Overview

Purpose: The MQDXP structure is a parameter that the queue manager passes to the data-conversion exit when the exit is invoked to convert the message data as part of the processing of the MQGET call. See the description of the MQCONVX call for details of the data conversion exit.

Character set and encoding: Character data in MQDXP is in the character set of the local queue manager; this is given by the CodedCharSetId queue manager attribute. Numeric data in MQDXP is in the native machine encoding; this is given by ENNAT.

Usage: Only the DXLEN, DXCC, DXREA and DXRES fields in MQDXP may be changed by the exit; changes to other fields are ignored. However, the DXLEN field cannot be changed if the message being converted is a segment that contains only part of a logical message.

When control returns to the queue manager from the exit, the queue manager checks the values returned in MQDXP. If the values returned are not valid, the queue manager continues processing as though the exit had returned XRFAIL in DXRES; however, the queue manager ignores the values of the DXCC and DXREA fields returned by the exit in this case, and uses instead the values those fields had on input to the exit. The following values in MQDXP cause this processing to occur:

• DXRES field not XROK and not XRFAIL

• DXCC field not CCOK and not CCWARN

• DXLEN field less than zero, or DXLEN field changed when the message being converted is a segment that contains only part of a logical message.