656 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C++
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			656 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C++
		
	
	
		
			Executable File
		
	
	
	
	
| //
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| // PKENGNC.CPP
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| //
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| //  Source file for ArchiveLib 2.0
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| //
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| //  Copyright (c) Greenleaf Software, Inc. 1994-1996
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| //  All Rights Reserved
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| //
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| // CONTENTS
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| //
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| //  ALPkCompressor::operator new()
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| //  ALPkCompressor::ALPkCompressor()
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| //  newALPkCompressor()
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| //  ALPkCompressor::~ALPkCompressor()
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| //  ALPkCompressor::Compress()
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| //  ALPkCompressor::Clone()
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| //
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| // DESCRIPTION
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| //
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| //  All of the source required to support the PKWare compatible compressor.
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| //
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| // REVISION HISTORY
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| //
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| //   February 14, 1996  2.0A : New release
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| 
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| #include "arclib.h"
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| #if !defined( AL_IBM )
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| #pragma hdrstop
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| #endif
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| 
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| #include "copyengn.h"
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| #include "pkengn.h"
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| #include "_openf.h"
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| #include "zutil.h"
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| #include "zlib.h"
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| 
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| //
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| // NAME
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| //
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| //  ALPkCompressor::operator new()
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| //
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| // PLATFORMS/ENVIRONMENTS
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| //
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| //  Console  Windows  PM
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| //  C++
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| //
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| // SHORT DESCRIPTION
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| //
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| //  Memory allocator used when ArchiveLib resides in a 16 bit DLL.
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| //
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| // C++ SYNOPSIS
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| //
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| //  #include "arclib.h"
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| //  #include "pkengn.h"
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| //
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| //  void * ALPkCompressor::operator new( size_t size )
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| //
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| // C SYNOPSIS
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| //
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| //  None.
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| //
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| // VB SYNOPSIS
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| //
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| //  None.
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| //
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| // DELPHI SYNOPSIS
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| //
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| //  None.
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| //
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| // ARGUMENTS
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| //
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| //  size  :  The number of bytes that the compiler has decided will be
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| //           necessary to construct a new ALPkCompressor object.
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| //
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| // DESCRIPTION
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| //
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| //  When using a DLL, it is easy to get into a dangerous situation when
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| //  creating objects whose ctor and dtor are both in the DLL.  The problem
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| //  arises because when you create an object using new, the memory for
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| //  the object will be allocated from the EXE.  However, when you destroy
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| //  the object using delete, the memory is freed inside the DLL.  Since
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| //  the DLL doesn't really own that memory, bad things can happen.
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| //
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| //  But, you say, won't the space just go back to the Windows heap regardless
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| //  of who tries to free it?  Maybe, but maybe not.  If the DLL is using
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| //  a subsegment allocation scheme, it might do some sort of local free
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| //  before returning the space to the windows heap.  That is the point where
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| //  you could conceivably cook your heap.
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| //
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| //  By providing our own version of operator new inside this class, we
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| //  ensure that all memory allocation for the class will be done from
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| //  inside the DLL, not the EXE calling the DLL.
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| //
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| //  Incidentally, I suspect that this function never gets called.  If an
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| //  object of a derived archive class is being created, it should use
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| //  its own new operator, rendering this one useless.
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| //
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| // RETURNS
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| //
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| //  A pointer to some memory that should have been pulled out of the
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| //  heap for the DLL.
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| //
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| // EXAMPLE
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| //
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| // SEE ALSO
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| //
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| // REVISION HISTORY
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| //
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| //   February 14, 1996  2.0A : New release
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| //
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| 
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| #if defined( AL_BUILDING_DLL )
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| 
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| void AL_DLL_FAR * AL_PROTO
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| ALPkCompressor::operator new( size_t size )  /* Tag protected function */
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| {
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|     return ::new char[ size ];
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| }
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| 
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| #endif
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| 
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| //
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| // NAME
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| //
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| //  ALPkCompressor::ALPkCompressor()
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| //
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| // PLATFORMS/ENVIRONMENTS
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| //
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| //  Console  Windows  PM
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| //  C++  C  VB  Delphi
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| //
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| // SHORT DESCRIPTION
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| //
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| //  Constructor for the PkWare deflate compressor engine.
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| //
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| // C++ SYNOPSIS
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| //
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| //  #include "arclib.h"
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| //  #include "pkengn.h"
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| //
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| //  ALPkCompressor::ALPkCompressor( int level = 6,
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| //                                  int window_bits = 13 /* or 15 */,
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| //                                  int mem_level = 6 /* or 8 */ )
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| //
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| // C SYNOPSIS
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| //
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| //  #include "arclib.h"
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| //  #include "pkengn.h"
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| //
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| //  hALCompressor newALPkCompressor( int level, int window_bits, int mem_level );
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| //
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| // VB SYNOPSIS
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| //
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| //  Declare Function newALPkCompressor Lib "AL20LW"
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| //    (ByVal level%, ByVal window_bits%, ByVal mem_level% ) As Long
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| //
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| // DELPHI SYNOPSIS
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| //
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| //  function newALPkCompressor( level : Integer;
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| //                              window_bits : Integer;
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| //                              mem_level : Integer ) : hALCompressor;
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| //
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| // ARGUMENTS
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| //
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| //  level       : A number between 1 and 9.  1 gives the best speed, 9 gives
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| //                the best compression.
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| //
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| //  window_bits :
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| //
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| //  mem_level   : How much memory should be allocated for the internal
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| //                compression state. memLevel=1 uses minimum memory but
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| //                is slow and reduces compression ratio; memLevel=9 uses
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| //                maximum memory for optimal speed. (quoted from zlib.h)
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| //
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| //  Note that the C/VB/Delphi version of the ctor can use default parameter
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| //  values by simply passing AL_DEFAULT for each of the different numeric
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| //  parameters.
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| //
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| // DESCRIPTION
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| //
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| //  This constructor creates a new ALPkCompressor.  This compressor by
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| //  itself is a low cost object, with just a couple of data members that
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| //  help it remember what parameters to use when it comes time to
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| //  compress.  The compressor becomes a resource user when you call the
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| //  Compress() member function.
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| //
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| //  Create compressor objects when you are initializing a toolkit, or when
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| //  compressing files by hand, or when using an ALCompressedObject.
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| //
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| // RETURNS
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| //
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| //  The constructor doesn't return anything to C++ programmers.  C/VB/Delphi
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| //  programmers get a handle that points to the newly created object.
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| //
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| // EXAMPLE
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| //
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| // SEE ALSO
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| //
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| // REVISION HISTORY
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| //
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| //   February 14, 1996  2.0A : New release
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| //
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| 
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| AL_PROTO
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| ALPkCompressor::ALPkCompressor( int level /* = 6 */,  /* Tag public function */
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|                                 int window_bits /* = 13 or 15 */,
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|                                 int mem_level /* = 8 or 6 */ )
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|     : ALCompressor( AL_COMPRESSION_DEFLATE, "" )
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| {
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|     miWindowBits = window_bits;
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|     miMemLevel = mem_level;
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|     switch ( level ) {
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|         case 9 :
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|             mszCompressionType = "Deflate Maximum";
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|             option = MAXIMUM;
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|             miLevel = level;
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|             break;
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|         case 8 :
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|         case 7 :
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|         case 6 :
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|         case 5 :
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|         case 4 :
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|         case 3 :
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|         case 2 :
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|             option = NORMAL;
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|             mszCompressionType = "Deflate Normal";
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|             miLevel = level;
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|             break;
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|         case 1 :
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|             option = FAST;
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|             mszCompressionType = "Deflate Fast";
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|             miLevel = 1;
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|             break;
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|         case 0 :
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|             option = NORMAL;
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|             mszCompressionType = "Stored";
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|             miLevel = 0;
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|             break;
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|         default :
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|             option = NORMAL;
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|             mszCompressionType = "???";
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|             miLevel = -1;
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|             break;
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|     }
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| }
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| 
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| #if !defined( AL_NO_C )
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| 
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| extern "C" AL_LINKAGE hALCompressor AL_FUNCTION
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| newALPkCompressor( int level,  /* Tag public function */
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|                    int window_bits,
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|                    int mem_level )
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| {
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|     if ( level == AL_DEFAULT )
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|         level = 6;
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|     if ( window_bits == AL_DEFAULT )
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|         window_bits = AL_PK_DEFAULT_WINDOW_BITS;
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|     if ( mem_level == AL_DEFAULT )
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|         mem_level = AL_PK_DEFAULT_MEM_LEVEL;
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|     return (hALCompressor) new ALPkCompressor( level, window_bits, mem_level );
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| }
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| 
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| #endif
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| 
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| //
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| // NAME
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| //
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| //  ALPkCompressor::~ALPkCompressor()
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| //
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| // PLATFORMS/ENVIRONMENTS
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| //
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| //  Console  Windows  PM
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| //  C++
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| //
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| // SHORT DESCRIPTION
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| //
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| //  The PKWare deflate Compressor destructor.
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| //
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| // C++ SYNOPSIS
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| //
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| //  #include "arclib.h"
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| //  #include "pkengn.h"
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| //
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| //  ALPkCompressor::~ALPkCompressor()
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| //
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| // C SYNOPSIS
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| //
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| //  None.  C programmers need to call deleteALCompressor().
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| //
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| // VB SYNOPSIS
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| //
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| //  None.  VB programmers need to call deleteALCompressor().
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| //
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| // DELPHI SYNOPSIS
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| //
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| //  None.  Delphi programmers need to call deleteALCompressor().
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| //
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| // ARGUMENTS
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| //
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| //  None.
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| //
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| // DESCRIPTION
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| //
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| //  The destructor for objects of this class doesn't have to do
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| //  anything.  In debug mode, we at least check for the validity
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| //  of the object.
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| //
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| // RETURNS
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| //
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| //  Nothing.
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| //
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| // EXAMPLE
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| //
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| // SEE ALSO
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| //
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| // REVISION HISTORY
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| //
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| //   February 14, 1996  2.0A : New release
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| //
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| 
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| AL_PROTO
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| ALPkCompressor::~ALPkCompressor()  /* Tag public function */
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| {
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|     AL_ASSERT( GoodTag(), "~ALPkCompressor: Attempt to delete invalid object" );
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| }
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| 
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| //
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| // I've tried two different ways to feed data to the compressor.
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| // The "normal" way is to just give the engine a pointer to a buffer,
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| // then work on filling that buffer by calling my own Read routines.
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| // The hacked way ought to work better.  When hacked, I use the buffer
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| // in the storage object, instead of creating a standalong buffer.  This
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| // means the compressor has to be a friend of ALStorage, but that's
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| // manageable.  Right now, Hacked seems to be okay, and it saves some space
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| // so that's what we're doing.
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| //
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| // Changing to unhacked is possible, but the buffer allocation should then
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| // be done dynamically, as this static buffer's going to have trouble
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| // when inside a DLL.
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| //
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| 
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| #define HACK_INPUT
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| #define HACK_OUTPUT
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| 
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| #if !defined( HACK_OUTPUT )
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| const int OUTBUF_LEN = 1024;
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| static char outbuf[ OUTBUF_LEN ];
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| #endif
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| 
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| #if !defined( HACK_INPUT )
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| const int INBUF_LEN = 1024;
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| char inbuf[ INBUF_LEN ];
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| #endif
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| 
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| //
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| // NAME
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| //
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| //  ALPkCompressor::Compress()
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| //
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| // PLATFORMS/ENVIRONMENTS
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| //
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| //  Console  Windows  PM
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| //  C++
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| //
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| // SHORT DESCRIPTION
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| //
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| //  Compress using the deflate algorithm.
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| //
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| // C++ SYNOPSIS
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| //
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| //  #include "arclib.h"
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| //  #include "pkengn.h"
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| //
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| //  int ALPkCompressor::Compress( ALStorage& input,
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| //                                ALStorage& output );
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| //
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| // C SYNOPSIS
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| //
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| //  None, see the base class function ALCompress().
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| //
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| // VB SYNOPSIS
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| //
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| //  None, see the base class function ALCompress().
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| //
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| // DELPHI SYNOPSIS
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| //
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| //  None, see the base class function ALCompress().
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| //
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| // ARGUMENTS
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| //
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| //  input  : A reference to the input storage object.
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| //
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| //  output : A reference to the output storage object.
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| //
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| // DESCRIPTION
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| //
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| //  This is the virtual function that is called to compress data.
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| //  This section of code is really just a front end to the real engine,
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| //  which is found mostly in deflate.cpp
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| //
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| //  It's kind of hard to see what's going on here with the #ifdefs, but
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| //  it really isn't too complicated.  The deflate code wants a zstream
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| //  structure to work on.  We set up zstream to contain buffer pointers
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| //  to both the input and output streams.  We then sit in a loop calling
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| //  deflate() repeatedly.  The deflate() code compresses as much data
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| //  as it can, and returns.  After each call, I flush all the data I can,
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| //  load as much new data as I can, then try it again.  This repeats until
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| //  deflate() finally indicates that it's done.
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| //
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| //  After deflate is done, we have to check for errors on
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| //  any of the other objects involved in the compression, and return the
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| //  cumulative result.
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| //
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| //  This function will almost always be called indirectly, by means of
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| //  a virtual function call off the base class.  That's why you won't
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| //  see any C, VB, or Delphi functions here.  Those languages will only
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| //  be able to call the Compress() routine by way of the base class.
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| //
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| // RETURNS
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| //
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| //  AL_SUCCESS, or < AL_SUCCESS if something bad happens.
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| //
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| // EXAMPLE
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| //
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| // SEE ALSO
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| //
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| // REVISION HISTORY
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| //
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| //   February 14, 1996  2.0A : New release
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| //
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| 
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| int AL_PROTO
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| ALPkCompressor::Compress( ALStorage AL_DLL_FAR &input,  /* Tag public function */
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|                           ALStorage AL_DLL_FAR &output )
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| {
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| //
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| // Open the input and output files, and initialize CRC 32 checking.
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| //
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|     ALOpenFiles files( input, output );
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|     if ( input.mStatus < AL_SUCCESS )
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|         return mStatus = input.mStatus;
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|     if ( output.mStatus < AL_SUCCESS )
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|         return mStatus = output.mStatus;
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|     input.InitCrc32();
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| 
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|     int result;
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|     z_stream stream;
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| 
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|     stream.zalloc = 0;
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|     stream.zfree = 0;
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|     result = deflateInit2( &stream,
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|                            miLevel,
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|                            DEFLATED,
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|                            -miWindowBits,
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|                            miMemLevel,
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|                            0 );
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|     if ( result != 0 ) {
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|         deflateEnd( &stream );
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|         return mStatus.SetError( AL_CANT_CREATE_ENGINE,
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|                                  "Error creating deflate engine. "
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|                                  "ZLIB returned %d\n",
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|                                  result );
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|     }
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| #if defined( HACK_OUTPUT )
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|     output.FlushBuffer();
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|     stream.avail_out = output.muBufferSize;
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|     stream.next_out = (Byte ZL_FAR *) output.mpcBuffer;
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| #else
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|     stream.avail_out = OUTBUF_LEN;
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|     stream.next_out = (Byte ZL_FAR *) outbuf;
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| #endif
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|     stream.avail_in = 0;
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| #if !defined( HACK_INPUT )
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|     stream.next_in = (Byte ZL_FAR *) inbuf;
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| #endif
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|     for ( ; ; ) {
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|         if ( stream.avail_in == 0 ) {
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| #if !defined( HACK_INPUT )
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|             stream.avail_in = input.ReadBuffer( (unsigned char *) inbuf, INBUF_LEN );
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|             stream.next_in = (unsigned char *) inbuf;
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|             if ( stream.avail_in == 0 )
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|                 break;
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| #else
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|             if ( input.muReadIndex >= input.muBufferValidData ) {
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|                 if ( input.LoadBuffer( input.mlFilePointer ) < 0 )
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|                     break;
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|             }
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|             stream.avail_in = input.muBufferValidData - input.muReadIndex;
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|             stream.next_in = input.mpcBuffer + input.muReadIndex;
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|             input.muReadIndex += input.muBufferValidData;
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| #endif
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|         }
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|         result = deflate( &stream, Z_NO_FLUSH );
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| #if defined( HACK_OUTPUT )
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|         if ( stream.avail_out != output.muBufferSize ) {
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|             output.muWriteIndex = output.muBufferSize - stream.avail_out;
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|             output.FlushBuffer();
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|             stream.avail_out = output.muBufferSize;
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|             stream.next_out = (Byte ZL_FAR *) output.mpcBuffer;
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|         }
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| #else
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|         if ( stream.avail_out != OUTBUF_LEN ) {
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|             output.WriteBuffer( (unsigned char*) outbuf, OUTBUF_LEN - stream.avail_out );
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|             stream.avail_out = OUTBUF_LEN;
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|             stream.next_out = (Byte ZL_FAR *) outbuf;
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|         };
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| #endif
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|         if ( output.mStatus < AL_SUCCESS || result != Z_OK) {
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|             deflateEnd( &stream );
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|             return mStatus = output.mStatus;
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|         }
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|     }
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| //
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| // Now its time to start flushing
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| //
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|     for ( ; ; ) {
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|         result = deflate( &stream, Z_FINISH );
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| #if defined( HACK_OUTPUT )
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|         if ( stream.avail_out != output.muBufferSize ) {
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|             output.muWriteIndex = output.muBufferSize - stream.avail_out;
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|             output.FlushBuffer();
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|             stream.avail_out = output.muBufferSize;
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|             stream.next_out = (Byte ZL_FAR *) output.mpcBuffer;
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| #else
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|         if ( stream.avail_out != OUTBUF_LEN ) {
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|             output.WriteBuffer( (unsigned char *) outbuf, OUTBUF_LEN - stream.avail_out );
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|             stream.avail_out = OUTBUF_LEN;
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|             stream.next_out = (Byte ZL_FAR *) outbuf;
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| #endif
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|         };
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|         if ( result == Z_STREAM_END )
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|             break;
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|     }
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|     deflateEnd( &stream );
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| 
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| //
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| // Finally, check on the error status codes, then return.
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| //
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|     if ( input.mStatus < AL_SUCCESS )
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|         return mStatus = input.mStatus;
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|     if ( output.mStatus < AL_SUCCESS )
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|         return mStatus = output.mStatus;
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|     return mStatus;
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| }
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| 
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| //
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| // NAME
 | |
| //
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| //  ALPkCompressor::Clone()
 | |
| //
 | |
| // PLATFORMS/ENVIRONMENTS
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| //
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| //  Console  Windows  PM
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| //  C++
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| //
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| // SHORT DESCRIPTION
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| //
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| //  Create a copy of an existing Compressor
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| //
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| // C++ SYNOPSIS
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| //
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| //  #include "arclib.h"
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| //  #include "pkengn.h"
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| //
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| //  ALPkCompressor::Clone( int engine_type );
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| //
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| // C SYNOPSIS
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| //
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| //  No C equivalent.
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| //
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| // VB SYNOPSIS
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| //
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| //  No VB equivalent.
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| //
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| // DELPHI SYNOPSIS
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| //
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| //  No Delphi equivalent.
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| //
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| // ARGUMENTS
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| //
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| //  engine_type  :  This argument indicates what sort of engine the
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| //                  caller wants to create.  A value of either
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| //                  AL_COMPRESSION_DEFAULT, AL_COMPRESSION_DEFLATE,
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| //                  AL_DEFLATE_COPY, or AL_COPY will cause this function to
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| //                  create a clone.  Any other
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| //                  value (for example, AL_GREENLEAF), will return a 0,
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| //                  indicating that this object doesn't know how to
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| //                  perform that sort of compression.
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| //
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| // DESCRIPTION
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| //
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| //  Although this is a public function, it isn't really of any use
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| //  to end users.  Clone() is a virtual function for the base class
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| //  ALCompressor, and can be called to create a duplicate of an
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| //  existing compression engine.
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| //
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| //  Why is this useful?  It is useful because it allows us to use
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| //  what is the equivalent of a virtual constructor.  We can pass a
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| //  pointer to a PKWare engine to the archiving code, and it can then in
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| //  turn stuff copies of that engine into an ALEntryList without
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| //  having any idea what sort of compression engine it is actually creating.
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| //
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| // RETURNS
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| //
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| //  A copy of a newly created compression engine.  When this routine is
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| //  called, it will usually be called via a virtual function from a pointer
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| //  to a base class object, which means the resulting pointer will be
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| //  treated as an ALCompressor * by the code.
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| //
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| //  If this routine doesn't know how to create an engine of the correct type,
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| //  it returns a 0.  When performing compression into an archive, the
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| //  Clone() functions will usually be called with the AL_DEFAULT_COMPRESSION
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| //  engine type, meaning they are happy to take a copy of whatever engine
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| //  happens to show up first in the toolkit.
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| //
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| // EXAMPLE
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| //
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| // SEE ALSO
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| //
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| // REVISION HISTORY
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| //
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| //   February 14, 1996  2.0A : New release
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| //
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| 
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| ALCompressor AL_DLL_FAR * AL_PROTO
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| ALPkCompressor::Clone( int engine_type ) const  /* Tag public function */
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| {
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|     _option pk_option;
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|     ALPkCompressor *compressor;
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|     switch ( engine_type ) {
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|         case AL_COMPRESSION_COPY :
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|         case AL_COMPRESSION_DEFLATE_COPY :
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|             return new ALCopyCompressor();
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|         case AL_COMPRESSION_DEFLATE + 3 :
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|             pk_option = SUPER_FAST;
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|             break;
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|         case AL_COMPRESSION_DEFLATE + 2 :
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|             pk_option = FAST;
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|             break;
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|         case AL_COMPRESSION_DEFLATE + 1 :
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|             pk_option = MAXIMUM;
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|             break;
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|         case AL_COMPRESSION_DEFLATE + 0 :  /* Normal */
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|         case AL_COMPRESSION_DEFAULT :
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|             pk_option = NORMAL;
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|             break;
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|         default :
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|             return 0;
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|     }
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|     compressor = new ALPkCompressor( miLevel, miWindowBits, miMemLevel );
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|     if ( compressor )
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|         compressor->option = pk_option;
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|     return compressor;
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| }
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| 
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