Copyright 1996-2003 John D. Polstra.
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* This product includes software developed by John D. Polstra.
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* $Id: GzipWr.i3.html,v 1.3 2010-04-29 17:20:02 wagner Exp $
The GzipWr interface defines a subclass of StreamWr.T which writes to
a compressed stream, compressing the data written in the process.
INTERFACE GzipWr;
IMPORT OSError, StreamWr, Wr;
TYPE
T <: Public;
Public = StreamWr.T OBJECT METHODS
init(wr: Wr.T;
level: CompLevel := -1;
closeChild: BOOLEAN := TRUE): T RAISES {OSError.E};
END;
CompLevel = [-1 .. 9]; (* default, none, fastest .. best *)
The init method is supplied with a so-called child writer, which
must write bytes directly to the compressed stream. The optional
parameter level specifies the desired tradoff between compression
efficiency and speed.
If closeChild is TRUE (the default), then closing the Gzip writer
will also cause the child writer to be closed. If it is FALSE, then
the child writer will be left open.
PROCEDURE Cleanup(wr: T);
Frees all resources used by wr, without doing anything to the child.
Cleanup is a no-op if the resources have already been freed, e.g.,
by a call to Wr.Close.
END GzipWr.