ibrcommon/ibrcommon/appstreambuf.cpp

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/*
 * appstreambuf.cpp
 *
 *  Created on: 20.11.2009
 *      Author: morgenro
 */

#include "ibrcommon/config.h"
#include "ibrcommon/appstreambuf.h"

namespace ibrcommon
{
        appstreambuf::appstreambuf(std::string command, appstreambuf::Mode mode)
         : m_buf( BUF_SIZE+1 )
        {
                // execute the command
                if (mode == MODE_READ)
                {
                        setg(0, 0, 0);
                        _handle = popen(command.c_str(), "r");
                }
                else
                {
                        setp( &m_buf[0], &m_buf[0] + (m_buf.size() - 1) );
                        _handle = popen(command.c_str(), "w");
                }
        }

        appstreambuf::~appstreambuf()
        {
                // close the handle
                pclose(_handle);
        }

        int appstreambuf::underflow()
        {
                // read the stdout of the process
                size_t ret = 0;

                if (feof(_handle))
                        return std::char_traits<char>::eof();

                ret = fread(&m_buf[0], sizeof(char), m_buf.size(), _handle);

                // Since the input buffer content is now valid (or is new)
                // the get pointer should be initialized (or reset).
                setg(&m_buf[0], &m_buf[0], &m_buf[0] + ret);

                return std::char_traits<char>::not_eof(m_buf[0]);
        }

        int appstreambuf::sync()
        {
                int ret = std::char_traits<char>::eq_int_type(this->overflow(std::char_traits<char>::eof()),
                                std::char_traits<char>::eof()) ? -1 : 0;

                return ret;
        }

        std::char_traits<char>::int_type appstreambuf::overflow( std::char_traits<char>::int_type m )
        {
                char *ibegin = pbase();
                char *iend = pptr();

                // if there is nothing to send, just return
                if ( iend <= ibegin ) return std::char_traits<char>::not_eof(m);

                // mark the buffer as free
                setp( &m_buf[0], &m_buf[0] + (m_buf.size() - 1) );

                if(!std::char_traits<char>::eq_int_type(m, std::char_traits<char>::eof())) {
                        *iend++ = std::char_traits<char>::to_char_type(m);
                }

                // write the data
                int ret = 0;
                if ((ret = fwrite(pbase(), sizeof(char), (iend - ibegin), _handle)) != (iend - ibegin))
                {
                        return std::char_traits<char>::eof();
                }

                return std::char_traits<char>::not_eof(m);
        }
}