ExternalDataSource.cc

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/*---------------------------------------------------------------------\
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|                         |__  / \ / / . \ . \                         |
|                           / / \ V /|  _/  _/                         |
|                          / /__ | | | | | |                           |
|                         /_____||_| |_| |_|                           |
|                                                                      |
\---------------------------------------------------------------------*/
#define _GNU_SOURCE 1 // for ::getline

#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <string>

#include "zypp/base/Logger.h"
#include "zypp/base/ExternalDataSource.h"

using namespace std;

namespace zypp {
  namespace externalprogram {

    ExternalDataSource::ExternalDataSource (FILE *ifile, FILE *ofile)
      : inputfile (ifile),
        outputfile (ofile),
        linebuffer (0),
        linebuffer_size (0)
    {
    }


    ExternalDataSource::~ExternalDataSource ()
    {
      if (linebuffer)
        free (linebuffer);
      close ();
    }


    bool
    ExternalDataSource::send (const char *buffer, size_t length)
    {
      if (outputfile) {
        bool success = fwrite (buffer, length, 1, outputfile) != 0;
        fflush (outputfile);
        return success;
      }
      else
        return false;
    }


    bool
    ExternalDataSource::send (std::string s)
    {
      DBG << "send (" << s << ")";
      return send(s.data(), s.length());
    }


    string
    ExternalDataSource::receiveUpto (char c)
    {
      if (inputfile)
      {
        string result;
        while (true)
        {
            const size_t length = 4096;
            char buffer[length];
            char *writepointer = buffer;
            size_t readbytes = 0;
            int readc = -1;

            while (!feof(inputfile) && readbytes < length)
            {
                readc = fgetc(inputfile);
                if (readc == EOF) break;
                *writepointer++ = (char) readc;
                if ((char) readc == c) break;
                readbytes++;
            }
            *writepointer = 0;
            result += buffer;
            if (readbytes < length || (char) readc == c) break;

        }
        return result;
      }

      else return "";
    }


    size_t
    ExternalDataSource::receive (char *buffer, size_t length)
    {
      if (inputfile)
        return fread (buffer, 1, length, inputfile);
      else
        return 0;
    }

    void ExternalDataSource::setBlocking(bool mode)
    {
      if(!inputfile) return;

      int fd = ::fileno(inputfile);

      if(fd == -1)
        { ERR << strerror(errno) << endl; return; }

      int flags = ::fcntl(fd,F_GETFL);

      if(flags == -1)
        { ERR << strerror(errno) << endl; return; }

      if(!mode)
        flags = flags | O_NONBLOCK;
      else if(flags & O_NONBLOCK)
        flags = flags ^ O_NONBLOCK;

      flags = ::fcntl(fd,F_SETFL,flags);

      if(flags == -1)
        { ERR << strerror(errno) << endl; return; }
    }

    string
    ExternalDataSource::receiveLine()
    {
      if (inputfile)
      {
        ssize_t nread = getline (&linebuffer, &linebuffer_size, inputfile);
        if (nread == -1)
            return "";
        else
            return string (linebuffer, nread);
      }
      else
        return "";
    }


    int
    ExternalDataSource::close ()
    {
      if (inputfile && inputfile != outputfile)
        fclose (inputfile);
      if (outputfile)
        fclose (outputfile);
      inputfile = 0;
      outputfile = 0;
      return 0;
    }


  } // namespace externalprogram
} // namespace zypp

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