Browse Prior Art Database

Method for Concurrent Write and Reader Markup of a Wrap-Around Data Log

IP.com Disclosure Number: IPCOM000118976D
Original Publication Date: 1997-Oct-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 96K

Publishing Venue

IBM

Related People

Bennett, RB: AUTHOR [+2]

Abstract

Disclosed is a method for reader markup of a wrap-around data log when there is a single writer and one or more concurrent readers.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Method for Concurrent Write and Reader Markup of a Wrap-Around Data
Log

      Disclosed is a method for reader markup of a wrap-around data
log when there is a single writer and one or more concurrent readers.

      When readers (or viewers or formatters) view records in a data
log, it is often advantageous to be able to annotate each log record
for future reference (e.g., has been viewed and do not want to view
again.)  Such records often record a history of past events and only
need to be viewed once.  The current method describes how one or more
readers of a data log can markup a data log concurrently and
independently and  while the data log is also being written to.

      One can associate markup with log records and store it in
persistent storage along with the data log.  Markup of log records
can be done in connection with moving through a data log during log
read operations.  The markup is user-defined and associated with
particular log records.  Markup can be set or retrieved for a
particular log record while positioned on that record (while viewing
log records sequentially).  Alternatively, one can also set or
retrieve markup independent of this reading of the log record.  This
may be appropriate  for times where data log viewers are remote,
allowing markup of log records to be accumulated remotely, then sent
to a central location for  application to the data log without first
re-reading the data log. Keys  are assigned internally by the method
when a log record is added to the  data log.

      When a read instance of a data log is instantiated, a name can
be given to the reader's markup, which will be used for storing the
markup information in persistent storage (e.g., in a disk file).  At
such time the size (number of characters) of the markup information
is established.  Different viewers of the data log can establish
different names and sizes of the markup.

      Markup can only be associated with log records when the log
records are associated with a data log residing in persistent
storage.  This is consistent with the intention that markup is not
designed for use by data log writers, who can instantiate log record
objects before adding them to the data log.  Instead, markup is
associated with log records (by log readers) after the log records
have become part of a data log.  For this reason, getting and
retrieving markup are methods of the data log and not the log record
itself. Even ...