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Handling archived files

Modified on 2011/08/15 00:59 by Administrator Categorized as Tools

Handling archived files (32-bit mode)

You can download the historical data files in archived format. This will help you save disk space. The default file extension is *.z8. You can use our command-line utilities to quickly unpack/pack the data.

File Purpose Syntax
Version 1.0
Packs file (Zip-Archive). Accepts source (unpacked) and destination (packed) files as command line parameters. z8a InFile OutFile
Version 1.0
Unpacks file (Zip-Extract). Accepts source (packed) and destination (unpacked) files as command line parameters. z8e InFile OutFile
Version 1.2.3
ZLIB library used by the z8a and z8e utilities. It must be located in the same folder, or in one of the PATH folders, for example C:\Windows\System32\ For specifications, please refer to the original provider web site: http://www.zlib.net/

You don't have to always unpack the files prior to production use. You can use the zlibwapi32.dll, or any other library/interface that supports ZLIB stream decompression, to read z8 files and unpack them on the fly. Please refer to the Compressed File (*.z8) Specification for the way to handle these files.

High-performance 64-bit Compression/Decompression

You might want to leverage your 64-bit capable CPU by using the tool below. It offers 10-15% better compression and up to 50% better decompression speeds. For instance, an ITCH file decompression speed of is about 220 MB/Sec in 64-bit mode and only 160 MB/Sec in the 32-bit mode (on an Intel Q9550 CPU with DDR2-800 memory). Also, this tool does not require any DLL libraries.

File Purpose Syntax
Version 2.0
Compresses (-a switch) or decompresses (-e switch) files with a "z8" extension using 64-bit optimized ZLIB library. The destination file is optional: if omitted, the destination file will be based on the source file name with a letter "z" attached to or removed from the source file extension, for compressed and decompressed files, respectively. z8 (-a|-e) InFile [OutFile]