Page Printer Message Handler
Original Publication Date: 1992-Oct-01
Included in the Prior Art Database: 2005-Mar-25
Doescher, CL: AUTHOR [+2]
Disclosed is a Page Printer Message Handler design that allows for easy maintenance of error/warning messages that must be printed and delivered with a user's print file.
Page Printer Message Handler
a Page Printer Message Handler design that
allows for easy maintenance of error/warning messages that must be
printed and delivered with a user's print file.
Printers must keep track of both job-related and
page-related messages while printing a user's print file, so that
these messages may be printed with the user's document. A method of
handling these messages is necessary to insure that messages that
have already been printed are deleted in a timely fashion, and that
no messages are duplicated because of a reposition in the datastream
(which causes messages to be "rediscovered"). This invention
describes a method whereby these messages are handled correctly.
Printer Driver program creates and maintains a list of
Page Queue Entries (PQEs), one PQE for each page that has been
converted for printing. The Page Printer Message Handler keeps a
list of all page-related messages discovered on a print file page in
a list structure associated with the individual PQEs. It also keeps
a list of all job-related messages in the Job Record associated with
the current PQE. When a user's print file has been converted, these
messages are assembled and written to a file which is then sent to
the converter for conversion and subsequent printing.
components of the Page Printer Driver program must
call the Page Printer Message Handler functions to record errors
encountered in the conversion and printing of a user's print file.
The calling function must define the message as a page-related or a
job-related message. Page-related messages are appended to the
message list which is part of the appropriate PQE (see the figure).
Therefore, each PQE has a (possibly NULL) list of messages associated
with it. Job-related messages are appended to the message list which
is part of the appropriate Job Record (see the figure). Therefore,
each job has a (possibly NULL) list of messages associated with it.
When the user's print file has been processed, a Page Printer Message
Handler function is invoked to prepare these messages for possible
conversion and printing. This Page Printer Message Handler function
first formats and writes all job-related messages to a Message
Buffer, and then appends the page-related messages (in order) to this
Message Buffer. This Message Buffer is then sent to the converter
for processing in much the same manner as a user print file.
the asynchronous nature of the Page Printer Driver
program (the converter is typically converting ahead of the printer),
several problems can arise from the above simplified scenario.
First, the printer can encounter an error which involves backward