Handling an Incompletely Processed READ

A READ_LIST request can complete prematurely for either of the following reasons:

A request could time out before completion.
A request could require more buffer space than you provided.

When a READ_LIST request ends before returning all the information, IXLLIST:

Sets the IXLLIST return code to IXLRETCODEWARNING and the reason code to:
- IXLRSNCODETIMEOUT if the processing timed out
- IXLRSNCODEBUFFERFULL if the buffer was too small to hold all the output
- IXLRSNCODEBADBUFSIZE if the buffer was empty but still too small to hold the first list entry being read.
Returns in the LAALCTL field of the answer area, the complete set of list entry controls for the next list entry to be scanned.

To continue scanning the list, reissue the READ_LIST request with the ENTRYID keyword specifying the entry ID from the returned list entry controls for the next list entry to be scanned.

Be sure to process the data you received on the last request before reissuing the request. Continue reissuing the request until the return code indicates that all processing has completed.

If the request ended prematurely because the buffer was too small to hold the first entry to be read (for instance, your buffer is 4096 bytes but the data entry information is 65536 bytes), determine the size of the data entry for the list entry that caused the failure by checking the list entry control information returned in LAALCTL (mapped by the IXLYLCTL macro.) Note that the LAALCTL field is valid only when the request ended prematurely because the buffer could not hold all the requested information.

You must know the data element size to make this calculation because the list entry controls only indicate the number of data elements, not their size. If the buffer is too small to hold the information associated with the failing list entry, reissue the READ_LIST request with a buffer at least the size of the failing list entry's data entry.