scip_bandit.c

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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*                                                                           */
/*                  This file is part of the program and library             */
/*         SCIP --- Solving Constraint Integer Programs                      */
/*                                                                           */
/*    Copyright (C) 2002-2018 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 email to scip@zib.de.      */
/*                                                                           */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/**@file   scip_bandit.c
 * @brief  public functions for bandit algorithms
 * @author Gregor Hendel
 */

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

#include <assert.h>
#include "scip/scip.h"
#include "scip/set.h"
#include "scip/bandit.h"
#include "scip/struct_set.h"
#include "scip/struct_scip.h"
#include "scip/mem.h"

/** includes a bandit algorithm virtual function table  */
SCIP_RETCODE SCIPincludeBanditvtable(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_BANDITVTABLE**   banditvtable,       /**< bandit algorithm virtual function table */
   const char*           name,               /**< a name for the algorithm represented by this vtable */
   SCIP_DECL_BANDITFREE  ((*banditfree)),    /**< callback to free bandit specific data structures */
   SCIP_DECL_BANDITSELECT((*banditselect)),  /**< selection callback for bandit selector */
   SCIP_DECL_BANDITUPDATE((*banditupdate)),  /**< update callback for bandit algorithms */
   SCIP_DECL_BANDITRESET ((*banditreset))    /**< update callback for bandit algorithms */
   )
{
   SCIP_BANDITVTABLE* vtableptr;

   assert(scip != NULL);
   assert(banditvtable != NULL);

   if( SCIPfindBanditvtable(scip, name) != NULL )
   {
      SCIPerrorMessage("bandit VTable <%s> already included.\n", name);
       return SCIP_INVALIDDATA;
   }

   SCIP_CALL( SCIPbanditvtableCreate(&vtableptr, name,
         banditfree, banditselect, banditupdate, banditreset) );

   SCIP_CALL( SCIPsetIncludeBanditvtable(scip->set, vtableptr) );

   *banditvtable = vtableptr;

   return SCIP_OKAY;
}

/** returns the bandit virtual function table of the given name, or NULL if not existing */
SCIP_BANDITVTABLE* SCIPfindBanditvtable(
   SCIP*                 scip,               /**< SCIP data structure */
   const char*           name                /**< name of bandit algorithm virtual function table */
   )
{
   assert(scip != NULL);

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

/** reset the bandit algorithm */
SCIP_RETCODE SCIPresetBandit(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_BANDIT*          bandit,             /**< pointer to bandit algorithm data structure */
   SCIP_Real*            priorities,         /**< priorities for every action, or NULL if not needed */
   unsigned int          seed                /**< initial random seed for bandit selection */
   )
{
   assert(scip != NULL);
   assert(bandit != NULL);

   SCIP_CALL( SCIPbanditReset(SCIPbuffer(scip), bandit, priorities, SCIPinitializeRandomSeed(scip, (int)(seed % INT_MAX))) );

   return SCIP_OKAY;
}

/** calls destructor and frees memory of bandit algorithm */
SCIP_RETCODE SCIPfreeBandit(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_BANDIT**         bandit              /**< pointer to bandit algorithm data structure */
   )
{
   assert(scip != NULL);
   assert(bandit != NULL);
   assert(*bandit != NULL);

   SCIP_CALL( SCIPbanditFree(SCIPblkmem(scip), bandit) );

   return SCIP_OKAY;
}