File update performing comparison and compression as single process

• US 6,496,974 B1
• Filed: 04/28/2000
• Issued: 12/17/2002
• Est. Priority Date: 06/08/1998
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Sliger, Michael V., McGuire, Thomas D., Forbes, Jonathan A.
• Primary Examiner(s): DAM, TUAN QUANG
• Application Number:
  US09/561,393
• Time in Patent Office: 963 Days
• Field of Search: 717/106, 717/168-170, 717/174, 717/175, 707/10, 707/101, 707/202, 707/203, 710/1, 710/2, 341/51
• US Class Current: 717/106
• CPC Class Codes: G06F 8/658 Incremental updates; Differential updates
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99936 Pattern matching access
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

Rather than comparing an old file with a new file to generate a set of patching instructions, and then compressing the patching instructions to generate a compact patch file for transmission to a user, a patch file is generated in a single operation. A compressor is pre-initialized in accordance with the old version of the file (e.g. in an LZ77 compressor, the history window is pre-loaded with the file). The pre-initialized compressor then compresses the old file, producing a patch file from which the new file can be generated, as a single process. At the user'"'"'s computer, a parallel process is performed, with the user'"'"'s copy of the old file being used to pre-initialize a decompressor to which the patch file is then input. The output of the decompressor is the new file, again produced as a single process. The patch files generated and used in these processes are of significantly reduced size when compared to the prior art.

Claims

1. In a method of generating update data on a second computer and providing same to a first computer so that the first computer can upgrade an original file thereon to an upgraded file, the method including, on the second computer:

comparing the original and upgraded files to generate update data by which the former can be used to produce the latter, compressing said update data, and transferring the update data to the first computer, an improvement comprising performing both the comparing and compressing steps in a single process that both compares the original and upgraded files, and yields compressed update data.

2. In a method of upgrading an original file to an updated file by use of a patch file, the method including receiving the patch file, decompressing update data included in the patch file, and applying the decompressed update data to the original file to thereby yield the updated file, an improvement comprising performing both the decompressing and applying steps in a single process, wherein the decompression process yields the updated file.