30th September 2010

Overview

This page describes the new data and file MCP compression facilities recently implemented in the Metalogic MAGUS library. The features have been incorporated into both the FLEX and SUPERVISOR products for use by their Opal scripting engines. 

Both sets of functions handle GZip, ZLib and MZip compression - the latter is Metalogic's own compression format and is intended currently for use on MCP systems only. 

In general, GZip is used for interchange of files between MCP and non-MCP systems. It offers the best compression, but requires more CPU to perform the compression and to calculate the CRC-32 Checksum.

MZip is most useful for interchange of files between MCP systems. It is optimized for speed on the MCP Architecture and it retains the MCP File Attribute information.

ZLIB is useful for interchange of byte stream data, such as between a Browser and an HTTP Server.

Although Gzip is also valid in an HTTP ACCEPT-ENCODING, ZLib (compress) uses less CPU for the Adler-32
Checksum.  Note that GZIP will only compress FILESTRUCTURE=STREAM files.