blob: 6b268cdb9ad0edd55bab07cccd4274623cb0919c [file] [log] [blame]
// 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/files/file_util.h"
#include <windows.h>
#include <io.h>
#include <psapi.h>
#include <shellapi.h>
#include <shlobj.h>
#include <stddef.h>
#include <stdint.h>
#include <time.h>
#include <winsock2.h>
#include <algorithm>
#include <limits>
#include <string>
#include "base/files/file_enumerator.h"
#include "base/files/file_path.h"
#include "base/guid.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/metrics/histogram.h"
#include "base/process/process_handle.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;
// Deletes all files and directories in a path.
// Returns false on the first failure it encounters.
bool DeleteFileRecursive(const FilePath& path,
const FilePath::StringType& pattern,
bool recursive) {
FileEnumerator traversal(path, false,
FileEnumerator::FILES | FileEnumerator::DIRECTORIES,
pattern);
bool success = true;
for (FilePath current = traversal.Next(); !current.empty();
current = traversal.Next()) {
// Try to clear the read-only bit if we find it.
FileEnumerator::FileInfo info = traversal.GetInfo();
if ((info.find_data().dwFileAttributes & FILE_ATTRIBUTE_READONLY) &&
(recursive || !info.IsDirectory())) {
SetFileAttributes(
current.value().c_str(),
info.find_data().dwFileAttributes & ~FILE_ATTRIBUTE_READONLY);
}
if (info.IsDirectory()) {
if (recursive && (!DeleteFileRecursive(current, pattern, true) ||
!RemoveDirectory(current.value().c_str())))
success = false;
} else if (!::DeleteFile(current.value().c_str())) {
success = false;
}
}
return success;
}
// Appends |mode_char| to |mode| before the optional character set encoding; see
// https://msdn.microsoft.com/library/yeby3zcb.aspx for details.
void AppendModeCharacter(base::char16 mode_char, base::string16* mode) {
size_t comma_pos = mode->find(L',');
mode->insert(comma_pos == base::string16::npos ? mode->length() : comma_pos,
1, mode_char);
}
bool DoCopyFile(const FilePath& from_path,
const FilePath& to_path,
bool fail_if_exists) {
AssertBlockingAllowed();
if (from_path.ReferencesParent() || to_path.ReferencesParent())
return false;
// 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;
}
// Unlike the posix implementation that copies the file manually and discards
// the ACL bits, CopyFile() copies the complete SECURITY_DESCRIPTOR and access
// bits, which is usually not what we want. We can't do much about the
// SECURITY_DESCRIPTOR but at least remove the read only bit.
const wchar_t* dest = to_path.value().c_str();
if (!::CopyFile(from_path.value().c_str(), dest, fail_if_exists)) {
// Copy failed.
return false;
}
DWORD attrs = GetFileAttributes(dest);
if (attrs == INVALID_FILE_ATTRIBUTES) {
return false;
}
if (attrs & FILE_ATTRIBUTE_READONLY) {
SetFileAttributes(dest, attrs & ~FILE_ATTRIBUTE_READONLY);
}
return true;
}
bool DoCopyDirectory(const FilePath& from_path,
const FilePath& to_path,
bool recursive,
bool fail_if_exists) {
// NOTE(maruel): Previous version of this function used to call
// SHFileOperation(). This used to copy the file attributes and extended
// attributes, OLE structured storage, NTFS file system alternate data
// streams, SECURITY_DESCRIPTOR. In practice, this is not what we want, we
// want the containing directory to propagate its SECURITY_DESCRIPTOR.
AssertBlockingAllowed();
// 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;
}
// This function does not properly handle destinations within the source.
FilePath real_to_path = to_path;
if (PathExists(real_to_path)) {
real_to_path = MakeAbsoluteFilePath(real_to_path);
if (real_to_path.empty())
return false;
} else {
real_to_path = MakeAbsoluteFilePath(real_to_path.DirName());
if (real_to_path.empty())
return false;
}
FilePath real_from_path = MakeAbsoluteFilePath(from_path);
if (real_from_path.empty())
return false;
if (real_to_path == real_from_path || real_from_path.IsParent(real_to_path))
return false;
int traverse_type = FileEnumerator::FILES;
if (recursive)
traverse_type |= FileEnumerator::DIRECTORIES;
FileEnumerator traversal(from_path, recursive, traverse_type);
if (!PathExists(from_path)) {
DLOG(ERROR) << "CopyDirectory() couldn't stat source directory: "
<< from_path.value().c_str();
return false;
}
// TODO(maruel): This is not necessary anymore.
DCHECK(recursive || DirectoryExists(from_path));
FilePath current = from_path;
bool from_is_dir = DirectoryExists(from_path);
bool success = true;
FilePath from_path_base = from_path;
if (recursive && DirectoryExists(to_path)) {
// If the destination already exists and is a directory, then the
// top level of source needs to be copied.
from_path_base = from_path.DirName();
}
while (success && !current.empty()) {
// current is the source path, including from_path, so append
// the suffix after from_path to to_path to create the target_path.
FilePath target_path(to_path);
if (from_path_base != current) {
if (!from_path_base.AppendRelativePath(current, &target_path)) {
success = false;
break;
}
}
if (from_is_dir) {
if (!DirectoryExists(target_path) &&
!::CreateDirectory(target_path.value().c_str(), NULL)) {
DLOG(ERROR) << "CopyDirectory() couldn't create directory: "
<< target_path.value().c_str();
success = false;
}
} else if (!DoCopyFile(current, target_path, fail_if_exists)) {
DLOG(ERROR) << "CopyDirectory() couldn't create file: "
<< target_path.value().c_str();
success = false;
}
current = traversal.Next();
if (!current.empty())
from_is_dir = traversal.GetInfo().IsDirectory();
}
return success;
}
} // namespace
FilePath MakeAbsoluteFilePath(const FilePath& input) {
AssertBlockingAllowed();
wchar_t file_path[MAX_PATH];
if (!_wfullpath(file_path, input.value().c_str(), MAX_PATH))
return FilePath();
return FilePath(file_path);
}
bool DeleteFile(const FilePath& path, bool recursive) {
AssertBlockingAllowed();
if (path.empty())
return true;
if (path.value().length() >= MAX_PATH)
return false;
// Handle any path with wildcards.
if (path.BaseName().value().find_first_of(L"*?") !=
FilePath::StringType::npos) {
return DeleteFileRecursive(path.DirName(), path.BaseName().value(),
recursive);
}
DWORD attr = GetFileAttributes(path.value().c_str());
// We're done if we can't find the path.
if (attr == INVALID_FILE_ATTRIBUTES)
return true;
// We may need to clear the read-only bit.
if ((attr & FILE_ATTRIBUTE_READONLY) &&
!SetFileAttributes(path.value().c_str(),
attr & ~FILE_ATTRIBUTE_READONLY)) {
return false;
}
// Directories are handled differently if they're recursive.
if (!(attr & FILE_ATTRIBUTE_DIRECTORY))
return !!::DeleteFile(path.value().c_str());
// Handle a simple, single file delete.
if (!recursive || DeleteFileRecursive(path, L"*", true))
return !!RemoveDirectory(path.value().c_str());
return false;
}
bool DeleteFileAfterReboot(const FilePath& path) {
AssertBlockingAllowed();
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,
File::Error* error) {
AssertBlockingAllowed();
// 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;
File::Error move_error = File::OSErrorToFileError(GetLastError());
// 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;
}
// In the case of FILE_ERROR_NOT_FOUND from ReplaceFile, it is likely that
// |to_path| does not exist. In this case, the more relevant error comes
// from the call to MoveFile.
if (error) {
File::Error replace_error = File::OSErrorToFileError(GetLastError());
*error = replace_error == File::FILE_ERROR_NOT_FOUND ? move_error
: replace_error;
}
return false;
}
bool CopyDirectory(const FilePath& from_path,
const FilePath& to_path,
bool recursive) {
return DoCopyDirectory(from_path, to_path, recursive, false);
}
bool CopyDirectoryExcl(const FilePath& from_path,
const FilePath& to_path,
bool recursive) {
return DoCopyDirectory(from_path, to_path, recursive, true);
}
bool PathExists(const FilePath& path) {
AssertBlockingAllowed();
return (GetFileAttributes(path.value().c_str()) != INVALID_FILE_ATTRIBUTES);
}
bool PathIsWritable(const FilePath& path) {
AssertBlockingAllowed();
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) {
AssertBlockingAllowed();
DWORD fileattr = GetFileAttributes(path.value().c_str());
if (fileattr != INVALID_FILE_ATTRIBUTES)
return (fileattr & FILE_ATTRIBUTE_DIRECTORY) != 0;
return false;
}
bool GetTempDir(FilePath* path) {
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;
}
FilePath GetHomeDir() {
char16 result[MAX_PATH];
if (SUCCEEDED(SHGetFolderPath(NULL, CSIDL_PROFILE, NULL, SHGFP_TYPE_CURRENT,
result)) &&
result[0]) {
return FilePath(result);
}
// Fall back to the temporary directory on failure.
FilePath temp;
if (GetTempDir(&temp))
return temp;
// Last resort.
return FilePath(L"C:\\");
}
bool CreateTemporaryFile(FilePath* path) {
AssertBlockingAllowed();
FilePath temp_file;
if (!GetTempDir(path))
return false;
if (CreateTemporaryFileInDir(*path, &temp_file)) {
*path = temp_file;
return true;
}
return false;
}
// 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) {
AssertBlockingAllowed();
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) {
AssertBlockingAllowed();
// Use GUID instead of ::GetTempFileName() to generate unique file names.
// "Due to the algorithm used to generate file names, GetTempFileName can
// perform poorly when creating a large number of files with the same prefix.
// In such cases, it is recommended that you construct unique file names based
// on GUIDs."
// https://msdn.microsoft.com/en-us/library/windows/desktop/aa364991(v=vs.85).aspx
FilePath temp_name;
bool create_file_success = false;
// Although it is nearly impossible to get a duplicate name with GUID, we
// still use a loop here in case it happens.
for (int i = 0; i < 100; ++i) {
temp_name = dir.Append(ASCIIToUTF16(base::GenerateGUID()) + L".tmp");
File file(temp_name,
File::FLAG_CREATE | File::FLAG_READ | File::FLAG_WRITE);
if (file.IsValid()) {
file.Close();
create_file_success = true;
break;
}
}
if (!create_file_success) {
DPLOG(WARNING) << "Failed to get temporary file name in "
<< UTF16ToUTF8(dir.value());
return false;
}
wchar_t long_temp_name[MAX_PATH + 1];
DWORD long_name_len =
GetLongPathName(temp_name.value().c_str(), 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 = std::move(temp_name);
return true;
}
FilePath::StringType long_temp_name_str;
long_temp_name_str.assign(long_temp_name, long_name_len);
*temp_file = FilePath(std::move(long_temp_name_str));
return true;
}
bool CreateTemporaryDirInDir(const FilePath& base_dir,
const FilePath::StringType& prefix,
FilePath* new_dir) {
AssertBlockingAllowed();
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(IntToString16(GetCurrentProcId()));
new_dir_name.push_back('_');
new_dir_name.append(
IntToString16(RandInt(0, std::numeric_limits<int16_t>::max())));
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) {
AssertBlockingAllowed();
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,
File::Error* error) {
AssertBlockingAllowed();
// 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 = File::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 = File::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 != File::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 = File::OSErrorToFileError(error_code);
DLOG(WARNING) << "Failed to create directory " << full_path_str
<< ", last error is " << error_code << ".";
return false;
}
} else {
return true;
}
}
bool NormalizeFilePath(const FilePath& path, FilePath* real_path) {
AssertBlockingAllowed();
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) {
AssertBlockingAllowed();
// 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) {
AssertBlockingAllowed();
// 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
win::ScopedHandle file_handle(
::CreateFile(path.value().c_str(),
GENERIC_READ,
kFileShareAll,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL));
if (!file_handle.IsValid())
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.
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.IsValid())
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;
}
// 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, File::Info* results) {
AssertBlockingAllowed();
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 = Time::FromFileTime(attr.ftLastWriteTime);
results->last_accessed = Time::FromFileTime(attr.ftLastAccessTime);
results->creation_time = Time::FromFileTime(attr.ftCreationTime);
return true;
}
FILE* OpenFile(const FilePath& filename, const char* mode) {
// 'N' is unconditionally added below, so be sure there is not one already
// present before a comma in |mode|.
DCHECK(
strchr(mode, 'N') == nullptr ||
(strchr(mode, ',') != nullptr && strchr(mode, 'N') > strchr(mode, ',')));
AssertBlockingAllowed();
string16 w_mode = ASCIIToUTF16(mode);
AppendModeCharacter(L'N', &w_mode);
return _wfsopen(filename.value().c_str(), w_mode.c_str(), _SH_DENYNO);
}
FILE* FileToFILE(File file, const char* mode) {
if (!file.IsValid())
return NULL;
int fd =
_open_osfhandle(reinterpret_cast<intptr_t>(file.GetPlatformFile()), 0);
if (fd < 0)
return NULL;
file.TakePlatformFile();
FILE* stream = _fdopen(fd, mode);
if (!stream)
_close(fd);
return stream;
}
int ReadFile(const FilePath& filename, char* data, int max_size) {
AssertBlockingAllowed();
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.IsValid())
return -1;
DWORD read;
if (::ReadFile(file.Get(), data, max_size, &read, NULL))
return read;
return -1;
}
int WriteFile(const FilePath& filename, const char* data, int size) {
AssertBlockingAllowed();
win::ScopedHandle file(CreateFile(filename.value().c_str(), GENERIC_WRITE, 0,
NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL,
NULL));
if (!file.IsValid()) {
DPLOG(WARNING) << "CreateFile failed for path "
<< UTF16ToUTF8(filename.value());
return -1;
}
DWORD written;
BOOL result = ::WriteFile(file.Get(), data, size, &written, NULL);
if (result && static_cast<int>(written) == size)
return written;
if (!result) {
// WriteFile failed.
DPLOG(WARNING) << "writing file " << UTF16ToUTF8(filename.value())
<< " failed";
} else {
// Didn't write all the bytes.
DLOG(WARNING) << "wrote" << written << " bytes to "
<< UTF16ToUTF8(filename.value()) << " expected " << size;
}
return -1;
}
bool AppendToFile(const FilePath& filename, const char* data, int size) {
AssertBlockingAllowed();
win::ScopedHandle file(CreateFile(filename.value().c_str(),
FILE_APPEND_DATA,
0,
NULL,
OPEN_EXISTING,
0,
NULL));
if (!file.IsValid()) {
VPLOG(1) << "CreateFile failed for path " << UTF16ToUTF8(filename.value());
return false;
}
DWORD written;
BOOL result = ::WriteFile(file.Get(), data, size, &written, NULL);
if (result && static_cast<int>(written) == size)
return true;
if (!result) {
// WriteFile failed.
VPLOG(1) << "Writing file " << UTF16ToUTF8(filename.value()) << " failed";
} else {
// Didn't write all the bytes.
VPLOG(1) << "Only wrote " << written << " out of " << size << " byte(s) to "
<< UTF16ToUTF8(filename.value());
}
return false;
}
bool GetCurrentDirectory(FilePath* dir) {
AssertBlockingAllowed();
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;
}
bool SetCurrentDirectory(const FilePath& directory) {
AssertBlockingAllowed();
return ::SetCurrentDirectory(directory.value().c_str()) != 0;
}
int GetMaximumPathComponentLength(const FilePath& path) {
AssertBlockingAllowed();
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));
}
bool CopyFile(const FilePath& from_path, const FilePath& to_path) {
return DoCopyFile(from_path, to_path, false);
}
bool SetNonBlocking(int fd) {
unsigned long nonblocking = 1;
if (ioctlsocket(fd, FIONBIO, &nonblocking) == 0)
return true;
return false;
}
// -----------------------------------------------------------------------------
namespace internal {
bool MoveUnsafe(const FilePath& from_path, const FilePath& to_path) {
AssertBlockingAllowed();
// 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 (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 CopyAndDeleteDirectory(const FilePath& from_path,
const FilePath& to_path) {
AssertBlockingAllowed();
if (CopyDirectory(from_path, to_path, true)) {
if (DeleteFile(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