Nektar::LibUtilities::CppCommandLine Struct Reference

Helper structure to construct C++ command line argc and argv variables from a C++ vector. More...

#include <CppCommandLine.hpp>

Inheritance diagram for Nektar::LibUtilities::CppCommandLine:

Public Member Functions
	CppCommandLine ()=default
	CppCommandLine (std::vector< std::string > argv)
	Constructor.
	~CppCommandLine ()
	Destructor.
char **	GetArgv ()
	Returns the constructed argv.
int	GetArgc ()
	Returns the constructed argc.

Protected Member Functions
void	Setup (std::vector< std::string > &argv)

Private Attributes
char **	m_argv = nullptr
	Pointers for strings argv.
int	m_argc = 0
	Number of arguments argc.
std::vector< char >	m_buf
	Buffer for storage of the argument strings.

Detailed Description

Helper structure to construct C++ command line argc and argv variables from a C++ vector.

This is a useful class when setting up a call to SessionReader::CreateInstance, since arguments must be constructed to the right memory addresses, otherwise MPI (specifically OpenMPI) often tends to segfault.

Definition at line 53 of file CppCommandLine.hpp.

Constructor & Destructor Documentation

CppCommandLine() [1/2]

Nektar::LibUtilities::CppCommandLine::CppCommandLine ( )

default

CppCommandLine() [2/2]

Nektar::LibUtilities::CppCommandLine::CppCommandLine ( std::vector< std::string >  argv )

inline

Constructor.

Parameters

argv	List of command line arguments.

Definition at line 62 of file CppCommandLine.hpp.

    {
        Setup(argv);
    }

References Setup().

~CppCommandLine()

Nektar::LibUtilities::CppCommandLine::~CppCommandLine ( )

inline

Destructor.

Definition at line 70 of file CppCommandLine.hpp.

    {
        if (m_argv == nullptr)
        {
            return;
        }
 
        // Only single pointer delete is required since storage is in m_buf.
        delete[] m_argv;
    }

References m_argv.

Member Function Documentation

GetArgc()

int Nektar::LibUtilities::CppCommandLine::GetArgc ( )

inline

Returns the constructed argc.

Definition at line 92 of file CppCommandLine.hpp.

    {
        return m_argc;
    }

References m_argc.

Referenced by Field_Init(), NewPartition(), and SessionReader_CreateInstance().

GetArgv()

char ** Nektar::LibUtilities::CppCommandLine::GetArgv ( )

inline

Returns the constructed argv.

Definition at line 84 of file CppCommandLine.hpp.

    {
        return m_argv;
    }

References m_argv.

Referenced by Field_Init(), NewPartition(), and SessionReader_CreateInstance().

Setup()

void Nektar::LibUtilities::CppCommandLine::Setup ( std::vector< std::string > &  argv )

inlineprotected

Definition at line 98 of file CppCommandLine.hpp.

    {
        int i          = 0;
        size_t bufSize = 0;
        char *p;
 
        m_argc = argv.size();
        m_argv = new char *[m_argc + 1];
 
        // Create argc, argv to give to the session reader. Note that this needs
        // to be a contiguous block in memory, otherwise MPI (specifically
        // OpenMPI) will likely segfault.
        for (i = 0; i < m_argc; ++i)
        {
            bufSize += argv[i].size() + 1;
        }
 
        m_buf.resize(bufSize);
        for (i = 0, p = &m_buf[0]; i < m_argc; ++i)
        {
            std::string tmp = argv[i];
            std::copy(tmp.begin(), tmp.end(), p);
            p[tmp.size()] = '\0';
            m_argv[i]     = p;
            p += tmp.size() + 1;
        }
 
        m_argv[m_argc] = nullptr;
    }

References m_argc, m_argv, and m_buf.

Referenced by CppCommandLine(), and PyCppCommandLine::PyCppCommandLine().

Member Data Documentation

m_argc

int Nektar::LibUtilities::CppCommandLine::m_argc = 0

private

Number of arguments argc.

Definition at line 132 of file CppCommandLine.hpp.

Referenced by GetArgc(), and Setup().

m_argv

char** Nektar::LibUtilities::CppCommandLine::m_argv = nullptr

private

Pointers for strings argv.

Definition at line 130 of file CppCommandLine.hpp.

Referenced by GetArgv(), Setup(), and ~CppCommandLine().

m_buf

std::vector<char> Nektar::LibUtilities::CppCommandLine::m_buf

private

Buffer for storage of the argument strings.

Definition at line 134 of file CppCommandLine.hpp.

Referenced by Setup().