Copyright 1996-2003 John D. Polstra.
* All rights reserved.
*
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* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgment:
* This product includes software developed by John D. Polstra.
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* derived from this software without specific prior written permission.
*
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The GzipRd
interface defines a subclass of StreamRd.T
which reads from
a compressed stream, decompressing it in the process.
INTERFACE GzipRd;
IMPORT OSError, Rd, StreamRd;
TYPE
T <: Public;
Public = StreamRd.T OBJECT METHODS
init(rd: Rd.T;
maxChildRead: CARDINAL := LAST(CARDINAL);
closeChild: BOOLEAN := TRUE): T RAISES {OSError.E};
END;
The init
method is supplied with a so-called child reader, which
must supply bytes directly from the compressed stream.
The optional parameter maxChildRead
may be used to limit the
amount of read-ahead done on the child when filling the
decompression buffer. That sacrifices some efficiency, but it
tightens the relationship between the number of bytes read from
the parent and the number of bytes read from the child. (It is
useful when statistics are being gathered.)
If closeChild
is TRUE
(the default), then closing the Gzip reader
will also cause the child reader to be closed. If it is FALSE
, then
the child reader will be left open.
PROCEDURE Cleanup(rd: T);
Frees all resources used by rd
, without doing anything to the child.
Cleanup
is a no-op if the resources have already been freed, e.g.,
by a call to Rd.Close
.
END GzipRd.