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android / toolchain / capnproto / 2e88221d3dde22266bfccf40eaee6ff9b40d113d / . / c++ / src / kj / filesystem-disk-win32.c++
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// Copyright (c) 2015 Sandstorm Development Group, Inc. and contributors
// Licensed under the MIT License:
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#if _WIN32
// For Unix implementation, see filesystem-disk-unix.c++.
// Request Vista-level APIs.
#include "win32-api-version.h"
#include "filesystem.h"
#include "debug.h"
#include "encoding.h"
#include "vector.h"
#include <algorithm>
#include <wchar.h>
#include <windows.h>
#include <winioctl.h>
#include "windows-sanity.h"
namespace kj {
static Own<ReadableDirectory> newDiskReadableDirectory(AutoCloseHandle fd, Path&& path);
static Own<Directory> newDiskDirectory(AutoCloseHandle fd, Path&& path);
static AutoCloseHandle* getHandlePointerHack(File& file) { return nullptr; }
static AutoCloseHandle* getHandlePointerHack(Directory& dir);
static Path* getPathPointerHack(File& file) { return nullptr; }
static Path* getPathPointerHack(Directory& dir);
namespace {
struct REPARSE_DATA_BUFFER {
// From ntifs.h, which is part of the driver development kit so not necessarily available I
// guess.
ULONG ReparseTag;
USHORT ReparseDataLength;
USHORT Reserved;
union {
struct {
USHORT SubstituteNameOffset;
USHORT SubstituteNameLength;
USHORT PrintNameOffset;
USHORT PrintNameLength;
ULONG Flags;
WCHAR PathBuffer[1];
} SymbolicLinkReparseBuffer;
struct {
USHORT SubstituteNameOffset;
USHORT SubstituteNameLength;
USHORT PrintNameOffset;
USHORT PrintNameLength;
WCHAR PathBuffer[1];
} MountPointReparseBuffer;
struct {
UCHAR DataBuffer[1];
} GenericReparseBuffer;
};
};
#define HIDDEN_PREFIX ".kj-tmp."
// Prefix for temp files which should be hidden when listing a directory.
//
// If you change this, make sure to update the unit test.
static constexpr int64_t WIN32_EPOCH_OFFSET = 116444736000000000ull;
// Number of 100ns intervals from Jan 1, 1601 to Jan 1, 1970.
static Date toKjDate(FILETIME t) {
int64_t value = (static_cast<uint64_t>(t.dwHighDateTime) << 32) | t.dwLowDateTime;
return (value - WIN32_EPOCH_OFFSET) * (100 * kj::NANOSECONDS) + UNIX_EPOCH;
}
static FsNode::Type modeToType(DWORD attrs, DWORD reparseTag) {
if ((attrs & FILE_ATTRIBUTE_REPARSE_POINT) &&
reparseTag == IO_REPARSE_TAG_SYMLINK) {
return FsNode::Type::SYMLINK;
}
if (attrs & FILE_ATTRIBUTE_DIRECTORY) return FsNode::Type::DIRECTORY;
return FsNode::Type::FILE;
}
static FsNode::Metadata statToMetadata(const BY_HANDLE_FILE_INFORMATION& stats) {
uint64_t size = (implicitCast<uint64_t>(stats.nFileSizeHigh) << 32) | stats.nFileSizeLow;
// Assume file index is usually a small number, i.e. nFileIndexHigh is usually 0. So we try to
// put the serial number in the upper 32 bits and the index in the lower.
uint64_t hash = ((uint64_t(stats.dwVolumeSerialNumber) << 32)
^ (uint64_t(stats.nFileIndexHigh) << 32))
| (uint64_t(stats.nFileIndexLow));
return FsNode::Metadata {
modeToType(stats.dwFileAttributes, 0),
size,
// In theory, spaceUsed should be based on GetCompressedFileSize(), but requiring an extra
// syscall for something rarely used would be sad.
size,
toKjDate(stats.ftLastWriteTime),
stats.nNumberOfLinks,
hash
};
}
static FsNode::Metadata statToMetadata(const WIN32_FIND_DATAW& stats) {
uint64_t size = (implicitCast<uint64_t>(stats.nFileSizeHigh) << 32) | stats.nFileSizeLow;
return FsNode::Metadata {
modeToType(stats.dwFileAttributes, stats.dwReserved0),
size,
// In theory, spaceUsed should be based on GetCompressedFileSize(), but requiring an extra
// syscall for something rarely used would be sad.
size,
toKjDate(stats.ftLastWriteTime),
// We can't get the number of links without opening the file, apparently. Meh.
1,
// We can't produce a reliable hashCode without opening the file.
0
};
}
static Array<wchar_t> join16(ArrayPtr<const wchar_t> path, const wchar_t* file) {
// Assumes `path` ends with a NUL terminator (and `file` is of course NUL terminated as well).
size_t len = wcslen(file) + 1;
auto result = kj::heapArray<wchar_t>(path.size() + len);
memcpy(result.begin(), path.begin(), path.asBytes().size() - sizeof(wchar_t));
result[path.size() - 1] = '\\';
memcpy(result.begin() + path.size(), file, len * sizeof(wchar_t));
return result;
}
static String dbgStr(ArrayPtr<const wchar_t> wstr) {
if (wstr.size() > 0 && wstr[wstr.size() - 1] == L'\0') {
wstr = wstr.slice(0, wstr.size() - 1);
}
return decodeWideString(wstr);
}
static void rmrfChildren(ArrayPtr<const wchar_t> path) {
auto glob = join16(path, L"*");
WIN32_FIND_DATAW data;
HANDLE handle = FindFirstFileW(glob.begin(), &data);
if (handle == INVALID_HANDLE_VALUE) {
auto error = GetLastError();
if (error == ERROR_FILE_NOT_FOUND) return;
KJ_FAIL_WIN32("FindFirstFile", error, dbgStr(glob)) { return; }
}
KJ_DEFER(KJ_WIN32(FindClose(handle)) { break; });
do {
// Ignore "." and "..", ugh.
if (data.cFileName[0] == L'.') {
if (data.cFileName[1] == L'\0' ||
(data.cFileName[1] == L'.' && data.cFileName[2] == L'\0')) {
continue;
}
}
auto child = join16(path, data.cFileName);
// For rmrf purposes, we assume any "reparse points" are symlink-like, even if they aren't
// actually the "symbolic link" reparse type, because we don't want to recursively delete any
// shared content.
if ((data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) &&
!(data.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
rmrfChildren(child);
uint retryCount = 0;
retry:
KJ_WIN32_HANDLE_ERRORS(RemoveDirectoryW(child.begin())) {
case ERROR_DIR_NOT_EMPTY:
// On Windows, deleting a file actually only schedules it for deletion. Under heavy
// load it may take a bit for the deletion to go through. Or, if another process has
// the file open, it may not be deleted until that process closes it.
//
// We'll repeatedly retry for up to 100ms, then give up. This is awful but there's no
// way to tell for sure if the system is just being slow or if someone has the file
// open.
if (retryCount++ < 10) {
Sleep(10);
goto retry;
}
KJ_FALLTHROUGH;
default:
KJ_FAIL_WIN32("RemoveDirectory", error, dbgStr(child)) { break; }
}
} else {
KJ_WIN32(DeleteFileW(child.begin()));
}
} while (FindNextFileW(handle, &data));
auto error = GetLastError();
if (error != ERROR_NO_MORE_FILES) {
KJ_FAIL_WIN32("FindNextFile", error, dbgStr(path)) { return; }
}
}
static bool rmrf(ArrayPtr<const wchar_t> path) {
// Figure out whether this is a file or a directory.
//
// We use FindFirstFileW() because in the case of symlinks it will return info about the
// symlink rather than info about the target.
WIN32_FIND_DATAW data;
HANDLE handle = FindFirstFileW(path.begin(), &data);
if (handle == INVALID_HANDLE_VALUE) {
auto error = GetLastError();
if (error == ERROR_FILE_NOT_FOUND) return false;
KJ_FAIL_WIN32("FindFirstFile", error, dbgStr(path));
}
KJ_WIN32(FindClose(handle));
// For remove purposes, we assume any "reparse points" are symlink-like, even if they aren't
// actually the "symbolic link" reparse type, because we don't want to recursively delete any
// shared content.
if ((data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) &&
!(data.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
// directory
rmrfChildren(path);
KJ_WIN32(RemoveDirectoryW(path.begin()), dbgStr(path));
} else {
KJ_WIN32(DeleteFileW(path.begin()), dbgStr(path));
}
return true;
}
static Path getPathFromHandle(HANDLE handle) {
DWORD tryLen = MAX_PATH;
for (;;) {
auto temp = kj::heapArray<wchar_t>(tryLen + 1);
DWORD len = GetFinalPathNameByHandleW(handle, temp.begin(), tryLen, 0);
if (len == 0) {
KJ_FAIL_WIN32("GetFinalPathNameByHandleW", GetLastError());
}
if (len < temp.size()) {
return Path::parseWin32Api(temp.slice(0, len));
}
// Try again with new length.
tryLen = len;
}
}
struct MmapRange {
uint64_t offset;
uint64_t size;
};
static size_t getAllocationGranularity() {
SYSTEM_INFO info;
GetSystemInfo(&info);
return info.dwAllocationGranularity;
};
static MmapRange getMmapRange(uint64_t offset, uint64_t size) {
// Rounds the given offset down to the nearest page boundary, and adjusts the size up to match.
// (This is somewhat different from Unix: we do NOT round the size up to an even multiple of
// pages.)
static const uint64_t pageSize = getAllocationGranularity();
uint64_t pageMask = pageSize - 1;
uint64_t realOffset = offset & ~pageMask;
uint64_t end = offset + size;
return { realOffset, end - realOffset };
}
class MmapDisposer: public ArrayDisposer {
protected:
void disposeImpl(void* firstElement, size_t elementSize, size_t elementCount,
size_t capacity, void (*destroyElement)(void*)) const {
auto range = getMmapRange(reinterpret_cast<uintptr_t>(firstElement),
elementSize * elementCount);
void* mapping = reinterpret_cast<void*>(range.offset);
if (mapping != nullptr) {
KJ_ASSERT(UnmapViewOfFile(mapping)) { break; }
}
}
};
#if _MSC_VER && _MSC_VER < 1910 && !defined(__clang__)
// TODO(msvc): MSVC 2015 can't initialize a constexpr's vtable correctly.
const MmapDisposer mmapDisposer = MmapDisposer();
#else
constexpr MmapDisposer mmapDisposer = MmapDisposer();
#endif
void* win32Mmap(HANDLE handle, MmapRange range, DWORD pageProtect, DWORD access) {
HANDLE mappingHandle;
KJ_WIN32(mappingHandle = CreateFileMappingW(handle, NULL, pageProtect, 0, 0, NULL));
KJ_DEFER(KJ_WIN32(CloseHandle(mappingHandle)) { break; });
void* mapping = MapViewOfFile(mappingHandle, access,
static_cast<DWORD>(range.offset >> 32), static_cast<DWORD>(range.offset), range.size);
if (mapping == nullptr) {
KJ_FAIL_WIN32("MapViewOfFile", GetLastError());
}
// It's unclear from the documentation whether mappings will always start at a multiple of the
// allocation granularity, but we depend on that later, so check it...
KJ_ASSERT(getMmapRange(reinterpret_cast<uintptr_t>(mapping), 0).size == 0);
return mapping;
}
class DiskHandle {
// We need to implement each of ReadableFile, AppendableFile, File, ReadableDirectory, and
// Directory for disk handles. There is a lot of implementation overlap between these, especially
// stat(), sync(), etc. We can't have everything inherit from a common DiskFsNode that implements
// these because then we get diamond inheritance which means we need to make all our inheritance
// virtual which means downcasting requires RTTI which violates our goal of supporting compiling
// with no RTTI. So instead we have the DiskHandle class which implements all the methods without
// inheriting anything, and then we have DiskFile, DiskDirectory, etc. hold this and delegate to
// it. Ugly, but works.
public:
DiskHandle(AutoCloseHandle&& handle, Maybe<Path> dirPath)
: handle(kj::mv(handle)), dirPath(kj::mv(dirPath)) {}
AutoCloseHandle handle;
kj::Maybe<Path> dirPath; // needed for directories, empty for files
Array<wchar_t> nativePath(PathPtr path) const {
return KJ_ASSERT_NONNULL(dirPath).append(path).forWin32Api(true);
}
// OsHandle ------------------------------------------------------------------
AutoCloseHandle clone() const {
HANDLE newHandle;
KJ_WIN32(DuplicateHandle(GetCurrentProcess(), handle, GetCurrentProcess(), &newHandle,
0, FALSE, DUPLICATE_SAME_ACCESS));
return AutoCloseHandle(newHandle);
}
HANDLE getWin32Handle() const {
return handle.get();
}
// FsNode --------------------------------------------------------------------
FsNode::Metadata stat() const {
BY_HANDLE_FILE_INFORMATION stats;
KJ_WIN32(GetFileInformationByHandle(handle, &stats));
auto metadata = statToMetadata(stats);
// Get space usage, e.g. for sparse files. Apparently the correct way to do this is to query
// "compression".
FILE_COMPRESSION_INFO compInfo;
KJ_WIN32_HANDLE_ERRORS(GetFileInformationByHandleEx(
handle, FileCompressionInfo, &compInfo, sizeof(compInfo))) {
case ERROR_CALL_NOT_IMPLEMENTED:
// Probably WINE.
break;
default:
KJ_FAIL_WIN32("GetFileInformationByHandleEx(FileCompressionInfo)", error) { break; }
break;
} else {
metadata.spaceUsed = compInfo.CompressedFileSize.QuadPart;
}
return metadata;
}
void sync() const { KJ_WIN32(FlushFileBuffers(handle)); }
void datasync() const { KJ_WIN32(FlushFileBuffers(handle)); }
// ReadableFile --------------------------------------------------------------
size_t read(uint64_t offset, ArrayPtr<byte> buffer) const {
// ReadFile() probably never returns short reads unless it hits EOF. Unfortunately, though,
// this is not documented, and it's unclear whether we can rely on it.
size_t total = 0;
while (buffer.size() > 0) {
// Apparently, the way to fake pread() on Windows is to provide an OVERLAPPED structure even
// though we're not doing overlapped I/O.
OVERLAPPED overlapped;
memset(&overlapped, 0, sizeof(overlapped));
overlapped.Offset = static_cast<DWORD>(offset);
overlapped.OffsetHigh = static_cast<DWORD>(offset >> 32);
DWORD n;
KJ_WIN32_HANDLE_ERRORS(ReadFile(handle, buffer.begin(), buffer.size(), &n, &overlapped)) {
case ERROR_HANDLE_EOF:
// The documentation claims this shouldn't happen for synchronous reads, but it seems
// to happen for me, at least under WINE.
n = 0;
break;
default:
KJ_FAIL_WIN32("ReadFile", offset, buffer.size()) { return total; }
}
if (n == 0) break;
total += n;
offset += n;
buffer = buffer.slice(n, buffer.size());
}
return total;
}
Array<const byte> mmap(uint64_t offset, uint64_t size) const {
if (size == 0) return nullptr; // Windows won't allow zero-length mappings
auto range = getMmapRange(offset, size);
const void* mapping = win32Mmap(handle, range, PAGE_READONLY, FILE_MAP_READ);
return Array<const byte>(reinterpret_cast<const byte*>(mapping) + (offset - range.offset),
size, mmapDisposer);
}
Array<byte> mmapPrivate(uint64_t offset, uint64_t size) const {
if (size == 0) return nullptr; // Windows won't allow zero-length mappings
auto range = getMmapRange(offset, size);
void* mapping = win32Mmap(handle, range, PAGE_READONLY, FILE_MAP_COPY);
return Array<byte>(reinterpret_cast<byte*>(mapping) + (offset - range.offset),
size, mmapDisposer);
}
// File ----------------------------------------------------------------------
void write(uint64_t offset, ArrayPtr<const byte> data) const {
// WriteFile() probably never returns short writes unless there's no space left on disk.
// Unfortunately, though, this is not documented, and it's unclear whether we can rely on it.
while (data.size() > 0) {
// Apparently, the way to fake pwrite() on Windows is to provide an OVERLAPPED structure even
// though we're not doing overlapped I/O.
OVERLAPPED overlapped;
memset(&overlapped, 0, sizeof(overlapped));
overlapped.Offset = static_cast<DWORD>(offset);
overlapped.OffsetHigh = static_cast<DWORD>(offset >> 32);
DWORD n;
KJ_WIN32(WriteFile(handle, data.begin(), data.size(), &n, &overlapped));
KJ_ASSERT(n > 0, "WriteFile() returned zero?");
offset += n;
data = data.slice(n, data.size());
}
}
void zero(uint64_t offset, uint64_t size) const {
FILE_ZERO_DATA_INFORMATION info;
memset(&info, 0, sizeof(info));
info.FileOffset.QuadPart = offset;
info.BeyondFinalZero.QuadPart = offset + size;
DWORD dummy;
KJ_WIN32_HANDLE_ERRORS(DeviceIoControl(handle, FSCTL_SET_ZERO_DATA, &info,
sizeof(info), NULL, 0, &dummy, NULL)) {
case ERROR_NOT_SUPPORTED: {
// Dang. Let's do it the hard way.
static const byte ZEROS[4096] = { 0 };
while (size > sizeof(ZEROS)) {
write(offset, ZEROS);
size -= sizeof(ZEROS);
offset += sizeof(ZEROS);
}
write(offset, kj::arrayPtr(ZEROS, size));
break;
}
default:
KJ_FAIL_WIN32("DeviceIoControl(FSCTL_SET_ZERO_DATA)", error);
break;
}
}
void truncate(uint64_t size) const {
// SetEndOfFile() would require seeking the file. It looks like SetFileInformationByHandle()
// lets us avoid this!
FILE_END_OF_FILE_INFO info;
memset(&info, 0, sizeof(info));
info.EndOfFile.QuadPart = size;
KJ_WIN32_HANDLE_ERRORS(
SetFileInformationByHandle(handle, FileEndOfFileInfo, &info, sizeof(info))) {
case ERROR_CALL_NOT_IMPLEMENTED: {
// Wine doesn't implement this. :(
LONG currentHigh = 0;
LONG currentLow = SetFilePointer(handle, 0, &currentHigh, FILE_CURRENT);
if (currentLow == INVALID_SET_FILE_POINTER) {
KJ_FAIL_WIN32("SetFilePointer", GetLastError());
}
uint64_t current = (uint64_t(currentHigh) << 32) | uint64_t((ULONG)currentLow);
LONG endLow = size & 0x00000000ffffffffull;
LONG endHigh = size >> 32;
if (SetFilePointer(handle, endLow, &endHigh, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
KJ_FAIL_WIN32("SetFilePointer", GetLastError());
}
KJ_WIN32(SetEndOfFile(handle));
if (current < size) {
if (SetFilePointer(handle, currentLow, &currentHigh, FILE_BEGIN) ==
INVALID_SET_FILE_POINTER) {
KJ_FAIL_WIN32("SetFilePointer", GetLastError());
}
}
break;
}
default:
KJ_FAIL_WIN32("SetFileInformationByHandle", error);
}
}
class WritableFileMappingImpl final: public WritableFileMapping {
public:
WritableFileMappingImpl(Array<byte> bytes): bytes(kj::mv(bytes)) {}
ArrayPtr<byte> get() const override {
// const_cast OK because WritableFileMapping does indeed provide a writable view despite
// being const itself.
return arrayPtr(const_cast<byte*>(bytes.begin()), bytes.size());
}
void changed(ArrayPtr<byte> slice) const override {
KJ_REQUIRE(slice.begin() >= bytes.begin() && slice.end() <= bytes.end(),
"byte range is not part of this mapping");
// Nothing needed here -- NT tracks dirty pages.
}
void sync(ArrayPtr<byte> slice) const override {
KJ_REQUIRE(slice.begin() >= bytes.begin() && slice.end() <= bytes.end(),
"byte range is not part of this mapping");
// Zero is treated specially by FlushViewOfFile(), so check for it. (This also handles the
// case where `bytes` is actually empty and not a real mapping.)
if (slice.size() > 0) {
KJ_WIN32(FlushViewOfFile(slice.begin(), slice.size()));
}
}
private:
Array<byte> bytes;
};
Own<const WritableFileMapping> mmapWritable(uint64_t offset, uint64_t size) const {
if (size == 0) {
// Windows won't allow zero-length mappings
return heap<WritableFileMappingImpl>(nullptr);
}
auto range = getMmapRange(offset, size);
void* mapping = win32Mmap(handle, range, PAGE_READWRITE, FILE_MAP_ALL_ACCESS);
auto array = Array<byte>(reinterpret_cast<byte*>(mapping) + (offset - range.offset),
size, mmapDisposer);
return heap<WritableFileMappingImpl>(kj::mv(array));
}
// copy() is not optimized on Windows.
// ReadableDirectory ---------------------------------------------------------
template <typename Func>
auto list(bool needTypes, Func&& func) const
-> Array<Decay<decltype(func(instance<StringPtr>(), instance<FsNode::Type>()))>> {
PathPtr path = KJ_ASSERT_NONNULL(dirPath);
auto glob = join16(path.forWin32Api(true), L"*");
// TODO(perf): Use FindFileEx() with FindExInfoBasic? Not apparently supported on Vista.
// TODO(someday): Use NtQueryDirectoryObject() instead? It's "internal", but so much cleaner.
WIN32_FIND_DATAW data;
HANDLE handle = FindFirstFileW(glob.begin(), &data);
if (handle == INVALID_HANDLE_VALUE) {
auto error = GetLastError();
if (error == ERROR_FILE_NOT_FOUND) return nullptr;
KJ_FAIL_WIN32("FindFirstFile", error, dbgStr(glob));
}
KJ_DEFER(KJ_WIN32(FindClose(handle)) { break; });
typedef Decay<decltype(func(instance<StringPtr>(), instance<FsNode::Type>()))> Entry;
kj::Vector<Entry> entries;
do {
auto name = decodeUtf16(
arrayPtr(reinterpret_cast<char16_t*>(data.cFileName), wcslen(data.cFileName)));
if (name != "." && name != ".." && !name.startsWith(HIDDEN_PREFIX)) {
entries.add(func(name, modeToType(data.dwFileAttributes, data.dwReserved0)));
}
} while (FindNextFileW(handle, &data));
auto error = GetLastError();
if (error != ERROR_NO_MORE_FILES) {
KJ_FAIL_WIN32("FindNextFile", error, path);
}
auto result = entries.releaseAsArray();
std::sort(result.begin(), result.end());
return result;
}
Array<String> listNames() const {
return list(false, [](StringPtr name, FsNode::Type type) { return heapString(name); });
}
Array<ReadableDirectory::Entry> listEntries() const {
return list(true, [](StringPtr name, FsNode::Type type) {
return ReadableDirectory::Entry { type, heapString(name), };
});
}
bool exists(PathPtr path) const {
DWORD result = GetFileAttributesW(nativePath(path).begin());
if (result == INVALID_FILE_ATTRIBUTES) {
auto error = GetLastError();
switch (error) {
case ERROR_FILE_NOT_FOUND:
case ERROR_PATH_NOT_FOUND:
return false;
default:
KJ_FAIL_WIN32("GetFileAttributesEx(path)", error, path) { return false; }
}
} else {
return true;
}
}
Maybe<FsNode::Metadata> tryLstat(PathPtr path) const {
// We use FindFirstFileW() because in the case of symlinks it will return info about the
// symlink rather than info about the target.
WIN32_FIND_DATAW data;
HANDLE handle = FindFirstFileW(nativePath(path).begin(), &data);
if (handle == INVALID_HANDLE_VALUE) {
auto error = GetLastError();
if (error == ERROR_FILE_NOT_FOUND) return nullptr;
KJ_FAIL_WIN32("FindFirstFile", error, path);
} else {
KJ_WIN32(FindClose(handle));
return statToMetadata(data);
}
}
Maybe<Own<const ReadableFile>> tryOpenFile(PathPtr path) const {
HANDLE newHandle;
KJ_WIN32_HANDLE_ERRORS(newHandle = CreateFileW(
nativePath(path).begin(),
GENERIC_READ,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL)) {
case ERROR_FILE_NOT_FOUND:
case ERROR_PATH_NOT_FOUND:
return nullptr;
default:
KJ_FAIL_WIN32("CreateFile(path, OPEN_EXISTING)", error, path) { return nullptr; }
}
return newDiskReadableFile(kj::AutoCloseHandle(newHandle));
}
Maybe<AutoCloseHandle> tryOpenSubdirInternal(PathPtr path) const {
HANDLE newHandle;
KJ_WIN32_HANDLE_ERRORS(newHandle = CreateFileW(
nativePath(path).begin(),
GENERIC_READ,
// When opening directories, we do NOT use FILE_SHARE_DELETE, because we need the directory
// path to remain valid.
//
// TODO(someday): Use NtCreateFile() and related "internal" APIs that allow for
// openat()-like behavior?
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS, // apparently, this flag is required for directories
NULL)) {
case ERROR_FILE_NOT_FOUND:
case ERROR_PATH_NOT_FOUND:
return nullptr;
default:
KJ_FAIL_WIN32("CreateFile(directoryPath, OPEN_EXISTING)", error, path) { return nullptr; }
}
kj::AutoCloseHandle ownHandle(newHandle);
BY_HANDLE_FILE_INFORMATION info;
KJ_WIN32(GetFileInformationByHandle(ownHandle, &info));
KJ_REQUIRE(info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY, "not a directory", path);
return kj::mv(ownHandle);
}
Maybe<Own<const ReadableDirectory>> tryOpenSubdir(PathPtr path) const {
return tryOpenSubdirInternal(path).map([&](AutoCloseHandle&& handle) {
return newDiskReadableDirectory(kj::mv(handle), KJ_ASSERT_NONNULL(dirPath).append(path));
});
}
Maybe<String> tryReadlink(PathPtr path) const {
// Windows symlinks work differently from Unix. Generally they are set up by the system
// administrator and apps are expected to treat them transparently. Hence, on Windows, we act
// as if nothing is a symlink by always returning null here.
// TODO(someday): If we want to treat Windows symlinks more like Unix ones, start by reverting
// the comment that added this comment.
return nullptr;
}
// Directory -----------------------------------------------------------------
static LPSECURITY_ATTRIBUTES makeSecAttr(WriteMode mode) {
if (has(mode, WriteMode::PRIVATE)) {
KJ_UNIMPLEMENTED("WriteMode::PRIVATE on Win32 is not implemented");
}
return nullptr;
}
bool tryMkdir(PathPtr path, WriteMode mode, bool noThrow) const {
// Internal function to make a directory.
auto filename = nativePath(path);
KJ_WIN32_HANDLE_ERRORS(CreateDirectoryW(filename.begin(), makeSecAttr(mode))) {
case ERROR_ALREADY_EXISTS:
case ERROR_FILE_EXISTS: {
// Apparently this path exists.
if (!has(mode, WriteMode::MODIFY)) {
// Require exclusive create.
return false;
}
// MODIFY is allowed, so we just need to check whether the existing entry is a directory.
DWORD attr = GetFileAttributesW(filename.begin());
if (attr == INVALID_FILE_ATTRIBUTES) {
// CreateDirectory() says it already exists but we can't get attributes. Maybe it's a
// dangling link, or maybe we can't access it for some reason. Assume failure.
//
// TODO(someday): Maybe we should be creating the directory at the target of the
// link?
goto failed;
}
return attr & FILE_ATTRIBUTE_DIRECTORY;
}
case ERROR_PATH_NOT_FOUND:
if (has(mode, WriteMode::CREATE_PARENT) && path.size() > 0 &&
tryMkdir(path.parent(), WriteMode::CREATE | WriteMode::MODIFY |
WriteMode::CREATE_PARENT, true)) {
// Retry, but make sure we don't try to create the parent again.
return tryMkdir(path, mode - WriteMode::CREATE_PARENT, noThrow);
} else {
goto failed;
}
default:
failed:
if (noThrow) {
// Caller requested no throwing.
return false;
} else {
KJ_FAIL_WIN32("CreateDirectory", error, path);
}
}
return true;
}
kj::Maybe<Array<wchar_t>> createNamedTemporary(
PathPtr finalName, WriteMode mode, Path& kjTempPath,
Function<BOOL(const wchar_t*)> tryCreate) const {
// Create a temporary file which will eventually replace `finalName`.
//
// Calls `tryCreate` to actually create the temporary, passing in the desired path. tryCreate()
// is expected to behave like a win32 call, returning a BOOL and setting `GetLastError()` on
// error. tryCreate() MUST fail with ERROR_{FILE,ALREADY}_EXISTS if the path exists -- this is
// not checked in advance, since it needs to be checked atomically. In the case of
// ERROR_*_EXISTS, tryCreate() will be called again with a new path.
//
// Returns the temporary path that succeeded. Only returns nullptr if there was an exception
// but we're compiled with -fno-exceptions.
//
// The optional parameter `kjTempPath` is filled in with the KJ Path of the temporary.
if (finalName.size() == 0) {
KJ_FAIL_REQUIRE("can't replace self") { break; }
return nullptr;
}
static uint counter = 0;
static const DWORD pid = GetCurrentProcessId();
auto tempName = kj::str(HIDDEN_PREFIX, pid, '.', counter++, '.',
finalName.basename()[0], ".partial");
kjTempPath = finalName.parent().append(tempName);
auto path = nativePath(kjTempPath);
KJ_WIN32_HANDLE_ERRORS(tryCreate(path.begin())) {
case ERROR_ALREADY_EXISTS:
case ERROR_FILE_EXISTS:
// Try again with a new counter value.
return createNamedTemporary(finalName, mode, kj::mv(tryCreate));
case ERROR_PATH_NOT_FOUND:
if (has(mode, WriteMode::CREATE_PARENT) && finalName.size() > 1 &&
tryMkdir(finalName.parent(), WriteMode::CREATE | WriteMode::MODIFY |
WriteMode::CREATE_PARENT, true)) {
// Retry, but make sure we don't try to create the parent again.
mode = mode - WriteMode::CREATE_PARENT;
return createNamedTemporary(finalName, mode, kj::mv(tryCreate));
}
KJ_FALLTHROUGH;
default:
KJ_FAIL_WIN32("create(path)", error, path) { break; }
return nullptr;
}
return kj::mv(path);
}
kj::Maybe<Array<wchar_t>> createNamedTemporary(
PathPtr finalName, WriteMode mode, Function<BOOL(const wchar_t*)> tryCreate) const {
Path dummy = nullptr;
return createNamedTemporary(finalName, mode, dummy, kj::mv(tryCreate));
}
bool tryReplaceNode(PathPtr path, WriteMode mode,
Function<BOOL(const wchar_t*)> tryCreate) const {
// Replaces the given path with an object created by calling tryCreate().
//
// tryCreate() must behave like a win32 call which creates the node at the path passed to it,
// returning FALSE error. If the path passed to tryCreate already exists, it MUST fail with
// ERROR_{FILE,ALREADY}_EXISTS.
//
// When `mode` includes MODIFY, replaceNode() reacts to ERROR_*_EXISTS by creating the
// node in a temporary location and then rename()ing it into place.
if (path.size() == 0) {
KJ_FAIL_REQUIRE("can't replace self") { return false; }
}
auto filename = nativePath(path);
if (has(mode, WriteMode::CREATE)) {
// First try just cerating the node in-place.
KJ_WIN32_HANDLE_ERRORS(tryCreate(filename.begin())) {
case ERROR_ALREADY_EXISTS:
case ERROR_FILE_EXISTS:
// Target exists.
if (has(mode, WriteMode::MODIFY)) {
// Fall back to MODIFY path, below.
break;
} else {
return false;
}
case ERROR_PATH_NOT_FOUND:
if (has(mode, WriteMode::CREATE_PARENT) && path.size() > 0 &&
tryMkdir(path.parent(), WriteMode::CREATE | WriteMode::MODIFY |
WriteMode::CREATE_PARENT, true)) {
// Retry, but make sure we don't try to create the parent again.
return tryReplaceNode(path, mode - WriteMode::CREATE_PARENT, kj::mv(tryCreate));
}
KJ_FALLTHROUGH;
default:
KJ_FAIL_WIN32("create(path)", error, path) { return false; }
} else {
// Success.
return true;
}
}
// Either we don't have CREATE mode or the target already exists. We need to perform a
// replacement instead.
KJ_IF_MAYBE(tempPath, createNamedTemporary(path, mode, kj::mv(tryCreate))) {
if (tryCommitReplacement(path, *tempPath, mode)) {
return true;
} else {
KJ_WIN32_HANDLE_ERRORS(DeleteFileW(tempPath->begin())) {
case ERROR_FILE_NOT_FOUND:
// meh
break;
default:
KJ_FAIL_WIN32("DeleteFile(tempPath)", error, dbgStr(*tempPath));
}
return false;
}
} else {
// threw, but exceptions are disabled
return false;
}
}
Maybe<AutoCloseHandle> tryOpenFileInternal(PathPtr path, WriteMode mode, bool append) const {
DWORD disposition;
if (has(mode, WriteMode::MODIFY)) {
if (has(mode, WriteMode::CREATE)) {
disposition = OPEN_ALWAYS;
} else {
disposition = OPEN_EXISTING;
}
} else {
if (has(mode, WriteMode::CREATE)) {
disposition = CREATE_NEW;
} else {
// Neither CREATE nor MODIFY -- impossible to satisfy preconditions.
return nullptr;
}
}
DWORD access = GENERIC_READ | GENERIC_WRITE;
if (append) {
// FILE_GENERIC_WRITE includes both FILE_APPEND_DATA and FILE_WRITE_DATA, but we only want
// the former. There are also a zillion other bits that we need, annoyingly.
access = (FILE_READ_ATTRIBUTES | FILE_GENERIC_WRITE) & ~FILE_WRITE_DATA;
}
auto filename = path.toString();
HANDLE newHandle;
KJ_WIN32_HANDLE_ERRORS(newHandle = CreateFileW(
nativePath(path).begin(),
access,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
makeSecAttr(mode),
disposition,
FILE_ATTRIBUTE_NORMAL,
NULL)) {
case ERROR_PATH_NOT_FOUND:
if (has(mode, WriteMode::CREATE)) {
// A parent directory didn't exist. Maybe create it.
if (has(mode, WriteMode::CREATE_PARENT) && path.size() > 0 &&
tryMkdir(path.parent(), WriteMode::CREATE | WriteMode::MODIFY |
WriteMode::CREATE_PARENT, true)) {
// Retry, but make sure we don't try to create the parent again.
return tryOpenFileInternal(path, mode - WriteMode::CREATE_PARENT, append);
}
KJ_FAIL_REQUIRE("parent is not a directory", path) { return nullptr; }
} else {
// MODIFY-only mode. ERROR_PATH_NOT_FOUND = parent path doesn't exist = return null.
return nullptr;
}
case ERROR_FILE_NOT_FOUND:
if (!has(mode, WriteMode::CREATE)) {
// MODIFY-only mode. ERROR_FILE_NOT_FOUND = doesn't exist = return null.
return nullptr;
}
goto failed;
case ERROR_ALREADY_EXISTS:
case ERROR_FILE_EXISTS:
if (!has(mode, WriteMode::MODIFY)) {
// CREATE-only mode. ERROR_ALREADY_EXISTS = already exists = return null.
return nullptr;
}
goto failed;
default:
failed:
KJ_FAIL_WIN32("CreateFile", error, path) { return nullptr; }
}
return kj::AutoCloseHandle(newHandle);
}
bool tryCommitReplacement(
PathPtr toPath, ArrayPtr<const wchar_t> fromPath,
WriteMode mode, kj::Maybe<kj::PathPtr> pathForCreatingParents = nullptr) const {
// Try to use MoveFileEx() to replace `toPath` with `fromPath`.
auto wToPath = nativePath(toPath);
DWORD flags = has(mode, WriteMode::MODIFY) ? MOVEFILE_REPLACE_EXISTING : 0;
if (!has(mode, WriteMode::CREATE)) {
// Non-atomically verify that target exists. There's no way to make this atomic.
DWORD result = GetFileAttributesW(wToPath.begin());
if (result == INVALID_FILE_ATTRIBUTES) {
auto error = GetLastError();
switch (error) {
case ERROR_FILE_NOT_FOUND:
case ERROR_PATH_NOT_FOUND:
return false;
default:
KJ_FAIL_WIN32("GetFileAttributesEx(toPath)", error, toPath) { return false; }
}
}
}
KJ_WIN32_HANDLE_ERRORS(MoveFileExW(fromPath.begin(), wToPath.begin(), flags)) {
case ERROR_ALREADY_EXISTS:
case ERROR_FILE_EXISTS:
// We must not be in MODIFY mode.
return false;
case ERROR_PATH_NOT_FOUND:
KJ_IF_MAYBE(p, pathForCreatingParents) {
if (has(mode, WriteMode::CREATE_PARENT) &&
p->size() > 0 && tryMkdir(p->parent(),
WriteMode::CREATE | WriteMode::MODIFY | WriteMode::CREATE_PARENT, true)) {
// Retry, but make sure we don't try to create the parent again.
return tryCommitReplacement(toPath, fromPath, mode - WriteMode::CREATE_PARENT);
}
}
goto default_;
case ERROR_ACCESS_DENIED: {
// This often means that the target already exists and cannot be replaced, e.g. because
// it is a directory. Move it out of the way first, then move our replacement in, then
// delete the old thing.
if (has(mode, WriteMode::MODIFY)) {
KJ_IF_MAYBE(tempName,
createNamedTemporary(toPath, WriteMode::CREATE, [&](const wchar_t* tempName2) {
return MoveFileW(wToPath.begin(), tempName2);
})) {
KJ_WIN32_HANDLE_ERRORS(MoveFileW(fromPath.begin(), wToPath.begin())) {
default:
// Try to move back.
MoveFileW(tempName->begin(), wToPath.begin());
KJ_FAIL_WIN32("MoveFile", error, dbgStr(fromPath), dbgStr(wToPath)) {
return false;
}
}
// Succeeded, delete temporary.
rmrf(*tempName);
return true;
} else {
// createNamedTemporary() threw exception but exceptions are disabled.
return false;
}
} else {
// Not MODIFY, so no overwrite allowed. If the file really does exist, we need to return
// false.
if (GetFileAttributesW(wToPath.begin()) != INVALID_FILE_ATTRIBUTES) {
return false;
}
}
goto default_;
}
default:
default_:
KJ_FAIL_WIN32("MoveFileEx", error, dbgStr(wToPath), dbgStr(fromPath)) { return false; }
}
return true;
}
template <typename T>
class ReplacerImpl final: public Directory::Replacer<T> {
public:
ReplacerImpl(Own<T>&& object, const DiskHandle& parentDirectory,
Array<wchar_t>&& tempPath, Path&& path, WriteMode mode)
: Directory::Replacer<T>(mode),
object(kj::mv(object)), parentDirectory(parentDirectory),
tempPath(kj::mv(tempPath)), path(kj::mv(path)) {}
~ReplacerImpl() noexcept(false) {
if (!committed) {
object = Own<T>(); // Force close of handle before trying to delete.
if (kj::isSameType<T, File>()) {
KJ_WIN32(DeleteFileW(tempPath.begin())) { break; }
} else {
rmrfChildren(tempPath);
KJ_WIN32(RemoveDirectoryW(tempPath.begin())) { break; }
}
}
}
const T& get() override {
return *object;
}
bool tryCommit() override {
KJ_ASSERT(!committed, "already committed") { return false; }
// For directories, we intentionally don't use FILE_SHARE_DELETE on our handle because if the
// directory name changes our paths would be wrong. But, this means we can't rename the
// directory here to commit it. So, we need to close the handle and then re-open it
// afterwards. Ick.
AutoCloseHandle* objectHandle = getHandlePointerHack(*object);
if (kj::isSameType<T, Directory>()) {
*objectHandle = nullptr;
}
KJ_DEFER({
if (kj::isSameType<T, Directory>()) {
HANDLE newHandle = nullptr;
KJ_WIN32(newHandle = CreateFileW(
committed ? parentDirectory.nativePath(path).begin() : tempPath.begin(),
GENERIC_READ,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS, // apparently, this flag is required for directories
NULL)) { return; }
*objectHandle = AutoCloseHandle(newHandle);
*getPathPointerHack(*object) = KJ_ASSERT_NONNULL(parentDirectory.dirPath).append(path);
}
});
return committed = parentDirectory.tryCommitReplacement(
path, tempPath, Directory::Replacer<T>::mode);
}
private:
Own<T> object;
const DiskHandle& parentDirectory;
Array<wchar_t> tempPath;
Path path;
bool committed = false; // true if *successfully* committed (in which case tempPath is gone)
};
template <typename T>
class BrokenReplacer final: public Directory::Replacer<T> {
// For recovery path when exceptions are disabled.
public:
BrokenReplacer(Own<const T> inner)
: Directory::Replacer<T>(WriteMode::CREATE | WriteMode::MODIFY),
inner(kj::mv(inner)) {}
const T& get() override { return *inner; }
bool tryCommit() override { return false; }
private:
Own<const T> inner;
};
Maybe<Own<const File>> tryOpenFile(PathPtr path, WriteMode mode) const {
return tryOpenFileInternal(path, mode, false).map(newDiskFile);
}
Own<Directory::Replacer<File>> replaceFile(PathPtr path, WriteMode mode) const {
HANDLE newHandle_;
KJ_IF_MAYBE(temp, createNamedTemporary(path, mode,
[&](const wchar_t* candidatePath) {
newHandle_ = CreateFileW(
candidatePath,
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
makeSecAttr(mode),
CREATE_NEW,
FILE_ATTRIBUTE_NORMAL,
NULL);
return newHandle_ != INVALID_HANDLE_VALUE;
})) {
AutoCloseHandle newHandle(newHandle_);
return heap<ReplacerImpl<File>>(newDiskFile(kj::mv(newHandle)), *this, kj::mv(*temp),
path.clone(), mode);
} else {
// threw, but exceptions are disabled
return heap<BrokenReplacer<File>>(newInMemoryFile(nullClock()));
}
}
Own<const File> createTemporary() const {
HANDLE newHandle_;
KJ_IF_MAYBE(temp, createNamedTemporary(Path("unnamed"), WriteMode::CREATE,
[&](const wchar_t* candidatePath) {
newHandle_ = CreateFileW(
candidatePath,
GENERIC_READ | GENERIC_WRITE,
0,
NULL, // TODO(someday): makeSecAttr(WriteMode::PRIVATE), when it's implemented
CREATE_NEW,
FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE,
NULL);
return newHandle_ != INVALID_HANDLE_VALUE;
})) {
AutoCloseHandle newHandle(newHandle_);
return newDiskFile(kj::mv(newHandle));
} else {
// threw, but exceptions are disabled
return newInMemoryFile(nullClock());
}
}
Maybe<Own<AppendableFile>> tryAppendFile(PathPtr path, WriteMode mode) const {
return tryOpenFileInternal(path, mode, true).map(newDiskAppendableFile);
}
Maybe<Own<const Directory>> tryOpenSubdir(PathPtr path, WriteMode mode) const {
// Must create before open.
if (has(mode, WriteMode::CREATE)) {
if (!tryMkdir(path, mode, false)) return nullptr;
}
return tryOpenSubdirInternal(path).map([&](AutoCloseHandle&& handle) {
return newDiskDirectory(kj::mv(handle), KJ_ASSERT_NONNULL(dirPath).append(path));
});
}
Own<Directory::Replacer<Directory>> replaceSubdir(PathPtr path, WriteMode mode) const {
Path kjTempPath = nullptr;
KJ_IF_MAYBE(temp, createNamedTemporary(path, mode, kjTempPath,
[&](const wchar_t* candidatePath) {
return CreateDirectoryW(candidatePath, makeSecAttr(mode));
})) {
HANDLE subdirHandle_;
KJ_WIN32_HANDLE_ERRORS(subdirHandle_ = CreateFileW(
temp->begin(),
GENERIC_READ,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS, // apparently, this flag is required for directories
NULL)) {
default:
KJ_FAIL_WIN32("CreateFile(just-created-temporary, OPEN_EXISTING)", error, path) {
goto fail;
}
}
AutoCloseHandle subdirHandle(subdirHandle_);
return heap<ReplacerImpl<Directory>>(
newDiskDirectory(kj::mv(subdirHandle),
KJ_ASSERT_NONNULL(dirPath).append(kj::mv(kjTempPath))),
*this, kj::mv(*temp), path.clone(), mode);
} else {
// threw, but exceptions are disabled
fail:
return heap<BrokenReplacer<Directory>>(newInMemoryDirectory(nullClock()));
}
}
bool trySymlink(PathPtr linkpath, StringPtr content, WriteMode mode) const {
// We can't really create symlinks on Windows. Reasons:
// - We'd need to know whether the target is a file or a directory to pass the correct flags.
// That means we'd need to evaluate the link content and track down the target. What if the
// target doesn't exist? It's unclear if this is even allowed on Windows.
// - Apparently, creating symlinks is a privileged operation on Windows prior to Windows 10.
// The flag SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE is very new.
KJ_UNIMPLEMENTED(
"Creating symbolic links is not supported on Windows due to semantic differences.");
}
bool tryTransfer(PathPtr toPath, WriteMode toMode,
const Directory& fromDirectory, PathPtr fromPath,
TransferMode mode, const Directory& self) const {
KJ_REQUIRE(toPath.size() > 0, "can't replace self") { return false; }
// Try to get the "from" path.
Array<wchar_t> rawFromPath;
#if !KJ_NO_RTTI
// Oops, dynamicDowncastIfAvailable() doesn't work since this isn't a downcast, it's a
// side-cast...
if (auto dh = dynamic_cast<const DiskHandle*>(&fromDirectory)) {
rawFromPath = dh->nativePath(fromPath);
} else
#endif
KJ_IF_MAYBE(h, fromDirectory.getWin32Handle()) {
// Can't downcast to DiskHandle, but getWin32Handle() returns a handle... maybe RTTI is
// disabled? Or maybe this is some kind of wrapper?
rawFromPath = getPathFromHandle(*h).append(fromPath).forWin32Api(true);
} else {
// Not a disk directory, so fall back to default implementation.
return self.Directory::tryTransfer(toPath, toMode, fromDirectory, fromPath, mode);
}
if (mode == TransferMode::LINK) {
return tryReplaceNode(toPath, toMode, [&](const wchar_t* candidatePath) {
return CreateHardLinkW(candidatePath, rawFromPath.begin(), NULL);
});
} else if (mode == TransferMode::MOVE) {
return tryCommitReplacement(toPath, rawFromPath, toMode, toPath);
} else if (mode == TransferMode::COPY) {
// We can accellerate copies on Windows.
if (!has(toMode, WriteMode::CREATE)) {
// Non-atomically verify that target exists. There's no way to make this atomic.
if (!exists(toPath)) return false;
}
bool failIfExists = !has(toMode, WriteMode::MODIFY);
KJ_WIN32_HANDLE_ERRORS(
CopyFileW(rawFromPath.begin(), nativePath(toPath).begin(), failIfExists)) {
case ERROR_ALREADY_EXISTS:
case ERROR_FILE_EXISTS:
case ERROR_FILE_NOT_FOUND:
case ERROR_PATH_NOT_FOUND:
return false;
case ERROR_ACCESS_DENIED:
// This usually means that fromPath was a directory or toPath was a directory. Fall back
// to default implementation.
break;
default:
KJ_FAIL_WIN32("CopyFile", error, fromPath, toPath) { return false; }
} else {
// Copy succeeded.
return true;
}
}
// OK, we can't do anything efficient using the OS. Fall back to default implementation.
return self.Directory::tryTransfer(toPath, toMode, fromDirectory, fromPath, mode);
}
bool tryRemove(PathPtr path) const {
return rmrf(nativePath(path));
}
};
#define FSNODE_METHODS \
Maybe<void*> getWin32Handle() const override { return DiskHandle::getWin32Handle(); } \
\
Metadata stat() const override { return DiskHandle::stat(); } \
void sync() const override { DiskHandle::sync(); } \
void datasync() const override { DiskHandle::datasync(); }
class DiskReadableFile final: public ReadableFile, public DiskHandle {
public:
DiskReadableFile(AutoCloseHandle&& handle): DiskHandle(kj::mv(handle), nullptr) {}
Own<const FsNode> cloneFsNode() const override {
return heap<DiskReadableFile>(DiskHandle::clone());
}
FSNODE_METHODS
size_t read(uint64_t offset, ArrayPtr<byte> buffer) const override {
return DiskHandle::read(offset, buffer);
}
Array<const byte> mmap(uint64_t offset, uint64_t size) const override {
return DiskHandle::mmap(offset, size);
}
Array<byte> mmapPrivate(uint64_t offset, uint64_t size) const override {
return DiskHandle::mmapPrivate(offset, size);
}
};
class DiskAppendableFile final: public AppendableFile, public DiskHandle {
public:
DiskAppendableFile(AutoCloseHandle&& handle)
: DiskHandle(kj::mv(handle), nullptr),
stream(DiskHandle::handle.get()) {}
Own<const FsNode> cloneFsNode() const override {
return heap<DiskAppendableFile>(DiskHandle::clone());
}
FSNODE_METHODS
void write(const void* buffer, size_t size) override { stream.write(buffer, size); }
void write(ArrayPtr<const ArrayPtr<const byte>> pieces) override {
implicitCast<OutputStream&>(stream).write(pieces);
}
private:
HandleOutputStream stream;
};
class DiskFile final: public File, public DiskHandle {
public:
DiskFile(AutoCloseHandle&& handle): DiskHandle(kj::mv(handle), nullptr) {}
Own<const FsNode> cloneFsNode() const override {
return heap<DiskFile>(DiskHandle::clone());
}
FSNODE_METHODS
size_t read(uint64_t offset, ArrayPtr<byte> buffer) const override {
return DiskHandle::read(offset, buffer);
}
Array<const byte> mmap(uint64_t offset, uint64_t size) const override {
return DiskHandle::mmap(offset, size);
}
Array<byte> mmapPrivate(uint64_t offset, uint64_t size) const override {
return DiskHandle::mmapPrivate(offset, size);
}
void write(uint64_t offset, ArrayPtr<const byte> data) const override {
DiskHandle::write(offset, data);
}
void zero(uint64_t offset, uint64_t size) const override {
DiskHandle::zero(offset, size);
}
void truncate(uint64_t size) const override {
DiskHandle::truncate(size);
}
Own<const WritableFileMapping> mmapWritable(uint64_t offset, uint64_t size) const override {
return DiskHandle::mmapWritable(offset, size);
}
// copy() is not optimized on Windows.
};
class DiskReadableDirectory final: public ReadableDirectory, public DiskHandle {
public:
DiskReadableDirectory(AutoCloseHandle&& handle, Path&& path)
: DiskHandle(kj::mv(handle), kj::mv(path)) {}
Own<const FsNode> cloneFsNode() const override {
return heap<DiskReadableDirectory>(DiskHandle::clone(), KJ_ASSERT_NONNULL(dirPath).clone());
}
FSNODE_METHODS
Array<String> listNames() const override { return DiskHandle::listNames(); }
Array<Entry> listEntries() const override { return DiskHandle::listEntries(); }
bool exists(PathPtr path) const override { return DiskHandle::exists(path); }
Maybe<FsNode::Metadata> tryLstat(PathPtr path) const override {
return DiskHandle::tryLstat(path);
}
Maybe<Own<const ReadableFile>> tryOpenFile(PathPtr path) const override {
return DiskHandle::tryOpenFile(path);
}
Maybe<Own<const ReadableDirectory>> tryOpenSubdir(PathPtr path) const override {
return DiskHandle::tryOpenSubdir(path);
}
Maybe<String> tryReadlink(PathPtr path) const override { return DiskHandle::tryReadlink(path); }
};
class DiskDirectoryBase: public Directory, public DiskHandle {
public:
DiskDirectoryBase(AutoCloseHandle&& handle, Path&& path)
: DiskHandle(kj::mv(handle), kj::mv(path)) {}
bool exists(PathPtr path) const override { return DiskHandle::exists(path); }
Maybe<FsNode::Metadata> tryLstat(PathPtr path) const override { return DiskHandle::tryLstat(path); }
Maybe<Own<const ReadableFile>> tryOpenFile(PathPtr path) const override {
return DiskHandle::tryOpenFile(path);
}
Maybe<Own<const ReadableDirectory>> tryOpenSubdir(PathPtr path) const override {
return DiskHandle::tryOpenSubdir(path);
}
Maybe<String> tryReadlink(PathPtr path) const override { return DiskHandle::tryReadlink(path); }
Maybe<Own<const File>> tryOpenFile(PathPtr path, WriteMode mode) const override {
return DiskHandle::tryOpenFile(path, mode);
}
Own<Replacer<File>> replaceFile(PathPtr path, WriteMode mode) const override {
return DiskHandle::replaceFile(path, mode);
}
Maybe<Own<AppendableFile>> tryAppendFile(PathPtr path, WriteMode mode) const override {
return DiskHandle::tryAppendFile(path, mode);
}
Maybe<Own<const Directory>> tryOpenSubdir(PathPtr path, WriteMode mode) const override {
return DiskHandle::tryOpenSubdir(path, mode);
}
Own<Replacer<Directory>> replaceSubdir(PathPtr path, WriteMode mode) const override {
return DiskHandle::replaceSubdir(path, mode);
}
bool trySymlink(PathPtr linkpath, StringPtr content, WriteMode mode) const override {
return DiskHandle::trySymlink(linkpath, content, mode);
}
bool tryTransfer(PathPtr toPath, WriteMode toMode,
const Directory& fromDirectory, PathPtr fromPath,
TransferMode mode) const override {
return DiskHandle::tryTransfer(toPath, toMode, fromDirectory, fromPath, mode, *this);
}
// tryTransferTo() not implemented because we have nothing special we can do.
bool tryRemove(PathPtr path) const override {
return DiskHandle::tryRemove(path);
}
};
class DiskDirectory final: public DiskDirectoryBase {
public:
DiskDirectory(AutoCloseHandle&& handle, Path&& path)
: DiskDirectoryBase(kj::mv(handle), kj::mv(path)) {}
Own<const FsNode> cloneFsNode() const override {
return heap<DiskDirectory>(DiskHandle::clone(), KJ_ASSERT_NONNULL(dirPath).clone());
}
FSNODE_METHODS
Array<String> listNames() const override { return DiskHandle::listNames(); }
Array<Entry> listEntries() const override { return DiskHandle::listEntries(); }
Own<const File> createTemporary() const override {
return DiskHandle::createTemporary();
}
};
class RootDiskDirectory final: public DiskDirectoryBase {
// On Windows, the root directory is special.
//
// HACK: We only override a few functions of DiskDirectory, and we rely on the fact that
// Path::forWin32Api(true) throws an exception complaining about missing drive letter if the
// path is totally empty.
public:
RootDiskDirectory(): DiskDirectoryBase(nullptr, Path(nullptr)) {}
Own<const FsNode> cloneFsNode() const override {
return heap<RootDiskDirectory>();
}
Metadata stat() const override {
return { Type::DIRECTORY, 0, 0, UNIX_EPOCH, 1, 0 };
}
void sync() const override {}
void datasync() const override {}
Array<String> listNames() const override {
return KJ_MAP(e, listEntries()) { return kj::mv(e.name); };
}
Array<Entry> listEntries() const override {
DWORD drives = GetLogicalDrives();
if (drives == 0) {
KJ_FAIL_WIN32("GetLogicalDrives()", GetLastError()) { return nullptr; }
}
Vector<Entry> results;
for (uint i = 0; i < 26; i++) {
if (drives & (1 << i)) {
char name[2] = { static_cast<char>('A' + i), ':' };
results.add(Entry { FsNode::Type::DIRECTORY, kj::heapString(name, 2) });
}
}
return results.releaseAsArray();
}
Own<const File> createTemporary() const override {
KJ_FAIL_REQUIRE("can't create temporaries in Windows pseudo-root directory (the drive list)");
}
};
class DiskFilesystem final: public Filesystem {
public:
DiskFilesystem()
: DiskFilesystem(computeCurrentPath()) {}
DiskFilesystem(Path currentPath)
: current(KJ_ASSERT_NONNULL(root.tryOpenSubdirInternal(currentPath),
"path returned by GetCurrentDirectory() doesn't exist?"),
kj::mv(currentPath)) {}
const Directory& getRoot() const override {
return root;
}
const Directory& getCurrent() const override {
return current;
}
PathPtr getCurrentPath() const override {
return KJ_ASSERT_NONNULL(current.dirPath);
}
private:
RootDiskDirectory root;
DiskDirectory current;
static Path computeCurrentPath() {
DWORD tryLen = MAX_PATH;
for (;;) {
auto temp = kj::heapArray<wchar_t>(tryLen + 1);
DWORD len = GetCurrentDirectoryW(temp.size(), temp.begin());
if (len == 0) {
KJ_FAIL_WIN32("GetCurrentDirectory", GetLastError()) { break; }
return Path(".");
}
if (len < temp.size()) {
return Path::parseWin32Api(temp.slice(0, len));
}
// Try again with new length.
tryLen = len;
}
}
};
} // namespace
Own<ReadableFile> newDiskReadableFile(AutoCloseHandle fd) {
return heap<DiskReadableFile>(kj::mv(fd));
}
Own<AppendableFile> newDiskAppendableFile(AutoCloseHandle fd) {
return heap<DiskAppendableFile>(kj::mv(fd));
}
Own<File> newDiskFile(AutoCloseHandle fd) {
return heap<DiskFile>(kj::mv(fd));
}
Own<ReadableDirectory> newDiskReadableDirectory(AutoCloseHandle fd) {
return heap<DiskReadableDirectory>(kj::mv(fd), getPathFromHandle(fd));
}
static Own<ReadableDirectory> newDiskReadableDirectory(AutoCloseHandle fd, Path&& path) {
return heap<DiskReadableDirectory>(kj::mv(fd), kj::mv(path));
}
Own<Directory> newDiskDirectory(AutoCloseHandle fd) {
return heap<DiskDirectory>(kj::mv(fd), getPathFromHandle(fd));
}
static Own<Directory> newDiskDirectory(AutoCloseHandle fd, Path&& path) {
return heap<DiskDirectory>(kj::mv(fd), kj::mv(path));
}
Own<Filesystem> newDiskFilesystem() {
return heap<DiskFilesystem>();
}
static AutoCloseHandle* getHandlePointerHack(Directory& dir) {
return &static_cast<DiskDirectoryBase&>(dir).handle;
}
static Path* getPathPointerHack(Directory& dir) {
return &KJ_ASSERT_NONNULL(static_cast<DiskDirectoryBase&>(dir).dirPath);
}
} // namespace kj
#endif // _WIN32