초록 ▼

A method and file structure for generating an efficient difference files from and old file and a new file so that a difference file can be transmitted to a second computer system where the difference file and a duplicate of the old file can quickly be used to create a copy of the new file is disclos

A method and file structure for generating an efficient difference files from and old file and a new file so that a difference file can be transmitted to a second computer system where the difference file and a duplicate of the old file can quickly be used to create a copy of the new file is disclosed. A differencing process compares an old file and a new file to generate a difference file in which the old file is used as a database of byte strings. The differencing process reads strings of data from the new file, searches for the existence of those strings in the old file, and notes the locations in the old file in which strings in the new file are found and stores in a difference file an indication of the location where a matching string is found and an indication of the length. A specific file structure for the difference file is disclosed.

대표청구항 ▼

[ What is claimed is:] [1.] A method for generating a difference file comprising:a) reading new file data strings from a new file;b) searching an old file for the presence of old file data strings matching said new file data strings;c) when a match is found, storing in said difference file an indica

[ What is claimed is:] [1.] A method for generating a difference file comprising:a) reading new file data strings from a new file;b) searching an old file for the presence of old file data strings matching said new file data strings;c) when a match is found, storing in said difference file an indication of the position in said old file of said matching strings, along with an indication of a copy operation;d) when no match is found, storing said new file data string in a location where it will available to said difference file and storing in said difference file an indication of the location of said insert data along with an indication of an insert operation;e) repeating steps a) through d) until all data in said new file has been read and corresponding insert and copy operations have been written into said difference file.