Improve NativeFileStream

* Expose native file descriptor/handle to be able to
  use native APIs like POSIX sendfile()
* Fix using Boost.Iostreams under Windows
    * Make it compile
    * Workaround issue with append flag
sendfile
Martchus 3 years ago
parent e8d829cadd
commit 5bed21c9d2
  1. 194
      io/nativefilestream.cpp
  2. 61
      io/nativefilestream.h
  3. 15
      tests/iotests.cpp

@ -127,12 +127,93 @@ struct NativeFileParams {
#endif
};
/*!
* \class NativeFileStream::FileBuffer
* \brief The NativeFileStream::FileBuffer class holds an std::basic_streambuf<char> object obtained from a file path or a native file descriptor.
*/
/*!
* \brief Constructs a new FileBuffer object taking ownership of \a buffer.
*/
NativeFileStream::FileBuffer::FileBuffer(std::basic_streambuf<char> *buffer)
: buffer(buffer)
{
}
/*!
* \brief Opens a file buffer from the specified \a path.
* \remarks See NativeFileStream::open() for remarks on how \a path must be encoded.
*/
NativeFileStream::FileBuffer::FileBuffer(const string &path, ios_base::openmode openMode)
{
#ifdef PLATFORM_WINDOWS
// convert path to UTF-16
const auto widePath(makeWidePath(path));
#endif
// compute native params
const NativeFileParams nativeParams(openMode);
// open native file handle or descriptor
#ifdef CPP_UTILITIES_USE_GNU_CXX_STDIO_FILEBUF
#ifdef PLATFORM_WINDOWS
descriptor = _wopen(widePath.get(), nativeParams.openMode, nativeParams.permissions);
if (descriptor == -1) {
throw std::ios_base::failure("_wopen failed");
}
#else
descriptor = ::open(path.data(), nativeParams.openFlags, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
if (descriptor == -1) {
throw std::ios_base::failure("open failed");
}
#endif
buffer = make_unique<StreamBuffer>(descriptor, openMode);
#else // CPP_UTILITIES_USE_BOOST_IOSTREAMS
#ifdef PLATFORM_WINDOWS
handle = CreateFileW(widePath.get(), nativeParams.access, nativeParams.shareMode, nullptr, nativeParams.creation, FILE_ATTRIBUTE_NORMAL, nullptr);
if (handle == INVALID_HANDLE_VALUE) {
throw std::ios_base::failure("CreateFileW failed");
}
buffer = make_unique<StreamBuffer>(handle, boost::iostreams::close_handle);
// if we wanted to open assign the descriptor as well: descriptor = _open_osfhandle(reinterpret_cast<intptr_t>(handle), nativeParams.flags);
#else
descriptor = ::open(path.data(), nativeParams.openFlags, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
if (descriptor == -1) {
throw std::ios_base::failure("open failed");
}
buffer = make_unique<StreamBuffer>(descriptor, boost::iostreams::close_handle);
#endif
#endif
}
/*!
* \brief Opens a file buffer from the specified \a fileDescriptor.
* \remarks
* The specified \a openMode is only used when using __gnu_cxx::stdio_filebuf<char> and must be in accordance with how \a fileDescriptor
* has been opened.
*/
NativeFileStream::FileBuffer::FileBuffer(int fileDescriptor, ios_base::openmode openMode)
: descriptor(fileDescriptor)
{
#ifdef CPP_UTILITIES_USE_GNU_CXX_STDIO_FILEBUF
buffer = make_unique<StreamBuffer>(descriptor, openMode);
#else // CPP_UTILITIES_USE_BOOST_IOSTREAMS
CPP_UTILITIES_UNUSED(openMode)
#ifdef PLATFORM_WINDOWS
handle = reinterpret_cast<Handle>(_get_osfhandle(descriptor));
buffer = make_unique<StreamBuffer>(handle, boost::iostreams::close_handle);
#else
buffer = make_unique<StreamBuffer>(descriptor, boost::iostreams::close_handle);
#endif
#endif
}
/*!
* \brief Constructs a new NativeFileStream which is initially closed.
*/
NativeFileStream::NativeFileStream()
: iostream(new StreamBuffer)
, m_filebuf(rdbuf())
, m_data(rdbuf())
{
}
@ -140,9 +221,13 @@ NativeFileStream::NativeFileStream()
* \brief Moves the NativeFileStream.
*/
NativeFileStream::NativeFileStream(NativeFileStream &&other)
: iostream(other.m_filebuf.release())
, m_filebuf(rdbuf())
: iostream(other.m_data.buffer.release())
, m_data(rdbuf())
{
#ifdef PLATFORM_WINDOWS
m_data.handle = other.m_data.handle;
#endif
m_data.descriptor = other.m_data.descriptor;
}
/*!
@ -155,9 +240,9 @@ NativeFileStream::~NativeFileStream()
/*!
* \brief Returns whether the file is open.
*/
bool NativeFileStream::is_open() const
bool NativeFileStream::isOpen() const
{
return m_filebuf && static_cast<const StreamBuffer *>(m_filebuf.get())->is_open();
return m_data.buffer && static_cast<const StreamBuffer *>(m_data.buffer.get())->is_open();
}
/*!
@ -175,7 +260,7 @@ bool NativeFileStream::is_open() const
*/
void NativeFileStream::open(const string &path, ios_base::openmode openMode)
{
setFileBuffer(makeFileBuffer(path, openMode));
setData(FileBuffer(path, openMode), openMode);
}
/*!
@ -187,7 +272,7 @@ void NativeFileStream::open(const string &path, ios_base::openmode openMode)
*/
void NativeFileStream::open(int fileDescriptor, ios_base::openmode openMode)
{
setFileBuffer(makeFileBuffer(fileDescriptor, openMode));
setData(FileBuffer(fileDescriptor, openMode), openMode);
}
/*!
@ -195,96 +280,28 @@ void NativeFileStream::open(int fileDescriptor, ios_base::openmode openMode)
*/
void NativeFileStream::close()
{
if (m_filebuf) {
static_cast<StreamBuffer *>(m_filebuf.get())->close();
}
}
/*!
* \brief Internally called to assign the \a buffer taking. Takes ownership over \a buffer.
*/
void NativeFileStream::setFileBuffer(std::unique_ptr<std::basic_streambuf<char>> buffer)
{
rdbuf(buffer.get());
m_filebuf = std::move(buffer);
}
/*!
* \brief \brief Internally called by open().
*/
std::unique_ptr<std::basic_streambuf<char>> NativeFileStream::makeFileBuffer(const string &path, ios_base::openmode openMode)
{
#ifdef PLATFORM_WINDOWS
// convert path to UTF-16
const auto widePath(makeWidePath(path));
#endif
// compute native params
const NativeFileParams nativeParams(openMode);
#ifdef CPP_UTILITIES_USE_GNU_CXX_STDIO_FILEBUF
// open file handle to initialize stdio_filebuf
if (m_data.buffer) {
static_cast<StreamBuffer *>(m_data.buffer.get())->close();
#ifdef PLATFORM_WINDOWS
const int fileHandle = _wopen(widePath.get(), nativeParams.openMode, nativeParams.permissions);
if (fileHandle == -1) {
throw std::ios_base::failure("_wopen failed");
}
#else
const auto fileHandle = fopen(path.data(), nativeParams.openMode.data());
if (!fileHandle) {
throw std::ios_base::failure("fopen failed");
}
m_data.handle = nullptr;
#endif
return make_unique<StreamBuffer>(fileHandle, openMode);
#else // CPP_UTILITIES_USE_BOOST_IOSTREAMS
// create raw file descriptor to initialize boost::iostreams::file_descriptor
#ifdef PLATFORM_WINDOWS
const auto fileDescriptor
= CreateFileW(widePath.get(), nativeParams.access, nativeParams.shareMode, nullptr, nativeParams.creation, FILE_ATTRIBUTE_NORMAL);
if (fileDescriptor == INVALID_HANDLE_VALUE) {
throw std::ios_base::failure("CreateFileW failed");
}
#else
const auto fileDescriptor = ::open(path.data(), nativeParams.openFlags, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
if (fileDescriptor == -1) {
throw std::ios_base::failure("open failed");
m_data.descriptor = -1;
}
#endif
return make_unique<StreamBuffer>(fileDescriptor, boost::iostreams::close_handle);
#endif
}
/*!
* \brief Internally called by open().
* \brief Internally called to assign the buffer, file descriptor and handle.
*/
std::unique_ptr<std::basic_streambuf<char>> NativeFileStream::makeFileBuffer(int fileDescriptor, ios_base::openmode openMode)
void NativeFileStream::setData(FileBuffer data, std::ios_base::openmode openMode)
{
// compute native params
const NativeFileParams nativeParams(openMode);
#ifdef CPP_UTILITIES_USE_GNU_CXX_STDIO_FILEBUF
// open file handle to initialize stdio_filebuf
#ifdef PLATFORM_WINDOWS
const auto fileHandle = _get_osfhandle(fileDescriptor);
if (fileHandle == -1) {
throw std::ios_base::failure("_get_osfhandle failed");
}
const auto osFileHandle = _open_osfhandle(fileHandle, nativeParams.flags);
if (osFileHandle == -1) {
throw std::ios_base::failure("_open_osfhandle failed");
rdbuf(data.buffer.get());
m_data = std::move(data);
m_openMode = openMode;
#if defined(PLATFORM_WINDOWS) && defined(CPP_UTILITIES_USE_BOOST_IOSTREAMS)
// workaround append flag dysfunctioning
if (m_openMode & ios_base::app) {
seekp(0, ios_base::end);
}
#else
const auto fileHandle = fdopen(fileDescriptor, nativeParams.openMode.data());
if (!fileHandle) {
throw std::ios_base::failure("fdopen failed");
}
#endif
return make_unique<StreamBuffer>(fileDescriptor, openMode);
#else // CPP_UTILITIES_USE_BOOST_IOSTREAMS
// initialize boost::iostreams::file_descriptor from the specified fileDescriptor
return make_unique<StreamBuffer>(fileDescriptor, boost::iostreams::close_handle);
#endif
}
@ -301,6 +318,7 @@ std::unique_ptr<wchar_t[]> NativeFileStream::makeWidePath(const std::string &pat
}
return std::move(widePath.first);
}
#endif
#else

@ -17,6 +17,21 @@ namespace CppUtilities {
class CPP_UTILITIES_EXPORT NativeFileStream : public std::iostream {
public:
#ifdef PLATFORM_WINDOWS
using Handle = void *;
#endif
struct CPP_UTILITIES_EXPORT FileBuffer {
FileBuffer(std::basic_streambuf<char> *buffer);
FileBuffer(const std::string &path, ios_base::openmode openMode);
FileBuffer(int fileDescriptor, ios_base::openmode openMode);
std::unique_ptr<std::basic_streambuf<char>> buffer;
#ifdef PLATFORM_WINDOWS
Handle handle = nullptr;
#endif
int descriptor = -1;
};
NativeFileStream();
NativeFileStream(const std::string &path, std::ios_base::openmode openMode);
NativeFileStream(int fileDescriptor, std::ios_base::openmode openMode);
@ -24,34 +39,70 @@ public:
~NativeFileStream();
bool is_open() const;
bool isOpen() const;
void open(const std::string &path, std::ios_base::openmode openMode);
void open(int fileDescriptor, std::ios_base::openmode openMode);
void close();
static std::unique_ptr<std::basic_streambuf<char>> makeFileBuffer(const std::string &path, ios_base::openmode openMode);
static std::unique_ptr<std::basic_streambuf<char>> makeFileBuffer(int fileDescriptor, ios_base::openmode openMode);
int fileDescriptor();
#ifdef PLATFORM_WINDOWS
Handle fileHandle();
static std::unique_ptr<wchar_t[]> makeWidePath(const std::string &path);
#endif
private:
void setFileBuffer(std::unique_ptr<std::basic_streambuf<char>> buffer);
void setData(FileBuffer data, std::ios_base::openmode openMode);
std::unique_ptr<std::basic_streambuf<char>> m_filebuf;
FileBuffer m_data;
std::ios_base::openmode m_openMode;
};
/*!
* \brief Constructs a new NativeFileStream. The specified \a path is supposed to be UTF-8 encoded.
*/
inline NativeFileStream::NativeFileStream(const std::string &path, ios_base::openmode openMode)
: NativeFileStream()
{
open(path, openMode);
}
/*!
* \brief Constructs a new NativeFileStream. The specified \a fileDescriptor is either a POSIX file descriptor or a Windows CRT file descriptor.
*/
inline NativeFileStream::NativeFileStream(int fileDescriptor, ios_base::openmode openMode)
: NativeFileStream()
{
open(fileDescriptor, openMode);
}
/*!
* \brief Returns the native POSIX or Windows CRT file descriptor.
* \remarks Might not be populated if only a Windows file handle is used.
*/
inline int NativeFileStream::fileDescriptor()
{
return m_data.descriptor;
}
#ifdef PLATFORM_WINDOWS
/*!
* \brief Returns the native Windows file handle.
* \remarks Might not be populated if only a Windows CRT file descriptor is used.
*/
inline NativeFileStream::Handle NativeFileStream::fileHandle()
{
return m_data.handle;
}
#endif
/*!
* \brief Returns whether the file is open.
* \remarks Same as NativeFileStream::isOpen(); provided for API compatibility with std::fstream.
*/
inline bool NativeFileStream::is_open() const
{
return isOpen();
}
#else // CPP_UTILITIES_USE_NATIVE_FILE_BUFFER
using NativeFileStream = std::fstream;

@ -411,6 +411,11 @@ void IoTests::testNativeFileStream()
CPPUNIT_ASSERT(!fileStream.is_open());
fileStream.open(txtFilePath, ios_base::in);
CPPUNIT_ASSERT(fileStream.is_open());
#if defined(PLATFORM_WINDOWS) && defined(CPP_UTILITIES_USE_BOOST_IOSTREAMS)
CPPUNIT_ASSERT(fileStream.fileHandle() != nullptr);
#else
CPPUNIT_ASSERT(fileStream.fileDescriptor() != -1);
#endif
CPPUNIT_ASSERT_EQUAL(static_cast<char>(fileStream.get()), 'f');
fileStream.seekg(0, ios_base::end);
CPPUNIT_ASSERT_EQUAL(fileStream.tellg(), static_cast<NativeFileStream::pos_type>(47));
@ -421,10 +426,10 @@ void IoTests::testNativeFileStream()
CPPUNIT_FAIL("expected exception");
} catch (const std::ios_base::failure &failure) {
#ifdef PLATFORM_WINDOWS
#ifdef CPP_UTILITIES_USE_GNU_CXX_STDIO_FILEBUF
CPPUNIT_ASSERT_EQUAL("_wopen failed: iostream error"s, string(failure.what()));
#else // CPP_UTILITIES_USE_BOOST_IOSTREAMS
#ifdef CPP_UTILITIES_USE_BOOST_IOSTREAMS
CPPUNIT_ASSERT_EQUAL("CreateFileW failed: iostream error"s, string(failure.what()));
#else
CPPUNIT_ASSERT_EQUAL("_wopen failed: iostream error"s, string(failure.what()));
#endif
#else
CPPUNIT_ASSERT_EQUAL("open failed: iostream error"s, string(failure.what()));
@ -452,7 +457,9 @@ void IoTests::testNativeFileStream()
} catch (const std::ios_base::failure &failure) {
#ifndef PLATFORM_WINDOWS
TESTUTILS_ASSERT_LIKE(
"expected error message", "(fdopen failed|failed reading: Bad file descriptor): iostream error"s, string(failure.what()));
"expected error message", "(basic_ios::clear|failed reading: Bad file descriptor): iostream error"s, string(failure.what()));
#else
CPP_UTILITIES_UNUSED(failure)
#endif
}
fileStream.clear();

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