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tdlib-fork/tdutils/td/utils/port/FileFd.cpp
levlam 94f2fca814 Unify FileFd::read implementation.
GitOrigin-RevId: bfe86b448459ba7ef875256d99796122bb486e4d
2018-09-11 17:13:53 +03:00

457 lines
13 KiB
C++

//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/utils/port/FileFd.h"
#if TD_PORT_WINDOWS
#include "td/utils/misc.h" // for narrow_cast
#include "td/utils/port/Stat.h"
#include "td/utils/port/wstring_convert.h"
#endif
#include "td/utils/logging.h"
#include "td/utils/misc.h"
#include "td/utils/port/detail/PollableFd.h"
#include "td/utils/port/PollFlags.h"
#include "td/utils/port/sleep.h"
#include "td/utils/StringBuilder.h"
#include <cstring>
#if TD_PORT_POSIX
#include <fcntl.h>
#include <sys/file.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#endif
namespace td {
namespace {
struct PrintFlags {
int32 flags;
};
StringBuilder &operator<<(StringBuilder &sb, const PrintFlags &print_flags) {
auto flags = print_flags.flags;
if (flags &
~(FileFd::Write | FileFd::Read | FileFd::Truncate | FileFd::Create | FileFd::Append | FileFd::CreateNew)) {
return sb << "opened with invalid flags " << flags;
}
if (flags & FileFd::Create) {
sb << "opened/created ";
} else if (flags & FileFd::CreateNew) {
sb << "created ";
} else {
sb << "opened ";
}
if ((flags & FileFd::Write) && (flags & FileFd::Read)) {
if (flags & FileFd::Append) {
sb << "for reading and appending";
} else {
sb << "for reading and writing";
}
} else if (flags & FileFd::Write) {
if (flags & FileFd::Append) {
sb << "for appending";
} else {
sb << "for writing";
}
} else if (flags & FileFd::Read) {
sb << "for reading";
} else {
sb << "for nothing";
}
if (flags & FileFd::Truncate) {
sb << " with truncation";
}
return sb;
}
} // namespace
namespace detail {
class FileFdImpl {
public:
PollableFdInfo info;
};
} // namespace detail
FileFd::FileFd() = default;
FileFd::FileFd(FileFd &&) = default;
FileFd &FileFd::operator=(FileFd &&) = default;
FileFd::~FileFd() = default;
FileFd::FileFd(std::unique_ptr<detail::FileFdImpl> impl) : impl_(std::move(impl)) {
}
Result<FileFd> FileFd::open(CSlice filepath, int32 flags, int32 mode) {
if (flags & ~(Write | Read | Truncate | Create | Append | CreateNew)) {
return Status::Error(PSLICE() << "File \"" << filepath << "\" has failed to be " << PrintFlags{flags});
}
if ((flags & (Write | Read)) == 0) {
return Status::Error(PSLICE() << "File \"" << filepath << "\" can't be " << PrintFlags{flags});
}
#if TD_PORT_POSIX
int native_flags = 0;
if ((flags & Write) && (flags & Read)) {
native_flags |= O_RDWR;
} else if (flags & Write) {
native_flags |= O_WRONLY;
} else {
CHECK(flags & Read);
native_flags |= O_RDONLY;
}
if (flags & Truncate) {
native_flags |= O_TRUNC;
}
if (flags & Create) {
native_flags |= O_CREAT;
} else if (flags & CreateNew) {
native_flags |= O_CREAT;
native_flags |= O_EXCL;
}
if (flags & Append) {
native_flags |= O_APPEND;
}
int native_fd = detail::skip_eintr([&] { return ::open(filepath.c_str(), native_flags, static_cast<mode_t>(mode)); });
if (native_fd < 0) {
return OS_ERROR(PSLICE() << "File \"" << filepath << "\" can't be " << PrintFlags{flags});
}
return from_native_fd(NativeFd(native_fd));
#elif TD_PORT_WINDOWS
// TODO: support modes
auto r_filepath = to_wstring(filepath);
if (r_filepath.is_error()) {
return Status::Error(PSLICE() << "Failed to convert file path \" << filepath << \" to UTF-16");
}
auto w_filepath = r_filepath.move_as_ok();
DWORD desired_access = 0;
if ((flags & Write) && (flags & Read)) {
desired_access |= GENERIC_READ | GENERIC_WRITE;
} else if (flags & Write) {
desired_access |= GENERIC_WRITE;
} else {
CHECK(flags & Read);
desired_access |= GENERIC_READ;
}
// TODO: share mode
DWORD share_mode = FILE_SHARE_READ | FILE_SHARE_DELETE | FILE_SHARE_WRITE;
DWORD creation_disposition = 0;
if (flags & Create) {
if (flags & Truncate) {
creation_disposition = CREATE_ALWAYS;
} else {
creation_disposition = OPEN_ALWAYS;
}
} else if (flags & CreateNew) {
creation_disposition = CREATE_NEW;
} else {
if (flags & Truncate) {
creation_disposition = TRUNCATE_EXISTING;
} else {
creation_disposition = OPEN_EXISTING;
}
}
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP | WINAPI_PARTITION_SYSTEM)
auto handle = CreateFile(w_filepath.c_str(), desired_access, share_mode, nullptr, creation_disposition, 0, nullptr);
#else
auto handle = CreateFile2(w_filepath.c_str(), desired_access, share_mode, creation_disposition, nullptr);
#endif
if (handle == INVALID_HANDLE_VALUE) {
return OS_ERROR(PSLICE() << "File \"" << filepath << "\" can't be " << PrintFlags{flags});
}
auto native_fd = NativeFd(handle);
if (flags & Append) {
LARGE_INTEGER offset;
offset.QuadPart = 0;
auto set_pointer_res = SetFilePointerEx(handle, offset, nullptr, FILE_END);
if (!set_pointer_res) {
return OS_ERROR(PSLICE() << "Failed to seek to the end of file \"" << filepath << "\"");
}
}
return from_native_fd(std::move(native_fd));
#endif
}
FileFd FileFd::from_native_fd(NativeFd native_fd) {
auto impl = std::make_unique<detail::FileFdImpl>();
impl->info.set_native_fd(std::move(native_fd));
impl->info.add_flags(PollFlags::Write());
return FileFd(std::move(impl));
}
Result<size_t> FileFd::write(Slice slice) {
auto native_fd = get_native_fd().fd();
#if TD_PORT_POSIX
auto bytes_written = detail::skip_eintr([&] { return ::write(native_fd, slice.begin(), slice.size()); });
bool success = bytes_written >= 0;
#elif TD_PORT_WINDOWS
DWORD bytes_written = 0;
BOOL success = WriteFile(native_fd, slice.data(), narrow_cast<DWORD>(slice.size()), &bytes_written, nullptr);
#endif
if (success) {
return narrow_cast<size_t>(bytes_written);
}
return OS_ERROR(PSLICE() << "Write to [fd = " << native_fd << "] has failed");
}
Result<size_t> FileFd::read(MutableSlice slice) {
auto native_fd = get_native_fd().fd();
#if TD_PORT_POSIX
auto bytes_read = detail::skip_eintr([&] { return ::read(native_fd, slice.begin(), slice.size()); });
bool success = bytes_read >= 0;
bool is_eof = narrow_cast<size_t>(bytes_read) < slice.size();
#elif TD_PORT_WINDOWS
DWORD bytes_read = 0;
BOOL success = ReadFile(native_fd, slice.data(), narrow_cast<DWORD>(slice.size()), &bytes_read, nullptr);
bool is_eof = bytes_read == 0;
#endif
if (success) {
if (is_eof) {
get_poll_info().clear_flags(PollFlags::Read());
}
return static_cast<size_t>(bytes_read);
}
return OS_ERROR(PSLICE() << "Read from [fd = " << native_fd << "] has failed");
}
Result<size_t> FileFd::pwrite(Slice slice, int64 offset) {
if (offset < 0) {
return Status::Error("Offset must be non-negative");
}
auto native_fd = get_native_fd().fd();
#if TD_PORT_POSIX
TRY_RESULT(offset_off_t, narrow_cast_safe<off_t>(offset));
auto bytes_written =
detail::skip_eintr([&] { return ::pwrite(native_fd, slice.begin(), slice.size(), offset_off_t); });
bool success = bytes_written >= 0;
#elif TD_PORT_WINDOWS
DWORD bytes_written = 0;
OVERLAPPED overlapped;
std::memset(&overlapped, 0, sizeof(overlapped));
overlapped.Offset = static_cast<DWORD>(offset);
overlapped.OffsetHigh = static_cast<DWORD>(offset >> 32);
BOOL success = WriteFile(native_fd, slice.data(), narrow_cast<DWORD>(slice.size()), &bytes_written, &overlapped);
#endif
if (success) {
return narrow_cast<size_t>(bytes_written);
}
return OS_ERROR(PSLICE() << "Pwrite to [fd = " << native_fd << "] at [offset = " << offset << "] has failed");
}
Result<size_t> FileFd::pread(MutableSlice slice, int64 offset) {
if (offset < 0) {
return Status::Error("Offset must be non-negative");
}
auto native_fd = get_native_fd().fd();
#if TD_PORT_POSIX
TRY_RESULT(offset_off_t, narrow_cast_safe<off_t>(offset));
auto bytes_read = detail::skip_eintr([&] { return ::pread(native_fd, slice.begin(), slice.size(), offset_off_t); });
bool success = bytes_read >= 0;
#elif TD_PORT_WINDOWS
DWORD bytes_read = 0;
OVERLAPPED overlapped;
std::memset(&overlapped, 0, sizeof(overlapped));
overlapped.Offset = static_cast<DWORD>(offset);
overlapped.OffsetHigh = static_cast<DWORD>(offset >> 32);
BOOL success = ReadFile(native_fd, slice.data(), narrow_cast<DWORD>(slice.size()), &bytes_read, &overlapped);
#endif
if (success) {
return narrow_cast<size_t>(bytes_read);
}
return OS_ERROR(PSLICE() << "Pread from [fd = " << native_fd << "] at [offset = " << offset << "] has failed");
}
Status FileFd::lock(FileFd::LockFlags flags, int32 max_tries) {
if (max_tries <= 0) {
return Status::Error(0, "Can't lock file: wrong max_tries");
}
#if TD_PORT_POSIX
auto native_fd = get_native_fd().fd();
#elif TD_PORT_WINDOWS
auto native_fd = get_native_fd().fd();
#endif
while (true) {
#if TD_PORT_POSIX
struct flock lock;
std::memset(&lock, 0, sizeof(lock));
lock.l_type = static_cast<short>([&] {
switch (flags) {
case LockFlags::Read:
return F_RDLCK;
case LockFlags::Write:
return F_WRLCK;
case LockFlags::Unlock:
return F_UNLCK;
default:
UNREACHABLE();
return F_UNLCK;
}
}());
lock.l_whence = SEEK_SET;
if (fcntl(native_fd, F_SETLK, &lock) == -1) {
if (errno == EAGAIN) {
#elif TD_PORT_WINDOWS
OVERLAPPED overlapped;
std::memset(&overlapped, 0, sizeof(overlapped));
BOOL result;
if (flags == LockFlags::Unlock) {
result = UnlockFileEx(native_fd, 0, MAXDWORD, MAXDWORD, &overlapped);
} else {
DWORD dw_flags = LOCKFILE_FAIL_IMMEDIATELY;
if (flags == LockFlags::Write) {
dw_flags |= LOCKFILE_EXCLUSIVE_LOCK;
}
result = LockFileEx(native_fd, dw_flags, 0, MAXDWORD, MAXDWORD, &overlapped);
}
if (!result) {
if (GetLastError() == ERROR_LOCK_VIOLATION) {
#endif
if (--max_tries > 0) {
usleep_for(100000);
continue;
}
return OS_ERROR("Can't lock file because it is already in use; check for another program instance running");
}
return OS_ERROR("Can't lock file");
}
return Status::OK();
}
}
void FileFd::close() {
impl_.reset();
}
bool FileFd::empty() const {
return !impl_;
}
const NativeFd &FileFd::get_native_fd() const {
return get_poll_info().native_fd();
}
NativeFd FileFd::move_as_native_fd() {
auto res = get_poll_info().move_as_native_fd();
impl_.reset();
return res;
}
int64 FileFd::get_size() {
return stat().size_;
}
#if TD_PORT_WINDOWS
static uint64 filetime_to_unix_time_nsec(LONGLONG filetime) {
const auto FILETIME_UNIX_TIME_DIFF = 116444736000000000ll;
return static_cast<uint64>((filetime - FILETIME_UNIX_TIME_DIFF) * 100);
}
#endif
Stat FileFd::stat() {
CHECK(!empty());
#if TD_PORT_POSIX
return detail::fstat(get_native_fd().fd());
#elif TD_PORT_WINDOWS
Stat res;
FILE_BASIC_INFO basic_info;
auto status = GetFileInformationByHandleEx(get_native_fd().fd(), FileBasicInfo, &basic_info, sizeof(basic_info));
if (!status) {
auto error = OS_ERROR("Stat failed");
LOG(FATAL) << error;
}
res.atime_nsec_ = filetime_to_unix_time_nsec(basic_info.LastAccessTime.QuadPart);
res.mtime_nsec_ = filetime_to_unix_time_nsec(basic_info.LastWriteTime.QuadPart);
res.is_dir_ = (basic_info.FileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
res.is_reg_ = true;
FILE_STANDARD_INFO standard_info;
status = GetFileInformationByHandleEx(get_native_fd().fd(), FileStandardInfo, &standard_info, sizeof(standard_info));
if (!status) {
auto error = OS_ERROR("Stat failed");
LOG(FATAL) << error;
}
res.size_ = standard_info.EndOfFile.QuadPart;
return res;
#endif
}
Status FileFd::sync() {
CHECK(!empty());
#if TD_PORT_POSIX
if (fsync(get_native_fd().fd()) != 0) {
#elif TD_PORT_WINDOWS
if (FlushFileBuffers(get_native_fd().fd()) == 0) {
#endif
return OS_ERROR("Sync failed");
}
return Status::OK();
}
Status FileFd::seek(int64 position) {
CHECK(!empty());
#if TD_PORT_POSIX
TRY_RESULT(position_off_t, narrow_cast_safe<off_t>(position));
if (detail::skip_eintr([&] { return ::lseek(get_native_fd().fd(), position_off_t, SEEK_SET); }) < 0) {
#elif TD_PORT_WINDOWS
LARGE_INTEGER offset;
offset.QuadPart = position;
if (SetFilePointerEx(get_native_fd().fd(), offset, nullptr, FILE_BEGIN) == 0) {
#endif
return OS_ERROR("Seek failed");
}
return Status::OK();
}
Status FileFd::truncate_to_current_position(int64 current_position) {
CHECK(!empty());
#if TD_PORT_POSIX
TRY_RESULT(current_position_off_t, narrow_cast_safe<off_t>(current_position));
if (detail::skip_eintr([&] { return ::ftruncate(get_native_fd().fd(), current_position_off_t); }) < 0) {
#elif TD_PORT_WINDOWS
if (SetEndOfFile(get_native_fd().fd()) == 0) {
#endif
return OS_ERROR("Truncate failed");
}
return Status::OK();
}
PollableFdInfo &FileFd::get_poll_info() {
CHECK(!empty());
return impl_->info;
}
const PollableFdInfo &FileFd::get_poll_info() const {
CHECK(!empty());
return impl_->info;
}
} // namespace td