is/utils/pmap.c

/*
   This file contains routines for basic map object implementation.
*/

#include <petscvec.h>
#include <petscsf.h>

#undef __FUNCT__
#define __FUNCT__ "PetscLayoutCreate"
/*@C
     PetscLayoutCreate - Allocates PetscLayout space and sets the map contents to the default.

    Collective on MPI_Comm

   Input Parameters:
+    comm - the MPI communicator
-    map - pointer to the map

   Level: advanced

    Notes:
    Typical calling sequence
.vb
       PetscLayoutCreate(MPI_Comm,PetscLayout *);
       PetscLayoutSetBlockSize(PetscLayout,1);
       PetscLayoutSetSize(PetscLayout,N) // or PetscLayoutSetLocalSize(PetscLayout,n);
       PetscLayoutSetUp(PetscLayout);
.ve
    Optionally use any of the following:

+      PetscLayoutGetSize(PetscLayout,PetscInt *);
.      PetscLayoutGetLocalSize(PetscLayout,PetscInt *);
.      PetscLayoutGetRange(PetscLayout,PetscInt *rstart,PetscInt *rend);
.      PetscLayoutGetRanges(PetscLayout,const PetscInt *range[]);
-      PetscLayoutDestroy(PetscLayout*);

      The PetscLayout object and methods are intended to be used in the PETSc Vec and Mat implementions; it is often not needed in
      user codes unless you really gain something in their use.

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutSetLocalSize(), PetscLayoutSetSize(), PetscLayoutGetSize(), PetscLayoutGetLocalSize(), PetscLayout, PetscLayoutDestroy(),
          PetscLayoutGetRange(), PetscLayoutGetRanges(), PetscLayoutSetBlockSize(), PetscLayoutGetBlockSize(), PetscLayoutSetUp()

@*/
PetscErrorCode  PetscLayoutCreate(MPI_Comm comm,PetscLayout *map)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  ierr = PetscNew(map);CHKERRQ(ierr);

  (*map)->comm   = comm;
  (*map)->bs     = -1;
  (*map)->n      = -1;
  (*map)->N      = -1;
  (*map)->range  = 0;
  (*map)->rstart = 0;
  (*map)->rend   = 0;
  (*map)->trstarts = 0;
  PetscFunctionReturn(0);
}

/*@C
     PetscLayoutDestroy - Frees a map object and frees its range if that exists.

    Collective on MPI_Comm

   Input Parameters:
.    map - the PetscLayout

   Level: developer

      The PetscLayout object and methods are intended to be used in the PETSc Vec and Mat implementions; it is
      recommended they not be used in user codes unless you really gain something in their use.

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutSetLocalSize(), PetscLayoutSetSize(), PetscLayoutGetSize(), PetscLayoutGetLocalSize(), PetscLayout, PetscLayoutCreate(),
          PetscLayoutGetRange(), PetscLayoutGetRanges(), PetscLayoutSetBlockSize(), PetscLayoutGetBlockSize(), PetscLayoutSetUp()

@*/
#undef __FUNCT__
#define __FUNCT__ "PetscLayoutDestroy"
PetscErrorCode  PetscLayoutDestroy(PetscLayout *map)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  if (!*map) PetscFunctionReturn(0);
  if (!(*map)->refcnt--) {
    ierr = PetscFree((*map)->range);CHKERRQ(ierr);
    ierr = ISLocalToGlobalMappingDestroy(&(*map)->mapping);CHKERRQ(ierr);
    ierr = PetscFree((*map));CHKERRQ(ierr);
  }
  *map = NULL;
  PetscFunctionReturn(0);
}

/*@C
     PetscLayoutSetUp - given a map where you have set either the global or local
           size sets up the map so that it may be used.

    Collective on MPI_Comm

   Input Parameters:
.    map - pointer to the map

   Level: developer

    Notes: Typical calling sequence
       PetscLayoutCreate(MPI_Comm,PetscLayout *);
       PetscLayoutSetBlockSize(PetscLayout,1);
       PetscLayoutSetSize(PetscLayout,n) or PetscLayoutSetLocalSize(PetscLayout,N); or both
       PetscLayoutSetUp(PetscLayout);
       PetscLayoutGetSize(PetscLayout,PetscInt *);


       If the local size, global size are already set and range exists then this does nothing.

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutSetLocalSize(), PetscLayoutSetSize(), PetscLayoutGetSize(), PetscLayoutGetLocalSize(), PetscLayout, PetscLayoutDestroy(),
          PetscLayoutGetRange(), PetscLayoutGetRanges(), PetscLayoutSetBlockSize(), PetscLayoutGetBlockSize(), PetscLayoutCreate()

@*/
#undef __FUNCT__
#define __FUNCT__ "PetscLayoutSetUp"
PetscErrorCode  PetscLayoutSetUp(PetscLayout map)
{
  PetscMPIInt    rank,size;
  PetscInt       p;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  if ((map->n >= 0) && (map->N >= 0) && (map->range)) PetscFunctionReturn(0);

  ierr = MPI_Comm_size(map->comm, &size);CHKERRQ(ierr);
  ierr = MPI_Comm_rank(map->comm, &rank);CHKERRQ(ierr);
  if (map->n > 0) map->n = map->n/PetscAbs(map->bs);
  if (map->N > 0) map->N = map->N/PetscAbs(map->bs);
  ierr = PetscSplitOwnership(map->comm,&map->n,&map->N);CHKERRQ(ierr);
  map->n = map->n*PetscAbs(map->bs);
  map->N = map->N*PetscAbs(map->bs);
  if (!map->range) {
    ierr = PetscMalloc1(size+1, &map->range);CHKERRQ(ierr);
  }
  ierr = MPI_Allgather(&map->n, 1, MPIU_INT, map->range+1, 1, MPIU_INT, map->comm);CHKERRQ(ierr);

  map->range[0] = 0;
  for (p = 2; p <= size; p++) map->range[p] += map->range[p-1];

  map->rstart = map->range[rank];
  map->rend   = map->range[rank+1];
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscLayoutDuplicate"
/*@C

    PetscLayoutDuplicate - creates a new PetscLayout with the same information as a given one. If the PetscLayout already exists it is destroyed first.

     Collective on PetscLayout

    Input Parameter:
.     in - input PetscLayout to be duplicated

    Output Parameter:
.     out - the copy

   Level: developer

    Notes: PetscLayoutSetUp() does not need to be called on the resulting PetscLayout

.seealso: PetscLayoutCreate(), PetscLayoutDestroy(), PetscLayoutSetUp(), PetscLayoutReference()

@*/
PetscErrorCode  PetscLayoutDuplicate(PetscLayout in,PetscLayout *out)
{
  PetscMPIInt    size;
  PetscErrorCode ierr;
  MPI_Comm       comm = in->comm;

  PetscFunctionBegin;
  ierr = PetscLayoutDestroy(out);CHKERRQ(ierr);
  ierr = PetscLayoutCreate(comm,out);CHKERRQ(ierr);
  ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
  ierr = PetscMemcpy(*out,in,sizeof(struct _n_PetscLayout));CHKERRQ(ierr);
  ierr = PetscMalloc1(size+1,&(*out)->range);CHKERRQ(ierr);
  ierr = PetscMemcpy((*out)->range,in->range,(size+1)*sizeof(PetscInt));CHKERRQ(ierr);

  (*out)->refcnt = 0;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscLayoutReference"
/*@C

    PetscLayoutReference - Causes a PETSc Vec or Mat to share a PetscLayout with one that already exists. Used by Vec/MatDuplicate_XXX()

     Collective on PetscLayout

    Input Parameter:
.     in - input PetscLayout to be copied

    Output Parameter:
.     out - the reference location

   Level: developer

    Notes: PetscLayoutSetUp() does not need to be called on the resulting PetscLayout

    If the out location already contains a PetscLayout it is destroyed

.seealso: PetscLayoutCreate(), PetscLayoutDestroy(), PetscLayoutSetUp(), PetscLayoutDuplicate()

@*/
PetscErrorCode  PetscLayoutReference(PetscLayout in,PetscLayout *out)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  in->refcnt++;
  ierr = PetscLayoutDestroy(out);CHKERRQ(ierr);
  *out = in;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscLayoutSetISLocalToGlobalMapping"
/*@C

    PetscLayoutSetISLocalToGlobalMapping - sets a ISLocalGlobalMapping into a PetscLayout

     Collective on PetscLayout

    Input Parameter:
+     in - input PetscLayout
-     ltog - the local to global mapping


   Level: developer

    Notes: PetscLayoutSetUp() does not need to be called on the resulting PetscLayout

    If the ltog location already contains a PetscLayout it is destroyed

.seealso: PetscLayoutCreate(), PetscLayoutDestroy(), PetscLayoutSetUp(), PetscLayoutDuplicate()

@*/
PetscErrorCode  PetscLayoutSetISLocalToGlobalMapping(PetscLayout in,ISLocalToGlobalMapping ltog)
{
  PetscErrorCode ierr;
  PetscInt       bs;

  PetscFunctionBegin;
  ierr = ISLocalToGlobalMappingGetBlockSize(ltog,&bs);CHKERRQ(ierr);
  if (in->bs > 0 && in->bs != bs) SETERRQ2(in->comm,PETSC_ERR_PLIB,"Blocksize of layout %D must match that of mapping %D",in->bs,bs);
  ierr = PetscObjectReference((PetscObject)ltog);CHKERRQ(ierr);
  ierr = ISLocalToGlobalMappingDestroy(&in->mapping);CHKERRQ(ierr);
  in->mapping = ltog;
  PetscFunctionReturn(0);
}

/*@C
     PetscLayoutSetLocalSize - Sets the local size for a PetscLayout object.

    Collective on PetscLayout

   Input Parameters:
+    map - pointer to the map
-    n - the local size

   Level: developer

    Notes:
       Call this after the call to PetscLayoutCreate()

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutCreate(), PetscLayoutSetSize(), PetscLayoutGetSize(), PetscLayoutGetLocalSize(), PetscLayoutSetUp()
          PetscLayoutGetRange(), PetscLayoutGetRanges(), PetscLayoutSetBlockSize(), PetscLayoutGetBlockSize()

@*/
#undef __FUNCT__
#define __FUNCT__ "PetscLayoutSetLocalSize"
PetscErrorCode  PetscLayoutSetLocalSize(PetscLayout map,PetscInt n)
{
  PetscFunctionBegin;
  if (map->bs > 1 && n % map->bs) SETERRQ2(map->comm,PETSC_ERR_ARG_INCOMP,"Local size %D not compatible with block size %D",n,map->bs);
  map->n = n;
  PetscFunctionReturn(0);
}

/*@C
     PetscLayoutGetLocalSize - Gets the local size for a PetscLayout object.

    Not Collective

   Input Parameters:
.    map - pointer to the map

   Output Parameters:
.    n - the local size

   Level: developer

    Notes:
       Call this after the call to PetscLayoutSetUp()

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutCreate(), PetscLayoutSetSize(), PetscLayoutGetSize(), PetscLayoutGetLocalSize(), PetscLayoutSetUp()
          PetscLayoutGetRange(), PetscLayoutGetRanges(), PetscLayoutSetBlockSize(), PetscLayoutGetBlockSize()

@*/
#undef __FUNCT__
#define __FUNCT__ "PetscLayoutGetLocalSize"
PetscErrorCode  PetscLayoutGetLocalSize(PetscLayout map,PetscInt *n)
{
  PetscFunctionBegin;
  *n = map->n;
  PetscFunctionReturn(0);
}

/*@C
     PetscLayoutSetSize - Sets the global size for a PetscLayout object.

    Logically Collective on PetscLayout

   Input Parameters:
+    map - pointer to the map
-    n - the global size

   Level: developer

    Notes:
       Call this after the call to PetscLayoutCreate()

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutCreate(), PetscLayoutSetLocalSize(), PetscLayoutGetLocalSize(), PetscLayoutGetSize(), PetscLayoutSetUp()
          PetscLayoutGetRange(), PetscLayoutGetRanges(), PetscLayoutSetBlockSize(), PetscLayoutGetBlockSize()

@*/
#undef __FUNCT__
#define __FUNCT__ "PetscLayoutSetSize"
PetscErrorCode  PetscLayoutSetSize(PetscLayout map,PetscInt n)
{
  PetscFunctionBegin;
  map->N = n;
  PetscFunctionReturn(0);
}

/*@C
     PetscLayoutGetSize - Gets the global size for a PetscLayout object.

    Not Collective

   Input Parameters:
.    map - pointer to the map

   Output Parameters:
.    n - the global size

   Level: developer

    Notes:
       Call this after the call to PetscLayoutSetUp()

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutCreate(), PetscLayoutSetLocalSize(), PetscLayoutGetLocalSize(), PetscLayoutSetSize(), PetscLayoutSetUp()
          PetscLayoutGetRange(), PetscLayoutGetRanges(), PetscLayoutSetBlockSize(), PetscLayoutGetBlockSize()

@*/
#undef __FUNCT__
#define __FUNCT__ "PetscLayoutGetSize"
PetscErrorCode  PetscLayoutGetSize(PetscLayout map,PetscInt *n)
{
  PetscFunctionBegin;
  *n = map->N;
  PetscFunctionReturn(0);
}

/*@C
     PetscLayoutSetBlockSize - Sets the block size for a PetscLayout object.

    Logically Collective on PetscLayout

   Input Parameters:
+    map - pointer to the map
-    bs - the size

   Level: developer

    Notes:
       Call this after the call to PetscLayoutCreate()

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutCreate(), PetscLayoutSetLocalSize(), PetscLayoutGetLocalSize(), PetscLayoutGetBlockSize(),
          PetscLayoutGetRange(), PetscLayoutGetRanges(), PetscLayoutSetSize(), PetscLayoutGetSize(), PetscLayoutSetUp()

@*/
#undef __FUNCT__
#define __FUNCT__ "PetscLayoutSetBlockSize"
PetscErrorCode  PetscLayoutSetBlockSize(PetscLayout map,PetscInt bs)
{
  PetscFunctionBegin;
  if (bs < 0) PetscFunctionReturn(0);
  if (map->n > 0 && map->n % bs) SETERRQ2(map->comm,PETSC_ERR_ARG_INCOMP,"Local size %D not compatible with block size %D",map->n,bs);
  if (map->range && map->bs > 0 && map->bs != bs) SETERRQ2(map->comm,PETSC_ERR_ARG_INCOMP,"Cannot change block size %D to %D",map->bs,bs);
  if (map->mapping) {
    PetscInt       lbs;
    PetscErrorCode ierr;

    ierr = ISLocalToGlobalMappingGetBlockSize(map->mapping,&lbs);CHKERRQ(ierr);
    if (lbs != bs) SETERRQ2(map->comm,PETSC_ERR_PLIB,"Blocksize of localtoglobalmapping %D must match that of layout %D",lbs,bs);
  }
  map->bs = bs;
  PetscFunctionReturn(0);
}

/*@C
     PetscLayoutGetBlockSize - Gets the block size for a PetscLayout object.

    Not Collective

   Input Parameters:
.    map - pointer to the map

   Output Parameters:
.    bs - the size

   Level: developer

    Notes:
       Call this after the call to PetscLayoutSetUp()

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutCreate(), PetscLayoutSetLocalSize(), PetscLayoutGetLocalSize(), PetscLayoutSetSize(), PetscLayoutSetUp()
          PetscLayoutGetRange(), PetscLayoutGetRanges(), PetscLayoutSetBlockSize(), PetscLayoutGetSize()

@*/
#undef __FUNCT__
#define __FUNCT__ "PetscLayoutGetBlockSize"
PetscErrorCode  PetscLayoutGetBlockSize(PetscLayout map,PetscInt *bs)
{
  PetscFunctionBegin;
  *bs = PetscAbs(map->bs);
  PetscFunctionReturn(0);
}


/*@C
     PetscLayoutGetRange - gets the range of values owned by this process

    Not Collective

   Input Parameters:
.    map - pointer to the map

   Output Parameters:
+    rstart - first index owned by this process
-    rend - one more than the last index owned by this process

   Level: developer

    Notes:
       Call this after the call to PetscLayoutSetUp()

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutCreate(), PetscLayoutSetLocalSize(), PetscLayoutGetLocalSize(), PetscLayoutSetSize(),
          PetscLayoutGetSize(), PetscLayoutGetRanges(), PetscLayoutSetBlockSize(), PetscLayoutGetSize(), PetscLayoutSetUp()

@*/
#undef __FUNCT__
#define __FUNCT__ "PetscLayoutGetRange"
PetscErrorCode  PetscLayoutGetRange(PetscLayout map,PetscInt *rstart,PetscInt *rend)
{
  PetscFunctionBegin;
  if (rstart) *rstart = map->rstart;
  if (rend)   *rend   = map->rend;
  PetscFunctionReturn(0);
}

/*@C
     PetscLayoutGetRanges - gets the range of values owned by all processes

    Not Collective

   Input Parameters:
.    map - pointer to the map

   Output Parameters:
.    range - start of each processors range of indices (the final entry is one more then the
             last index on the last process)

   Level: developer

    Notes:
       Call this after the call to PetscLayoutSetUp()

    Fortran Notes:
      Not available from Fortran

.seealso: PetscLayoutCreate(), PetscLayoutSetLocalSize(), PetscLayoutGetLocalSize(), PetscLayoutSetSize(),
          PetscLayoutGetSize(), PetscLayoutGetRange(), PetscLayoutSetBlockSize(), PetscLayoutGetSize(), PetscLayoutSetUp()

@*/
#undef __FUNCT__
#define __FUNCT__ "PetscLayoutGetRanges"
PetscErrorCode  PetscLayoutGetRanges(PetscLayout map,const PetscInt *range[])
{
  PetscFunctionBegin;
  *range = map->range;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscSFSetGraphLayout"
/*@C
   PetscSFSetGraphLayout - Set a parallel star forest via global indices and a PetscLayout

   Collective

   Input Arguments:
+  sf - star forest
.  layout - PetscLayout defining the global space
.  nleaves - number of leaf vertices on the current process, each of these references a root on any process
.  ilocal - locations of leaves in leafdata buffers, pass NULL for contiguous storage
-  iremote - remote locations of root vertices for each leaf on the current process

   Level: intermediate

.seealso: PetscSFCreate(), PetscSFView(), PetscSFSetGraph(), PetscSFGetGraph()
@*/
PetscErrorCode PetscSFSetGraphLayout(PetscSF sf,PetscLayout layout,PetscInt nleaves,const PetscInt *ilocal,PetscCopyMode localmode,const PetscInt *iremote)
{
  PetscErrorCode ierr;
  PetscInt       i,nroots;
  PetscSFNode    *remote;

  PetscFunctionBegin;
  ierr = PetscLayoutGetLocalSize(layout,&nroots);CHKERRQ(ierr);
  ierr = PetscMalloc1(nleaves,&remote);CHKERRQ(ierr);
  for (i=0; i<nleaves; i++) {
    PetscInt owner = -1;
    ierr = PetscLayoutFindOwner(layout,iremote[i],&owner);CHKERRQ(ierr);
    remote[i].rank  = owner;
    remote[i].index = iremote[i] - layout->range[owner];
  }
  ierr = PetscSFSetGraph(sf,nroots,nleaves,ilocal,localmode,remote,PETSC_OWN_POINTER);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}