/*-------------------------------------------------------------*/
/*--- 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) 1996-2000 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.
--*/

/*--
   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"


extern
int bz_config_ok ( void );
extern
void* default_bzalloc ( void* opaque, Int32 items, Int32 size );
extern
void default_bzfree ( void* opaque, void* addr );

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



/*---------------------------------------------------*/
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 BZ2_bzCompressInit
                    ( bz_stream* strm,
                     int        blockSize100k,
                     int        verbosity,
                     int        workFactor )
{
   Int32   n;
   EState* s;

   if (!bz_config_ok()) return BZ_CONFIG_ERROR;

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

   strm->state          = s;
   strm->total_in_lo32  = 0;
   strm->total_in_hi32  = 0;
   strm->total_out_lo32 = 0;
   strm->total_out_hi32 = 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] = (UChar)ch; s->nblock++;
         break;
      case 2:
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         break;
      case 3:
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         break;
      default:
         s->inUse[s->state_in_len-4] = True;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = ((UChar)(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] = (UChar)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_lo32++;
         if (s->strm->total_in_lo32 == 0) s->strm->total_in_hi32++;
      }

   } 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_lo32++;
         if (s->strm->total_in_lo32 == 0) s->strm->total_in_hi32++;
         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_lo32++;
      if (s->strm->total_out_lo32 == 0) s->strm->total_out_hi32++;
   }

   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 );
            BZ2_compressBlock ( s, (Bool)(s->mode == BZ_M_FINISHING) );
            s->state = BZ_S_OUTPUT;
         }
         else
         if (s->nblock >= s->nblockMAX) {
            BZ2_compressBlock ( s, False );
            s->state = BZ_S_OUTPUT;
         }
         else
         if (s->strm->avail_in == 0) {
            break;
         }
      }

   }

   return progress_in || progress_out;
}


/*---------------------------------------------------*/
int BZ2_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 BZ2_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;
}


#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* BZ2_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 = BZ2_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 BZ2_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 = BZ2_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 BZ2_bzWriteClose
                  ( int*          bzerror,
                    BZFILE*       b,
                    int           abandon,
                    unsigned int* nbytes_in,
                    unsigned int* nbytes_out )
{
   BZ2_bzWriteClose64 ( bzerror, b, abandon,
                        nbytes_in, NULL, nbytes_out, NULL );
}


void BZ2_bzWriteClose64
                  ( int*          bzerror,
                    BZFILE*       b,
                    int           abandon,
                    unsigned int* nbytes_in_lo32,
                    unsigned int* nbytes_in_hi32,
                    unsigned int* nbytes_out_lo32,
                    unsigned int* nbytes_out_hi32 )
{
   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_lo32 != NULL) *nbytes_in_lo32 = 0;
   if (nbytes_in_hi32 != NULL) *nbytes_in_hi32 = 0;
   if (nbytes_out_lo32 != NULL) *nbytes_out_lo32 = 0;
   if (nbytes_out_hi32 != NULL) *nbytes_out_hi32 = 0;

   if ((!abandon) && bzf->lastErr == BZ_OK) {
      while (True) {
         bzf->strm.avail_out = BZ_MAX_UNUSED;
         bzf->strm.next_out = bzf->buf;
         ret = BZ2_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_lo32 != NULL)
      *nbytes_in_lo32 = bzf->strm.total_in_lo32;
   if (nbytes_in_hi32 != NULL)
      *nbytes_in_hi32 = bzf->strm.total_in_hi32;
   if (nbytes_out_lo32 != NULL)
      *nbytes_out_lo32 = bzf->strm.total_out_lo32;
   if (nbytes_out_hi32 != NULL)
      *nbytes_out_hi32 = bzf->strm.total_out_hi32;

   BZ_SETERR(BZ_OK);
   BZ2_bzCompressEnd ( &(bzf->strm) );
   free ( bzf );
}


/*---------------------------------------------------*/
BZFILE* BZ2_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 = BZ2_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 BZ2_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)BZ2_bzDecompressEnd ( &(bzf->strm) );
   free ( bzf );
}


/*---------------------------------------------------*/
int BZ2_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 = BZ2_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 BZ2_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 BZ2_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 = BZ2_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 = BZ2_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;
   BZ2_bzCompressEnd ( &strm );
   return BZ_OK;

   output_overflow:
   BZ2_bzCompressEnd ( &strm );
   return BZ_OUTBUFF_FULL;

   errhandler:
   BZ2_bzCompressEnd ( &strm );
   return ret;
}


/*---------------------------------------------------*/
int BZ2_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 = BZ2_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 = BZ2_bzDecompress ( &strm );
   if (ret == BZ_OK) goto output_overflow_or_eof;
   if (ret != BZ_STREAM_END) goto errhandler;

   /* normal termination */
   *destLen -= strm.avail_out;
   BZ2_bzDecompressEnd ( &strm );
   return BZ_OK;

   output_overflow_or_eof:
   if (strm.avail_out > 0) {
      BZ2_bzDecompressEnd ( &strm );
      return BZ_UNEXPECTED_EOF;
   } else {
      BZ2_bzDecompressEnd ( &strm );
      return BZ_OUTBUFF_FULL;
   };

   errhandler:
   BZ2_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 * BZ2_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 = BZ2_bzWriteOpen(&bzerr,fp,blockSize100k,
                             verbosity,workFactor);
   } else {
      bzfp = BZ2_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 * BZ2_bzopen
               ( const char *path,
                 const char *mode )
{
   return bzopen_or_bzdopen(path,-1,mode,/*bzopen*/0);
}


/*---------------------------------------------------*/
BZFILE * BZ2_bzdopen
               ( int fd,
                 const char *mode )
{
   return bzopen_or_bzdopen(NULL,fd,mode,/*bzdopen*/1);
}


/*---------------------------------------------------*/
int BZ2_bzread (BZFILE* b, void* buf, int len )
{
   int bzerr, nread;
   if (((bzFile*)b)->lastErr == BZ_STREAM_END) return 0;
   nread = BZ2_bzRead(&bzerr,b,buf,len);
   if (bzerr == BZ_OK || bzerr == BZ_STREAM_END) {
      return nread;
   } else {
      return -1;
   }
}


/*---------------------------------------------------*/
int BZ2_bzwrite (BZFILE* b, void* buf, int len )
{
   int bzerr;

   BZ2_bzWrite(&bzerr,b,buf,len);
   if(bzerr == BZ_OK){
      return len;
   }else{
      return -1;
   }
}


/*---------------------------------------------------*/
int BZ2_bzflush (BZFILE *b)
{
   /* do nothing now... */
   return 0;
}


/*---------------------------------------------------*/
void BZ2_bzclose (BZFILE* b)
{
   int bzerr;
   FILE *fp = ((bzFile *)b)->handle;

   if (b==NULL) {return;}
   if(((bzFile*)b)->writing){
      BZ2_bzWriteClose(&bzerr,b,0,NULL,NULL);
      if(bzerr != BZ_OK){
         BZ2_bzWriteClose(NULL,b,1,NULL,NULL);
      }
   }else{
      BZ2_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"
      ,"CONFIG_ERROR"
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
};


const char * BZ2_bzerror (BZFILE *b, int *errnum)
{
   int err = ((bzFile *)b)->lastErr;

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