Browse Prior Art Database

Method for Transmitting Only Document Change Data

IP.com Disclosure Number: IPCOM000042984D
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
Document File: 2 page(s) / 14K

Publishing Venue

IBM

Related People

Gladney, HM: AUTHOR

Abstract

This invention relates to a method for replicating document change data originating at one of several local cache-supported terminals interactively networked through a CPU. The method steps include (a) locally caching documents and updating local logs and directories (b) responsive to updating of the local cache documents through a counterpart terminal, comparing the form and content identities of the changed document with designated other cache directories and (c) upon a match entering only the updates, upon a complete mismatch entering the entire document and updates, and upon a forms identity match entering only the content updates. This invention applies to the transmission of documents (i.e.

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Method for Transmitting Only Document Change Data

This invention relates to a method for replicating document change data originating at one of several local cache-supported terminals interactively networked through a CPU. The method steps include (a) locally caching documents and updating local logs and directories (b) responsive to updating of the local cache documents through a counterpart terminal, comparing the form and content identities of the changed document with designated other cache directories and (c) upon a match entering only the updates, upon a complete mismatch entering the entire document and updates, and upon a forms identity match entering only the content updates. This invention applies to the transmission of documents (i.e., forms and associated contents) and is most useful if any form may have different contents in different transmissions, if documents will be redisplayed, but the receiving processor cannot store all documents, and if there may be small changes between subsequent versions of the same content. The invention contemplates having the receiving processor cache documents so that the form is transmitted, only once, so that no content set is retransmitted if it has been recently transmitted and so that if a change is made to a content set, only the change need be transmitted. There are two service programs: one in the originating processor (OP), and one in the receiving processor (RP). These programs act as interfaces between application programs in each processor and the transmission medium. OP accepts a document (form and content), a form ID, and a content ID from an application. For every distinct form, it remembers the last transmission request and the current transmission request. RP implements a cache which remembers a base version of each document, for as many of the most recently used documents as possible. The cache also remembers the most recent transmission for every document form. The output of RP after each transmission is a completely reconstructed document. Depending on the application, the base version of a document either contains the original content (e.g., for display screen output) or the most...