Actual source code: isreg.c


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

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

  7: /*@
  8:    ISCreate - Creates an index set object. `IS` are objects used to do efficient indexing into other data structures such as `Vec` and `Mat`

 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

 26: .seealso: [](sec_scatter), `IS`, `ISType()`, `ISSetType()`, `ISCreateGeneral()`, `ISCreateStride()`, `ISCreateBlock()`, `ISAllGather()`
 27: @*/
 28: PetscErrorCode ISCreate(MPI_Comm comm, IS *is)
 29: {
 31:   ISInitializePackage();

 33:   PetscHeaderCreate(*is, IS_CLASSID, "IS", "Index Set", "IS", comm, ISDestroy, ISView);
 34:   PetscLayoutCreate(comm, &(*is)->map);
 35:   return 0;
 36: }

 38: /*@C
 39:   ISSetType - Builds a index set, for a particular `ISType`

 41:   Collective

 43:   Input Parameters:
 44: + is    - The index set object
 45: - method - The name of the index set type

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

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

 53:   Use `ISDuplicate()` to make a duplicate

 55:   Level: intermediate

 57: .seealso: [](sec_scatter), `IS`, `ISGENERAL`, `ISBLOCK`, `ISGetType()`, `ISCreate()`
 58: @*/
 59: PetscErrorCode ISSetType(IS is, ISType method)
 60: {
 61:   PetscErrorCode (*r)(IS);
 62:   PetscBool match;

 65:   PetscObjectTypeCompare((PetscObject)is, method, &match);
 66:   if (match) return 0;

 68:   ISRegisterAll();
 69:   PetscFunctionListFind(ISList, method, &r);
 71:   PetscTryTypeMethod(is, destroy);
 72:   is->ops->destroy = NULL;

 74:   (*r)(is);
 75:   PetscObjectChangeTypeName((PetscObject)is, method);
 76:   return 0;
 77: }

 79: /*@C
 80:   ISGetType - Gets the index set type name, `ISType`, (as a string) from the `IS`.

 82:   Not Collective

 84:   Input Parameter:
 85: . is  - The index set

 87:   Output Parameter:
 88: . type - The index set type name

 90:   Level: intermediate

 92: .seealso: [](sec_scatter), `IS`, `ISType`, `ISSetType()`, `ISCreate()`
 93: @*/
 94: PetscErrorCode ISGetType(IS is, ISType *type)
 95: {
 98:   if (!ISRegisterAllCalled) ISRegisterAll();
 99:   *type = ((PetscObject)is)->type_name;
100:   return 0;
101: }

103: /*--------------------------------------------------------------------------------------------------------------------*/

105: /*@C
106:   ISRegister - Adds a new index set implementation

108:   Not Collective

110:   Input Parameters:
111: + name        - The name of a new user-defined creation routine
112: - create_func - The creation routine itself

114:   Sample usage:
115: .vb
116:     ISRegister("my_is_name",  MyISCreate);
117: .ve

119:   Then, your vector type can be chosen with the procedural interface via
120: .vb
121:     ISCreate(MPI_Comm, IS *);
122:     ISSetType(IS,"my_is_name");
123: .ve
124:    or at runtime via the option
125: .vb
126:     -is_type my_is_name
127: .ve

129:   Level: developer

131:   Notes:
132:   `ISRegister()` may be called multiple times to add several user-defined vectors

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

137: .seealso: [](sec_scatter), `IS`, `ISType`, `ISSetType()`, `ISRegisterAll()`, `ISRegisterDestroy()`, `ISRegister()`
138: @*/
139: PetscErrorCode ISRegister(const char sname[], PetscErrorCode (*function)(IS))
140: {
141:   ISInitializePackage();
142:   PetscFunctionListAdd(&ISList, sname, function);
143:   return 0;
144: }