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Diffstat (limited to '')
-rw-r--r-- | src/handle.cpp | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/src/handle.cpp b/src/handle.cpp new file mode 100644 index 0000000..a6ab3a5 --- /dev/null +++ b/src/handle.cpp @@ -0,0 +1,153 @@ +// Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com> +// This file is part of the "winapi-common" project. +// For details, see https://github.com/egor-tensin/winapi-common. +// Distributed under the MIT License. + +#include <winapi/error.hpp> +#include <winapi/handle.hpp> +#include <winapi/workarounds.hpp> + +#include <boost/config.hpp> + +#include <windows.h> + +#include <cassert> +#include <cstddef> +#include <sstream> +#include <stdexcept> + +namespace winapi { +namespace { + +std::runtime_error write_file_incomplete(std::size_t expected, std::size_t actual) { + std::ostringstream oss; + oss << "WriteFile could only write " << actual << " bytes instead of " << expected; + return std::runtime_error{oss.str()}; +} + +bool is_invalid_handle(HANDLE handle) { + return handle == NULL || handle == INVALID_HANDLE_VALUE; +} + +bool is_std_handle(HANDLE handle) { + return handle == ::GetStdHandle(STD_INPUT_HANDLE) || + handle == ::GetStdHandle(STD_OUTPUT_HANDLE) || + handle == ::GetStdHandle(STD_ERROR_HANDLE); +} + +} // namespace + +Handle::Handle(HANDLE impl) : m_impl{impl} {} + +Handle::Handle(Handle&& other) BOOST_NOEXCEPT_OR_NOTHROW { + swap(other); +} + +Handle& Handle::operator=(Handle other) BOOST_NOEXCEPT_OR_NOTHROW { + swap(other); + return *this; +} + +void Handle::swap(Handle& other) BOOST_NOEXCEPT_OR_NOTHROW { + using std::swap; + swap(m_impl, other.m_impl); +} + +bool Handle::is_invalid() const { + return !m_impl || is_invalid_handle(m_impl.get()); +} + +void Handle::close() { + m_impl.reset(); +} + +bool Handle::is_std() const { + return is_std_handle(m_impl.get()); +} + +Handle Handle::std_in() { + return Handle{::GetStdHandle(STD_INPUT_HANDLE)}; +} + +Handle Handle::std_out() { + return Handle{::GetStdHandle(STD_OUTPUT_HANDLE)}; +} + +Handle Handle::std_err() { + return Handle{::GetStdHandle(STD_ERROR_HANDLE)}; +} + +bool Handle::read_chunk(Buffer& buffer) const { + buffer.resize(max_chunk_size); + DWORD nb_read = 0; + + const auto ret = ::ReadFile(m_impl.get(), buffer.data(), buffer.size(), &nb_read, NULL); + + buffer.resize(nb_read); + + if (ret) { + return nb_read != 0; + } + + const auto ec = GetLastError(); + + switch (ec) { + case ERROR_BROKEN_PIPE: + // We've been reading from an anonymous pipe, and it's been closed. + return false; + default: + throw error::windows(ec, "ReadFile"); + } +} + +Handle::Buffer Handle::read() const { + Buffer buffer; + Buffer chunk; + + while (true) { + const auto next = read_chunk(chunk); + + buffer.reserve(buffer.size() + chunk.size()); + buffer.insert(buffer.cend(), chunk.cbegin(), chunk.cend()); + + if (!next) { + break; + } + } + + return buffer; +} + +void Handle::write(const void* data, std::size_t nb) const { + DWORD nb_written = 0; + + const auto ret = ::WriteFile(m_impl.get(), data, nb, &nb_written, NULL); + + if (!ret) { + throw error::windows(GetLastError(), "WriteFile"); + } + + if (nb != nb_written) { + throw write_file_incomplete(nb, nb_written); + } +} + +void Handle::write(const Buffer& buffer) const { + write(buffer.data(), buffer.size()); +} + +void Handle::inherit(bool yes) const { + if (!::SetHandleInformation(m_impl.get(), HANDLE_FLAG_INHERIT, yes ? 1 : 0)) { + throw error::windows(GetLastError(), "SetHandleInformation"); + } +} + +void Handle::Close::operator()(HANDLE impl) const { + if (is_invalid_handle(impl) || is_std_handle(impl)) + return; + const auto ret = ::CloseHandle(impl); + assert(ret); + WINAPI_UNUSED_PARAMETER(ret); +} + +} // namespace winapi |