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

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

   bzip2/libbzip2 version 1.0.6 of 6 September 2010
   Copyright (C) 1996-2010 Julian Seward <jseward@bzip.org>

   Please read the WARNING, DISCLAIMER and PATENTS sections in the
   README file.

   This program is released under the terms of the license contained
   in the file LICENSE.
   ------------------------------------------------------------------ */

/* 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 BZ2_bz__AssertH__fail ( int errcode )
{
   fprintf(stderr,
      "\n\nbzip2/libbzip2: internal error number %d.\n"
      "This is a bug in bzip2/libbzip2, %s.\n"
      "Please report it to me at: jseward@bzip.org.  If this happened\n"
      "when 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, 10 December 2007.\n\n",
      errcode,
      BZ2_bzlibVersion()
   );

   if (errcode == 1007) {
   fprintf(stderr,
      "\n*** A special note about internal error number 1007 ***\n"
      "\n"
      "Experience suggests that a common cause of i.e. 1007\n"
      "is unreliable memory or other hardware.  The 1007 assertion\n"
      "just happens to cross-check the results of huge numbers of\n"
      "memory reads/writes, and so acts (unintendedly) as a stress\n"
      "test of your memory system.\n"
      "\n"
      "I suggest the following: try compressing the file again,\n"
      "possibly monitoring progress in detail with the -vv flag.\n"
      "\n"
      "* If the error cannot be reproduced, and/or happens at different\n"
      "  points in compression, you may have a flaky memory system.\n"
      "  Try a memory-test program.  I have used Memtest86\n"
      "  (www.memtest86.com).  At the time of writing it is free (GPLd).\n"
      "  Memtest86 tests memory much more thorougly than your BIOSs\n"
      "  power-on test, and may find failures that the BIOS doesn't.\n"
      "\n"
      "* If the error can be repeatably reproduced, this is a bug in\n"
      "  bzip2, and I would very much like to hear about it.  Please\n"
      "  let me know, and, ideally, save a copy of the file causing the\n"
      "  problem -- without which I will be unable to investigate it.\n"
      "\n"
   );
   }

   exit(3);
}
#endif


/*---------------------------------------------------*/
static
int bz_config_ok ( void )
{
   if (sizeof(int)   != 4) return 0;
   if (sizeof(short) != 2) return 0;
   if (sizeof(char)  != 1) return 0;
   return 1;
}


/*---------------------------------------------------*/
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 );
}


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

/*---------------------------------------------------*/
int BZ_API(BZ2_bzDecompressInit)
                     ( bz_stream* strm,
                       int        verbosity,
                       int        small )
{
   DState* s;

   if (!bz_config_ok()) return BZ_CONFIG_ERROR;

   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_lo32      = 0;
   strm->total_in_hi32      = 0;
   strm->total_out_lo32     = 0;
   strm->total_out_hi32     = 0;
   s->smallDecompress       = (Bool)small;
   s->ll4                   = NULL;
   s->ll16                  = NULL;
   s->tt                    = NULL;
   s->currBlockNo           = 0;
   s->verbosity             = verbosity;

   return BZ_OK;
}


/*---------------------------------------------------*/
/* Return  True iff data corruption is discovered.
   Returns False if there is no problem.
*/
static
Bool 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 False;
            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_lo32++;
            if (s->strm->total_out_lo32 == 0) s->strm->total_out_hi32++;
         }

         /* can a new run be started? */
         if (s->nblock_used == s->save_nblock+1) return False;

         /* Only caused by corrupt data stream? */
         if (s->nblock_used > s->save_nblock+1)
            return True;

         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;
      Int32         ro_blockSize100k     = s->blockSize100k;
      /* end restore */

      UInt32       avail_out_INIT = cs_avail_out;
      Int32        s_save_nblockPP = s->save_nblock+1;
      unsigned int total_out_lo32_old;

      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--;
            }
         }
         /* Only caused by corrupt data stream? */
         if (c_nblock_used > s_save_nblockPP)
            return True;

         /* 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:
      total_out_lo32_old = s->strm->total_out_lo32;
      s->strm->total_out_lo32 += (avail_out_INIT - cs_avail_out);
      if (s->strm->total_out_lo32 < total_out_lo32_old)
         s->strm->total_out_hi32++;

      /* 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 */
   }
   return False;
}



/*---------------------------------------------------*/
__inline__ Int32 BZ2_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;
}


/*---------------------------------------------------*/
/* Return  True iff data corruption is discovered.
   Returns False if there is no problem.
*/
static
Bool 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 False;
            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_lo32++;
            if (s->strm->total_out_lo32 == 0) s->strm->total_out_hi32++;
         }

         /* can a new run be started? */
         if (s->nblock_used == s->save_nblock+1) return False;

         /* Only caused by corrupt data stream? */
         if (s->nblock_used > s->save_nblock+1)
            return True;

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

         /* can a new run be started? */
         if (s->nblock_used == s->save_nblock+1) return False;

         /* Only caused by corrupt data stream? */
         if (s->nblock_used > s->save_nblock+1)
            return True;

         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(BZ2_bzDecompress) ( bz_stream *strm )
{
   Bool    corrupt;
   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)
            corrupt = unRLE_obuf_to_output_SMALL ( s ); else
            corrupt = unRLE_obuf_to_output_FAST  ( s );
         if (corrupt) return BZ_DATA_ERROR;
         if (s->nblock_used == s->save_nblock+1 && s->state_out_len == 0) {
            BZ_FINALISE_CRC ( s->calculatedBlockCRC );
            if (s->verbosity >= 3)
               VPrintf2 ( " {0x%08x, 0x%08x}", 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 = BZ2_decompress ( s );
         if (r == BZ_STREAM_END) {
            if (s->verbosity >= 3)
               VPrintf2 ( "\n    combined CRCs: stored = 0x%08x, computed = 0x%08x",
                          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(BZ2_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;
}


/*---------------------------------------------------*/
/*--
   Code contributed by Yoshioka Tsuneo (tsuneo@rr.iij4u.or.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 "0.9.5d, 4-Sept-1999".
--*/
const char * BZ_API(BZ2_bzlibVersion)(void)
{
   return BZ_VERSION;
}


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