mpsinput.cpp

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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*                                                                           */
/*                  This file is part of the class library                   */
/*       SoPlex --- the Sequential object-oriented simPlex.                  */
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/*  Copyright (c) 1996-2023 Zuse Institute Berlin (ZIB)                      */
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/*  Licensed under the Apache License, Version 2.0 (the "License");          */
/*  you may not use this file except in compliance with the License.         */
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/*      http://www.apache.org/licenses/LICENSE-2.0                           */
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/*  distributed under the License is distributed on an "AS IS" BASIS,        */
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/*  See the License for the specific language governing permissions and      */
/*  limitations under the License.                                           */
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/*  You should have received a copy of the Apache-2.0 license                */
/*  along with SoPlex; see the file LICENSE. If not email to soplex@zib.de.  */
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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/**@file  mpsinput.cpp
 * @brief Read MPS format files.
 */

#include <assert.h>
#include <ctype.h>
#include <string.h>

#include "soplex/spxdefines.h"
#include "soplex/mpsinput.h"
#include "soplex/spxout.h"

#define PATCH_CHAR    '_'
#define BLANK         ' '

namespace soplex
{

/// fill the line from \p pos up to column 80 with blanks.
static void clear_from(char* buf, int pos)
{
   for(int i = pos; i < 80; i++)
      buf[i] = BLANK;

   buf[80] = '\0';
}

/// change all blanks inside a field to #PATCH_CHAR.
static void patch_field(char* buf, int beg, int end)
{
   while((beg <= end) && (buf[end] == BLANK))
      end--;

   while((beg <= end) && (buf[beg] == BLANK))
      beg++;

   for(int i = beg; i <= end; i++)
      if(buf[i] == BLANK)
         buf[i] = PATCH_CHAR;
}

/// read a MPS format data line and parse the fields.
bool MPSInput::readLine()
{
   int   len;
   int   space;
   char* s;
   bool  is_marker;
   bool  is_comment;

   do
   {
      m_f0 = m_f1 = m_f2 = m_f3 = m_f4 = m_f5 = 0;
      is_marker = false;

      // Read until we have a non-empty, non-comment line.
      do
      {
         if(!m_input.getline(m_buf, sizeof(m_buf)).good() && !m_input.eof())
            return false;

         m_lineno++;

         SPxOut::debug(this, "DMPSIN01 Line {} {}\n", m_lineno, m_buf);

         /* check if comment line */
         is_comment = true;

         if(m_buf[0] == '*')
            continue;

         /* normalize line and check if it is empty */
         len = int(strlen(m_buf));

         for(int i = 0; i < len; i++)
         {
            if(m_buf[i] == '\t' || m_buf[i] == '\n' || m_buf[i] == '\r')
               m_buf[i] = BLANK;
            else if(m_buf[i] != BLANK)
               is_comment = false;
         }
      }
      while(is_comment);

      len = int(strlen(m_buf));

      if(len < 80)
         clear_from(m_buf, len);

      assert(strlen(m_buf) >= 80);

      /* Look for new section
       */
      if(*m_buf != BLANK)
      {
         m_f0 = strtok(&m_buf[0], " ");

         assert(m_f0 != 0);

         m_f1 = strtok(0, " ");

         return true;
      }

      if(!m_is_new_format)
      {
         /* Test for fixed format comments
          */
         if((m_buf[14] == '$') && (m_buf[13] == ' '))
            clear_from(m_buf, 14);
         else if((m_buf[39] == '$') && (m_buf[38] == ' '))
            clear_from(m_buf, 39);

         /* Test for fixed format
          */
         space = m_buf[12] | m_buf[13]
                 | m_buf[22] | m_buf[23]
                 | m_buf[36] | m_buf[37] | m_buf[38]
                 | m_buf[47] | m_buf[48]
                 | m_buf[61] | m_buf[62] | m_buf[63];

         if(space == BLANK || len < 13)
         {
            /* Now we have space at the right positions.
             * But are there also the non space where they
             * should be ?
             */
            bool number = isdigit(m_buf[24]) || isdigit(m_buf[25])
                          || isdigit(m_buf[26]) || isdigit(m_buf[27])
                          || isdigit(m_buf[28]) || isdigit(m_buf[29])
                          || isdigit(m_buf[30]) || isdigit(m_buf[31])
                          || isdigit(m_buf[32]) || isdigit(m_buf[33])
                          || isdigit(m_buf[34]) || isdigit(m_buf[35]);

            /* len < 13 is handle ROW lines with embedded spaces
             * in the names correctly
             */
            if(number || len < 13)
            {
               /* Now we assume fixed format, so we patch possible embedded spaces.
                */
               patch_field(m_buf,  4, 12);
               patch_field(m_buf, 14, 22);
               patch_field(m_buf, 39, 47);
            }
            else
            {
               if(m_section == COLUMNS || m_section == RHS
                     || m_section == RANGES  || m_section == BOUNDS)
                  m_is_new_format = true;
            }
         }
         else
         {
            m_is_new_format = true;
         }
      }

      s = &m_buf[1];

      /* At this point it is not clear if we have a indicator field.
       * If there is none (e.g. empty) f1 will be the first name field.
       * If there is one, f2 will be the first name field.
       *
       * Initially comment marks '$' ar only allowed in the beginning
       * of the 2nd and 3rd name field. We test all fields but the first.
       * This makes no difference, since if the $ is at the start of a value
       * field, the line will be errornous anyway.
       */
      do
      {
         if(0 == (m_f1 = strtok(s, " ")))
            break;

         if((0 == (m_f2 = strtok(0, " "))) || (*m_f2 == '$'))
         {
            m_f2 = 0;
            break;
         }

         if(!strcmp(m_f2, "'MARKER'"))
            is_marker = true;

         if((0 == (m_f3 = strtok(0, " "))) || (*m_f3 == '$'))
         {
            m_f3 = 0;
            break;
         }

         if(is_marker)
         {
            if(!strcmp(m_f3, "'INTORG'"))
               m_is_integer = true;
            else if(!strcmp(m_f3, "'INTEND'"))
               m_is_integer = false;
            else
               break; // unknown marker
         }

         if(!strcmp(m_f3, "'MARKER'"))
            is_marker = true;

         if((0 == (m_f4 = strtok(0, " "))) || (*m_f4 == '$'))
         {
            m_f4 = 0;
            break;
         }

         if(is_marker)
         {
            if(!strcmp(m_f4, "'INTORG'"))
               m_is_integer = true;
            else if(!strcmp(m_f4, "'INTEND'"))
               m_is_integer = false;
            else
               break; // unknown marker
         }

         if((0 == (m_f5 = strtok(0, " "))) || (*m_f5 == '$'))
            m_f5 = 0;
      }
      while(false);
   }
   while(is_marker);

   SPxOut::debug(this, "DMPSIN02 -----------------------------------------------\n"
                 "DMPSIN03 f0={}\n"
                 "DMPSIN04 f1={}\n"
                 "DMPSIN05 f2={}\n"
                 "DMPSIN07 f4={}\n"
                 "DMPSIN06 f3={}\n"
                 "DMPSIN08 f5={}\n"
                 "DMPSIN09 -----------------------------------------------\n",
                 ((m_f0 == 0) ? "nil" : m_f0),
                 ((m_f1 == 0) ? "nil" : m_f1),
                 ((m_f2 == 0) ? "nil" : m_f2),
                 ((m_f3 == 0) ? "nil" : m_f3),
                 ((m_f4 == 0) ? "nil" : m_f4),
                 ((m_f5 == 0) ? "nil" : m_f5));
   return true;
}

/// Insert \p name as field 1 and shift all other fields up.
void MPSInput::insertName(const char* name, bool second)
{
   m_f5 = m_f4;
   m_f4 = m_f3;
   m_f3 = m_f2;

   if(second)
      m_f2 = name;
   else
   {
      m_f2 = m_f1;
      m_f1 = name;
   }
}

} // namespace soplex