bzlib_decompress.c

u-boot-1.1.6 源码包

	    j++;
	    if (j >= nGroups) RETURN(BZ_DATA_ERROR);
	 }
	 s->selectorMtf[i] = j;
      }

      /*--- Undo the MTF values for the selectors. ---*/
      {
	 UChar pos[BZ_N_GROUPS], tmp, v;
	 for (v = 0; v < nGroups; v++) pos[v] = v;

	 for (i = 0; i < nSelectors; i++) {
	    v = s->selectorMtf[i];
	    tmp = pos[v];
	    while (v > 0) { pos[v] = pos[v-1]; v--; }
	    pos[0] = tmp;
	    s->selector[i] = tmp;
	 }
      }

      /*--- Now the coding tables ---*/
      for (t = 0; t < nGroups; t++) {
	 GET_BITS(BZ_X_CODING_1, curr, 5);
	 for (i = 0; i < alphaSize; i++) {
	    while (True) {
	       if (curr < 1 || curr > 20) RETURN(BZ_DATA_ERROR);
	       GET_BIT(BZ_X_CODING_2, uc);
	       if (uc == 0) break;
	       GET_BIT(BZ_X_CODING_3, uc);
	       if (uc == 0) curr++; else curr--;
	    }
	    s->len[t][i] = curr;
	 }
      }

      /*--- Create the Huffman decoding tables ---*/
      for (t = 0; t < nGroups; t++) {
	 minLen = 32;
	 maxLen = 0;
	 for (i = 0; i < alphaSize; i++) {
	    if (s->len[t][i] > maxLen) maxLen = s->len[t][i];
	    if (s->len[t][i] < minLen) minLen = s->len[t][i];
	 }
	 BZ2_hbCreateDecodeTables (
	    &(s->limit[t][0]),
	    &(s->base[t][0]),
	    &(s->perm[t][0]),
	    &(s->len[t][0]),
	    minLen, maxLen, alphaSize
	 );
	 s->minLens[t] = minLen;
      }

      /*--- Now the MTF values ---*/

      EOB      = s->nInUse+1;
      nblockMAX = 100000 * s->blockSize100k;
      groupNo  = -1;
      groupPos = 0;

      for (i = 0; i <= 255; i++) s->unzftab[i] = 0;

      /*-- MTF init --*/
      {
	 Int32 ii, jj, kk;
	 kk = MTFA_SIZE-1;
	 for (ii = 256 / MTFL_SIZE - 1; ii >= 0; ii--) {
	    for (jj = MTFL_SIZE-1; jj >= 0; jj--) {
	       s->mtfa[kk] = (UChar)(ii * MTFL_SIZE + jj);
	       kk--;
	    }
	    s->mtfbase[ii] = kk + 1;
	 }
      }
      /*-- end MTF init --*/

      nblock = 0;
      GET_MTF_VAL(BZ_X_MTF_1, BZ_X_MTF_2, nextSym);

      while (True) {

#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
	WATCHDOG_RESET();
#endif
	 if (nextSym == EOB) break;

	 if (nextSym == BZ_RUNA || nextSym == BZ_RUNB) {

	    es = -1;
	    N = 1;
	    do {
	       if (nextSym == BZ_RUNA) es = es + (0+1) * N; else
	       if (nextSym == BZ_RUNB) es = es + (1+1) * N;
	       N = N * 2;
	       GET_MTF_VAL(BZ_X_MTF_3, BZ_X_MTF_4, nextSym);
	    }
	       while (nextSym == BZ_RUNA || nextSym == BZ_RUNB);

	    es++;
	    uc = s->seqToUnseq[ s->mtfa[s->mtfbase[0]] ];
	    s->unzftab[uc] += es;

	    if (s->smallDecompress)
	       while (es > 0) {
		  if (nblock >= nblockMAX) RETURN(BZ_DATA_ERROR);
		  s->ll16[nblock] = (UInt16)uc;
		  nblock++;
		  es--;
	       }
	    else
	       while (es > 0) {
		  if (nblock >= nblockMAX) RETURN(BZ_DATA_ERROR);
		  s->tt[nblock] = (UInt32)uc;
		  nblock++;
		  es--;
	       };

	    continue;

	 } else {

	    if (nblock >= nblockMAX) RETURN(BZ_DATA_ERROR);

	    /*-- uc = MTF ( nextSym-1 ) --*/
	    {
	       Int32 ii, jj, kk, pp, lno, off;
	       UInt32 nn;
	       nn = (UInt32)(nextSym - 1);

	       if (nn < MTFL_SIZE) {
		  /* avoid general-case expense */
		  pp = s->mtfbase[0];
		  uc = s->mtfa[pp+nn];
		  while (nn > 3) {
		     Int32 z = pp+nn;
		     s->mtfa[(z)  ] = s->mtfa[(z)-1];
		     s->mtfa[(z)-1] = s->mtfa[(z)-2];
		     s->mtfa[(z)-2] = s->mtfa[(z)-3];
		     s->mtfa[(z)-3] = s->mtfa[(z)-4];
		     nn -= 4;
		  }
		  while (nn > 0) {
		     s->mtfa[(pp+nn)] = s->mtfa[(pp+nn)-1]; nn--;
		  };
		  s->mtfa[pp] = uc;
	       } else {
		  /* general case */
		  lno = nn / MTFL_SIZE;
		  off = nn % MTFL_SIZE;
		  pp = s->mtfbase[lno] + off;
		  uc = s->mtfa[pp];
		  while (pp > s->mtfbase[lno]) {
		     s->mtfa[pp] = s->mtfa[pp-1]; pp--;
		  };
		  s->mtfbase[lno]++;
		  while (lno > 0) {
		     s->mtfbase[lno]--;
		     s->mtfa[s->mtfbase[lno]]
			= s->mtfa[s->mtfbase[lno-1] + MTFL_SIZE - 1];
		     lno--;
		  }
		  s->mtfbase[0]--;
		  s->mtfa[s->mtfbase[0]] = uc;
		  if (s->mtfbase[0] == 0) {
		     kk = MTFA_SIZE-1;
		     for (ii = 256 / MTFL_SIZE-1; ii >= 0; ii--) {
#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
			WATCHDOG_RESET();
#endif
			for (jj = MTFL_SIZE-1; jj >= 0; jj--) {
			   s->mtfa[kk] = s->mtfa[s->mtfbase[ii] + jj];
			   kk--;
			}
			s->mtfbase[ii] = kk + 1;
		     }
		  }
	       }
	    }
	    /*-- end uc = MTF ( nextSym-1 ) --*/

	    s->unzftab[s->seqToUnseq[uc]]++;
	    if (s->smallDecompress)
	       s->ll16[nblock] = (UInt16)(s->seqToUnseq[uc]); else
	       s->tt[nblock]   = (UInt32)(s->seqToUnseq[uc]);
	    nblock++;

	    GET_MTF_VAL(BZ_X_MTF_5, BZ_X_MTF_6, nextSym);
	    continue;
	 }
      }

      /* Now we know what nblock is, we can do a better sanity
	 check on s->origPtr.
      */
      if (s->origPtr < 0 || s->origPtr >= nblock)
	 RETURN(BZ_DATA_ERROR);

      s->state_out_len = 0;
      s->state_out_ch  = 0;
      BZ_INITIALISE_CRC ( s->calculatedBlockCRC );
      s->state = BZ_X_OUTPUT;
      if (s->verbosity >= 2) VPrintf0 ( "rt+rld" );

      /*-- Set up cftab to facilitate generation of T^(-1) --*/
      s->cftab[0] = 0;
      for (i = 1; i <= 256; i++) s->cftab[i] = s->unzftab[i-1];
      for (i = 1; i <= 256; i++) s->cftab[i] += s->cftab[i-1];

      if (s->smallDecompress) {

	 /*-- Make a copy of cftab, used in generation of T --*/
	 for (i = 0; i <= 256; i++) s->cftabCopy[i] = s->cftab[i];

	 /*-- compute the T vector --*/
	 for (i = 0; i < nblock; i++) {
	    uc = (UChar)(s->ll16[i]);
	    SET_LL(i, s->cftabCopy[uc]);
	    s->cftabCopy[uc]++;
	 }

	 /*-- Compute T^(-1) by pointer reversal on T --*/
	 i = s->origPtr;
	 j = GET_LL(i);
	 do {
	    Int32 tmp = GET_LL(j);
	    SET_LL(j, i);
	    i = j;
	    j = tmp;
	 }
	    while (i != s->origPtr);

#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
	WATCHDOG_RESET();
#endif
	 s->tPos = s->origPtr;
	 s->nblock_used = 0;
	 if (s->blockRandomised) {
	    BZ_RAND_INIT_MASK;
	    BZ_GET_SMALL(s->k0); s->nblock_used++;
	    BZ_RAND_UPD_MASK; s->k0 ^= BZ_RAND_MASK;
	 } else {
	    BZ_GET_SMALL(s->k0); s->nblock_used++;
	 }

      } else {

#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
	WATCHDOG_RESET();
#endif
	 /*-- compute the T^(-1) vector --*/
	 for (i = 0; i < nblock; i++) {
	    uc = (UChar)(s->tt[i] & 0xff);
	    s->tt[s->cftab[uc]] |= (i << 8);
	    s->cftab[uc]++;
	 }

	 s->tPos = s->tt[s->origPtr] >> 8;
	 s->nblock_used = 0;
	 if (s->blockRandomised) {
	    BZ_RAND_INIT_MASK;
	    BZ_GET_FAST(s->k0); s->nblock_used++;
	    BZ_RAND_UPD_MASK; s->k0 ^= BZ_RAND_MASK;
	 } else {
	    BZ_GET_FAST(s->k0); s->nblock_used++;
	 }

      }

      RETURN(BZ_OK);


    endhdr_2:

      GET_UCHAR(BZ_X_ENDHDR_2, uc);
      if (uc != 0x72) RETURN(BZ_DATA_ERROR);
      GET_UCHAR(BZ_X_ENDHDR_3, uc);
      if (uc != 0x45) RETURN(BZ_DATA_ERROR);
      GET_UCHAR(BZ_X_ENDHDR_4, uc);
      if (uc != 0x38) RETURN(BZ_DATA_ERROR);
      GET_UCHAR(BZ_X_ENDHDR_5, uc);
      if (uc != 0x50) RETURN(BZ_DATA_ERROR);
      GET_UCHAR(BZ_X_ENDHDR_6, uc);
      if (uc != 0x90) RETURN(BZ_DATA_ERROR);

      s->storedCombinedCRC = 0;
      GET_UCHAR(BZ_X_CCRC_1, uc);
      s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
      GET_UCHAR(BZ_X_CCRC_2, uc);
      s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
      GET_UCHAR(BZ_X_CCRC_3, uc);
      s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
      GET_UCHAR(BZ_X_CCRC_4, uc);
      s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);

      s->state = BZ_X_IDLE;
      RETURN(BZ_STREAM_END);

      default: AssertH ( False, 4001 );
   }

   AssertH ( False, 4002 );

   save_state_and_return:

   s->save_i           = i;
   s->save_j           = j;
   s->save_t           = t;
   s->save_alphaSize   = alphaSize;
   s->save_nGroups     = nGroups;
   s->save_nSelectors  = nSelectors;
   s->save_EOB         = EOB;
   s->save_groupNo     = groupNo;
   s->save_groupPos    = groupPos;
   s->save_nextSym     = nextSym;
   s->save_nblockMAX   = nblockMAX;
   s->save_nblock      = nblock;
   s->save_es          = es;
   s->save_N           = N;
   s->save_curr        = curr;
   s->save_zt          = zt;
   s->save_zn          = zn;
   s->save_zvec        = zvec;
   s->save_zj          = zj;
   s->save_gSel        = gSel;
   s->save_gMinlen     = gMinlen;
   s->save_gLimit      = gLimit;
   s->save_gBase       = gBase;
   s->save_gPerm       = gPerm;

   return retVal;
}


/*-------------------------------------------------------------*/
/*--- end                                      decompress.c ---*/
/*-------------------------------------------------------------*/

#endif /* CONFIG_BZIP2 */