To make the discussion more concrete on the length (text=4095, name=255
octets), here are the attributes in IPP/1.0 that are involved:
The 'text' and 'name' attribute involved are:
Supplied by client?
Operation Attributes:
document-name (name) Yes
Job Attributes:
job-name (name) Yes
job-originating-user (name) Yes
job-state-message (text) No
job-message-from-operator (text) No (at least not in V1.0)
Printer Attributes:
printer-name (name) No
printer-location (text) No
printer-info (text) No
printer-make-and-model (text) No
printer-state-message (text) No
printer-message-from-operator (text) No (at least not in V1.0)
So far the initial reaction (Don and Carl-Uno) is that the full length is
intended to be supported by the Printer object. Fine with me if we agree
to that.
The reason that I brought up the issue, is that in SNMP the MAX length is
separate from the MIN required for conformance. So we need to discuss
and clarify the document. Else we will have some interoperability
problems.
Tom
At 17:18 10/20/1997 PDT, Tom Hastings wrote:
>Our current Model text gives upper bounds on the lengths of the 'text' and
>'name' attributes as 4095 and 255 octets, respectively. However, we don't
>say how many of those octets a Printer object SHALL store. We also don't
>say what happens if a client supplies a value that is longer than
>the maximum size that a Printer supports.
>>These are two issues that will affect interoperability.
>>I suggest that we add two sentences something like:
>>A Printer object SHALL support at least nnn octets in requests and responses.
>If a client supplies a value that exceeds nnn, the Printer object SHALL
>truncate the value on the right after the nnn-th octet.
>>I propose that 'nnn' be 255 for text and 127 for names. UTF-8 takes about
>1.7 octets per character on average for Western European names.
>>Comments? Lets discuss at Wednesdays telecon.
>>Thanks,
>Tom
>>Here is the current text:
>>>4.1.1 'text'
>>The 'text' attribute syntax is a sequence of one or more characters with a
>limit of 1 to 4095 octets. The Printer object SHALL support UTF-8 [28] and
>MAY support additional charsets provided that they are registered with IANA
>[54].
>>...
>>>4.1.2 'name'
>>The 'name' attribute syntax is the same as 'text', including the MANDATORY
>support of UTF-8 and the exception natural language mechanism, except that
>the sequence of characters is limited so that its encoded form is of length
>1 to 255 octets. This syntax type is used for user-friendly strings, such
>as a Printer name, that, for humans, are more meaningful than identifiers.
>>...
>>>>