/* Copyright 2004,2007,2011-2013 IPB, Universite de Bordeaux, INRIA & CNRS
**
** This file is part of the Scotch software package for static mapping,
** graph partitioning and sparse matrix ordering.
**
** This software is governed by the CeCILL-C license under French law
** and abiding by the rules of distribution of free software. You can
** use, modify and/or redistribute the software under the terms of the
** CeCILL-C license as circulated by CEA, CNRS and INRIA at the following
** URL: "http://www.cecill.info".
** 
** As a counterpart to the access to the source code and rights to copy,
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** only with a limited warranty and the software's author, the holder of
** the economic rights, and the successive licensors have only limited
** liability.
** 
** In this respect, the user's attention is drawn to the risks associated
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** software by the user in light of its specific status of free software,
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** 
** The fact that you are presently reading this means that you have had
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*/
/************************************************************/
/**                                                        **/
/**   NAME       : graph_coarsen.h                         **/
/**                                                        **/
/**   AUTHOR     : Francois PELLEGRINI                     **/
/**                Sebastien FOURESTIER (v6.0)             **/
/**                                                        **/
/**   FUNCTION   : These lines are the data declarations   **/
/**                for the source graph coarsening         **/
/**                functions.                              **/
/**                                                        **/
/**   DATES      : # Version 0.0  : from : 02 dec 1992     **/
/**                                 to     18 may 1993     **/
/**                # Version 1.3  : from : 30 apr 1994     **/
/**                                 to     18 may 1994     **/
/**                # Version 2.0  : from : 06 jun 1994     **/
/**                                 to     18 aug 1994     **/
/**                # Version 3.0  : from : 07 jul 1995     **/
/**                                 to     28 sep 1995     **/
/**                # Version 3.1  : from : 28 nov 1995     **/
/**                                 to     28 nov 1995     **/
/**                # Version 3.2  : from : 07 sep 1996     **/
/**                                 to     17 sep 1998     **/
/**                # Version 4.0  : from : 13 dec 2001     **/
/**                                 to     05 dec 2004     **/
/**                # Version 6.0  : from : 09 mar 2011     **/
/**                                 to     02 nov 2012     **/
/**                                                        **/
/************************************************************/

/*
**  The defines.
*/

#ifdef SCOTCH_PTHREAD
#define GRAPHCOARSENTHREAD
#endif /* SCOTCH_PTHREAD */

/** Prime number for hashing vertex numbers. **/

#define GRAPHCOARSENHASHPRIME       1049          /* Prime number */

/*
**  The type and structure definitions.
*/

/*+ Here are the edge matching function types for coarsening. +*/

typedef enum GraphCoarsenType_ {
  GRAPHCOARHEM,                                   /*+ Heavy-edge matching       +*/
  GRAPHCOARSCN,                                   /*+ Scanning (first) matching +*/
  GRAPHCOARNBR                                    /*+ Number of matching types  +*/
} GraphCoarsenType;

/*+ The multinode table element, which contains
    pairs of based indices of collapsed vertices.
    Both values are equal for uncollapsed vertices.
    As the base values of the fine and coarse graphs
    may be different, the values of the collapsed
    vertices are set with respect to the base value
    of the fine graph.                               +*/

typedef struct GraphCoarsenMulti_  {
  Gnum                      vertnum[2];           /*+ Numbers of the collapsed vertices of a multinode +*/
} GraphCoarsenMulti;

/*+ A table made of such elements is used during
    coarsening to build the edge array of the new
    graph, after the labeling of the vertices.    +*/

typedef struct GraphCoarsenHash_ {
  Gnum                      vertorgnum;           /*+ Origin vertex (i.e. pass) number +*/
  Gnum                      vertendnum;           /*+ Other end vertex number          +*/
  Gnum                      edgenum;              /*+ Number of corresponding edge     +*/
} GraphCoarsenHash;

/*+ The matching and coarsening routine
    parameter structure. It contains the
    thread-independent data.             +*/

typedef struct GraphCoarsenData_ {
  ThreadGroupHeader         thrddat;              /*+ Thread handling data                            +*/
  const Graph *             finegrafptr;          /*+ Fine graph to perform matching on               +*/
  const Anum *              fineparotax;          /*+ Old part array                                  +*/
  const Anum *              finepfixtax;          /*+ Array of fixed vertices                         +*/
  Gnum                      finevfixnbr;          /*+ Number of fine fixed vertices                   +*/
  Gnum *                    finematetax;          /*+ Fine mate array / fine-to-coarse array          +*/
  Graph *                   coargrafptr;          /*+ Coarse graph to build                           +*/
  Gnum                      coarvertmax;          /*+ Maximum number of vertices to get               +*/
  Gnum                      coarvertnbr;          /*+ Global number of coarse vertices after matching +*/
  GraphCoarsenMulti *       coarmulttax;          /*+ Multinode array                                 +*/
  Gnum                      coarhashmsk;          /*+ Hash table mask                                 +*/
#ifdef SCOTCH_PTHREAD
  int * restrict            finelocktax;          /*+ Matching lock array (if any)                    +*/
  Gnum * restrict           finequeutab;          /*+ Matching queue array (if any)                   +*/
  void                   (* fendptr) (void *);    /*+ Pointer to final / sequential match routine     +*/
  void                   (* fmidptr) (void *);    /*+ Pointer to intermediate match routine (if any)  +*/
#endif /* SCOTCH_PTHREAD */
  void                   (* fbegptr) (void *);    /*+ Pointer to beginning match routine (if any)     +*/
} GraphCoarsenData;

/*+ The thread-specific data block. +*/

typedef struct GraphCoarsenThread_ {
  ThreadHeader              thrddat;              /*+ Thread management data                                    +*/
  Gunum                     randval;              /*+ Per-thread unsigned random value                          +*/
  GraphCoarsenHash *        coarhashtab;          /*+ End vertex hash table (may be local)                      +*/
  Gnum                      coarvertnnd;          /*+ After-last coarse vertex number                           +*/
  Gnum                      coarvertbas;          /*+ Minimum coarse vertex number; for prefix scan             +*/
  Gnum                      coarvertnbr;          /*+ Number of coarse vertices to date; TRICK: scan dummy area +*/
  Gnum                      coaredloadj;          /*+ (Local) coarse edge load sum adjust                       +*/
  Gnum                      coardegrmax;          /*+ (Local) maximum degree                                    +*/
  Gnum                      coaredgebas;          /*+ Minimum coarse edge number; for prefix scan               +*/
  Gnum                      finevertbas;          /*+ Start of fine vertex range; TRICK: scan dummy area        +*/
  Gnum                      finevertnnd;          /*+ End of fine vertex range                                  +*/
  Gnum                      finequeubas;          /*+ Minimum perturbation or queue index for matching          +*/
  Gnum                      finequeunnd;          /*+ After-last perturbation or queue index for matching       +*/
} GraphCoarsenThread;

/*
**  The function prototypes.
*/

#ifndef GRAPH_COARSEN
#define static
#endif

int                         graphCoarsen        (const Graph * restrict const, Graph * restrict const, GraphCoarsenMulti * restrict * const, const Gnum, const double, const Anum * restrict const, const Anum * restrict const, const Gnum, Gnum * restrict const);

#ifdef GRAPHCOARSENTHREAD
static void                 graphCoarsenEdgeCt  (GraphCoarsenThread *);
#endif /* GRAPHCOARSENTHREAD */
static void                 graphCoarsenEdgeLl  (GraphCoarsenThread *);
static void                 graphCoarsenEdgeLu  (GraphCoarsenThread *);

#undef static
