tdlight/tdutils/td/utils/port/FileFd.cpp
levlam 36562f351c Better error message.
GitOrigin-RevId: 90f177a01b941a8fe029fb6363858260a0ca1f3b
2018-05-10 21:39:01 +03:00

486 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/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
const Fd &FileFd::get_fd() const {
return fd_;
}
Fd &FileFd::get_fd() {
return fd_;
}
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 = 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});
}
FileFd result;
result.fd_ = Fd(native_fd, Fd::Mode::Owner);
#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});
}
if (flags & Append) {
LARGE_INTEGER offset;
offset.QuadPart = 0;
auto set_pointer_res = SetFilePointerEx(handle, offset, nullptr, FILE_END);
if (!set_pointer_res) {
auto res = OS_ERROR(PSLICE() << "Failed to seek to the end of file \"" << filepath << "\"");
CloseHandle(handle);
return res;
}
}
FileFd result;
result.fd_ = Fd::create_file_fd(handle);
#endif
result.fd_.update_flags(Fd::Flag::Write);
return std::move(result);
}
Result<size_t> FileFd::write(Slice slice) {
#if TD_PORT_POSIX
CHECK(!fd_.empty());
int native_fd = get_native_fd();
auto write_res = skip_eintr([&] { return ::write(native_fd, slice.begin(), slice.size()); });
if (write_res >= 0) {
return narrow_cast<size_t>(write_res);
}
auto write_errno = errno;
auto error = Status::PosixError(write_errno, PSLICE() << "Write to [fd = " << native_fd << "] has failed");
if (write_errno != EAGAIN
#if EAGAIN != EWOULDBLOCK
&& write_errno != EWOULDBLOCK
#endif
&& write_errno != EIO) {
LOG(ERROR) << error;
}
return std::move(error);
#elif TD_PORT_WINDOWS
return fd_.write(slice);
#endif
}
Result<size_t> FileFd::read(MutableSlice slice) {
#if TD_PORT_POSIX
CHECK(!fd_.empty());
int native_fd = get_native_fd();
auto read_res = skip_eintr([&] { return ::read(native_fd, slice.begin(), slice.size()); });
auto read_errno = errno;
if (read_res >= 0) {
if (narrow_cast<size_t>(read_res) < slice.size()) {
fd_.clear_flags(Read);
}
return static_cast<size_t>(read_res);
}
auto error = Status::PosixError(read_errno, PSLICE() << "Read from [fd = " << native_fd << "] has failed");
if (read_errno != EAGAIN
#if EAGAIN != EWOULDBLOCK
&& read_errno != EWOULDBLOCK
#endif
&& read_errno != EIO) {
LOG(ERROR) << error;
}
return std::move(error);
#elif TD_PORT_WINDOWS
return fd_.read(slice);
#endif
}
Result<size_t> FileFd::pwrite(Slice slice, int64 offset) {
if (offset < 0) {
return Status::Error("Offset must be non-negative");
}
#if TD_PORT_POSIX
TRY_RESULT(offset_off_t, narrow_cast_safe<off_t>(offset));
CHECK(!fd_.empty());
int native_fd = get_native_fd();
auto pwrite_res = skip_eintr([&] { return ::pwrite(native_fd, slice.begin(), slice.size(), offset_off_t); });
if (pwrite_res >= 0) {
return narrow_cast<size_t>(pwrite_res);
}
auto pwrite_errno = errno;
auto error = Status::PosixError(
pwrite_errno, PSLICE() << "Pwrite to [fd = " << native_fd << "] at [offset = " << offset << "] has failed");
if (pwrite_errno != EAGAIN
#if EAGAIN != EWOULDBLOCK
&& pwrite_errno != EWOULDBLOCK
#endif
&& pwrite_errno != EIO) {
LOG(ERROR) << error;
}
return std::move(error);
#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);
auto res =
WriteFile(fd_.get_io_handle(), slice.data(), narrow_cast<DWORD>(slice.size()), &bytes_written, &overlapped);
if (!res) {
return OS_ERROR("Failed to pwrite");
}
return bytes_written;
#endif
}
Result<size_t> FileFd::pread(MutableSlice slice, int64 offset) {
if (offset < 0) {
return Status::Error("Offset must be non-negative");
}
#if TD_PORT_POSIX
TRY_RESULT(offset_off_t, narrow_cast_safe<off_t>(offset));
CHECK(!fd_.empty());
int native_fd = get_native_fd();
auto pread_res = skip_eintr([&] { return ::pread(native_fd, slice.begin(), slice.size(), offset_off_t); });
if (pread_res >= 0) {
return narrow_cast<size_t>(pread_res);
}
auto pread_errno = errno;
auto error = Status::PosixError(
pread_errno, PSLICE() << "Pread from [fd = " << native_fd << "] at [offset = " << offset << "] has failed");
if (pread_errno != EAGAIN
#if EAGAIN != EWOULDBLOCK
&& pread_errno != EWOULDBLOCK
#endif
&& pread_errno != EIO) {
LOG(ERROR) << error;
}
return std::move(error);
#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);
auto res = ReadFile(fd_.get_io_handle(), slice.data(), narrow_cast<DWORD>(slice.size()), &bytes_read, &overlapped);
if (!res) {
return OS_ERROR("Failed to pread");
}
return bytes_read;
#endif
}
Status FileFd::lock(FileFd::LockFlags flags, int32 max_tries) {
if (max_tries <= 0) {
return Status::Error(0, "Can't lock file: wrong max_tries");
}
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(get_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(fd_.get_io_handle(), 0, MAXDWORD, MAXDWORD, &overlapped);
} else {
DWORD dw_flags = LOCKFILE_FAIL_IMMEDIATELY;
if (flags == LockFlags::Write) {
dw_flags |= LOCKFILE_EXCLUSIVE_LOCK;
}
result = LockFileEx(fd_.get_io_handle(), 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() {
fd_.close();
}
bool FileFd::empty() const {
return fd_.empty();
}
#if TD_PORT_POSIX
int FileFd::get_native_fd() const {
return fd_.get_native_fd();
}
#endif
int32 FileFd::get_flags() const {
return fd_.get_flags();
}
void FileFd::update_flags(Fd::Flags mask) {
fd_.update_flags(mask);
}
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());
#elif TD_PORT_WINDOWS
Stat res;
FILE_BASIC_INFO basic_info;
auto status = GetFileInformationByHandleEx(fd_.get_io_handle(), 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(fd_.get_io_handle(), 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(fd_.get_native_fd()) != 0) {
#elif TD_PORT_WINDOWS
if (FlushFileBuffers(fd_.get_io_handle()) == 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 (skip_eintr([&] { return ::lseek(fd_.get_native_fd(), position_off_t, SEEK_SET); }) < 0) {
#elif TD_PORT_WINDOWS
LARGE_INTEGER offset;
offset.QuadPart = position;
if (SetFilePointerEx(fd_.get_io_handle(), 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 (skip_eintr([&] { return ::ftruncate(fd_.get_native_fd(), current_position_off_t); }) < 0) {
#elif TD_PORT_WINDOWS
if (SetEndOfFile(fd_.get_io_handle()) == 0) {
#endif
return OS_ERROR("Truncate failed");
}
return Status::OK();
}
} // namespace td