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/*
	WARNING: This file was generated by dkct.
	Changes you make here will be lost if dkct is run again!
	You should modify the original source and run dkct on it.
	Original source: dk4strmco.ctr
*/

/*
Copyright (C) 2016-2017, Dirk Krause

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice,
  this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above opyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.
* Neither the name of the author nor the names of contributors may be used
  to endorse or promote products derived from this software without specific
  prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.
IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef DK4STRMCO_H_INCLUDED
/** Avoid multiple inclusions. */
#define DK4STRMCO_H_INCLUDED 1


#line 9 "dk4strmco.ctr"

/**	@file	dk4strmco.h	Compression streams.

A compression stream is an additional dk4_stream_t object on top of
an existring stream (referred to as downside stream).

Data written to the compression stream is compressed using one or multiple
algorithms:

- Run-length encoding as preprocessing.
- Flate compression or LZW compression.
- ASCII-Hex or ASCII-85 output encoding.

The results of the compression operations are passed to the downside stream.

Note: Closing the compression stream does not close the downside stream.

So you create a mixed stream (i.e. for PDF files) containing both plain
text and compressed chunks. To add a compressed chunk open a compression
stream on top of the existing output stream, pass data to the compression
stream, close the compression stream and continue writing to the output
stream.

*/

#ifndef	DK4CONF_H_INCLUDED
#include "dk4conf.h"
#endif

#ifndef	DK4ERROR_H_INCLUDED
#include "dk4error.h"
#endif

#ifndef	DK4STRM_H_INCLUDED
#include "dk4strm.h"
#endif


/**	Preprocessing before compression.
*/
enum dk4_strmco_pp {
	DK4_STRMCO_PP_NONE	= 0 ,	/**< No preprocessing. */
	DK4_STRMCO_PP_RUNLENGTH		/**< Use run-length before real compression. */
};


/**	Compression method.
*/
enum dk4_strmco_co {
	DK4_STRMCO_CO_NONE	= 0 ,	/**< No compression. */
	DK4_STRMCO_CO_FLATE	,		/**< Use flate compression. */
	DK4_STRMCO_CO_LZW			/**< Use LZW compression for PS level 2. */
};


/**	Output encoding.
*/
enum dk4_strmco_oe {
	DK4_STRMCO_OE_NONE	= 0 ,	/**< No output encoding. */
	DK4_STRMCO_OE_HEX ,			/**< Hexadecimal encoding. */
	DK4_STRMCO_OE_ASCII85		/**< ASCII85 encoding. */
};


/**	Flags for compression stream.
*/
enum {
	DK4_STRMCO_FL_EOD_PP	= 1 ,	/**< Write EOD marker at end of preproc. */
	DK4_STRMCO_FL_EOD_OE	= 2 ,	/**< Write EOD marker at end of out enc. */
	DK4_STRMCO_FL_NL_OE		= 4 ,	/**< Break output lines before 80. */
	DK4_STRMCO_FL_CR_NL		= 8 ,	/**< Use CR/NL combination. */
	DK4_STRMCO_FL_UPPER_OE	= 16 ,	/**< Upper case characters in hex digits. */
};


#ifdef	__cplusplus
extern "C" {
#endif

/**	Open a compressing stream on top of an existing stream.
	Only write operations can be performed on the new stream, no
	read operations.
	@param	strm	Low-level destination stream, must be writable.
	@param	pp		Preprocessing method.
	@param	co		Compression method.
	@param	oe		Output encoding.
	@param	fl		Flags.
	@param	erp		Error report, may be NULL.
	@return	Valid pointer to new stream on success, NULL on error.
*/
dk4_stream_t *
dk4strmco_open(
	dk4_stream_t		*strm,
	enum dk4_strmco_pp	 pp,
	enum dk4_strmco_co	 co,
	enum dk4_strmco_oe	 oe,
	int					 fl,
	dk4_er_t			*erp
);

#ifdef	__cplusplus
}
#endif


/* vim: set ai sw=4 ts=4 : */

#endif