These functions read/write data to/from the buffer in the ``external32'' data
format specified in Section External Data Representation: ``external32''
, and calculate the size needed
for packing. Their first arguments specify the data format, for future
extensibility, but
currently
the only valid value of the datarep
argument is ``external32.''
Advice to users.
These functions could be used, for example, to send typed data in a portable
format from one MPI implementation to another.
( End of advice to users.)
The buffer will contain exactly the packed data, without headers. MPI_BYTE should be used to send and receive data that is packed using MPI_PACK_EXTERNAL.
Rationale.
MPI_PACK_EXTERNAL specifies that there is no header on the message
and further
specifies the exact format of the data. Since MPI_PACK may (and is
allowed
to) use a header, the datatype MPI_PACKED cannot be used for data
packed with
MPI_PACK_EXTERNAL.
( End of rationale.)
| MPI_PACK_EXTERNAL(datarep, inbuf, incount, datatype, outbuf, outsize, position ) | |
| IN datarep | data representation (string) |
| IN inbuf | input buffer start (choice) |
| IN incount | number of input data items (integer) |
| IN datatype | datatype of each input data item (handle) |
| OUT outbuf | output buffer start (choice) |
| IN outsize | output buffer size, in bytes (integer) |
| INOUT position | current position in buffer, in bytes (integer) |
int MPI_Pack_external(char *datarep, void *inbuf, int incount, MPI_Datatype datatype, void *outbuf, MPI_Aint outsize, MPI_Aint *position)
MPI_PACK_EXTERNAL(DATAREP, INBUF, INCOUNT, DATATYPE, OUTBUF, OUTSIZE, POSITION, IERROR)
INTEGER INCOUNT, DATATYPE, IERROR
INTEGER(KIND=MPI_ADDRESS_KIND) OUTSIZE, POSITION
CHARACTER*(*) DATAREP
<type> INBUF(*), OUTBUF(*)
void MPI::Datatype::Pack_external(const char* datarep, const void* inbuf, int incount, void* outbuf, MPI::Aint outsize, MPI::Aint& position) const
| MPI_UNPACK_EXTERNAL(datarep, inbuf, insize, position, outbuf, outsize, position ) | |
| IN datarep | data representation (string) |
| IN inbuf | input buffer start (choice) |
| IN insize | input buffer size, in bytes (integer) |
| INOUT position | current position in buffer, in bytes (integer) |
| OUT outbuf | output buffer start (choice) |
| IN outcount | number of output data items (integer) |
| IN datatype | datatype of output data item (handle) |
MPI_UNPACK_EXTERNAL(DATAREP, INBUF, INSIZE, POSITION, OUTBUF, OUTCOUNT, DATATYPE, IERROR)
INTEGER OUTCOUNT, DATATYPE, IERROR
INTEGER(KIND=MPI_ADDRESS_KIND) INSIZE, POSITION
CHARACTER*(*) DATAREP
<type> INBUF(*), OUTBUF(*)
void MPI::Datatype::Unpack_external(const char* datarep, const void* inbuf, MPI::Aint insize, MPI::Aint& position, void* outbuf, int outcount) const
| MPI_PACK_EXTERNAL_SIZE( datarep, incount, datatype, size ) | |
| IN datarep | data representation (string) |
| IN incount | number of input data items (integer) |
| IN datatype | datatype of each input data item (handle) |
| OUT size | output buffer size, in bytes (integer) |
int MPI_Pack_external_size(char *datarep, int incount, MPI_Datatype datatype, MPI_Aint *size)
MPI_PACK_EXTERNAL_SIZE(DATAREP, INCOUNT, DATATYPE, SIZE, IERROR)
INTEGER INCOUNT, DATATYPE, IERROR
INTEGER(KIND=MPI_ADDRESS_KIND) SIZE
CHARACTER*(*) DATAREP
MPI::Aint MPI::Datatype::Pack_external_size(const char* datarep, int incount) const