
/*-------------------------------------------------------------*/
/*--- Library top-level functions.                          ---*/
/*---                                               bzlib.c ---*/
/*-------------------------------------------------------------*/

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

  Copyright (C) 1996-1999 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 0.9.5 of 24 May 1999

  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.
--*/

/*--
   CHANGES
   ~~~~~~~
   0.9.0 -- original version.

   0.9.0a/b -- no changes in this file.

   0.9.0c
      * made zero-length BZ_FLUSH work correctly in bzCompress().
      * fixed bzWrite/bzRead to ignore zero-length requests.
      * fixed bzread to correctly handle read requests after EOF.
      * wrong parameter order in call to bzDecompressInit in
        bzBuffToBuffDecompress.  Fixed.
--*/

#include "bzlib_private.h"


/*---------------------------------------------------*/
/*--- Compression stuff                           ---*/
/*---------------------------------------------------*/


/*---------------------------------------------------*/
#ifndef BZ_NO_STDIO
void bz__AssertH__fail ( int errcode )
{
   fprintf(stderr, 
      "\n\nbzip2/libbzip2, v0.9.5d: internal error number %d.\n"
      "This is a bug in bzip2/libbzip2, v0.9.5d.  Please report\n"
      "it to me at: jseward@acm.org.  If this happened when\n"
      "you were using some program which uses libbzip2 as a\n"
      "component, you should also report this bug to the author(s)\n"
      "of that program.  Please make an effort to report this bug;\n"
      "timely and accurate bug reports eventually lead to higher\n"
      "quality software.  Thanks.  Julian Seward, 4 Sept 1999.\n\n",
      errcode
   );
   exit(3);
}
#endif


/*---------------------------------------------------*/
static
void* default_bzalloc ( void* opaque, Int32 items, Int32 size )
{
   void* v = malloc ( items * size );
   return v;
}

static
void default_bzfree ( void* opaque, void* addr )
{
   if (addr != NULL) free ( addr );
}


/*---------------------------------------------------*/
static
void prepare_new_block ( EState* s )
{
   Int32 i;
   s->nblock = 0;
   s->numZ = 0;
   s->state_out_pos = 0;
   BZ_INITIALISE_CRC ( s->blockCRC );
   for (i = 0; i < 256; i++) s->inUse[i] = False;
   s->blockNo++;
}


/*---------------------------------------------------*/
static
void init_RL ( EState* s )
{
   s->state_in_ch  = 256;
   s->state_in_len = 0;
}


static
Bool isempty_RL ( EState* s )
{
   if (s->state_in_ch < 256 && s->state_in_len > 0)
      return False; else
      return True;
}


/*---------------------------------------------------*/
int BZ_API(bzCompressInit) 
                    ( bz_stream* strm, 
                     int        blockSize100k,
                     int        verbosity,
                     int        workFactor )
{
   Int32   n;
   EState* s;

   if (strm == NULL || 
       blockSize100k < 1 || blockSize100k > 9 ||
       workFactor < 0 || workFactor > 250)
     return BZ_PARAM_ERROR;

   if (workFactor == 0) workFactor = 30;
   if (strm->bzalloc == NULL) strm->bzalloc = default_bzalloc;
   if (strm->bzfree == NULL) strm->bzfree = default_bzfree;

   s = BZALLOC( sizeof(EState) );
   if (s == NULL) return BZ_MEM_ERROR;
   s->strm = strm;

   s->arr1 = NULL;
   s->arr2 = NULL;
   s->ftab = NULL;

   n       = 100000 * blockSize100k;
   s->arr1 = BZALLOC( n                  * sizeof(UInt32) );
   s->arr2 = BZALLOC( (n+BZ_N_OVERSHOOT) * sizeof(UInt32) );
   s->ftab = BZALLOC( 65537              * sizeof(UInt32) );

   if (s->arr1 == NULL || s->arr2 == NULL || s->ftab == NULL) {
      if (s->arr1 != NULL) BZFREE(s->arr1);
      if (s->arr2 != NULL) BZFREE(s->arr2);
      if (s->ftab != NULL) BZFREE(s->ftab);
      if (s       != NULL) BZFREE(s);
      return BZ_MEM_ERROR;
   }

   s->blockNo           = 0;
   s->state             = BZ_S_INPUT;
   s->mode              = BZ_M_RUNNING;
   s->combinedCRC       = 0;
   s->blockSize100k     = blockSize100k;
   s->nblockMAX         = 100000 * blockSize100k - 19;
   s->verbosity         = verbosity;
   s->workFactor        = workFactor;

   s->block             = (UInt16*)s->arr2;
   s->mtfv              = (UInt16*)s->arr1;
   s->zbits             = NULL;
   s->ptr               = (UInt32*)s->arr1;

   strm->state          = s;
   strm->total_in       = 0;
   strm->total_out      = 0;
   init_RL ( s );
   prepare_new_block ( s );
   return BZ_OK;
}


/*---------------------------------------------------*/
static
void add_pair_to_block ( EState* s )
{
   Int32 i;
   UChar ch = (UChar)(s->state_in_ch);
   for (i = 0; i < s->state_in_len; i++) {
      BZ_UPDATE_CRC( s->blockCRC, ch );
   }
   s->inUse[s->state_in_ch] = True;
   switch (s->state_in_len) {
      case 1:
         s->block[s->nblock] = (UInt16)ch; s->nblock++;
         break;
      case 2:
         s->block[s->nblock] = (UInt16)ch; s->nblock++;
         s->block[s->nblock] = (UInt16)ch; s->nblock++;
         break;
      case 3:
         s->block[s->nblock] = (UInt16)ch; s->nblock++;
         s->block[s->nblock] = (UInt16)ch; s->nblock++;
         s->block[s->nblock] = (UInt16)ch; s->nblock++;
         break;
      default:
         s->inUse[s->state_in_len-4] = True;
         s->block[s->nblock] = (UInt16)ch; s->nblock++;
         s->block[s->nblock] = (UInt16)ch; s->nblock++;
         s->block[s->nblock] = (UInt16)ch; s->nblock++;
         s->block[s->nblock] = (UInt16)ch; s->nblock++;
         s->block[s->nblock] = ((UInt16)(s->state_in_len-4));
         s->nblock++;
         break;
   }
}


/*---------------------------------------------------*/
static
void flush_RL ( EState* s )
{
   if (s->state_in_ch < 256) add_pair_to_block ( s );
   init_RL ( s );
}


/*---------------------------------------------------*/
#define ADD_CHAR_TO_BLOCK(zs,zchh0)               \
{                                                 \
   UInt32 zchh = (UInt32)(zchh0);                 \
   /*-- fast track the common case --*/           \
   if (zchh != zs->state_in_ch &&                 \
       zs->state_in_len == 1) {                   \
      UChar ch = (UChar)(zs->state_in_ch);        \
      BZ_UPDATE_CRC( zs->blockCRC, ch );          \
      zs->inUse[zs->state_in_ch] = True;          \
      zs->block[zs->nblock] = (UInt16)ch;         \
      zs->nblock++;                               \
      zs->state_in_ch = zchh;                     \
   }                                              \
   else                                           \
   /*-- general, uncommon cases --*/              \
   if (zchh != zs->state_in_ch ||                 \
      zs->state_in_len == 255) {                  \
      if (zs->state_in_ch < 256)                  \
         add_pair_to_block ( zs );                \
      zs->state_in_ch = zchh;                     \
      zs->state_in_len = 1;                       \
   } else {                                       \
      zs->state_in_len++;                         \
   }                                              \
}


/*---------------------------------------------------*/
static
Bool copy_input_until_stop ( EState* s )
{
   Bool progress_in = False;

   if (s->mode == BZ_M_RUNNING) {

      /*-- fast track the common case --*/
      while (True) {
         /*-- block full? --*/
         if (s->nblock >= s->nblockMAX) break;
         /*-- no input? --*/
         if (s->strm->avail_in == 0) break;
         progress_in = True;
         ADD_CHAR_TO_BLOCK ( s, (UInt32)(*((UChar*)(s->strm->next_in))) ); 
         s->strm->next_in++;
         s->strm->avail_in--;
         s->strm->total_in++;
      }

   } else {

      /*-- general, uncommon case --*/
      while (True) {
         /*-- block full? --*/
         if (s->nblock >= s->nblockMAX) break;
         /*-- no input? --*/
         if (s->strm->avail_in == 0) break;
         /*-- flush/finish end? --*/
         if (s->avail_in_expect == 0) break;
         progress_in = True;
         ADD_CHAR_TO_BLOCK ( s, (UInt32)(*((UChar*)(s->strm->next_in))) ); 
         s->strm->next_in++;
         s->strm->avail_in--;
         s->strm->total_in++;
         s->avail_in_expect--;
      }
   }
   return progress_in;
}


/*---------------------------------------------------*/
static
Bool copy_output_until_stop ( EState* s )
{
   Bool progress_out = False;

   while (True) {

      /*-- no output space? --*/
      if (s->strm->avail_out == 0) break;

      /*-- block done? --*/
      if (s->state_out_pos >= s->numZ) break;

      progress_out = True;
      *(s->strm->next_out) = s->zbits[s->state_out_pos];
      s->state_out_pos++;
      s->strm->avail_out--;
      s->strm->next_out++;
      s->strm->total_out++;
      
   }

   return progress_out;
}


/*---------------------------------------------------*/
static
Bool handle_compress ( bz_stream* strm )
{
   Bool progress_in  = False;
   Bool progress_out = False;
   EState* s = strm->state;
   
   while (True) {

      if (s->state == BZ_S_OUTPUT) {
         progress_out |= copy_output_until_stop ( s );
         if (s->state_out_pos < s->numZ) break;
         if (s->mode == BZ_M_FINISHING && 
             s->avail_in_expect == 0 &&
             isempty_RL(s)) break;
         prepare_new_block ( s );
         s->state = BZ_S_INPUT;
         if (s->mode == BZ_M_FLUSHING && 
             s->avail_in_expect == 0 &&
             isempty_RL(s)) break;
      }

      if (s->state == BZ_S_INPUT) {
         progress_in |= copy_input_until_stop ( s );
         if (s->mode != BZ_M_RUNNING && s->avail_in_expect == 0) {
            flush_RL ( s );
            compressBlock ( s, (Bool)(s->mode == BZ_M_FINISHING) );
            s->state = BZ_S_OUTPUT;
         }
         else
         if (s->nblock >= s->nblockMAX) {
            compressBlock ( s, False );
            s->state = BZ_S_OUTPUT;
         }
         else
         if (s->strm->avail_in == 0) {
            break;
         }
      }

   }

   return progress_in || progress_out;
}


/*---------------------------------------------------*/
int BZ_API(bzCompress) ( bz_stream *strm, int action )
{
   Bool progress;
   EState* s;
   if (strm == NULL) return BZ_PARAM_ERROR;
   s = strm->state;
   if (s == NULL) return BZ_PARAM_ERROR;
   if (s->strm != strm) return BZ_PARAM_ERROR;

   preswitch:
   switch (s->mode) {

      case BZ_M_IDLE:
         return BZ_SEQUENCE_ERROR;

      case BZ_M_RUNNING:
         if (action == BZ_RUN) {
            progress = handle_compress ( strm );
            return progress ? BZ_RUN_OK : BZ_PARAM_ERROR;
         } 
         else
	 if (action == BZ_FLUSH) {
            s->avail_in_expect = strm->avail_in;
            s->mode = BZ_M_FLUSHING;
            goto preswitch;
         }
         else
         if (action == BZ_FINISH) {
            s->avail_in_expect = strm->avail_in;
            s->mode = BZ_M_FINISHING;
            goto preswitch;
         }
         else 
            return BZ_PARAM_ERROR;

      case BZ_M_FLUSHING:
         if (action != BZ_FLUSH) return BZ_SEQUENCE_ERROR;
         if (s->avail_in_expect != s->strm->avail_in) return BZ_SEQUENCE_ERROR;
         progress = handle_compress ( strm );
         if (s->avail_in_expect > 0 || !isempty_RL(s) ||
             s->state_out_pos < s->numZ) return BZ_FLUSH_OK;
         s->mode = BZ_M_RUNNING;
         return BZ_RUN_OK;

      case BZ_M_FINISHING:
         if (action != BZ_FINISH) return BZ_SEQUENCE_ERROR;
         if (s->avail_in_expect != s->strm->avail_in) return BZ_SEQUENCE_ERROR;
         progress = handle_compress ( strm );
         if (!progress) return BZ_SEQUENCE_ERROR;
         if (s->avail_in_expect > 0 || !isempty_RL(s) ||
             s->state_out_pos < s->numZ) return BZ_FINISH_OK;
         s->mode = BZ_M_IDLE;
         return BZ_STREAM_END;
   }
   return BZ_OK; /*--not reached--*/
}


/*---------------------------------------------------*/
int BZ_API(bzCompressEnd)  ( bz_stream *strm )
{
   EState* s;
   if (strm == NULL) return BZ_PARAM_ERROR;
   s = strm->state;
   if (s == NULL) return BZ_PARAM_ERROR;
   if (s->strm != strm) return BZ_PARAM_ERROR;

   if (s->arr1 != NULL) BZFREE(s->arr1);
   if (s->arr2 != NULL) BZFREE(s->arr2);
   if (s->ftab != NULL) BZFREE(s->ftab);
   BZFREE(strm->state);

   strm->state = NULL;   

   return BZ_OK;
}


/*---------------------------------------------------*/
/*--- Decompression stuff                         ---*/
/*---------------------------------------------------*/

/*---------------------------------------------------*/
int BZ_API(bzDecompressInit) 
                     ( bz_stream* strm, 
                       int        verbosity,
                       int        small )
{
   DState* s;

   if (strm == NULL) return BZ_PARAM_ERROR;
   if (small != 0 && small != 1) return BZ_PARAM_ERROR;
   if (verbosity < 0 || verbosity > 4) return BZ_PARAM_ERROR;

   if (strm->bzalloc == NULL) strm->bzalloc = default_bzalloc;
   if (strm->bzfree == NULL) strm->bzfree = default_bzfree;

   s = BZALLOC( sizeof(DState) );
   if (s == NULL) return BZ_MEM_ERROR;
   s->strm                  = strm;
   strm->state              = s;
   s->state                 = BZ_X_MAGIC_1;
   s->bsLive                = 0;
   s->bsBuff                = 0;
   s->calculatedCombinedCRC = 0;
   strm->total_in           = 0;
   strm->total_out          = 0;
   s->smallDecompress       = (Bool)small;
   s->ll4                   = NULL;
   s->ll16                  = NULL;
   s->tt                    = NULL;
   s->currBlockNo           = 0;
   s->verbosity             = verbosity;

   return BZ_OK;
}


/*---------------------------------------------------*/
static
void unRLE_obuf_to_output_FAST ( DState* s )
{
   UChar k1;

   if (s->blockRandomised) {

      while (True) {
         /* try to finish existing run */
         while (True) {
            if (s->strm->avail_out == 0) return;
            if (s->state_out_len == 0) break;
            *( (UChar*)(s->strm->next_out) ) = s->state_out_ch;
            BZ_UPDATE_CRC ( s->calculatedBlockCRC, s->state_out_ch );
            s->state_out_len--;
            s->strm->next_out++;
            s->strm->avail_out--;
            s->strm->total_out++;
         }
   
         /* can a new run be started? */
         if (s->nblock_used == s->save_nblock+1) return;
               
   
         s->state_out_len = 1;
         s->state_out_ch = s->k0;
         BZ_GET_FAST(k1); BZ_RAND_UPD_MASK; 
         k1 ^= BZ_RAND_MASK; s->nblock_used++;
         if (s->nblock_used == s->save_nblock+1) continue;
         if (k1 != s->k0) { s->k0 = k1; continue; };
   
         s->state_out_len = 2;
         BZ_GET_FAST(k1); BZ_RAND_UPD_MASK; 
         k1 ^= BZ_RAND_MASK; s->nblock_used++;
         if (s->nblock_used == s->save_nblock+1) continue;
         if (k1 != s->k0) { s->k0 = k1; continue; };
   
         s->state_out_len = 3;
         BZ_GET_FAST(k1); BZ_RAND_UPD_MASK; 
         k1 ^= BZ_RAND_MASK; s->nblock_used++;
         if (s->nblock_used == s->save_nblock+1) continue;
         if (k1 != s->k0) { s->k0 = k1; continue; };
   
         BZ_GET_FAST(k1); BZ_RAND_UPD_MASK; 
         k1 ^= BZ_RAND_MASK; s->nblock_used++;
         s->state_out_len = ((Int32)k1) + 4;
         BZ_GET_FAST(s->k0); BZ_RAND_UPD_MASK; 
         s->k0 ^= BZ_RAND_MASK; s->nblock_used++;
      }

   } else {

      /* restore */
      UInt32        c_calculatedBlockCRC = s->calculatedBlockCRC;
      UChar         c_state_out_ch       = s->state_out_ch;
      Int32         c_state_out_len      = s->state_out_len;
      Int32         c_nblock_used        = s->nblock_used;
      Int32         c_k0                 = s->k0;
      UInt32*       c_tt                 = s->tt;
      UInt32        c_tPos               = s->tPos;
      char*         cs_next_out          = s->strm->next_out;
      unsigned int  cs_avail_out         = s->strm->avail_out;
      /* end restore */

      UInt32 avail_out_INIT = cs_avail_out;
      Int32  s_save_nblockPP = s->save_nblock+1;

      while (True) {

         /* try to finish existing run */
         if (c_state_out_len > 0) {
            while (True) {
               if (cs_avail_out == 0) goto return_notr;
               if (c_state_out_len == 1) break;
               *( (UChar*)(cs_next_out) ) = c_state_out_ch;
               BZ_UPDATE_CRC ( c_calculatedBlockCRC, c_state_out_ch );
               c_state_out_len--;
               cs_next_out++;
               cs_avail_out--;
            }
            s_state_out_len_eq_one:
            {
               if (cs_avail_out == 0) { 
                  c_state_out_len = 1; goto return_notr;
               };
               *( (UChar*)(cs_next_out) ) = c_state_out_ch;
               BZ_UPDATE_CRC ( c_calculatedBlockCRC, c_state_out_ch );
               cs_next_out++;
               cs_avail_out--;
            }
         }   
         /* can a new run be started? */
         if (c_nblock_used == s_save_nblockPP) {
            c_state_out_len = 0; goto return_notr;
         };   
         c_state_out_ch = c_k0;
         BZ_GET_FAST_C(k1); c_nblock_used++;
         if (k1 != c_k0) { 
            c_k0 = k1; goto s_state_out_len_eq_one; 
         };
         if (c_nblock_used == s_save_nblockPP) 
            goto s_state_out_len_eq_one;
   
         c_state_out_len = 2;
         BZ_GET_FAST_C(k1); c_nblock_used++;
         if (c_nblock_used == s_save_nblockPP) continue;
         if (k1 != c_k0) { c_k0 = k1; continue; };
   
         c_state_out_len = 3;
         BZ_GET_FAST_C(k1); c_nblock_used++;
         if (c_nblock_used == s_save_nblockPP) continue;
         if (k1 != c_k0) { c_k0 = k1; continue; };
   
         BZ_GET_FAST_C(k1); c_nblock_used++;
         c_state_out_len = ((Int32)k1) + 4;
         BZ_GET_FAST_C(c_k0); c_nblock_used++;
      }

      return_notr:
      s->strm->total_out += (avail_out_INIT - cs_avail_out);

      /* save */
      s->calculatedBlockCRC = c_calculatedBlockCRC;
      s->state_out_ch       = c_state_out_ch;
      s->state_out_len      = c_state_out_len;
      s->nblock_used        = c_nblock_used;
      s->k0                 = c_k0;
      s->tt                 = c_tt;
      s->tPos               = c_tPos;
      s->strm->next_out     = cs_next_out;
      s->strm->avail_out    = cs_avail_out;
      /* end save */
   }
}


/*---------------------------------------------------*/
__inline__ Int32 indexIntoF ( Int32 indx, Int32 *cftab )
{
   Int32 nb, na, mid;
   nb = 0;
   na = 256;
   do {
      mid = (nb + na) >> 1;
      if (indx >= cftab[mid]) nb = mid; else na = mid;
   }
   while (na - nb != 1);
   return nb;
}


/*---------------------------------------------------*/
static
void unRLE_obuf_to_output_SMALL ( DState* s )
{
   UChar k1;

   if (s->blockRandomised) {

      while (True) {
         /* try to finish existing run */
         while (True) {
            if (s->strm->avail_out == 0) return;
            if (s->state_out_len == 0) break;
            *( (UChar*)(s->strm->next_out) ) = s->state_out_ch;
            BZ_UPDATE_CRC ( s->calculatedBlockCRC, s->state_out_ch );
            s->state_out_len--;
            s->strm->next_out++;
            s->strm->avail_out--;
            s->strm->total_out++;
         }
   
         /* can a new run be started? */
         if (s->nblock_used == s->save_nblock+1) return;
               
   
         s->state_out_len = 1;
         s->state_out_ch = s->k0;
         BZ_GET_SMALL(k1); BZ_RAND_UPD_MASK; 
         k1 ^= BZ_RAND_MASK; s->nblock_used++;
         if (s->nblock_used == s->save_nblock+1) continue;
         if (k1 != s->k0) { s->k0 = k1; continue; };
   
         s->state_out_len = 2;
         BZ_GET_SMALL(k1); BZ_RAND_UPD_MASK; 
         k1 ^= BZ_RAND_MASK; s->nblock_used++;
         if (s->nblock_used == s->save_nblock+1) continue;
         if (k1 != s->k0) { s->k0 = k1; continue; };
   
         s->state_out_len = 3;
         BZ_GET_SMALL(k1); BZ_RAND_UPD_MASK; 
         k1 ^= BZ_RAND_MASK; s->nblock_used++;
         if (s->nblock_used == s->save_nblock+1) continue;
         if (k1 != s->k0) { s->k0 = k1; continue; };
   
         BZ_GET_SMALL(k1); BZ_RAND_UPD_MASK; 
         k1 ^= BZ_RAND_MASK; s->nblock_used++;
         s->state_out_len = ((Int32)k1) + 4;
         BZ_GET_SMALL(s->k0); BZ_RAND_UPD_MASK; 
         s->k0 ^= BZ_RAND_MASK; s->nblock_used++;
      }

   } else {

      while (True) {
         /* try to finish existing run */
         while (True) {
            if (s->strm->avail_out == 0) return;
            if (s->state_out_len == 0) break;
            *( (UChar*)(s->strm->next_out) ) = s->state_out_ch;
            BZ_UPDATE_CRC ( s->calculatedBlockCRC, s->state_out_ch );
            s->state_out_len--;
            s->strm->next_out++;
            s->strm->avail_out--;
            s->strm->total_out++;
         }
   
         /* can a new run be started? */
         if (s->nblock_used == s->save_nblock+1) return;
   
         s->state_out_len = 1;
         s->state_out_ch = s->k0;
         BZ_GET_SMALL(k1); s->nblock_used++;
         if (s->nblock_used == s->save_nblock+1) continue;
         if (k1 != s->k0) { s->k0 = k1; continue; };
   
         s->state_out_len = 2;
         BZ_GET_SMALL(k1); s->nblock_used++;
         if (s->nblock_used == s->save_nblock+1) continue;
         if (k1 != s->k0) { s->k0 = k1; continue; };
   
         s->state_out_len = 3;
         BZ_GET_SMALL(k1); s->nblock_used++;
         if (s->nblock_used == s->save_nblock+1) continue;
         if (k1 != s->k0) { s->k0 = k1; continue; };
   
         BZ_GET_SMALL(k1); s->nblock_used++;
         s->state_out_len = ((Int32)k1) + 4;
         BZ_GET_SMALL(s->k0); s->nblock_used++;
      }

   }
}


/*---------------------------------------------------*/
int BZ_API(bzDecompress) ( bz_stream *strm )
{
   DState* s;
   if (strm == NULL) return BZ_PARAM_ERROR;
   s = strm->state;
   if (s == NULL) return BZ_PARAM_ERROR;
   if (s->strm != strm) return BZ_PARAM_ERROR;

   while (True) {
      if (s->state == BZ_X_IDLE) return BZ_SEQUENCE_ERROR;
      if (s->state == BZ_X_OUTPUT) {
         if (s->smallDecompress)
            unRLE_obuf_to_output_SMALL ( s ); else
            unRLE_obuf_to_output_FAST  ( s );
         if (s->nblock_used == s->save_nblock+1 && s->state_out_len == 0) {
            BZ_FINALISE_CRC ( s->calculatedBlockCRC );
            if (s->verbosity >= 3) 
               VPrintf2 ( " {0x%x, 0x%x}", s->storedBlockCRC, 
                          s->calculatedBlockCRC );
            if (s->verbosity >= 2) VPrintf0 ( "]" );
            if (s->calculatedBlockCRC != s->storedBlockCRC)
               return BZ_DATA_ERROR;
            s->calculatedCombinedCRC 
               = (s->calculatedCombinedCRC << 1) | 
                    (s->calculatedCombinedCRC >> 31);
            s->calculatedCombinedCRC ^= s->calculatedBlockCRC;
            s->state = BZ_X_BLKHDR_1;
         } else {
            return BZ_OK;
         }
      }
      if (s->state >= BZ_X_MAGIC_1) {
         Int32 r = decompress ( s );
         if (r == BZ_STREAM_END) {
            if (s->verbosity >= 3)
               VPrintf2 ( "\n    combined CRCs: stored = 0x%x, computed = 0x%x", 
                          s->storedCombinedCRC, s->calculatedCombinedCRC );
            if (s->calculatedCombinedCRC != s->storedCombinedCRC)
               return BZ_DATA_ERROR;
            return r;
         }
         if (s->state != BZ_X_OUTPUT) return r;
      }
   }

   AssertH ( 0, 6001 );

   return 0;  /*NOTREACHED*/
}


/*---------------------------------------------------*/
int BZ_API(bzDecompressEnd)  ( bz_stream *strm )
{
   DState* s;
   if (strm == NULL) return BZ_PARAM_ERROR;
   s = strm->state;
   if (s == NULL) return BZ_PARAM_ERROR;
   if (s->strm != strm) return BZ_PARAM_ERROR;

   if (s->tt   != NULL) BZFREE(s->tt);
   if (s->ll16 != NULL) BZFREE(s->ll16);
   if (s->ll4  != NULL) BZFREE(s->ll4);

   BZFREE(strm->state);
   strm->state = NULL;

   return BZ_OK;
}


#ifndef BZ_NO_STDIO
/*---------------------------------------------------*/
/*--- File I/O stuff                              ---*/
/*---------------------------------------------------*/

#define BZ_SETERR(eee)                    \
{                                         \
   if (bzerror != NULL) *bzerror = eee;   \
   if (bzf != NULL) bzf->lastErr = eee;   \
}

typedef 
   struct {
      FILE*     handle;
      Char      buf[BZ_MAX_UNUSED];
      Int32     bufN;
      Bool      writing;
      bz_stream strm;
      Int32     lastErr;
      Bool      initialisedOk;
   }
   bzFile;


/*---------------------------------------------*/
static Bool myfeof ( FILE* f )
{
   Int32 c = fgetc ( f );
   if (c == EOF) return True;
   ungetc ( c, f );
   return False;
}


/*---------------------------------------------------*/
BZFILE* BZ_API(bzWriteOpen) 
                    ( int*  bzerror,      
                      FILE* f, 
                      int   blockSize100k, 
                      int   verbosity,
                      int   workFactor )
{
   Int32   ret;
   bzFile* bzf = NULL;

   BZ_SETERR(BZ_OK);

   if (f == NULL ||
       (blockSize100k < 1 || blockSize100k > 9) ||
       (workFactor < 0 || workFactor > 250) ||
       (verbosity < 0 || verbosity > 4))
      { BZ_SETERR(BZ_PARAM_ERROR); return NULL; };

   if (ferror(f))
      { BZ_SETERR(BZ_IO_ERROR); return NULL; };

   bzf = malloc ( sizeof(bzFile) );
   if (bzf == NULL)
      { BZ_SETERR(BZ_MEM_ERROR); return NULL; };

   BZ_SETERR(BZ_OK);
   bzf->initialisedOk = False;
   bzf->bufN          = 0;
   bzf->handle        = f;
   bzf->writing       = True;
   bzf->strm.bzalloc  = NULL;
   bzf->strm.bzfree   = NULL;
   bzf->strm.opaque   = NULL;

   if (workFactor == 0) workFactor = 30;
   ret = bzCompressInit ( &(bzf->strm), blockSize100k, 
                          verbosity, workFactor );
   if (ret != BZ_OK)
      { BZ_SETERR(ret); free(bzf); return NULL; };

   bzf->strm.avail_in = 0;
   bzf->initialisedOk = True;
   return bzf;   
}


/*---------------------------------------------------*/
void BZ_API(bzWrite)
             ( int*    bzerror, 
               BZFILE* b, 
               void*   buf, 
               int     len )
{
   Int32 n, n2, ret;
   bzFile* bzf = (bzFile*)b;

   BZ_SETERR(BZ_OK);
   if (bzf == NULL || buf == NULL || len < 0)
      { BZ_SETERR(BZ_PARAM_ERROR); return; };
   if (!(bzf->writing))
      { BZ_SETERR(BZ_SEQUENCE_ERROR); return; };
   if (ferror(bzf->handle))
      { BZ_SETERR(BZ_IO_ERROR); return; };

   if (len == 0)
      { BZ_SETERR(BZ_OK); return; };

   bzf->strm.avail_in = len;
   bzf->strm.next_in  = buf;

   while (True) {
      bzf->strm.avail_out = BZ_MAX_UNUSED;
      bzf->strm.next_out = bzf->buf;
      ret = bzCompress ( &(bzf->strm), BZ_RUN );
      if (ret != BZ_RUN_OK)
         { BZ_SETERR(ret); return; };

      if (bzf->strm.avail_out < BZ_MAX_UNUSED) {
         n = BZ_MAX_UNUSED - bzf->strm.avail_out;
         n2 = fwrite ( (void*)(bzf->buf), sizeof(UChar), 
                       n, bzf->handle );
         if (n != n2 || ferror(bzf->handle))
            { BZ_SETERR(BZ_IO_ERROR); return; };
      }

      if (bzf->strm.avail_in == 0)
         { BZ_SETERR(BZ_OK); return; };
   }
}


/*---------------------------------------------------*/
void BZ_API(bzWriteClose)
                  ( int*          bzerror, 
                    BZFILE*       b, 
                    int           abandon,
                    unsigned int* nbytes_in,
                    unsigned int* nbytes_out )
{
   Int32   n, n2, ret;
   bzFile* bzf = (bzFile*)b;

   if (bzf == NULL)
      { BZ_SETERR(BZ_OK); return; };
   if (!(bzf->writing))
      { BZ_SETERR(BZ_SEQUENCE_ERROR); return; };
   if (ferror(bzf->handle))
      { BZ_SETERR(BZ_IO_ERROR); return; };

   if (nbytes_in != NULL) *nbytes_in = 0;
   if (nbytes_out != NULL) *nbytes_out = 0;

   if ((!abandon) && bzf->lastErr == BZ_OK) {
      while (True) {
         bzf->strm.avail_out = BZ_MAX_UNUSED;
         bzf->strm.next_out = bzf->buf;
         ret = bzCompress ( &(bzf->strm), BZ_FINISH );
         if (ret != BZ_FINISH_OK && ret != BZ_STREAM_END)
            { BZ_SETERR(ret); return; };

         if (bzf->strm.avail_out < BZ_MAX_UNUSED) {
            n = BZ_MAX_UNUSED - bzf->strm.avail_out;
            n2 = fwrite ( (void*)(bzf->buf), sizeof(UChar), 
                          n, bzf->handle );
            if (n != n2 || ferror(bzf->handle))
               { BZ_SETERR(BZ_IO_ERROR); return; };
         }

         if (ret == BZ_STREAM_END) break;
      }
   }

   if ( !abandon && !ferror ( bzf->handle ) ) {
      fflush ( bzf->handle );
      if (ferror(bzf->handle))
         { BZ_SETERR(BZ_IO_ERROR); return; };
   }

   if (nbytes_in != NULL) *nbytes_in = bzf->strm.total_in;
   if (nbytes_out != NULL) *nbytes_out = bzf->strm.total_out;

   BZ_SETERR(BZ_OK);
   bzCompressEnd ( &(bzf->strm) );
   free ( bzf );
}


/*---------------------------------------------------*/
BZFILE* BZ_API(bzReadOpen) 
                   ( int*  bzerror, 
                     FILE* f, 
                     int   verbosity,
                     int   small,
                     void* unused,
                     int   nUnused )
{
   bzFile* bzf = NULL;
   int     ret;

   BZ_SETERR(BZ_OK);

   if (f == NULL || 
       (small != 0 && small != 1) ||
       (verbosity < 0 || verbosity > 4) ||
       (unused == NULL && nUnused != 0) ||
       (unused != NULL && (nUnused < 0 || nUnused > BZ_MAX_UNUSED)))
      { BZ_SETERR(BZ_PARAM_ERROR); return NULL; };

   if (ferror(f))
      { BZ_SETERR(BZ_IO_ERROR); return NULL; };

   bzf = malloc ( sizeof(bzFile) );
   if (bzf == NULL) 
      { BZ_SETERR(BZ_MEM_ERROR); return NULL; };

   BZ_SETERR(BZ_OK);

   bzf->initialisedOk = False;
   bzf->handle        = f;
   bzf->bufN          = 0;
   bzf->writing       = False;
   bzf->strm.bzalloc  = NULL;
   bzf->strm.bzfree   = NULL;
   bzf->strm.opaque   = NULL;
   
   while (nUnused > 0) {
      bzf->buf[bzf->bufN] = *((UChar*)(unused)); bzf->bufN++;
      unused = ((void*)( 1 + ((UChar*)(unused))  ));
      nUnused--;
   }

   ret = bzDecompressInit ( &(bzf->strm), verbosity, small );
   if (ret != BZ_OK)
      { BZ_SETERR(ret); free(bzf); return NULL; };

   bzf->strm.avail_in = bzf->bufN;
   bzf->strm.next_in  = bzf->buf;

   bzf->initialisedOk = True;
   return bzf;   
}


/*---------------------------------------------------*/
void BZ_API(bzReadClose) ( int *bzerror, BZFILE *b )
{
   bzFile* bzf = (bzFile*)b;

   BZ_SETERR(BZ_OK);
   if (bzf == NULL)
      { BZ_SETERR(BZ_OK); return; };

   if (bzf->writing)
      { BZ_SETERR(BZ_SEQUENCE_ERROR); return; };

   if (bzf->initialisedOk)
      (void)bzDecompressEnd ( &(bzf->strm) );
   free ( bzf );
}


/*---------------------------------------------------*/
int BZ_API(bzRead) 
           ( int*    bzerror, 
             BZFILE* b, 
             void*   buf, 
             int     len )
{
   Int32   n, ret;
   bzFile* bzf = (bzFile*)b;

   BZ_SETERR(BZ_OK);

   if (bzf == NULL || buf == NULL || len < 0)
      { BZ_SETERR(BZ_PARAM_ERROR); return 0; };

   if (bzf->writing)
      { BZ_SETERR(BZ_SEQUENCE_ERROR); return 0; };

   if (len == 0)
      { BZ_SETERR(BZ_OK); return 0; };

   bzf->strm.avail_out = len;
   bzf->strm.next_out = buf;

   while (True) {

      if (ferror(bzf->handle)) 
         { BZ_SETERR(BZ_IO_ERROR); return 0; };

      if (bzf->strm.avail_in == 0 && !myfeof(bzf->handle)) {
         n = fread ( bzf->buf, sizeof(UChar), 
                     BZ_MAX_UNUSED, bzf->handle );
         if (ferror(bzf->handle))
            { BZ_SETERR(BZ_IO_ERROR); return 0; };
         bzf->bufN = n;
         bzf->strm.avail_in = bzf->bufN;
         bzf->strm.next_in = bzf->buf;
      }

      ret = bzDecompress ( &(bzf->strm) );

      if (ret != BZ_OK && ret != BZ_STREAM_END)
         { BZ_SETERR(ret); return 0; };

      if (ret == BZ_OK && myfeof(bzf->handle) && 
          bzf->strm.avail_in == 0 && bzf->strm.avail_out > 0)
         { BZ_SETERR(BZ_UNEXPECTED_EOF); return 0; };

      if (ret == BZ_STREAM_END)
         { BZ_SETERR(BZ_STREAM_END);
           return len - bzf->strm.avail_out; };
      if (bzf->strm.avail_out == 0)
         { BZ_SETERR(BZ_OK); return len; };
      
   }

   return 0; /*not reached*/
}


/*---------------------------------------------------*/
void BZ_API(bzReadGetUnused) 
                     ( int*    bzerror, 
                       BZFILE* b, 
                       void**  unused, 
                       int*    nUnused )
{
   bzFile* bzf = (bzFile*)b;
   if (bzf == NULL)
      { BZ_SETERR(BZ_PARAM_ERROR); return; };
   if (bzf->lastErr != BZ_STREAM_END)
      { BZ_SETERR(BZ_SEQUENCE_ERROR); return; };
   if (unused == NULL || nUnused == NULL)
      { BZ_SETERR(BZ_PARAM_ERROR); return; };

   BZ_SETERR(BZ_OK);
   *nUnused = bzf->strm.avail_in;
   *unused = bzf->strm.next_in;
}
#endif


/*---------------------------------------------------*/
/*--- Misc convenience stuff                      ---*/
/*---------------------------------------------------*/

/*---------------------------------------------------*/
int BZ_API(bzBuffToBuffCompress) 
                         ( char*         dest, 
                           unsigned int* destLen,
                           char*         source, 
                           unsigned int  sourceLen,
                           int           blockSize100k, 
                           int           verbosity, 
                           int           workFactor )
{
   bz_stream strm;
   int ret;

   if (dest == NULL || destLen == NULL || 
       source == NULL ||
       blockSize100k < 1 || blockSize100k > 9 ||
       verbosity < 0 || verbosity > 4 ||
       workFactor < 0 || workFactor > 250) 
      return BZ_PARAM_ERROR;

   if (workFactor == 0) workFactor = 30;
   strm.bzalloc = NULL;
   strm.bzfree = NULL;
   strm.opaque = NULL;
   ret = bzCompressInit ( &strm, blockSize100k, 
                          verbosity, workFactor );
   if (ret != BZ_OK) return ret;

   strm.next_in = source;
   strm.next_out = dest;
   strm.avail_in = sourceLen;
   strm.avail_out = *destLen;

   ret = bzCompress ( &strm, BZ_FINISH );
   if (ret == BZ_FINISH_OK) goto output_overflow;
   if (ret != BZ_STREAM_END) goto errhandler;

   /* normal termination */
   *destLen -= strm.avail_out;   
   bzCompressEnd ( &strm );
   return BZ_OK;

   output_overflow:
   bzCompressEnd ( &strm );
   return BZ_OUTBUFF_FULL;

   errhandler:
   bzCompressEnd ( &strm );
   return ret;
}


/*---------------------------------------------------*/
int BZ_API(bzBuffToBuffDecompress) 
                           ( char*         dest, 
                             unsigned int* destLen,
                             char*         source, 
                             unsigned int  sourceLen,
                             int           small,
                             int           verbosity )
{
   bz_stream strm;
   int ret;

   if (dest == NULL || destLen == NULL || 
       source == NULL ||
       (small != 0 && small != 1) ||
       verbosity < 0 || verbosity > 4) 
          return BZ_PARAM_ERROR;

   strm.bzalloc = NULL;
   strm.bzfree = NULL;
   strm.opaque = NULL;
   ret = bzDecompressInit ( &strm, verbosity, small );
   if (ret != BZ_OK) return ret;

   strm.next_in = source;
   strm.next_out = dest;
   strm.avail_in = sourceLen;
   strm.avail_out = *destLen;

   ret = bzDecompress ( &strm );
   if (ret == BZ_OK) goto output_overflow_or_eof;
   if (ret != BZ_STREAM_END) goto errhandler;

   /* normal termination */
   *destLen -= strm.avail_out;
   bzDecompressEnd ( &strm );
   return BZ_OK;

   output_overflow_or_eof:
   if (strm.avail_out > 0) {
      bzDecompressEnd ( &strm );
      return BZ_UNEXPECTED_EOF;
   } else {
      bzDecompressEnd ( &strm );
      return BZ_OUTBUFF_FULL;
   };      

   errhandler:
   bzDecompressEnd ( &strm );
   return ret; 
}


/*---------------------------------------------------*/
/*--
   Code contributed by Yoshioka Tsuneo
   (QWF00133@niftyserve.or.jp/tsuneo-y@is.aist-nara.ac.jp),
   to support better zlib compatibility.
   This code is not _officially_ part of libbzip2 (yet);
   I haven't tested it, documented it, or considered the
   threading-safeness of it.
   If this code breaks, please contact both Yoshioka and me.
--*/
/*---------------------------------------------------*/

/*---------------------------------------------------*/
/*--
   return version like "0.9.0c".
--*/
const char * BZ_API(bzlibVersion)(void)
{
   return BZ_VERSION;
}


#ifndef BZ_NO_STDIO
/*---------------------------------------------------*/

#if defined(_WIN32) || defined(OS2) || defined(MSDOS)
#   include <fcntl.h>
#   include <io.h>
#   define SET_BINARY_MODE(file) setmode(fileno(file),O_BINARY)
#else
#   define SET_BINARY_MODE(file)
#endif
static
BZFILE * bzopen_or_bzdopen
               ( const char *path,   /* no use when bzdopen */
                 int fd,             /* no use when bzdopen */
                 const char *mode,
                 int open_mode)      /* bzopen: 0, bzdopen:1 */
{
   int    bzerr;
   char   unused[BZ_MAX_UNUSED];
   int    blockSize100k = 9;
   int    writing       = 0;
   char   mode2[10]     = "";
   FILE   *fp           = NULL;
   BZFILE *bzfp         = NULL;
   int    verbosity     = 0;
   int    workFactor    = 30;
   int    smallMode     = 0;
   int    nUnused       = 0; 

   if (mode == NULL) return NULL;
   while (*mode) {
      switch (*mode) {
      case 'r':
         writing = 0; break;
      case 'w':
         writing = 1; break;
      case 's':
         smallMode = 1; break;
      default:
         if (isdigit((int)(*mode))) {
            blockSize100k = *mode-'0';
         }
      }
      mode++;
   }
   strcat(mode2, writing ? "w" : "r" );
   strcat(mode2,"b");   /* binary mode */

   if (open_mode==0) {
      if (path==NULL || strcmp(path,"")==0) {
        fp = (writing ? stdout : stdin);
        SET_BINARY_MODE(fp);
      } else {
        fp = fopen(path,mode2);
      }
   } else {
#ifdef BZ_STRICT_ANSI
      fp = NULL;
#else
      fp = fdopen(fd,mode2);
#endif
   }
   if (fp == NULL) return NULL;

   if (writing) {
      /* Guard against total chaos and anarchy -- JRS */
      if (blockSize100k < 1) blockSize100k = 1;
      if (blockSize100k > 9) blockSize100k = 9; 
      bzfp = bzWriteOpen(&bzerr,fp,blockSize100k,verbosity,workFactor);
   } else {
      bzfp = bzReadOpen(&bzerr,fp,verbosity,smallMode,unused,nUnused);
   }
   if (bzfp == NULL) {
      if (fp != stdin && fp != stdout) fclose(fp);
      return NULL;
   }
   return bzfp;
}


/*---------------------------------------------------*/
/*--
   open file for read or write.
      ex) bzopen("file","w9")
      case path="" or NULL => use stdin or stdout.
--*/
BZFILE * BZ_API(bzopen)
               ( const char *path,
                 const char *mode )
{
   return bzopen_or_bzdopen(path,-1,mode,/*bzopen*/0);
}


/*---------------------------------------------------*/
BZFILE * BZ_API(bzdopen)
               ( int fd,
                 const char *mode )
{
   return bzopen_or_bzdopen(NULL,fd,mode,/*bzdopen*/1);
}


/*---------------------------------------------------*/
int BZ_API(bzread) (BZFILE* b, void* buf, int len )
{
   int bzerr, nread;
   if (((bzFile*)b)->lastErr == BZ_STREAM_END) return 0;
   nread = bzRead(&bzerr,b,buf,len);
   if (bzerr == BZ_OK || bzerr == BZ_STREAM_END) {
      return nread;
   } else {
      return -1;
   }
}


/*---------------------------------------------------*/
int BZ_API(bzwrite) (BZFILE* b, void* buf, int len )
{
   int bzerr;

   bzWrite(&bzerr,b,buf,len);
   if(bzerr == BZ_OK){
      return len;
   }else{
      return -1;
   }
}


/*---------------------------------------------------*/
int BZ_API(bzflush) (BZFILE *b)
{
   /* do nothing now... */
   return 0;
}


/*---------------------------------------------------*/
void BZ_API(bzclose) (BZFILE* b)
{
   int bzerr;
   FILE *fp = ((bzFile *)b)->handle;
   
   if (b==NULL) {return;}
   if(((bzFile*)b)->writing){
      bzWriteClose(&bzerr,b,0,NULL,NULL);
      if(bzerr != BZ_OK){
         bzWriteClose(NULL,b,1,NULL,NULL);
      }
   }else{
      bzReadClose(&bzerr,b);
   }
   if(fp!=stdin && fp!=stdout){
      fclose(fp);
   }
}


/*---------------------------------------------------*/
/*--
   return last error code 
--*/
static char *bzerrorstrings[] = {
       "OK"
      ,"SEQUENCE_ERROR"
      ,"PARAM_ERROR"
      ,"MEM_ERROR"
      ,"DATA_ERROR"
      ,"DATA_ERROR_MAGIC"
      ,"IO_ERROR"
      ,"UNEXPECTED_EOF"
      ,"OUTBUFF_FULL"
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
};


const char * BZ_API(bzerror) (BZFILE *b, int *errnum)
{
   int err = ((bzFile *)b)->lastErr;

   if(err>0) err = 0;
   *errnum = err;
   return bzerrorstrings[err*-1];
}
#endif


/*-------------------------------------------------------------*/
/*--- end                                           bzlib.c ---*/
/*-------------------------------------------------------------*/