_as_string[MAX_PATH]; |
| wchar_t drive[] = L" :"; |
| |
| // For each string in the drive mapping, get the junction that links |
| // to it. If that junction is a prefix of |device_path|, then we |
| // know that |drive| is the real path prefix. |
| while (*drive_map_ptr) { |
| drive[0] = drive_map_ptr[0]; // Copy the drive letter. |
| |
| if (QueryDosDevice(drive, device_path_as_string, MAX_PATH)) { |
| FilePath device_path(device_path_as_string); |
| if (device_path == nt_device_path || |
| device_path.IsParent(nt_device_path)) { |
| *out_drive_letter_path = FilePath(drive + |
| nt_device_path.value().substr(wcslen(device_path_as_string))); |
| return true; |
| } |
| } |
| // Move to the next drive letter string, which starts one |
| // increment after the '\0' that terminates the current string. |
| while (*drive_map_ptr++); |
| } |
| |
| // No drive matched. The path does not start with a device junction |
| // that is mounted as a drive letter. This means there is no drive |
| // letter path to the volume that holds |device_path|, so fail. |
| return false; |
| } |
| |
| bool NormalizeToNativeFilePath(const FilePath& path, FilePath* nt_path) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| // In Vista, GetFinalPathNameByHandle() would give us the real path |
| // from a file handle. If we ever deprecate XP, consider changing the |
| // code below to a call to GetFinalPathNameByHandle(). The method this |
| // function uses is explained in the following msdn article: |
| // http://msdn.microsoft.com/en-us/library/aa366789(VS.85).aspx |
| base::win::ScopedHandle file_handle( |
| ::CreateFile(path.value().c_str(), |
| GENERIC_READ, |
| kFileShareAll, |
| NULL, |
| OPEN_EXISTING, |
| FILE_ATTRIBUTE_NORMAL, |
| NULL)); |
| if (!file_handle) |
| return false; |
| |
| // Create a file mapping object. Can't easily use MemoryMappedFile, because |
| // we only map the first byte, and need direct access to the handle. You can |
| // not map an empty file, this call fails in that case. |
| base::win::ScopedHandle file_map_handle( |
| ::CreateFileMapping(file_handle.Get(), |
| NULL, |
| PAGE_READONLY, |
| 0, |
| 1, // Just one byte. No need to look at the data. |
| NULL)); |
| if (!file_map_handle) |
| return false; |
| |
| // Use a view of the file to get the path to the file. |
| void* file_view = MapViewOfFile(file_map_handle.Get(), |
| FILE_MAP_READ, 0, 0, 1); |
| if (!file_view) |
| return false; |
| |
| // The expansion of |path| into a full path may make it longer. |
| // GetMappedFileName() will fail if the result is longer than MAX_PATH. |
| // Pad a bit to be safe. If kMaxPathLength is ever changed to be less |
| // than MAX_PATH, it would be nessisary to test that GetMappedFileName() |
| // not return kMaxPathLength. This would mean that only part of the |
| // path fit in |mapped_file_path|. |
| const int kMaxPathLength = MAX_PATH + 10; |
| wchar_t mapped_file_path[kMaxPathLength]; |
| bool success = false; |
| HANDLE cp = GetCurrentProcess(); |
| if (::GetMappedFileNameW(cp, file_view, mapped_file_path, kMaxPathLength)) { |
| *nt_path = FilePath(mapped_file_path); |
| success = true; |
| } |
| ::UnmapViewOfFile(file_view); |
| return success; |
| } |
| |
| int GetMaximumPathComponentLength(const FilePath& path) { |
| base::ThreadRestrictions::AssertIOAllowed(); |
| |
| wchar_t volume_path[MAX_PATH]; |
| if (!GetVolumePathNameW(path.NormalizePathSeparators().value().c_str(), |
| volume_path, |
| arraysize(volume_path))) { |
| return -1; |
| } |
| |
| DWORD max_length = 0; |
| if (!GetVolumeInformationW(volume_path, NULL, 0, NULL, &max_length, NULL, |
| NULL, 0)) { |
| return -1; |
| } |
| |
| // Length of |path| with path separator appended. |
| size_t prefix = path.StripTrailingSeparators().value().size() + 1; |
| // The whole path string must be shorter than MAX_PATH. That is, it must be |
| // prefix + component_length < MAX_PATH (or equivalently, <= MAX_PATH - 1). |
| int whole_path_limit = std::max(0, MAX_PATH - 1 - static_cast<int>(prefix)); |
| return std::min(whole_path_limit, static_cast<int>(max_length)); |
| } |
| |
| } // namespace file_util |
| |
| namespace base { |
| namespace internal { |
| |
| bool MoveUnsafe(const FilePath& from_path, const FilePath& to_path) { |
| ThreadRestrictions::AssertIOAllowed(); |
| |
| // NOTE: I suspect we could support longer paths, but that would involve |
| // analyzing all our usage of files. |
| if (from_path.value().length() >= MAX_PATH || |
| to_path.value().length() >= MAX_PATH) { |
| return false; |
| } |
| if (MoveFileEx(from_path.value().c_str(), to_path.value().c_str(), |
| MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING) != 0) |
| return true; |
| |
| // Keep the last error value from MoveFileEx around in case the below |
| // fails. |
| bool ret = false; |
| DWORD last_error = ::GetLastError(); |
| |
| if (file_util::DirectoryExists(from_path)) { |
| // MoveFileEx fails if moving directory across volumes. We will simulate |
| // the move by using Copy and Delete. Ideally we could check whether |
| // from_path and to_path are indeed in different volumes. |
| ret = internal::CopyAndDeleteDirectory(from_path, to_path); |
| } |
| |
| if (!ret) { |
| // Leave a clue about what went wrong so that it can be (at least) picked |
| // up by a PLOG entry. |
| ::SetLastError(last_error); |
| } |
| |
| return ret; |
| } |
| |
| bool CopyFileUnsafe(const FilePath& from_path, const FilePath& to_path) { |
| ThreadRestrictions::AssertIOAllowed(); |
| |
| // NOTE: I suspect we could support longer paths, but that would involve |
| // analyzing all our usage of files. |
| if (from_path.value().length() >= MAX_PATH || |
| to_path.value().length() >= MAX_PATH) { |
| return false; |
| } |
| return (::CopyFile(from_path.value().c_str(), to_path.value().c_str(), |
| false) != 0); |
| } |
| |
| bool CopyAndDeleteDirectory(const FilePath& from_path, |
| const FilePath& to_path) { |
| ThreadRestrictions::AssertIOAllowed(); |
| if (CopyDirectory(from_path, to_path, true)) { |
| if (Delete(from_path, true)) |
| return true; |
| |
| // Like Move, this function is not transactional, so we just |
| // leave the copied bits behind if deleting from_path fails. |
| // If to_path exists previously then we have already overwritten |
| // it by now, we don't get better off by deleting the new bits. |
| } |
| return false; |
| } |
| |
| } // namespace internal |
| } // namespace base |
