path: root/src/cmd/bzip2/lib/bzlib_private.h

/*
 * THIS FILE IS NOT IDENTICAL TO THE ORIGINAL
 * FROM THE BZIP2 DISTRIBUTION.
 *
 * It has been modified, mainly to break the library
 * into smaller pieces.
 *
 * Russ Cox
 * rsc@plan9.bell-labs.com
 * July 2000
 */


/*-------------------------------------------------------------*/
/*--- Private header file for the library.						---*/
/*---													  bzlib_private.h ---*/
/*-------------------------------------------------------------*/

/*--
  This file is a part of bzip2 and/or libbzip2, a program and
  library for lossless, block-sorting data compression.

  Copyright (C) 1996-2000 Julian R Seward.  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  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. The origin of this software must not be misrepresented; you must 
	  not claim that you wrote the original software.	If you use this 
	  software in a product, an acknowledgment in the product 
	  documentation would be appreciated but is not required.

  3. Altered source versions must be plainly marked as such, and must
	  not be misrepresented as being the original software.

  4. The name of the author may not be used to endorse or promote 
	  products derived from this software without specific prior written 
	  permission.

  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.

  Julian Seward, Cambridge, UK.
  jseward@acm.org
  bzip2/libbzip2 version 1.0 of 21 March 2000

  This program is based on (at least) the work of:
	  Mike Burrows
	  David Wheeler
	  Peter Fenwick
	  Alistair Moffat
	  Radford Neal
	  Ian H. Witten
	  Robert Sedgewick
	  Jon L. Bentley

  For more information on these sources, see the manual.
--*/


#ifndef _BZLIB_PRIVATE_H
#define _BZLIB_PRIVATE_H

/*-- General stuff. --*/

#define BZ_VERSION  "1.0.1, 23-June-2000"

#ifndef __GNUC__
#define __inline__  /* */
#endif 

/* these #defines can be overridden by bzlib_stdio.h */
extern void bz_internal_error ( int errcode );
#define AssertH(cond,errcode) \
	{ if (!(cond)) bz_internal_error ( errcode ); }
#define AssertD(cond,msg) /* */
#define VPrintf0(zf) USED(zf)
#define VPrintf1(zf,za1) do { USED(zf); USED(za1); } while(0)
#define VPrintf2(zf,za1,za2) do { USED(zf); USED(za1); USED(za2); } while(0)
#define VPrintf3(zf,za1,za2,za3) do { USED(zf); USED(za1); USED(za2); USED(za3); } while(0)
#define VPrintf4(zf,za1,za2,za3,za4) do { USED(zf); USED(za1); USED(za2); USED(za3); USED(za4); } while(0)
#define VPrintf5(zf,za1,za2,za3,za4,za5) do { USED(zf); USED(za1); USED(za2); USED(za3); USED(za4); USED(za5); } while(0)

#define BZALLOC(nnn) (strm->bzalloc)(strm->opaque,(nnn),1)
#define BZFREE(ppp)	(strm->bzfree)(strm->opaque,(ppp))


/*-- Constants for the back end. --*/

#define BZ_MAX_ALPHA_SIZE 258
#define BZ_MAX_CODE_LEN		23

#define BZ_RUNA 0
#define BZ_RUNB 1

#define BZ_N_GROUPS 6
#define BZ_G_SIZE	  50
#define BZ_N_ITERS  4

#define BZ_MAX_SELECTORS (2 + (900000 / BZ_G_SIZE))



/*-- Stuff for randomising repetitive blocks. --*/

extern Int32 BZ2_rNums[512];

#define BZ_RAND_DECLS								  \
	Int32 rNToGo;										  \
	Int32 rTPos											  \

#define BZ_RAND_INIT_MASK							  \
	s->rNToGo = 0;										  \
	s->rTPos	 = 0										  \

#define BZ_RAND_MASK ((s->rNToGo == 1) ? 1 : 0)

#define BZ_RAND_UPD_MASK							  \
	if (s->rNToGo == 0) {							  \
		s->rNToGo = BZ2_rNums[s->rTPos];			  \
		s->rTPos++;										  \
		if (s->rTPos == 512) s->rTPos = 0;		  \
	}														  \
	s->rNToGo--;



/*-- Stuff for doing CRCs. --*/

extern UInt32 BZ2_crc32Table[256];

#define BZ_INITIALISE_CRC(crcVar)				  \
{															  \
	crcVar = 0xffffffffL;							  \
}

#define BZ_FINALISE_CRC(crcVar)					  \
{															  \
	crcVar = ~(crcVar);								  \
}

#define BZ_UPDATE_CRC(crcVar,cha)				  \
{															  \
	crcVar = (crcVar << 8) ^						  \
				BZ2_crc32Table[(crcVar >> 24) ^	  \
									((UChar)cha)];		  \
}



/*-- States and modes for compression. --*/

#define BZ_M_IDLE		  1
#define BZ_M_RUNNING	  2
#define BZ_M_FLUSHING  3
#define BZ_M_FINISHING 4

#define BZ_S_OUTPUT	  1
#define BZ_S_INPUT	  2

#define BZ_N_RADIX 2
#define BZ_N_QSORT 12
#define BZ_N_SHELL 18
#define BZ_N_OVERSHOOT (BZ_N_RADIX + BZ_N_QSORT + BZ_N_SHELL + 2)




/*-- Structure holding all the compression-side stuff. --*/

typedef
	struct {
		/* pointer back to the struct bz_stream */
		bz_stream* strm;

		/* mode this stream is in, and whether inputting */
		/* or outputting data */
		Int32		mode;
		Int32		state;

		/* remembers avail_in when flush/finish requested */
		UInt32	avail_in_expect;

		/* for doing the block sorting */
		UInt32*	arr1;
		UInt32*	arr2;
		UInt32*	ftab;
		Int32		origPtr;

		/* aliases for arr1 and arr2 */
		UInt32*	ptr;
		UChar*	block;
		UInt16*	mtfv;
		UChar*	zbits;

		/* for deciding when to use the fallback sorting algorithm */
		Int32		workFactor;

		/* run-length-encoding of the input */
		UInt32	state_in_ch;
		Int32		state_in_len;
		BZ_RAND_DECLS;

		/* input and output limits and current posns */
		Int32		nblock;
		Int32		nblockMAX;
		Int32		numZ;
		Int32		state_out_pos;

		/* map of bytes used in block */
		Int32		nInUse;
		Bool		inUse[256];
		UChar		unseqToSeq[256];

		/* the buffer for bit stream creation */
		UInt32	bsBuff;
		Int32		bsLive;

		/* block and combined CRCs */
		UInt32	blockCRC;
		UInt32	combinedCRC;

		/* misc administratium */
		Int32		verbosity;
		Int32		blockNo;
		Int32		blockSize100k;

		/* stuff for coding the MTF values */
		Int32		nMTF;
		Int32		mtfFreq	  [BZ_MAX_ALPHA_SIZE];
		UChar		selector	  [BZ_MAX_SELECTORS];
		UChar		selectorMtf[BZ_MAX_SELECTORS];

		UChar		len	  [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
		Int32		code	  [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
		Int32		rfreq	  [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
		/* second dimension: only 3 needed; 4 makes index calculations faster */
		UInt32	len_pack[BZ_MAX_ALPHA_SIZE][4];

	}
	EState;



/*-- externs for compression. --*/

extern void 
BZ2_blockSort ( EState* );

extern void 
BZ2_compressBlock ( EState*, Bool );

extern void 
BZ2_bsInitWrite ( EState* );

extern void 
BZ2_hbAssignCodes ( Int32*, UChar*, Int32, Int32, Int32 );

extern void 
BZ2_hbMakeCodeLengths ( UChar*, Int32*, Int32, Int32 );



/*-- states for decompression. --*/

#define BZ_X_IDLE			 1
#define BZ_X_OUTPUT		 2

#define BZ_X_MAGIC_1		 10
#define BZ_X_MAGIC_2		 11
#define BZ_X_MAGIC_3		 12
#define BZ_X_MAGIC_4		 13
#define BZ_X_BLKHDR_1	 14
#define BZ_X_BLKHDR_2	 15
#define BZ_X_BLKHDR_3	 16
#define BZ_X_BLKHDR_4	 17
#define BZ_X_BLKHDR_5	 18
#define BZ_X_BLKHDR_6	 19
#define BZ_X_BCRC_1		 20
#define BZ_X_BCRC_2		 21
#define BZ_X_BCRC_3		 22
#define BZ_X_BCRC_4		 23
#define BZ_X_RANDBIT		 24
#define BZ_X_ORIGPTR_1	 25
#define BZ_X_ORIGPTR_2	 26
#define BZ_X_ORIGPTR_3	 27
#define BZ_X_MAPPING_1	 28
#define BZ_X_MAPPING_2	 29
#define BZ_X_SELECTOR_1	 30
#define BZ_X_SELECTOR_2	 31
#define BZ_X_SELECTOR_3	 32
#define BZ_X_CODING_1	 33
#define BZ_X_CODING_2	 34
#define BZ_X_CODING_3	 35
#define BZ_X_MTF_1		 36
#define BZ_X_MTF_2		 37
#define BZ_X_MTF_3		 38
#define BZ_X_MTF_4		 39
#define BZ_X_MTF_5		 40
#define BZ_X_MTF_6		 41
#define BZ_X_ENDHDR_2	 42
#define BZ_X_ENDHDR_3	 43
#define BZ_X_ENDHDR_4	 44
#define BZ_X_ENDHDR_5	 45
#define BZ_X_ENDHDR_6	 46
#define BZ_X_CCRC_1		 47
#define BZ_X_CCRC_2		 48
#define BZ_X_CCRC_3		 49
#define BZ_X_CCRC_4		 50



/*-- Constants for the fast MTF decoder. --*/

#define MTFA_SIZE 4096
#define MTFL_SIZE 16



/*-- Structure holding all the decompression-side stuff. --*/

typedef
	struct {
		/* pointer back to the struct bz_stream */
		bz_stream* strm;

		/* state indicator for this stream */
		Int32		state;

		/* for doing the final run-length decoding */
		UChar		state_out_ch;
		Int32		state_out_len;
		Bool		blockRandomised;
		BZ_RAND_DECLS;

		/* the buffer for bit stream reading */
		UInt32	bsBuff;
		Int32		bsLive;

		/* misc administratium */
		Int32		blockSize100k;
		Bool		smallDecompress;
		Int32		currBlockNo;
		Int32		verbosity;

		/* for undoing the Burrows-Wheeler transform */
		Int32		origPtr;
		UInt32	tPos;
		Int32		k0;
		Int32		unzftab[256];
		Int32		nblock_used;
		Int32		cftab[257];
		Int32		cftabCopy[257];

		/* for undoing the Burrows-Wheeler transform (FAST) */
		UInt32	*tt;

		/* for undoing the Burrows-Wheeler transform (SMALL) */
		UInt16	*ll16;
		UChar		*ll4;

		/* stored and calculated CRCs */
		UInt32	storedBlockCRC;
		UInt32	storedCombinedCRC;
		UInt32	calculatedBlockCRC;
		UInt32	calculatedCombinedCRC;

		/* map of bytes used in block */
		Int32		nInUse;
		Bool		inUse[256];
		Bool		inUse16[16];
		UChar		seqToUnseq[256];

		/* for decoding the MTF values */
		UChar		mtfa	 [MTFA_SIZE];
		Int32		mtfbase[256 / MTFL_SIZE];
		UChar		selector	  [BZ_MAX_SELECTORS];
		UChar		selectorMtf[BZ_MAX_SELECTORS];
		UChar		len  [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];

		Int32		limit	 [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
		Int32		base	 [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
		Int32		perm	 [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
		Int32		minLens[BZ_N_GROUPS];

		/* save area for scalars in the main decompress code */
		Int32		save_i;
		Int32		save_j;
		Int32		save_t;
		Int32		save_alphaSize;
		Int32		save_nGroups;
		Int32		save_nSelectors;
		Int32		save_EOB;
		Int32		save_groupNo;
		Int32		save_groupPos;
		Int32		save_nextSym;
		Int32		save_nblockMAX;
		Int32		save_nblock;
		Int32		save_es;
		Int32		save_N;
		Int32		save_curr;
		Int32		save_zt;
		Int32		save_zn; 
		Int32		save_zvec;
		Int32		save_zj;
		Int32		save_gSel;
		Int32		save_gMinlen;
		Int32*	save_gLimit;
		Int32*	save_gBase;
		Int32*	save_gPerm;

	}
	DState;



/*-- Macros for decompression. --*/

#define BZ_GET_FAST(cccc)							 \
	 s->tPos = s->tt[s->tPos];						 \
	 cccc = (UChar)(s->tPos & 0xff);				 \
	 s->tPos >>= 8;

#define BZ_GET_FAST_C(cccc)						 \
	 c_tPos = c_tt[c_tPos];							 \
	 cccc = (UChar)(c_tPos & 0xff);				 \
	 c_tPos >>= 8;

#define SET_LL4(i,n)														  \
	{ if (((i) & 0x1) == 0)												  \
		  s->ll4[(i) >> 1] = (s->ll4[(i) >> 1] & 0xf0) | (n); else	  \
		  s->ll4[(i) >> 1] = (s->ll4[(i) >> 1] & 0x0f) | ((n) << 4);  \
	}

#define GET_LL4(i)									  \
	((((UInt32)(s->ll4[(i) >> 1])) >> (((i) << 2) & 0x4)) & 0xF)

#define SET_LL(i,n)									\
	{ s->ll16[i] = (UInt16)(n & 0x0000ffff);	\
	  SET_LL4(i, n >> 16);							\
	}

#define GET_LL(i) \
	(((UInt32)s->ll16[i]) | (GET_LL4(i) << 16))

#define BZ_GET_SMALL(cccc)										\
		cccc = BZ2_indexIntoF ( s->tPos, s->cftab );		\
		s->tPos = GET_LL(s->tPos);


/*-- externs for decompression. --*/

extern Int32 
BZ2_indexIntoF ( Int32, Int32* );

extern Int32 
BZ2_decompress ( DState* );

extern void 
BZ2_hbCreateDecodeTables ( Int32*, Int32*, Int32*, UChar*,
									Int32,  Int32, Int32 );


#endif

/* sometimes not including <stdio.h> makes this necessary */
#ifndef NULL
#define NULL 0
#endif

/* internal library functions */
extern int
bz_config_ok( void );

extern void*
default_bzalloc( void*, Int32, Int32 );

extern void
default_bzfree( void*, void* );

/*-------------------------------------------------------------*/
/*--- end											  bzlib_private.h ---*/
/*-------------------------------------------------------------*/