ctx

Optional pointer to a caller-supplied context or other data type. This pointer will be passed as the ctx argument to any caller-supplied routines, such as the one supplied as the inspect argument. A value of NULL can be passed for this argument.

input_type

Input type indicator describing the input source to use, either a dequeue context or a caller-supplied routine. There are only two valid values: MTA_DECODE_DQ, MTA_DECODE_PROC.

input

For input_type=MTA_DECODE_DQ, input must be a pointer to a dequeue context created by mtaDequeueStart().

For input_type=MTA_DECODE_PROC, input must be the address of a routine of type mta_decode_read_t.

output_type

Optional output type indicator describing the output destination to use, either an enqueue context or a caller-supplied routine. Valid values are: 0, MTA_DECODE_NQ, MTA_DECODE_PROC. When a value of 0 is supplied, the output argument is ignored.

output

For output_type=MTA_DECODE_NQ, output must be a pointer to an enqueue context created with mtaEnqueueStart().

For output_type=MTA_DECODE_PROC, output must be the address of a routine to type mta_decode_write_t. This argument is ignored when a value of 0 is supplied for output_type.

inspect

The address of an inspection routine of type mta_decode_inspect_t.

item_code

An optional list of item codes. The list must be terminated with an integer argument with value 0.