Expand Management Programming Manual

SPI PROGRAMMING CONSIDERATIONS FOR THE EXPAND SUBSYSTEM
Receiving and Decoding the Response Buffer
RECEIVING AND DECODING THE RESPONSE BUFFER
The following programming considerations apply when an applica-
tion receives and decodes the response buffer for an EXPAND
response.
In responses to EXPAND commands that operate on objects, a
response record always contains response information for the
operation of the command on a single object.
The EXPAND subsystem supports multiple response records in a
single reply message. The number of response records returned in
one reply message is controlled by the value of the header token
ZSPI-TKN-MAXRESP in the command.
If multiple response records are to be returned in one reply
message (or if the command is PROBE or is INFO with ZEXP-TKN-
INFO-NCP-OPT specified), the recommended buffer size in bytes for
the response is a predefined value with the symbolic name ZEXP-
VAL-MAXBUFLEN. If a single response record is to be returned in
each reply message (for commands other than PROBE and INFO with
ZEXP-TKN-INFO-NCP-OPT), the recommended buffer size in bytes for
the response is the predefined value ZEXP-VAL-BUFLEN.
The EXPAND subsystem does support multiple response records over
multiple messages (continuation) by returning a context token
when a response is continued.
The EXPAND subsystem also supports the use of the token ZSPI-
TKN-RESPONSE-TYPE, which allows an application to specify, in a
command operating on multiple objects, which kinds of response
records should be returned--one for every object, or only those
for objects on which errors or warnings occurred. If no value is
specified for this token, the EXPAND subsystem returns a response
record for every object.
Note that for commands such as the INFO command whose purpose
is to return information, using ZSPI-TKN-RESPONSE-TYPE to request
the return of only those response records for objects on which
errors or warnings occurred can result in no information being
returned.
The responses to the INFO, PROBE, RESETSTATS, STATISTICS, and
STATUS commands each contain an extensible structured token that
returns the requested information.
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