Updating data processing files

Claim 5

The method of claim 2 wherein said evaluating step includes the steps of: associative comparing a base file line hash total calculated with respect to a data line from said base text file and an update file line hash total calculated with respect to a data line from said update text file; responsive to said line hash totals comparing equal, entering synchronous mode; sequentially repeating said associative comparing step and maintaining a count n of equal comparison since entering synchronous mode, until said line hash totals compare unequal or until an end of file is encountered, and thereupon terminating synchronous mode; and responsive to said count n, generating for said data stream control information identifying unchanged lines.

Claim 6

The method of claim 3 further comprising the steps of: responsive to said line hash totals comparing unequal while in synchronous mode, entering search mode; maintaining in a first stack base file line hash totals selected for processing since entering search mode; maintaining in a second stack update file line hash totals selected for processing since entering search mode; sequentially processing selected base file line hash totals and update file line hash totals to identify data lines deleted from said base text file; and generating for said data stream control information identifying deleted lines.

Claim 7

The method of claim 4 wherein said sequentially processing step further is executed to identify data lines modified or added to said base text file; and selecting from said update text file for said data stream data lines identified as modified or added to said base text file.

Claim 8

The method of claim 5 wherein said sequentially processing step comprises the steps of: comparing each base file line hash total selected for processing with the update file line hash totals in said second stack and comparing each update file line hash total selected for processing with the base file line hash totals in said first stack until a first pair of line hash totals are found which compare equal; responsive to the finding of said first pair of line hash totals, sequentially comparing update file line hash totals with sequential base file line hash totals to determine the number of consecutive pairs of line hash totals which compare equal subsequent to and including said first pair, and responsive thereto if only one consecutive pair of line hash totals compare equal, ignoring the compare equal of said first pair and continuing search model if a first plurality, less than a predetermined count, of consecutive pairs of line hash totals compare equal, entering a compare count entry representing said first plurality into a compare-fail stack and continuing search mode; and if a second plurality, equal to said predetermined count, of consecutive pairs of line hash totals compare equal, examining said compare-fail stack to identify a smallest entry having the smallest compare count which does not interfere with any of a nest of larger entries with larger compare counts, all of which larger entries do not interfere with said second plurality of consecutive pairs, and setting the end of each of said first and second stacks to the entries corresponding to said smallest entry, the entries remaining in said first stack representing lines to be deleted, and the entries in said second stack representing new or modified lines; and clearing said first and second stacks and terminating search mode.

Claim 9

A method as claimed in claim 2 for operating an computing system including a host computer and a terminal computing apparatus comprising storage means for storing data signals and including a direct access storage device and a main storage device, the terminal computing apparatus further including a processor unit means, an user input/output means, and a communication means; including operating said communication means to receive from said host computer a copy of a base text file including a plurality of data lines; operating said communication means to transmit said data stream to said host computer; and responsive to said data stream, modifying a host copy of said base text file to provide at the host a copy of said update text file. 8. The method of claim 7 comprising the further steps of generating a file hash total at said host computer with respect to said base text file; communicating said file hash total to said terminal computing apparatus; and communicating to said host computer in said data stream said file hash total for comparison with a file hash total generated with respect to said base text file to assure synchronization between said base text file and said update text file.

Claim 10

A distributed data processing system including a microcomputer having a data storage device and a display, a host computer, and a communication link interconnecting the microcomputer and the host computer, said processing system comprising: means for transmitting a complete file including a plurality of lines to be updated from said host to said microcomputer; means for storing the complete file on said data storage device; means for creating and storing at said microcomputer an uneditable file containing a hash total for each line in said complete file; means for modifying the complete file stored at said microcomputer by selectively replacing, deleting, and adding lines at selected locations within the file to provide a modified file; means for calculating hash values for each line of the modified file for comparison with the hash values in the uneditable file to identify the changed lines; means for generating a data stream of replaced and added lines and control information specifying the location of replaced, added, and deleted lines; and means for transmitting the data stream to said host computer for updating the complete file at said host.

Claim 11

A distributed data processing system including a microcomputer having a data storage device and a display, a host computer, and a communication link interconnecting the microcomputer and the host computer, said processing system comprising: means for transmitting a complete file including a plurality of lines to be updated from said host to said microcomputer; means for storing the complete file on said data storage device; means for creating and storing at said microcomputer an uneditable file containing a hash total for each line in said complete file; means for modifying the complete file stored at said microcomputer by selectively replacing, deleting, and adding lines at selected locations within the file to provide a modified file; means for calculating hash values for each line of the modified file for comparison with the hash values in the uneditable file to identify the changed lines; means for generating a data stream of replaced and added lines and control information specifying the location of replaced, added, and deleted lines; and means for transmitting the data stream to said host computer for updating the complete file at said host.