xref: /plan9/sys/src/cmd/bzip2/lib/bzlib_private.h (revision 59cc4ca53493a3c6d2349fe2b7f7c40f7dce7294)

/*
 * 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) /* */
#define VPrintf1(zf,za1) /* */
#define VPrintf2(zf,za1,za2) /* */
#define VPrintf3(zf,za1,za2,za3) /* */
#define VPrintf4(zf,za1,za2,za3,za4) /* */
#define VPrintf5(zf,za1,za2,za3,za4,za5) /* */

#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 ---*/
/*-------------------------------------------------------------*/