Patent ID: 7836099
Filing Date: 2010-11-16
Classification: H04L,Y10S

Abstract:
1. A data structure stored in a computer-readable medium for archiving and retrieving one or more data blocks stored in a single file, comprising: a table of contents comprising n data block identifier and offset pairs, where n is a positive integer, wherein the offset indicates the location of the data block identified by the data block identifier; a dictionary, including a series of entries each comprising a match string, and a plurality of match length, offset pairs; and a file comprising n data blocks, each data block comprising an information portion and a compressed content portion, wherein the information portions comprise email headers and the content portions comprise email bodies, and wherein, if partially decompressed, at least one location in a content portion contains a pointer to a dictionary entry indicating that a substring of the match string having a length equal to the match length was removed from that location; wherein the data structure is further executed in at least one email server to store archival email files and to selectively decompress an email body of a data block given its data block identifier; wherein one of the n data blocks is identified by the table of contents and the compressed content portion is decompressed without decompressing other data blocks in the file by the email server using a given data block identifier to look up the corresponding data block in the table of contents, partially decompressing the email body, and using the pointers and dictionary to fully decompress the email body.