IPP> MOD/PRO - ISSUE Do we need to represent "unknown" value or not?

IPP> MOD/PRO - ISSUE Do we need to represent "unknown" value or not?

IPP> MOD/PRO - ISSUE Do we need to represent "unknown" value or not?

Robert Herriot Robert.Herriot at Eng.Sun.COM
Tue Oct 28 16:54:39 EST 1997


Though the issue you raise for unknown values could arise for any type,
not just integers.




> From hastings at cp10.es.xerox.com Mon Oct 27 18:00:42 1997
> 
> Currently the Model document has copied some integer attributes from the Job 
> Montoring MIB where a -2 value indicates that the Printer object does not
> (yet) know what the correct value is, i.e., the value is "unknown".
> 
> The current Model document describes the -2 values as unknown, but the
> allowed range is constrained to 0:MAX:
> 
> Alternatives:
> 
> 1. Specify that the Printer object SHALL not return an attribute when
> the value is "unknown".
> 
> 2. Add "unknown" as an out of band value in the Protocol.
> 
> 3. Clarify that the current out of band value "no-value" may be used
> for when the Printer doesn't know the value.
> 
> 4. Increase the range, so that -2 is a legal value, as in the Job Monitoring
> MIB.
> 
> 
> 
> The attribute so effected are:
> 
> 4.2.16	job-k-octets (integer(0:2**31 - 1))
> 
> This attribute specifies the total size of the document data in K octets,
> i.e., in units of 1024 octets requested to be  processed in the job.  The
> value SHALL be rounded up, so that a job between 1 and 1024 octets SHALL be
> indicated as being 1, 1025 to 2048 SHALL be 2, etc. 
> 
> This value SHALL not include the multiplicative factors contributed by the
> number of copies specified by the "copies" attribute, independent of
> whether the device can process multiple copies without making multiple
> passes over the document data and independent of whether the output is
> collated or not.  Thus the value is independent of the implementation.
> 
> Note:  This attribute and the following two attributes ("job-impressions"
> and "job-media-sheets") are not intended to be counters; they are intended
> to be useful routing and scheduling information if known. For these three
> attributes,  the Printer may try to compute the value if it is not supplied
> in the create request.  Even if the client does supply a value for this
> attribute in the create request, the Printer may choose to change the value
> if the Printer is able to compute a value which is more accurate than the
> client supplied value.  The Printer may be able to determine the correct
> value for this attribute either right at job submission time or at any
> later point in time.  If the value of this attribute is unknown, the
> Printer may choose to respond with a value of '-2' (which signifies
> "unknown") rather than choose to not support the attribute at all. 
> 
> 4.2.17	job-impressions (integer(0:2**31 - 1))
> 
> This attribute specifies the total number of impressions of the document(s)
> being requested by this job to produce. 
> 
> This value SHALL not include the multiplicative factors contributed by the
> number of copies specified by the "copies" attribute, independent of
> whether the device can process multiple copies without making multiple
> passes over the document data and independent of whether the output is
> collated or not.  Thus the value is independent of the implementation.
> 
> 4.2.18	job-media-sheets (integer(0:2**31 - 1))
> 
> This attribute specifies the total number of media sheets to be processed
> for this job. 
> 
> Unlike the "job-k-octets" and the "job-impressions" attributes, this value
> SHALL include the multiplicative factors contributes by the number of
> copies specified by the "copies" attribute
> 
> 4.3.16	job-k-octets-processed (integer(0:2**31 - 1))
> 
> This attribute specifies the number of octets processed in K octets, i.e.,
> in units of 1024 octets.  The value SHALL be rounded up, so that a job
> between 1 and 1024 octets SHALL be indicated as being 1, 1025 to 2048 SHALL
> be 2, etc. 
> For implementations where multiple copies are produced by the interpreter
> with only a single pass over the data, the final value SHALL be equal to
> the value of the "job-k-octets" attribute.  For implementations where
> multiple copies are produced by the interpreter by processing the data for
> each copy, the final value SHALL be a multiple of the value of the
> "job-k-octets" attribute.
> 
> Note: This attribute and the following two attributes
> ("job-impressions-completed" and "job-sheets-completed") are intended to be
> counters. That is, if the "job-state" is 'processing' or
> 'processing-stopped', this value is intended to contain the amount of the
> job that has been processed to the time at which the attributes are
> requested.  For any of these three attributes, the Printer may choose to
> return the value '-2' (which represents "unknown") rather than choose to
> not support the attribute at all.
> 
> 4.3.17	job-impressions-completed  (integer(0:2**31 - 1))
> 
> This job attribute specifies the number of impressions completed for the
> job so far.  For printing devices, the impressions completed includes
> interpreting, marking, and stacking the output. This attribute is intended
> to be a counter as in the Job Monitoring MIB.
> 
> For implementations where multiple copies are produced by the interpreter
> with only a single pass over the data, the final value SHALL be equal to
> the value of the "job-impressions" attribute.  For implementations where
> multiple copies are produced by the interpreter by processing the data for
> each copy, the final value SHALL be a multiple of the value of the
> "job-impressions" attribute.
> 
> 4.3.18	job-media-sheets-completed (integer(0:2**31 - 1))
> 
> This job attribute specifies the media-sheets completed marking and
> stacking for the entire job so far whether those sheets have been processed
> on one side or on both. This attribute is intended to be a counter as in
> the Job Monitoring MIB.
> 
> 
> 



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