/*@C
DMCompositeGetLocalISs - Gets index sets for each component of a composite local vector
Not Collective
Input Arguments:
. dm - composite DM
Output Arguments:
. is - array of serial index sets for each each component of the DMComposite
Level: intermediate
Notes:
At present, a composite local vector does not normally exist. This function is used to provide index sets for
MatGetLocalSubMatrix(). In the future, the scatters for each entry in the DMComposite may be be merged into a single
scatter to a composite local vector. The user should not typically need to know which is being done.
To get the composite global indices at all local points (including ghosts), use DMCompositeGetISLocalToGlobalMappings().
To get index sets for pieces of the composite global vector, use DMCompositeGetGlobalISs().
Each returned IS should be destroyed with ISDestroy(), the array should be freed with PetscFree().
.seealso: DMCompositeGetGlobalISs(), DMCompositeGetISLocalToGlobalMappings(), MatGetLocalSubMatrix(), MatCreateLocalRef()
@*/
PetscErrorCode DMCompositeGetLocalISs(DM dm,IS **is)
{
PetscErrorCode ierr;
DM_Composite *com = (DM_Composite*)dm->data;
struct DMCompositeLink *link;
PetscInt cnt,start;
PetscFunctionBegin;
PetscValidHeaderSpecific(dm,DM_CLASSID,1);
PetscValidPointer(is,2);
ierr = PetscMalloc(com->nmine*sizeof(IS),is);CHKERRQ(ierr);
for (cnt=0,start=0,link=com->next; link; start+=link->nlocal,cnt++,link=link->next) {
PetscInt bs;
ierr = ISCreateStride(PETSC_COMM_SELF,link->nlocal,start,1,&(*is)[cnt]);CHKERRQ(ierr);
ierr = DMGetBlockSize(link->dm,&bs);CHKERRQ(ierr);
ierr = ISSetBlockSize((*is)[cnt],bs);CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
static PetscErrorCode VecSetUp_NestIS_Private(Vec V,PetscInt nb,IS is[])
{
Vec_Nest *ctx = (Vec_Nest*)V->data;
PetscInt i,offset,m,n,M,N;
PetscErrorCode ierr;
PetscFunctionBegin;
if (is) { /* Do some consistency checks and reference the is */
offset = V->map->rstart;
for (i=0; i<ctx->nb; i++) {
ierr = ISGetSize(is[i],&M);CHKERRQ(ierr);
ierr = VecGetSize(ctx->v[i],&N);CHKERRQ(ierr);
if (M != N) SETERRQ3(PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_INCOMP,"In slot %D, IS of size %D is not compatible with Vec of size %D",i,M,N);
ierr = ISGetLocalSize(is[i],&m);CHKERRQ(ierr);
ierr = VecGetLocalSize(ctx->v[i],&n);CHKERRQ(ierr);
if (m != n) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"In slot %D, IS of local size %D is not compatible with Vec of local size %D",i,m,n);
#if defined(PETSC_USE_DEBUG)
{ /* This test can be expensive */
PetscInt start;
PetscBool contiguous;
ierr = ISContiguousLocal(is[i],offset,offset+n,&start,&contiguous);CHKERRQ(ierr);
if (!contiguous) SETERRQ1(PetscObjectComm((PetscObject)V),PETSC_ERR_SUP,"Index set %D is not contiguous with layout of matching vector",i);
if (start != 0) SETERRQ1(PetscObjectComm((PetscObject)V),PETSC_ERR_SUP,"Index set %D introduces overlap or a hole",i);
}
#endif
ierr = PetscObjectReference((PetscObject)is[i]);CHKERRQ(ierr);
ctx->is[i] = is[i];
offset += n;
}
} else { /* Create a contiguous ISStride for each entry */
offset = V->map->rstart;
for (i=0; i<ctx->nb; i++) {
PetscInt bs;
ierr = VecGetLocalSize(ctx->v[i],&n);CHKERRQ(ierr);
ierr = VecGetBlockSize(ctx->v[i],&bs);CHKERRQ(ierr);
ierr = ISCreateStride(((PetscObject)ctx->v[i])->comm,n,offset,1,&ctx->is[i]);CHKERRQ(ierr);
ierr = ISSetBlockSize(ctx->is[i],bs);CHKERRQ(ierr);
offset += n;
}
}
PetscFunctionReturn(0);
}
static PetscErrorCode VecNestSetSubVec_Private(Vec X,PetscInt idxm,Vec x)
{
Vec_Nest *bx = (Vec_Nest*)X->data;
PetscInt i,offset=0,n=0,bs;
IS is;
PetscErrorCode ierr;
PetscBool issame = PETSC_FALSE;
PetscInt N=0;
/* check if idxm < bx->nb */
if (idxm >= bx->nb) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Out of range index value %D maximum %D",idxm,bx->nb);
PetscFunctionBegin;
ierr = VecDestroy(&bx->v[idxm]);CHKERRQ(ierr); /* destroy the existing vector */
ierr = VecDuplicate(x,&bx->v[idxm]);CHKERRQ(ierr); /* duplicate the layout of given vector */
ierr = VecCopy(x,bx->v[idxm]);CHKERRQ(ierr); /* copy the contents of the given vector */
/* check if we need to update the IS for the block */
offset = X->map->rstart;
for (i=0; i<idxm; i++) {
n=0;
ierr = VecGetLocalSize(bx->v[i],&n);CHKERRQ(ierr);
offset += n;
}
/* get the local size and block size */
ierr = VecGetLocalSize(x,&n);CHKERRQ(ierr);
ierr = VecGetBlockSize(x,&bs);CHKERRQ(ierr);
/* create the new IS */
ierr = ISCreateStride(PetscObjectComm((PetscObject)x),n,offset,1,&is);CHKERRQ(ierr);
ierr = ISSetBlockSize(is,bs);CHKERRQ(ierr);
/* check if they are equal */
ierr = ISEqual(is,bx->is[idxm],&issame);CHKERRQ(ierr);
if (!issame) {
/* The IS of given vector has a different layout compared to the existing block vector.
Destroy the existing reference and update the IS. */
ierr = ISDestroy(&bx->is[idxm]);CHKERRQ(ierr);
ierr = ISDuplicate(is,&bx->is[idxm]);CHKERRQ(ierr);
ierr = ISCopy(is,bx->is[idxm]);CHKERRQ(ierr);
offset += n;
/* Since the current IS[idxm] changed, we need to update all the subsequent IS */
for (i=idxm+1; i<bx->nb; i++) {
/* get the local size and block size */
ierr = VecGetLocalSize(bx->v[i],&n);CHKERRQ(ierr);
ierr = VecGetBlockSize(bx->v[i],&bs);CHKERRQ(ierr);
/* destroy the old and create the new IS */
ierr = ISDestroy(&bx->is[i]);CHKERRQ(ierr);
ierr = ISCreateStride(((PetscObject)bx->v[i])->comm,n,offset,1,&bx->is[i]);CHKERRQ(ierr);
ierr = ISSetBlockSize(bx->is[i],bs);CHKERRQ(ierr);
offset += n;
}
n=0;
ierr = VecSize_Nest_Recursive(X,PETSC_TRUE,&N);CHKERRQ(ierr);
ierr = VecSize_Nest_Recursive(X,PETSC_FALSE,&n);CHKERRQ(ierr);
ierr = PetscLayoutSetSize(X->map,N);CHKERRQ(ierr);
ierr = PetscLayoutSetLocalSize(X->map,n);CHKERRQ(ierr);
}
ierr = ISDestroy(&is);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
void PETSC_STDCALL issetblocksize_(IS is,PetscInt *bs, int *__ierr ){
*__ierr = ISSetBlockSize(
(IS)PetscToPointer((is) ),*bs);
}
