2:  #include <petsc/private/isimpl.h>

  4: PetscFunctionList ISList              = NULL;
  5: PetscBool         ISRegisterAllCalled = PETSC_FALSE;

  7: /*@
  8:    ISCreate - Creates an index set object.

 10:    Collective

 12:    Input Parameters:
 13: .  comm - the MPI communicator

 15:    Output Parameter:
 16: .  is - the new index set

 18:    Notes:
 19:    When the communicator is not MPI_COMM_SELF, the operations on IS are NOT
 20:    conceptually the same as MPI_Group operations. The IS are then
 21:    distributed sets of indices and thus certain operations on them are
 22:    collective.

 24:    Level: beginner


 27: .seealso: ISCreateGeneral(), ISCreateStride(), ISCreateBlock(), ISAllGather()
 28: @*/
 29: PetscErrorCode  ISCreate(MPI_Comm comm,IS *is)
 30: {

 35:   ISInitializePackage();

 37:   PetscHeaderCreate(*is,IS_CLASSID,"IS","Index Set","IS",comm,ISDestroy,ISView);
 38:   PetscLayoutCreate(comm, &(*is)->map);
 39:   return(0);
 40: }

 42: /*@C
 43:   ISSetType - Builds a index set, for a particular implementation.

 45:   Collective on IS

 47:   Input Parameters:
 48: + is    - The index set object
 49: - method - The name of the index set type

 51:   Options Database Key:
 52: . -is_type <type> - Sets the index set type; use -help for a list of available types

 54:   Notes:
 55:   See "petsc/include/petscis.h" for available istor types (for instance, ISGENERAL, ISSTRIDE, or ISBLOCK).

 57:   Use ISDuplicate() to make a duplicate

 59:   Level: intermediate


 62: .seealso: ISGetType(), ISCreate()
 63: @*/
 64: PetscErrorCode  ISSetType(IS is, ISType method)
 65: {
 66:   PetscErrorCode (*r)(IS);
 67:   PetscBool      match;

 72:   PetscObjectTypeCompare((PetscObject) is, method, &match);
 73:   if (match) return(0);

 75:   ISRegisterAll();
 76:   PetscFunctionListFind(ISList,method,&r);
 77:   if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown IS type: %s", method);
 78:   if (is->ops->destroy) {
 79:     (*is->ops->destroy)(is);
 80:     is->ops->destroy = NULL;
 81:   }
 82:   (*r)(is);
 83:   PetscObjectChangeTypeName((PetscObject)is,method);
 84:   return(0);
 85: }

 87: /*@C
 88:   ISGetType - Gets the index set type name (as a string) from the IS.

 90:   Not Collective

 92:   Input Parameter:
 93: . is  - The index set

 95:   Output Parameter:
 96: . type - The index set type name

 98:   Level: intermediate

100: .seealso: ISSetType(), ISCreate()
101: @*/
102: PetscErrorCode  ISGetType(IS is, ISType *type)
103: {

109:   if (!ISRegisterAllCalled) {
110:     ISRegisterAll();
111:   }
112:   *type = ((PetscObject)is)->type_name;
113:   return(0);
114: }


117: /*--------------------------------------------------------------------------------------------------------------------*/

119: /*@C
120:   ISRegister - Adds a new index set implementation

122:   Not Collective

124:   Input Parameters:
125: + name        - The name of a new user-defined creation routine
126: - create_func - The creation routine itself

128:   Notes:
129:   ISRegister() may be called multiple times to add several user-defined vectors

131:   Sample usage:
132: .vb
133:     ISRegister("my_is_name",  MyISCreate);
134: .ve

136:   Then, your vector type can be chosen with the procedural interface via
137: .vb
138:     ISCreate(MPI_Comm, IS *);
139:     ISSetType(IS,"my_is_name");
140: .ve
141:    or at runtime via the option
142: .vb
143:     -is_type my_is_name
144: .ve

146:   This is no ISSetFromOptions() and the current implementations do not have a way to dynamically determine type, so
147:   dynamic registration of custom IS types will be of limited use to users.

149:   Level: developer

151: .seealso: ISRegisterAll(), ISRegisterDestroy(), ISRegister()

153:   Level: advanced
154: @*/
155: PetscErrorCode  ISRegister(const char sname[], PetscErrorCode (*function)(IS))
156: {

160:   ISInitializePackage();
161:   PetscFunctionListAdd(&ISList,sname,function);
162:   return(0);
163: }