scip_pricer.c

Go to the documentation of this file.

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*                                                                           */
/*                  This file is part of the program and library             */
/*         SCIP --- Solving Constraint Integer Programs                      */
/*                                                                           */
/*    Copyright (C) 2002-2019 Konrad-Zuse-Zentrum                            */
/*                            fuer Informationstechnik Berlin                */
/*                                                                           */
/*  SCIP is distributed under the terms of the ZIB Academic License.         */
/*                                                                           */
/*  You should have received a copy of the ZIB Academic License              */
/*  along with SCIP; see the file COPYING. If not visit scip.zib.de.         */
/*                                                                           */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/**@file   scip_pricer.c
 * @brief  public methods for variable pricer plugins
 * @author Tobias Achterberg
 * @author Timo Berthold
 * @author Gerald Gamrath
 * @author Robert Lion Gottwald
 * @author Stefan Heinz
 * @author Gregor Hendel
 * @author Thorsten Koch
 * @author Alexander Martin
 * @author Marc Pfetsch
 * @author Michael Winkler
 * @author Kati Wolter
 *
 * @todo check all SCIP_STAGE_* switches, and include the new stages TRANSFORMED and INITSOLVE
 */

/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/

#include <ctype.h>
#include <stdarg.h>
#include <assert.h>
#include <string.h>
#if defined(_WIN32) || defined(_WIN64)
#else
#include <strings.h> /*lint --e{766}*/
#endif


#include "lpi/lpi.h"
#include "nlpi/exprinterpret.h"
#include "nlpi/nlpi.h"
#include "scip/benders.h"
#include "scip/benderscut.h"
#include "scip/branch.h"
#include "scip/branch_nodereopt.h"
#include "scip/clock.h"
#include "scip/compr.h"
#include "scip/concsolver.h"
#include "scip/concurrent.h"
#include "scip/conflict.h"
#include "scip/conflictstore.h"
#include "scip/cons.h"
#include "scip/cons_linear.h"
#include "scip/cutpool.h"
#include "scip/cuts.h"
#include "scip/debug.h"
#include "scip/def.h"
#include "scip/dialog.h"
#include "scip/dialog_default.h"
#include "scip/disp.h"
#include "scip/event.h"
#include "scip/heur.h"
#include "scip/heur_ofins.h"
#include "scip/heur_reoptsols.h"
#include "scip/heur_trivialnegation.h"
#include "scip/heuristics.h"
#include "scip/history.h"
#include "scip/implics.h"
#include "scip/interrupt.h"
#include "scip/lp.h"
#include "scip/mem.h"
#include "scip/message_default.h"
#include "scip/misc.h"
#include "scip/nlp.h"
#include "scip/nodesel.h"
#include "scip/paramset.h"
#include "scip/presol.h"
#include "scip/presolve.h"
#include "scip/pricer.h"
#include "scip/pricestore.h"
#include "scip/primal.h"
#include "scip/prob.h"
#include "scip/prop.h"
#include "scip/reader.h"
#include "scip/relax.h"
#include "scip/reopt.h"
#include "scip/retcode.h"
#include "scip/scipbuildflags.h"
#include "scip/scipcoreplugins.h"
#include "scip/scipgithash.h"
#include "scip/sepa.h"
#include "scip/sepastore.h"
#include "scip/set.h"
#include "scip/sol.h"
#include "scip/solve.h"
#include "scip/stat.h"
#include "scip/syncstore.h"
#include "scip/table.h"
#include "scip/tree.h"
#include "scip/var.h"
#include "scip/visual.h"
#include "xml/xml.h"

#include "scip/scip_pricer.h"

#include "scip/pub_message.h"


/* In debug mode, we include the SCIP's structure in scip.c, such that no one can access
 * this structure except the interface methods in scip.c.
 * In optimized mode, the structure is included in scip.h, because some of the methods
 * are implemented as defines for performance reasons (e.g. the numerical comparisons)
 */
#ifndef NDEBUG
#include "scip/struct_scip.h"
#endif

/** creates a variable pricer and includes it in SCIP
 *  To use the variable pricer for solving a problem, it first has to be activated with a call to SCIPactivatePricer().
 *  This should be done during the problem creation stage.
 *
 *  @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
 *          SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
 *
 *  @pre This method can be called if SCIP is in one of the following stages:
 *       - \ref SCIP_STAGE_INIT
 *       - \ref SCIP_STAGE_PROBLEM
 *
 *  @note method has all pricer callbacks as arguments and is thus changed every time a new callback is added
 *        in future releases; consider using SCIPincludePricerBasic() and setter functions
 *        if you seek for a method which is less likely to change in future releases
 */
SCIP_RETCODE SCIPincludePricer(
   SCIP*                 scip,               /**< SCIP data structure */
   const char*           name,               /**< name of variable pricer */
   const char*           desc,               /**< description of variable pricer */
   int                   priority,           /**< priority of the variable pricer */
   SCIP_Bool             delay,              /**< should the pricer be delayed until no other pricers or already existing
                                              *   problem variables with negative reduced costs are found?
                                              *   if this is set to FALSE it may happen that the pricer produces columns
                                              *   that already exist in the problem (which are also priced in by the
                                              *   default problem variable pricing in the same round) */
   SCIP_DECL_PRICERCOPY  ((*pricercopy)),    /**< copy method of variable pricer or NULL if you don't want to copy your plugin into sub-SCIPs */
   SCIP_DECL_PRICERFREE  ((*pricerfree)),    /**< destructor of variable pricer */
   SCIP_DECL_PRICERINIT  ((*pricerinit)),    /**< initialize variable pricer */
   SCIP_DECL_PRICEREXIT  ((*pricerexit)),    /**< deinitialize variable pricer */
   SCIP_DECL_PRICERINITSOL((*pricerinitsol)),/**< solving process initialization method of variable pricer */
   SCIP_DECL_PRICEREXITSOL((*pricerexitsol)),/**< solving process deinitialization method of variable pricer */
   SCIP_DECL_PRICERREDCOST((*pricerredcost)),/**< reduced cost pricing method of variable pricer for feasible LPs */
   SCIP_DECL_PRICERFARKAS((*pricerfarkas)),  /**< Farkas pricing method of variable pricer for infeasible LPs */
   SCIP_PRICERDATA*      pricerdata          /**< variable pricer data */
   )
{
   SCIP_PRICER* pricer;

   SCIP_CALL( SCIPcheckStage(scip, "SCIPincludePricer", TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE) );

   /* check whether pricer is already present */
   if( SCIPfindPricer(scip, name) != NULL )
   {
      SCIPerrorMessage("pricer <%s> already included.\n", name);
      return SCIP_INVALIDDATA;
   }

   SCIP_CALL( SCIPpricerCreate(&pricer, scip->set, scip->messagehdlr, scip->mem->setmem,
         name, desc, priority, delay,
         pricercopy,
         pricerfree, pricerinit, pricerexit, pricerinitsol, pricerexitsol, pricerredcost, pricerfarkas, pricerdata) );
   SCIP_CALL( SCIPsetIncludePricer(scip->set, pricer) );

   return SCIP_OKAY;
}

/** creates a variable pricer and includes it in SCIP with all non-fundamental callbacks set to NULL;
 *  if needed, these can be added afterwards via setter functions SCIPsetPricerCopy(), SCIPsetPricerFree(),
 *  SCIPsetPricerInity(), SCIPsetPricerExit(), SCIPsetPricerInitsol(), SCIPsetPricerExitsol(),
 *  SCIPsetPricerFarkas();
 *
 *  To use the variable pricer for solving a problem, it first has to be activated with a call to SCIPactivatePricer().
 *  This should be done during the problem creation stage.
 *
 *  @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
 *          SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
 *
 *  @pre This method can be called if SCIP is in one of the following stages:
 *       - \ref SCIP_STAGE_INIT
 *       - \ref SCIP_STAGE_PROBLEM
 *
 *  @note if you want to set all callbacks with a single method call, consider using SCIPincludePricer() instead
 */
SCIP_RETCODE SCIPincludePricerBasic(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_PRICER**         pricerptr,          /**< reference to a pricer, or NULL */
   const char*           name,               /**< name of variable pricer */
   const char*           desc,               /**< description of variable pricer */
   int                   priority,           /**< priority of the variable pricer */
   SCIP_Bool             delay,              /**< should the pricer be delayed until no other pricers or already existing
                                              *   problem variables with negative reduced costs are found?
                                              *   if this is set to FALSE it may happen that the pricer produces columns
                                              *   that already exist in the problem (which are also priced in by the
                                              *   default problem variable pricing in the same round) */
   SCIP_DECL_PRICERREDCOST((*pricerredcost)),/**< reduced cost pricing method of variable pricer for feasible LPs */
   SCIP_DECL_PRICERFARKAS((*pricerfarkas)),  /**< Farkas pricing method of variable pricer for infeasible LPs */
   SCIP_PRICERDATA*      pricerdata          /**< variable pricer data */
   )
{
   SCIP_PRICER* pricer;

   SCIP_CALL( SCIPcheckStage(scip, "SCIPincludePricerBasic", TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE) );

   /* check whether pricer is already present */
   if( SCIPfindPricer(scip, name) != NULL )
   {
      SCIPerrorMessage("pricer <%s> already included.\n", name);
      return SCIP_INVALIDDATA;
   }

   SCIP_CALL( SCIPpricerCreate(&pricer, scip->set, scip->messagehdlr, scip->mem->setmem,
         name, desc, priority, delay,
         NULL,
         NULL, NULL, NULL, NULL, NULL, pricerredcost, pricerfarkas, pricerdata) );
   SCIP_CALL( SCIPsetIncludePricer(scip->set, pricer) );

   if( pricerptr != NULL )
      *pricerptr = pricer;

   return SCIP_OKAY;
}

/** sets copy method of pricer
 *
 *  @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
 *          SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
 *
 *  @pre This method can be called if SCIP is in one of the following stages:
 *       - \ref SCIP_STAGE_INIT
 *       - \ref SCIP_STAGE_PROBLEM
 */
SCIP_RETCODE SCIPsetPricerCopy(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_PRICER*          pricer,             /**< pricer */
   SCIP_DECL_PRICERCOPY ((*pricercopy))     /**< copy method of pricer or NULL if you don't want to copy your plugin into sub-SCIPs */
   )
{
   SCIP_CALL( SCIPcheckStage(scip, "SCIPsetPricerCopy", TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE) );

   assert(pricer != NULL);

   SCIPpricerSetCopy(pricer, pricercopy);

   return SCIP_OKAY;
}

/** sets destructor method of pricer
 *
 *  @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
 *          SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
 *
 *  @pre This method can be called if SCIP is in one of the following stages:
 *       - \ref SCIP_STAGE_INIT
 *       - \ref SCIP_STAGE_PROBLEM
 */
SCIP_RETCODE SCIPsetPricerFree(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_PRICER*          pricer,             /**< pricer */
   SCIP_DECL_PRICERFREE ((*pricerfree))      /**< destructor of pricer */
   )
{
   SCIP_CALL( SCIPcheckStage(scip, "SCIPsetPricerFree", TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE) );

   assert(pricer != NULL);

   SCIPpricerSetFree(pricer, pricerfree);

   return SCIP_OKAY;
}

/** sets initialization method of pricer
 *
 *  @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
 *          SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
 *
 *  @pre This method can be called if SCIP is in one of the following stages:
 *       - \ref SCIP_STAGE_INIT
 *       - \ref SCIP_STAGE_PROBLEM
 */
SCIP_RETCODE SCIPsetPricerInit(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_PRICER*          pricer,             /**< pricer */
   SCIP_DECL_PRICERINIT  ((*pricerinit))     /**< initialize pricer */
   )
{
   SCIP_CALL( SCIPcheckStage(scip, "SCIPsetPricerInit", TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE) );

   assert(pricer != NULL);

   SCIPpricerSetInit(pricer, pricerinit);

   return SCIP_OKAY;
}

/** sets deinitialization method of pricer
 *
 *  @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
 *          SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
 *
 *  @pre This method can be called if SCIP is in one of the following stages:
 *       - \ref SCIP_STAGE_INIT
 *       - \ref SCIP_STAGE_PROBLEM
 */
SCIP_RETCODE SCIPsetPricerExit(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_PRICER*          pricer,             /**< pricer */
   SCIP_DECL_PRICEREXIT  ((*pricerexit))     /**< deinitialize pricer */
   )
{
   SCIP_CALL( SCIPcheckStage(scip, "SCIPsetPricerExit", TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE) );

   assert(pricer != NULL);

   SCIPpricerSetExit(pricer, pricerexit);

   return SCIP_OKAY;
}

/** sets solving process initialization method of pricer
 *
 *  @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
 *          SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
 *
 *  @pre This method can be called if SCIP is in one of the following stages:
 *       - \ref SCIP_STAGE_INIT
 *       - \ref SCIP_STAGE_PROBLEM
 */
SCIP_RETCODE SCIPsetPricerInitsol(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_PRICER*          pricer,             /**< pricer */
   SCIP_DECL_PRICERINITSOL ((*pricerinitsol))/**< solving process initialization method of pricer */
   )
{
   SCIP_CALL( SCIPcheckStage(scip, "SCIPsetPricerInitsol", TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE) );

   assert(pricer != NULL);

   SCIPpricerSetInitsol(pricer, pricerinitsol);

   return SCIP_OKAY;
}

/** sets solving process deinitialization method of pricer
 *
 *  @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
 *          SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
 *
 *  @pre This method can be called if SCIP is in one of the following stages:
 *       - \ref SCIP_STAGE_INIT
 *       - \ref SCIP_STAGE_PROBLEM
 */
SCIP_RETCODE SCIPsetPricerExitsol(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_PRICER*          pricer,             /**< pricer */
   SCIP_DECL_PRICEREXITSOL((*pricerexitsol)) /**< solving process deinitialization method of pricer */
   )
{
   SCIP_CALL( SCIPcheckStage(scip, "SCIPsetPricerExitsol", TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE) );

   assert(pricer != NULL);

   SCIPpricerSetExitsol(pricer, pricerexitsol);

   return SCIP_OKAY;
}

/** returns the variable pricer of the given name, or NULL if not existing */
SCIP_PRICER* SCIPfindPricer(
   SCIP*                 scip,               /**< SCIP data structure */
   const char*           name                /**< name of variable pricer */
   )
{
   assert(scip != NULL);
   assert(scip->set != NULL);
   assert(name != NULL);

   return SCIPsetFindPricer(scip->set, name);
}

/** returns the array of currently available variable pricers; active pricers are in the first slots of the array */
SCIP_PRICER** SCIPgetPricers(
   SCIP*                 scip                /**< SCIP data structure */
   )
{
   assert(scip != NULL);
   assert(scip->set != NULL);

   SCIPsetSortPricers(scip->set);

   return scip->set->pricers;
}

/** returns the number of currently available variable pricers */
int SCIPgetNPricers(
   SCIP*                 scip                /**< SCIP data structure */
   )
{
   assert(scip != NULL);
   assert(scip->set != NULL);

   return scip->set->npricers;
}

/** returns the number of currently active variable pricers, that are used in the LP solving loop */
int SCIPgetNActivePricers(
   SCIP*                 scip                /**< SCIP data structure */
   )
{
   assert(scip != NULL);
   assert(scip->set != NULL);

   return scip->set->nactivepricers;
}

/** sets the priority priority of a variable pricer */
SCIP_RETCODE SCIPsetPricerPriority(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_PRICER*          pricer,             /**< variable pricer */
   int                   priority            /**< new priority of the variable pricer */
   )
{
   assert(scip != NULL);
   assert(scip->set != NULL);

   SCIPpricerSetPriority(pricer, scip->set, priority);

   return SCIP_OKAY;
}

/** activates pricer to be used for the current problem
 *  This method should be called during the problem creation stage for all pricers that are necessary to solve
 *  the problem model.
 *  The pricers are automatically deactivated when the problem is freed.
 *
 *  @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
 *          SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
 *
 *  @pre This method can be called if SCIP is in one of the following stages:
 *       - \ref SCIP_STAGE_PROBLEM
 */
SCIP_RETCODE SCIPactivatePricer(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_PRICER*          pricer              /**< variable pricer */
   )
{
   SCIP_CALL( SCIPcheckStage(scip, "SCIPactivatePricer", FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE) );

   SCIP_CALL( SCIPpricerActivate(pricer, scip->set) );

   return SCIP_OKAY;
}

/** deactivates pricer
 *
 *  @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
 *          SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
 *
 *  @pre This method can be called if SCIP is in one of the following stages:
 *       - \ref SCIP_STAGE_PROBLEM
 *       - \ref SCIP_STAGE_EXITSOLVE
 */
SCIP_RETCODE SCIPdeactivatePricer(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_PRICER*          pricer              /**< variable pricer */
   )
{
   SCIP_CALL( SCIPcheckStage(scip, "SCIPdeactivatePricer", FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE, FALSE, FALSE) );

   SCIP_CALL( SCIPpricerDeactivate(pricer, scip->set) );

   return SCIP_OKAY;
}