Pointer

class brainstem.stem.Pointer(module, index)[source]

Access the reflex scratchpad from a host computer.

The Pointers access the pad which is a shared memory area on a BrainStem module. The interface allows the use of the brainstem scratchpad from the host, and provides a mechanism for allowing the host application and brainstem relexes to communicate.

The Pointer allows access to the pad in a similar manner as a file pointer accesses the underlying file. The cursor position can be set via setOffset. A read of a character short or int can be made from that cursor position. In addition the mode of the pointer can be set so that the cursor position automatically increments or set so that it does not this allows for multiple reads of the same pad value, or reads of multi-record values, via and incrementing pointer.

Useful Constants:
  • POINTER_MODE_STATIC (0)

  • POINTER_MODE_INCREMENT (1)

getChar()[source]

Get the value of the pad at the current cursor position.

If the mode is increment this read will increment the cursor by 1 byte.

Returns

Result object, containing NO_ERROR and the value

or a non zero Error code.

Return type

Result

getInt()[source]

Get the value of the pad at the current cursor position.

If the mode is increment this read will increment the cursor by 4 bytes.

Returns

Result object, containing NO_ERROR and the value

or a non zero Error code.

Return type

Result

getMode()[source]

Get the pointer offset for this pointer.

Returns

Result object, containing NO_ERROR and the current mode

or a non zero Error code.

Return type

Result

getOffset()[source]

Get the pointer offset for this pointer.

Returns

Result object, containing NO_ERROR and the current offset

or a non zero Error code.

Return type

Result

getShort()[source]

Get the value of the pad at the current cursor position.

If the mode is increment this read will increment the cursor by 2 bytes.

Returns

Result object, containing NO_ERROR and the value

or a non zero Error code.

Return type

Result

getTransferStore()[source]

Get the open slot handle for this pointer.

Returns

Result object, containing NO_ERROR and the handle

or a non zero Error code.

Return type

Result

setChar(charVal)[source]

Set a value at the current cursor position within the pad.

If the mode is increment this write will increment the cursor by 1 byte.

Param:
charVal (char): The value to set into the pad at the current

pointer position.

Returns

Return NO_ERROR on success, or one of the common sets of return error codes on failure.

Return type

Result.error

setInt(intVal)[source]

Set a value at the current cursor position within the pad.

If the mode is increment this write will increment the cursor by 4 bytes.

Param:
short (short): The value to set into the pad at the current

pointer position.

Returns

Return NO_ERROR on success, or one of the common sets of return error codes on failure.

Return type

Result.error

setMode(mode)[source]

Set the pointer offset for this pointer.

Param:

mode (char): The mode. One of POINTER_MODE_STATIC or POINTER_MODE_INCREMENT

Returns

Return NO_ERROR on success, or one of the common sets of return error codes on failure.

Return type

Result.error

setOffset(offset)[source]

Set the pointer offset for this pointer.

Param:

offset (char): The byte offset within the pad (0 - 255).

Returns

Return NO_ERROR on success, or one of the common sets of return error codes on failure.

Return type

Result.error

setShort(shortVal)[source]

Set a value at the current cursor position within the pad.

If the mode is increment this write will increment the cursor by 2 bytes.

Param:
shortVal (short): The value to set into the pad at the current

pointer position.

Returns

Return NO_ERROR on success, or one of the common sets of return error codes on failure.

Return type

Result.error

setTransferStore(handle)[source]

Set store slot handle for the pad to store and store to pad transfer.

Param:

handle (char): The handle. Open slot handle id.

Returns

Return NO_ERROR on success, or one of the common sets of return error codes on failure.

Return type

Result.error

transferToStore(length)[source]

Transfer length bytes from the pad cursor position into the open store handle.

If the mode is increment the transfer will increment the cursor by length bytes.

Returns

Return NO_ERROR on success, or one of the common sets of return error codes on failure.

Return type

Result.error

transterFromStore(length)[source]

Transfer length bytes from the open store handle to the cursor position in the pad.

If the mode is increment the transfer will increment the cursor by length bytes.

Returns

Return NO_ERROR on success, or one of the common sets of return error codes on failure.

Return type

Result.error