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%%	options

copyright owner	=	Dirk Krause
copyright year	=	2015-xxxx
license		=	bsd



%%	header

/**	@file	dk4rle.h	Run length encoder as
described in the PS and PDF specifications.

Use the dk4rle_init() function to initialize the encoder first.

Add binary data byte by byte, use dk4rle_add(). If this function
returns DK4_EDSTM_ACCEPT, the byte was successfully stored in the encoder,
no further action is necessary. If the function returns DK4_EDSTM_FINISHED,
either a run or a sequence of literal bytes was completed; use
dk4rle_output() to retrieve the output data.

After passing all bytes to the encoder there is probably data in the
encoder not yet retrieved. Use the dk4rle_finish() function to check.
If the function returns DK4_EDSTM_FINISHED, use dk4rle_output() to retrieve
the final output data.
*/

#include "dk4error.h"

/**	Run-length encoder.
*/
typedef struct {
  unsigned char	 ob[144];	/**< Buffer for both input and output. */
  unsigned char	*ib;		/**< Pointer to ob[1], input buffer. */
  size_t	 oused;		/**< Output buffer size. */
  size_t	 iused;		/**< Number of input bytes available. */
  size_t	 ao_si;		/**< Index to save bytes from after output. */
  size_t	 ao_ss;		/**< Size of buffer part to save after out. */
  size_t	 ao_iu;		/**< Number of input bytes after output. */
  int		 ao_st;		/**< New state after output. */
  int		 st;		/**< Current state. */
  int		 lwo;		/**< Flag: Last operation was output. */
  int		 weod;		/**< Flag: Write EOD marker at end. */
} dk4_rl_enc_t;

#ifdef __cplusplus
extern "C" {
#endif

/**	Initialize encoder before using it.
	@param	enc	Encoder to initialize.
	@param	weod	Flag: Write EOD marker at end of data.
	@param	erp	Error report, may be NULL.

	Error codes:
	- DK4_E_INVALID_ARGUMENTS	if enc is NULL.
*/
void
dk4rle_init(dk4_rl_enc_t *enc, int weod, dk4_er_t *erp);

/**	Add a single byte to the encoder.
	@param	enc	Encoder.
	@param	ibyte	Input byte to process.
	@param	erp	Error report, may be NULL.
	@return	Action to take, one from:
	- DK4_EDSTM_ACCEPT<br>
	  if the input byte was successfully stored in the internal data
	  structures without completing a run. No further action
	  necessary.
	- DK4_EDSTM_FINISHED<br>
	  if a run was completed. Use dk4rle_output() to obtain the
	  output data.
	- DK4_EDSTM_ERROR<br>
	  if an error occured.

	Error codes:
	- DK4_E_INVALID_ARGUMENTS	if enc is NULL.
*/
int
dk4rle_add(dk4_rl_enc_t *enc, unsigned char ibyte, dk4_er_t *erp);

/**	Finish data stream, process final data still stored in the
	encoder.
	@param	enc	Encoder.
	@param	erp	Error report, may be NULL.
	@return	Action to take, one from:
	- DK4_EDSTM_ACCEPT<br>
	  if the input byte was successfully stored in the internal data
	  structures without completing a run. No further action
	  necessary.
	- DK4_EDSTM_FINISHED<br>
	  if a run was completed. Use dk4rle_output() to obtain the
	  output data.
	- DK4_EDSTM_ERROR<br>
	  if an error occured.

	Error codes:
	- DK4_E_INVALID_ARGUMENTS	if enc is NULL.
*/
int
dk4rle_finish(dk4_rl_enc_t *enc, dk4_er_t *erp);

/**	Retrieve encoder output.
	@param	dptr	Address of pointer to set to output bytes, should
			be initialized to NULL.
	@param	szptr	Address of size variable for buffer length,
			should be initialized to 0.
	@param	enc	Encoder.
	@param	erp	Error report, may be NULL.
	@return	1 if there is data available, 0 otherwise.

	Error codes:
	- DK4_E_INVALID_ARGUMENTS	if enc is NULL.
*/
int
dk4rle_output(
  const unsigned char **dptr, size_t *szptr, dk4_rl_enc_t *enc, dk4_er_t *erp
);

#ifdef __cplusplus
}
#endif



%%	module

#include "dk4rle.h"
#include "dk4edstm.h"
#include "dk4mem.h"
#include "dk4memcpl.h"



$!trace-include



/**	Run length encoder state.
*/
enum {
			/**	No run detected yet.
			*/
  RLE_ENC_STATE_NO_RUN	= 0,

			/**	Currently in a run.
			*/
  RLE_ENC_STATE_RUN
};



/**	Calculate byte for a run length.
	@param	sz	Length of the run.
	@return	Byte value to indicate length.
*/
static
unsigned char
dk4rle_run_length_byte(size_t sz)
{
  return ((unsigned char)(257 - sz));
}



/**	Calculate byte for a literal length.
	@param	sz	Length of literal data.
	@return	Byte value to indicate the length.
*/
static
unsigned char
dk4rle_literal_length_byte(size_t sz)
{
  return ((unsigned char)(sz - 1));
}




void
dk4rle_init(dk4_rl_enc_t *enc, int weod, dk4_er_t *erp)
{
  if (NULL != enc) {
    enc->ib = &(enc->ob[1]);
    enc->oused = 0;
    enc->iused = 0;
    enc->ao_si = 0;
    enc->ao_ss = 0;
    enc->ao_iu = 0;
    enc->ao_st = RLE_ENC_STATE_NO_RUN;
    enc->st    = RLE_ENC_STATE_NO_RUN;
    enc->lwo = 0;
    enc->weod = ((0 != weod) ? 1 : 0);
  } else {
    dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS);
  }
}



static
void
dk4rle_process_lwo(dk4_rl_enc_t *enc)
{
  if (0 < enc->ao_ss) {
    dk4mem_cpy_to_left(
      enc->ib,
      &((enc->ib)[enc->ao_si]),
      enc->ao_ss,
      NULL
    );
  }
  enc->iused = enc->ao_iu;
  enc->st    = enc->ao_st;
  enc->lwo   = 0;
}



int
dk4rle_add(dk4_rl_enc_t *enc, unsigned char ibyte, dk4_er_t *erp)
{
  int		 back	=	DK4_EDSTM_ERROR;
  int		 cr	=	0;		/* Flag: Change to run */
  $? "+ dk4rle_add %02x", (unsigned)ibyte
  if (NULL != enc) {
    if (0 != enc->lwo) { dk4rle_process_lwo(enc); }
    $? ". index = %u", (unsigned)(enc->iused)
    back = DK4_EDSTM_ACCEPT;
    (enc->ib)[enc->iused] = ibyte;
    enc->iused += 1;
    switch (enc->st) {
      case RLE_ENC_STATE_RUN : {
        /*
		In a run.
	*/
	if ((enc->ib)[enc->iused - 1] != (enc->ib)[enc->iused - 2]) {
	  $? ". end of run"
	  /*
	  	End of run, change to normal mode.
	  */
	  enc->ob[0] = dk4rle_run_length_byte(enc->iused - 1);
	  enc->oused = 2;
	  back = DK4_EDSTM_FINISHED;
	  enc->ao_si = enc->iused - 1;
	  enc->ao_ss = 1;
	  enc->ao_iu = 1;
	  enc->ao_st = RLE_ENC_STATE_NO_RUN;
	} else {
	  /*
	  	No end of run, continue.
	  */
	  if (128 <= enc->iused) {
	    $? ". run at limit"
	    /*
	    	Full 128 byte run, output.
	    */
	    enc->ob[0] = dk4rle_run_length_byte(128);
	    enc->oused = 2;
	    back = DK4_EDSTM_FINISHED;
	    enc->ao_si = 0;
	    enc->ao_ss = 0;
	    enc->ao_iu = 0;
	    enc->ao_st = RLE_ENC_STATE_NO_RUN;
	  }
	}
      } break;
      default : {
        /*
		Not in a run.
	*/
	if (4 <= enc->iused) {
	  if (enc->ib[enc->iused - 1] == enc->ib[enc->iused - 2]) {
	    if (enc->ib[enc->iused - 1] == enc->ib[enc->iused - 3]) {
	      if (enc->ib[enc->iused - 1] == enc->ib[enc->iused - 4]) {
	        cr = 1;		$? ". change to run"
	      }
	    }
	  }
	}
	if (1 == cr) {
	  $? ". start run"
	  if (4 < enc->iused) {
	    enc->ob[0] = dk4rle_literal_length_byte(enc->iused - 4);
	    enc->oused = (enc->iused - 3);
	    back = DK4_EDSTM_FINISHED;
	    enc->ao_si = enc->iused - 4;
	    enc->ao_ss = 4;
	    enc->ao_iu = 4;
	    enc->ao_st = RLE_ENC_STATE_RUN;
	  } else {
	    enc->st = RLE_ENC_STATE_RUN;
	  }
	} else {
	  if (128 <= enc->iused) {
	    if ((enc->ib)[127] == (enc->ib)[126]) {
	      if ((enc->ib)[127] == (enc->ib)[125]) {	$? ". save last 3"
	        enc->ob[0] = dk4rle_literal_length_byte(125);
		enc->oused = 126;
		back = DK4_EDSTM_FINISHED;
		enc->ao_si = 125;
		enc->ao_ss = 3;
		enc->ao_iu = 3;
		enc->ao_st = RLE_ENC_STATE_NO_RUN;
	      } else {			$? ". limit reached, save last 2"
	        enc->ob[0] = dk4rle_literal_length_byte(126);
		enc->oused = 127;
		back = DK4_EDSTM_FINISHED;
		enc->ao_si = 126;
		enc->ao_ss = 2;
		enc->ao_iu = 2;
		enc->ao_st = RLE_ENC_STATE_NO_RUN;
	      }
	    } else {			$? ". limit reached, output all"
	      enc->ob[0] = dk4rle_literal_length_byte(128);
	      enc->oused = 129;
	      back = DK4_EDSTM_FINISHED;
	      enc->ao_si = 0;
	      enc->ao_ss = 0;
	      enc->ao_iu = 0;
	      enc->ao_st = RLE_ENC_STATE_NO_RUN;
	    }
	  }
	}
      } break;
    }
    if (DK4_EDSTM_FINISHED == back) {
      enc->lwo = 1;		$? ". finished"
    }
  } else {
    dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS);
  } $? "- dk4rle_add %d", back
  return back;
}



int
dk4rle_finish(dk4_rl_enc_t *enc, dk4_er_t *erp)
{
  int		 back	=	DK4_EDSTM_ERROR;
  $? "+ dk4rle_finish"
  if (NULL != enc) {
    if (0 != enc->lwo) { dk4rle_process_lwo(enc); }
    back = DK4_EDSTM_ACCEPT;
    if (0 < enc->iused) {		$? ". input available"
      switch (enc->st) {
        case RLE_ENC_STATE_RUN : {	$? ". final run"
	  enc->ob[0] = dk4rle_run_length_byte(enc->iused);
	  enc->oused = 2;
	  back = DK4_EDSTM_FINISHED;
	  enc->ao_si = 0;
	  enc->ao_ss = 0;
	  enc->ao_iu = 0;
	  enc->ao_st = RLE_ENC_STATE_NO_RUN;
	  if (0 != enc->weod) {		$? ". add eod"
	    enc->ob[2] = (unsigned char)128;
	    enc->oused = 3;
	  }
	} break;
	default : {			$? ". final literal bytes"
	  enc->ob[0] = dk4rle_literal_length_byte(enc->iused);
	  enc->oused = enc->iused + 1;
	  back = DK4_EDSTM_FINISHED;
	  enc->ao_si = 0;
	  enc->ao_ss = 0;
	  enc->ao_iu = 0;
	  enc->ao_st = RLE_ENC_STATE_NO_RUN;
	  if (0 != enc->weod) {		$? ". add eod"
	    enc->ob[enc->iused] = (unsigned char)128;
	    enc->oused += 1;
	  }
	} break;
      }
    } else {
      if (0 != enc->weod) {		$? ". write eod"
        enc->ob[0] = (unsigned char)128;
	enc->oused = 1;
	back = DK4_EDSTM_FINISHED;
	enc->ao_si = 0;
	enc->ao_ss = 0;
	enc->ao_iu = 0;
	enc->ao_st = RLE_ENC_STATE_NO_RUN;
      }
    }
    if (DK4_EDSTM_FINISHED == back) {
      enc->lwo = 1;
    }
  } else {
    dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS);
  } $? "- dk4rle_finish %d", back
  return back;
}



int
dk4rle_output(
  const unsigned char **dptr, size_t *szptr, dk4_rl_enc_t *enc, dk4_er_t *erp
)
{
  int		 back	=	0;
  if ((NULL != enc) && (NULL != dptr) && (NULL != szptr)) {
    if (0 < enc->oused) {
      *dptr = &(enc->ob[0]);
      *szptr = enc->oused;
      back = 1;
    } else {
      *dptr = NULL; *szptr = 0;
    }
  } else {
    dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS);
  }
  return back;
}



/*
	Below is the first working code for the module.
	This code worked perfectly fine, but for performance reasons
	I wanted to avoid the memory copy operations from input buffer
	to output buffer.
	If there is any problem with the current code, we have the chance
	to go back and test with the original code.
*/
#if 0
/* ---------- Header ---------- */
#include "dk4error.h"

/**	Run length encoder.
*/
typedef struct {
  unsigned char		ob[144];	/**< Output buffer. */
  unsigned char		ib[128];	/**< Input buffer. */
  size_t		iused;		/**< Number of bytes in ib. */
  size_t		oused;		/**< Number of bytes in ob. */
  int			st;		/**< Current state. */
  int			weod;		/**< Flag: Write EOD marker at end. */
} dk4_rl_enc_t;


#ifdef __cplusplus
extern "C" {
#endif

/**	Initialize encoder before using it.
	@param	enc	Encoder to initialize.
	@param	weod	Flag: Write EOD marker at end of data.
	@param	erp	Error report, may be NULL.

	Error codes:
	- DK4_E_INVALID_ARGUMENTS	if enc is NULL.
*/
void
dk4rle_init(dk4_rl_enc_t *enc, int weod, dk4_er_t *erp);

/**	Add a single byte to the encoder.
	@param	enc	Encoder.
	@param	ibyte	Input byte to process.
	@param	erp	Error report, may be NULL.
	@return	Action to take, one from:
	- DK4_EDSTM_ACCEPT<br>
	  if the input byte was successfully stored in the internal data
	  structures without completing a run. No further action
	  necessary.
	- DK4_EDSTM_FINISHED<br>
	  if a run was completed. Use dk4rle_output() to obtain the
	  output data.
	- DK4_EDSTM_ERROR<br>
	  if an error occured.

	Error codes:
	- DK4_E_INVALID_ARGUMENTS	if enc is NULL.
*/
int
dk4rle_add(dk4_rl_enc_t *enc, unsigned char ibyte, dk4_er_t *erp);

/**	Finish data stream, process final data still stored in the
	encoder.
	@param	enc	Encoder.
	@param	erp	Error report, may be NULL.
	@return	Action to take, one from:
	- DK4_EDSTM_ACCEPT<br>
	  if the input byte was successfully stored in the internal data
	  structures without completing a run. No further action
	  necessary.
	- DK4_EDSTM_FINISHED<br>
	  if a run was completed. Use dk4rle_output() to obtain the
	  output data.
	- DK4_EDSTM_ERROR<br>
	  if an error occured.

	Error codes:
	- DK4_E_INVALID_ARGUMENTS	if enc is NULL.
*/
int
dk4rle_finish(dk4_rl_enc_t *enc, dk4_er_t *erp);

/**	Retrieve encoder output.
	@param	dptr	Address of pointer to set to output bytes, should
			be initialized to NULL.
	@param	szptr	Address of size variable for buffer length,
			should be initialized to 0.
	@param	enc	Encoder.
	@param	erp	Error report, may be NULL.
	@return	1 if there is data available, 0 otherwise.

	Error codes:
	- DK4_E_INVALID_ARGUMENTS	if enc is NULL.
*/
int
dk4rle_output(
  const unsigned char **dptr, size_t *szptr, dk4_rl_enc_t *enc, dk4_er_t *erp
);

#ifdef __cplusplus
}
#endif
/* ---------------------------- */

/* ---------- Module ---------- */
#include "dk4rle.h"
#include "dk4edstm.h"
#include "dk4mem.h"
#include "dk4memcpl.h"

$!trace-include

/**	Run length encoder state.
*/
enum {
			/**	No run detected yet.
			*/
  RLE_ENC_STATE_NO_RUN	= 0,

			/**	Currently in a run.
			*/
  RLE_ENC_STATE_RUN
};

void
dk4rle_init(dk4_rl_enc_t *enc, int weod, dk4_er_t *erp)
{
  $? "+ dk4rle_init"
  if (NULL != enc) {
    DK4_MEMRES(enc, sizeof(dk4_rl_enc_t));
    enc->st = RLE_ENC_STATE_NO_RUN;
    enc->iused = 0;
    enc->oused = 0;
    enc->weod = ((0 != weod) ? 1 : 0);
  } else {
    dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS);
  } $? "- dk4rle_init"
}

/**	Calculate byte for a run length.
	@param	sz	Length of the run.
	@return	Byte value to indicate length.
*/
static
unsigned char
dk4rle_run_length_byte(size_t sz)
{
  return ((unsigned char)(257 - sz));
}

/**	Calculate byte for a literal length.
	@param	sz	Length of literal data.
	@return	Byte value to indicate the length.
*/
static
unsigned char
dk4rle_literal_length_byte(size_t sz)
{
  return ((unsigned char)(sz - 1));
}

int
dk4rle_add(dk4_rl_enc_t *enc, unsigned char ibyte, dk4_er_t *erp)
{
  int		 back	=	DK4_EDSTM_ERROR;
  int		 cr	=	0;			/* Flag: Change run */
  $? "+ dk4rle_add"
  if (NULL != enc) {				$? ". enc"
    $? ". iused = %u", (unsigned)(enc->iused)
    back = DK4_EDSTM_ACCEPT;			$? ". back"
    enc->ib[enc->iused] = ibyte;		$? ". ib[used]"
    enc->iused += 1;				$? ". iused += 1"
    switch (enc->st) {
      case RLE_ENC_STATE_RUN : {		$? ". in run"
        if (enc->ib[enc->iused - 1] != enc->ib[enc->iused - 2]) {
	  /*	Copy data to output buffer.
	  */
	  enc->ob[1] = enc->ib[enc->iused - 2];
	  /*	Set run-length byte.
	  */
	  enc->ob[0] = dk4rle_run_length_byte(enc->iused - 1);
	  /*	Set total byte size.
	  */
	  enc->oused = 2;
	  /*	Keep input byte.
	  */
	  enc->ib[0] = enc->ib[enc->iused - 1];
	  /*	Number of input bytes is 1 now.
	  */
	  enc->iused = 1;
	  /*	Output ready.
	  */
	  back = DK4_EDSTM_FINISHED;
	  /*	No longer in a run.
	  */
	  enc->st = RLE_ENC_STATE_NO_RUN;
	} else {
	  if (128 <= enc->iused) {
	    /*	Copy data to output buffer.
	    */
	    enc->ob[1] = enc->ib[0];
	    /*	Set run-length byte.
	    */
	    enc->ob[0] = dk4rle_run_length_byte(128);
	    /*	Set total byte size.
	    */
	    enc->oused = 2;
	    /*	No input bytes available.
	    */
	    enc->iused = 0;
	    /*	Output ready.
	    */
	    back = DK4_EDSTM_FINISHED;
	    /*	No longer in a run.
	    */
	    enc->st = RLE_ENC_STATE_NO_RUN;
	  }
	}
      } break;
      default : {			$? ". not in a run"
        if (4 <= enc->iused) {						$? ". 4"
	  if (enc->ib[enc->iused - 1] == enc->ib[enc->iused - 2]) {	$? ". 2"
	    if (enc->ib[enc->iused - 1] == enc->ib[enc->iused - 3]) {	$? ". 3"
	      if (enc->ib[enc->iused - 1] == enc->ib[enc->iused - 4]) {	$? ". 4"
	        cr = 1;
	      }
	    }
	  }
	  if (1 == cr) {		$? ". start of run found"
	    /*
	    	Start of run.
	    */
	    if (4 < enc->iused) {
	      /*
	      		Output the literal data before run.
	      */
	      /*	Copy data to output buffer.
	      */
	      DK4_MEMCPY( &(enc->ob[1]), &(enc->ib[0]), (enc->iused - 4));
	      /*	Set run-length byte.
	      */
	      enc->ob[0] = dk4rle_literal_length_byte(enc->iused - 4);
	      /*	Set total byte size.
	      */
	      enc->oused = enc->iused - 3;
	      /*	Keep last 4 bytes.
	      */
	      dk4mem_cpy_to_left(
	        &(enc->ib[0]),
		&(enc->ib[enc->iused - 4]),
		4, NULL
	      );
	      /*	Number of used input bytes is 4.
	      */
	      enc->iused = 4;
	      back = DK4_EDSTM_FINISHED;
	    }
	    enc->st = RLE_ENC_STATE_RUN;
	  } else {			$? ". no start of run found"
	    if (128 <= enc->iused) {
	      if (enc->ib[enc->iused - 1] == enc->ib[enc->iused - 2]) {
	        if (enc->ib[enc->iused - 1] == enc->ib[enc->iused - 3]) {
		  /*
		  	Keep final 3 bytes, potentially start of run.
		  */
		  /*	Copy data to output buffer.
		  */
		  DK4_MEMCPY( &(enc->ob[1]), &(enc->ib[0]), 125);
		  /*	Set run-length byte.
		  */
		  enc->ob[0] = dk4rle_literal_length_byte(128 - 3);
		  /*	Set total byte size.
		  */
		  enc->oused = 126;
		  /*	Keep last 3 bytes.
		  */
		  dk4mem_cpy_to_left(
		    &(enc->ib[0]),
		    &(enc->ib[125]),
		    3, NULL
		  );
		  /*	Number of used bytes is 2.
		  */
		  enc->iused = 3;
		} else {
		  /*
		  	Keep final 2 bytes, potentially start of run.
		  */
		  /*	Copy data.
		  */
		  DK4_MEMCPY( &(enc->ob[1]), &(enc->ib[0]), 126 );
		  /*	Set run-length byte.
		  */
		  enc->ob[0] = dk4rle_literal_length_byte(128 - 2);
		  /*	Set total byte size.
		  */
		  enc->oused = 127;
		  /*	Keep last 2 bytes.
		  */
		  dk4mem_cpy_to_left(
		    &(enc->ib[0]),
		    &(enc->ib[126]),
		    2, NULL
		  );
		  /*	Number of used bytes is 2.
		  */
		  enc->iused = 2;
		}
	      } else {
	        /*
			No need to keep any final bytes.
		*/
	        /*	Copy data.
		*/
	        DK4_MEMCPY( &(enc->ob[1]), &(enc->ib[0]), enc->iused );
		/*	Set run-length byte.
		*/
		enc->ob[0] = dk4rle_literal_length_byte(128);
		/*	Set total byte size.
		*/
		enc->oused = 129;
		/*	No input byte in buffer.
		*/
		enc->iused = 0;
	      }
	      back = DK4_EDSTM_FINISHED;
	    }
	  }
	}
      } break;
    }
  } else {				$? "! enc"
    dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS);
  } $? "- dk4rle_add %d", back
  return back;
}

int
dk4rle_finish(dk4_rl_enc_t *enc, dk4_er_t *erp)
{
  int		 back	=	DK4_EDSTM_ERROR;
  $? "+ dk4rle_finish"
  if (NULL != enc) {
    back = DK4_EDSTM_ACCEPT;
    if (0 < enc->iused) {
      switch (enc->st) {
        case RLE_ENC_STATE_RUN : {
	  /*	Copy data to output buffer.
	  */
	  enc->ob[1] = enc->ib[0];
	  /*	Set run-length byte.
	  */
	  enc->ob[0] = dk4rle_run_length_byte(enc->iused);
	  /*	Set total byte size.
	  */
	  enc->oused = 2;
	  if (0 != enc->weod) {
	    /*	Add EOD marker.
	    */
	    enc->ob[2] = (unsigned char)128;
	    enc->oused = 3;
	  }
	} break;
	default : {
	  /*	Copy data to output buffer.
	  */
	  DK4_MEMCPY( &(enc->ob[1]), &(enc->ib[0]), enc->iused );
	  /*	Set literal length byte.
	  */
	  enc->ob[0] = dk4rle_literal_length_byte(enc->iused);
	  /*	Set total byte size.
	  */
	  enc->oused = 1 + enc->iused;
	  if (0 != enc->weod) {
	    /*	Add EOD marker.
	    */
	    enc->ob[1 + enc->iused] = (unsigned char)128;
	    enc->oused += 1;
	  }
	} break;
      }
      back = DK4_EDSTM_FINISHED;
    } else {
      if (0 != enc->weod) {
        enc->ob[0] = (unsigned char)128;
	enc->oused = 1;
	back = DK4_EDSTM_FINISHED;
      }
    }
    enc->iused = 0;
    enc->st = RLE_ENC_STATE_NO_RUN;
  } else {
    dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS);
  } $? "- dk4rle_finish %d", back
  return back;
}

int
dk4rle_output(
  const unsigned char **dptr, size_t *szptr, dk4_rl_enc_t *enc, dk4_er_t *erp
)
{
  int		 back	=	0;
  $? "+ dk4rle_output"
  if (NULL != enc) {
    if (0 < enc->oused) {
      *dptr = &(enc->ob[0]);
      *szptr = enc->oused;
      back = 1;
    }
  } else {
    dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS);
  } $? "- dk4rle_output %d", back
  return back;
}
/* ---------------------------- */
#endif