PowerToys/tools/HandlesExperiment/FileLocksmithLib/IPC.cpp

#include "pch.h"

#include "IPC.h"

#define FILE_LOCKSMITH_IPC_PIPE_NAME L"\\\\.\\pipe\\FileLocksmith-cdc0e7ad-e8c6-47fd-a63d-c1c90d73b2e3"

constexpr DWORD DefaultPipeBufferSize = 8192;
constexpr DWORD DefaultPipeTimeoutMillis = 200;

namespace ipc
{
	Writer::Writer()
	{
		start();
	}

	Writer::~Writer()
	{
		finish();
	}

	HRESULT Writer::start()
	{
		SECURITY_ATTRIBUTES sa;
		sa.nLength = sizeof(SECURITY_ATTRIBUTES);
		sa.lpSecurityDescriptor = NULL;
		sa.bInheritHandle = TRUE;

		if (!CreatePipe(&m_read_pipe, &m_write_pipe, &sa, 0))
		{
			return HRESULT_FROM_WIN32(GetLastError());
		}

		return S_OK;
	}

	HRESULT Writer::add_path(LPCWSTR path)
	{
		int length = lstrlenW(path);
		DWORD written;
		if (!WriteFile(m_write_pipe, path, length * sizeof(WCHAR), &written, NULL))
		{
			return HRESULT_FROM_WIN32(GetLastError());
		}

		if (written != length * sizeof(WCHAR))
		{
			return E_FAIL;
		}

		WCHAR line_break = L'\n';
		if (!WriteFile(m_write_pipe, &line_break, sizeof(WCHAR), &written, NULL))
		{
			return HRESULT_FROM_WIN32(GetLastError());
		}

		if (written != sizeof(WCHAR))
		{
			return E_FAIL;
		}

		return S_OK;
	}

	void Writer::finish()
	{
		add_path(L"");

		if (m_write_pipe)
		{
			CloseHandle(m_write_pipe);
			m_write_pipe = NULL;
		}

		if (m_read_pipe)
		{
			CloseHandle(m_read_pipe);
			m_read_pipe = NULL;
		}
	}

	HANDLE Writer::get_read_handle()
	{
		HANDLE result = m_read_pipe;
		m_read_pipe = NULL;
		return result;
	}

	std::vector<std::wstring> read_paths_from_stdin()
	{
		std::vector<std::wstring> result;
		std::wstring line;
		
		bool finished = false;

		while (!finished)
		{
			WCHAR ch;
			// We have to read data like this
			if (!std::cin.read(reinterpret_cast<char*>(&ch), 2))
			{
				finished = true;
			}
			else if (ch == L'\n')
			{
				if (line.empty())
				{
					finished = true;
				}
				else
				{
					result.push_back(line);
					line = {};
				}
			}
			else
			{
				line += ch;
			}
		}

		return result;
	}
}