1: #include <petsc/private/partitionerimpl.h>

  3: typedef struct {
  4:   PetscInt unused;
  5: } PetscPartitioner_Gather;

  7: static PetscErrorCode PetscPartitionerDestroy_Gather(PetscPartitioner part)
  8: {
  9:   PetscFunctionBegin;
 10:   PetscCall(PetscFree(part->data));
 11:   PetscFunctionReturn(PETSC_SUCCESS);
 12: }

 14: static PetscErrorCode PetscPartitionerPartition_Gather(PetscPartitioner part, PetscInt nparts, PetscInt numVertices, PetscInt start[], PetscInt adjacency[], PetscSection vertSection, PetscSection edgeSection, PetscSection targetSection, PetscSection partSection, IS *partition)
 15: {
 16:   PetscFunctionBegin;
 17:   PetscCall(ISCreateStride(PETSC_COMM_SELF, numVertices, 0, 1, partition));
 18:   PetscCall(PetscSectionSetDof(partSection, 0, numVertices));
 19:   for (PetscInt np = 1; np < nparts; ++np) PetscCall(PetscSectionSetDof(partSection, np, 0));
 20:   PetscFunctionReturn(PETSC_SUCCESS);
 21: }

 23: static PetscErrorCode PetscPartitionerInitialize_Gather(PetscPartitioner part)
 24: {
 25:   PetscFunctionBegin;
 26:   part->noGraph        = PETSC_TRUE;
 27:   part->ops->destroy   = PetscPartitionerDestroy_Gather;
 28:   part->ops->partition = PetscPartitionerPartition_Gather;
 29:   PetscFunctionReturn(PETSC_SUCCESS);
 30: }

 32: /*MC
 33:   PETSCPARTITIONERGATHER = "gather" - A PetscPartitioner object

 35:   Level: intermediate

 37: .seealso: `PetscPartitionerType`, `PetscPartitionerCreate()`, `PetscPartitionerSetType()`
 38: M*/

 40: PETSC_EXTERN PetscErrorCode PetscPartitionerCreate_Gather(PetscPartitioner part)
 41: {
 42:   PetscPartitioner_Gather *p;

 44:   PetscFunctionBegin;
 46:   PetscCall(PetscNew(&p));
 47:   part->data = p;

 49:   PetscCall(PetscPartitionerInitialize_Gather(part));
 50:   PetscFunctionReturn(PETSC_SUCCESS);
 51: }