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Compression property

Determines level of compression used.


An Integer value. Determines level of the compression.


  • Basic
object.Compression [= value]
The Compression(object,value) syntax has these parts:
objectAn expression evaluating to an object of type wodFtpDLX.
valueAn Integer value.


Before connecting to the server, you can decide if you want to use wodFtpDLX's internal compression. If so, you should set Compression property to any value between 1 and 9 (1 for lowest compression, 9 for highest compression). If you don't want compression to be used, set this parameter to 0.

Compression setting will act differently in SFTP and in FTP protocols. While SFTP protocol knows about compression, and is usually used, FTP server needs to have 'deflate compression' extension, as explained in 'draft-preston-ftpext-deflate-02.txt' document. If server supports it, wodFtpDLX will automatically send 'MODE Z' command to enable compression. If it gets positive response back from the server, compression will be used on data channel for directory lists, file downloads and file uploads. This way you can get significant speed increase when transferring non-compressed files, without losing your CPU speed. So far this compression model has been tested with Serv-U FTP server.

You can change Compression setting during the connection. Typically, clients use compression level 6 for optimum performance (default value).