MI Portal Support Functions

MI Portal is an agent program that issues MI instructions in behalf of client. It isn't a compiler and some functions enabled by an MI or HLL compiler cannot be achieved via MI Portal without extra support; for example, defining a uninitialized pointer, or copy client-side data into storage addressed by a space pointer. For this reason, MI Portal instroduced a bundle of support function. They are:

• Release an Allocated MI Pointer (RELEASE_PTR)
• Read Data from Address (READ_FROM_ADDR)
• Write Data to Address (WRITE_TO_ADDR)
• Allocated an New null Pointer (NEW_PTR)

Release an Allocated MI Pointer (RELEASE_PTR)

Prototype

Index     Operand 1
hex 0006  Pointer ID

• Operand 1: 16-byte Pointer ID of the MI pointer to release

Description: This function allows client to release an MI pointer preiously allocated as being requested by the client.

MI Portal caches MI pointers on behalf of a single client at the server side (in an indepedent index object). Although the upper limit of number pointers can create is very high, it's still reasonable to release an MI pointer when it wouldn't be referred to anymore.

Remarks:

MI Portal stores MI pointers requested by a client in a max 1 TB index object. The entry length of the index object is 32 bytes, 16 bytes the key value and 16 bytes for an MI pointer value. Therefore, MI Portal could preserved approximately 34,359,738,368 MI pointers for a single client.

Read Data from Address (READ_FROM_ADDR)

Prototype

Index     Operand 1     Operand 2       Operand 3
hex 0008  Pointer ID    Buffer          Number of bytes

• Operand 1: ID of the space pointer addressing source storage
• Operand 2: Buffer
• Operand 3: Number of bytes to read from storage into operand 2

Description: This function allows client to read specified bytes of data addressed by a space pointer from an IBM i server.

Write Data to Address (WRITE_TO_ADDR)

Prototype

Index     Operand 1     Operand 2       Operand 3
hex 0009  Pointer ID    Buffer          Number of bytes

• Operand 1: ID of the space pointer addressing target storage
• Operand 2: Buffer
• Operand 3: Number of bytes to write to storage addressed by operand 1

Description: This function writes specified bytes of client data into the storage addressed by operand 1 at an IBM i server.

Allocated an New null Pointer (NEW_PTR)

Prototype

Index     Operand 1
hex 000F  Pointer ID

• Operand 1: 16-byte Pointer ID of the newly allocated MI pointer

Description: This function allocates a new null MI pointer at the server side and returns the 16-byte pointer ID of the pointer.

NEW_PTR allows client to instantiate a null pointer at the server side.