Microsoft Corporation
PARTIAL DOWNLOADS OF COMPRESSED DATA

Abstract:

A client is able to decompress an internal portion of a compressed file on a server without having to download and decompress the part of the compressed file that precedes the internal portion. Initially, when the file is compressed, the state of the compressor, e.g., a dictionary, is periodically captured and stored in association with positions in the compressed file. A server stores the compressor states and positions in association with the compressed file. The client identifies the internal section of the compressed file to the server. The server selects a compressor state whose position is closest to the internal section. The server sends the client the selected compressor state and the internal portion of the compressed file. The client primes a decompressor with the sent compressor state, and the primed decompressor then decompresses the internal portion of the compressed file.