Browse Prior Art Database

Unique Key Generation to Guarantee Proper Interdependency Relationship between Different Files Derived from a Common Source File

IP.com Disclosure Number: IPCOM000116999D
Original Publication Date: 1995-Dec-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 88K

Publishing Venue

IBM

Related People

Kaiserswerth, M: AUTHOR [+2]

Abstract

Disclosed is a method to guarantee proper interdependence of documents or files. The basic problem is sketched in Fig. 1: An application B relies on the proper relation of two documents, or files, respectively, namely 1 and 2, where file 2 has been created by some other program A. File 2, however, is only valid with respect to a specific version of file 1, i.e., as soon as file 1 is modified, file 2 becomes invalid and must be recreated.

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Unique Key Generation to Guarantee Proper Interdependency Relationship
between Different Files Derived from a Common Source File

      Disclosed is a method to guarantee proper interdependence of
documents or files.  The basic problem is sketched in Fig. 1: An
application B relies on the proper relation of two documents, or
files, respectively, namely 1 and 2, where file 2 has been created by
some other program A.  File 2, however, is only valid with respect to
a specific version of file 1, i.e., as soon as file 1 is modified,
file 2 becomes invalid and must be recreated.

      A similar situation is sketched in Fig. 2, where two documents
2 and 3 are derived from some common document 1.  Application C must
be able to detect version conflicts to guarantee that both documents
are based on the same version of the original document 1.

      The common approach to guarantee proper dependencies is to
generate some unique key or identification for document 1 and then
store that key with all documents derived from the original as
indicated by the small boxed numbers in Figs. 1 and 2.  By comparing
the keys obtained via different paths, one can check whether the
dependency condition is indeed satisfied.

      Usually the original's creation or modification time is used as
key, stored with the derived files.  Obviously this key changes when
the original is modified and thus would also change in the derived
files.

      Such a scheme works fine when operating on a single system.  It
becomes unusable in a distributed environment.  Here operations A, B,
and C might all happen on different systems.  However, when copying a
file 1 to another system, one actually creates a new file 1' and this
new file will have a different timesta...