decompress.c revision 78556
178556Sobrien
278556Sobrien/*-------------------------------------------------------------*/
378556Sobrien/*--- Decompression machinery                               ---*/
478556Sobrien/*---                                          decompress.c ---*/
578556Sobrien/*-------------------------------------------------------------*/
678556Sobrien
778556Sobrien/*--
878556Sobrien  This file is a part of bzip2 and/or libbzip2, a program and
978556Sobrien  library for lossless, block-sorting data compression.
1078556Sobrien
1178556Sobrien  Copyright (C) 1996-2000 Julian R Seward.  All rights reserved.
1278556Sobrien
1378556Sobrien  Redistribution and use in source and binary forms, with or without
1478556Sobrien  modification, are permitted provided that the following conditions
1578556Sobrien  are met:
1678556Sobrien
1778556Sobrien  1. Redistributions of source code must retain the above copyright
1878556Sobrien     notice, this list of conditions and the following disclaimer.
1978556Sobrien
2078556Sobrien  2. The origin of this software must not be misrepresented; you must
2178556Sobrien     not claim that you wrote the original software.  If you use this
2278556Sobrien     software in a product, an acknowledgment in the product
2378556Sobrien     documentation would be appreciated but is not required.
2478556Sobrien
2578556Sobrien  3. Altered source versions must be plainly marked as such, and must
2678556Sobrien     not be misrepresented as being the original software.
2778556Sobrien
2878556Sobrien  4. The name of the author may not be used to endorse or promote
2978556Sobrien     products derived from this software without specific prior written
3078556Sobrien     permission.
3178556Sobrien
3278556Sobrien  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
3378556Sobrien  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
3478556Sobrien  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
3578556Sobrien  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
3678556Sobrien  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
3778556Sobrien  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
3878556Sobrien  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
3978556Sobrien  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
4078556Sobrien  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
4178556Sobrien  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
4278556Sobrien  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
4378556Sobrien
4478556Sobrien  Julian Seward, Cambridge, UK.
4578556Sobrien  jseward@acm.org
4678556Sobrien  bzip2/libbzip2 version 1.0 of 21 March 2000
4778556Sobrien
4878556Sobrien  This program is based on (at least) the work of:
4978556Sobrien     Mike Burrows
5078556Sobrien     David Wheeler
5178556Sobrien     Peter Fenwick
5278556Sobrien     Alistair Moffat
5378556Sobrien     Radford Neal
5478556Sobrien     Ian H. Witten
5578556Sobrien     Robert Sedgewick
5678556Sobrien     Jon L. Bentley
5778556Sobrien
5878556Sobrien  For more information on these sources, see the manual.
5978556Sobrien--*/
6078556Sobrien
6178556Sobrien
6278556Sobrien#include "bzlib_private.h"
6378556Sobrien
6478556Sobrien
6578556Sobrien/*---------------------------------------------------*/
6678556Sobrienstatic
6778556Sobrienvoid makeMaps_d ( DState* s )
6878556Sobrien{
6978556Sobrien   Int32 i;
7078556Sobrien   s->nInUse = 0;
7178556Sobrien   for (i = 0; i < 256; i++)
7278556Sobrien      if (s->inUse[i]) {
7378556Sobrien         s->seqToUnseq[s->nInUse] = i;
7478556Sobrien         s->nInUse++;
7578556Sobrien      }
7678556Sobrien}
7778556Sobrien
7878556Sobrien
7978556Sobrien/*---------------------------------------------------*/
8078556Sobrien#define RETURN(rrr)                               \
8178556Sobrien   { retVal = rrr; goto save_state_and_return; };
8278556Sobrien
8378556Sobrien#define GET_BITS(lll,vvv,nnn)                     \
8478556Sobrien   case lll: s->state = lll;                      \
8578556Sobrien   while (True) {                                 \
8678556Sobrien      if (s->bsLive >= nnn) {                     \
8778556Sobrien         UInt32 v;                                \
8878556Sobrien         v = (s->bsBuff >>                        \
8978556Sobrien             (s->bsLive-nnn)) & ((1 << nnn)-1);   \
9078556Sobrien         s->bsLive -= nnn;                        \
9178556Sobrien         vvv = v;                                 \
9278556Sobrien         break;                                   \
9378556Sobrien      }                                           \
9478556Sobrien      if (s->strm->avail_in == 0) RETURN(BZ_OK);  \
9578556Sobrien      s->bsBuff                                   \
9678556Sobrien         = (s->bsBuff << 8) |                     \
9778556Sobrien           ((UInt32)                              \
9878556Sobrien              (*((UChar*)(s->strm->next_in))));   \
9978556Sobrien      s->bsLive += 8;                             \
10078556Sobrien      s->strm->next_in++;                         \
10178556Sobrien      s->strm->avail_in--;                        \
10278556Sobrien      s->strm->total_in_lo32++;                   \
10378556Sobrien      if (s->strm->total_in_lo32 == 0)            \
10478556Sobrien         s->strm->total_in_hi32++;                \
10578556Sobrien   }
10678556Sobrien
10778556Sobrien#define GET_UCHAR(lll,uuu)                        \
10878556Sobrien   GET_BITS(lll,uuu,8)
10978556Sobrien
11078556Sobrien#define GET_BIT(lll,uuu)                          \
11178556Sobrien   GET_BITS(lll,uuu,1)
11278556Sobrien
11378556Sobrien/*---------------------------------------------------*/
11478556Sobrien#define GET_MTF_VAL(label1,label2,lval)           \
11578556Sobrien{                                                 \
11678556Sobrien   if (groupPos == 0) {                           \
11778556Sobrien      groupNo++;                                  \
11878556Sobrien      if (groupNo >= nSelectors)                  \
11978556Sobrien         RETURN(BZ_DATA_ERROR);                   \
12078556Sobrien      groupPos = BZ_G_SIZE;                       \
12178556Sobrien      gSel = s->selector[groupNo];                \
12278556Sobrien      gMinlen = s->minLens[gSel];                 \
12378556Sobrien      gLimit = &(s->limit[gSel][0]);              \
12478556Sobrien      gPerm = &(s->perm[gSel][0]);                \
12578556Sobrien      gBase = &(s->base[gSel][0]);                \
12678556Sobrien   }                                              \
12778556Sobrien   groupPos--;                                    \
12878556Sobrien   zn = gMinlen;                                  \
12978556Sobrien   GET_BITS(label1, zvec, zn);                    \
13078556Sobrien   while (1) {                                    \
13178556Sobrien      if (zn > 20 /* the longest code */)         \
13278556Sobrien         RETURN(BZ_DATA_ERROR);                   \
13378556Sobrien      if (zvec <= gLimit[zn]) break;              \
13478556Sobrien      zn++;                                       \
13578556Sobrien      GET_BIT(label2, zj);                        \
13678556Sobrien      zvec = (zvec << 1) | zj;                    \
13778556Sobrien   };                                             \
13878556Sobrien   if (zvec - gBase[zn] < 0                       \
13978556Sobrien       || zvec - gBase[zn] >= BZ_MAX_ALPHA_SIZE)  \
14078556Sobrien      RETURN(BZ_DATA_ERROR);                      \
14178556Sobrien   lval = gPerm[zvec - gBase[zn]];                \
14278556Sobrien}
14378556Sobrien
14478556Sobrien
14578556Sobrien/*---------------------------------------------------*/
14678556SobrienInt32 BZ2_decompress ( DState* s )
14778556Sobrien{
14878556Sobrien   UChar      uc;
14978556Sobrien   Int32      retVal;
15078556Sobrien   Int32      minLen, maxLen;
15178556Sobrien   bz_stream* strm = s->strm;
15278556Sobrien
15378556Sobrien   /* stuff that needs to be saved/restored */
15478556Sobrien   Int32  i;
15578556Sobrien   Int32  j;
15678556Sobrien   Int32  t;
15778556Sobrien   Int32  alphaSize;
15878556Sobrien   Int32  nGroups;
15978556Sobrien   Int32  nSelectors;
16078556Sobrien   Int32  EOB;
16178556Sobrien   Int32  groupNo;
16278556Sobrien   Int32  groupPos;
16378556Sobrien   Int32  nextSym;
16478556Sobrien   Int32  nblockMAX;
16578556Sobrien   Int32  nblock;
16678556Sobrien   Int32  es;
16778556Sobrien   Int32  N;
16878556Sobrien   Int32  curr;
16978556Sobrien   Int32  zt;
17078556Sobrien   Int32  zn;
17178556Sobrien   Int32  zvec;
17278556Sobrien   Int32  zj;
17378556Sobrien   Int32  gSel;
17478556Sobrien   Int32  gMinlen;
17578556Sobrien   Int32* gLimit;
17678556Sobrien   Int32* gBase;
17778556Sobrien   Int32* gPerm;
17878556Sobrien
17978556Sobrien   if (s->state == BZ_X_MAGIC_1) {
18078556Sobrien      /*initialise the save area*/
18178556Sobrien      s->save_i           = 0;
18278556Sobrien      s->save_j           = 0;
18378556Sobrien      s->save_t           = 0;
18478556Sobrien      s->save_alphaSize   = 0;
18578556Sobrien      s->save_nGroups     = 0;
18678556Sobrien      s->save_nSelectors  = 0;
18778556Sobrien      s->save_EOB         = 0;
18878556Sobrien      s->save_groupNo     = 0;
18978556Sobrien      s->save_groupPos    = 0;
19078556Sobrien      s->save_nextSym     = 0;
19178556Sobrien      s->save_nblockMAX   = 0;
19278556Sobrien      s->save_nblock      = 0;
19378556Sobrien      s->save_es          = 0;
19478556Sobrien      s->save_N           = 0;
19578556Sobrien      s->save_curr        = 0;
19678556Sobrien      s->save_zt          = 0;
19778556Sobrien      s->save_zn          = 0;
19878556Sobrien      s->save_zvec        = 0;
19978556Sobrien      s->save_zj          = 0;
20078556Sobrien      s->save_gSel        = 0;
20178556Sobrien      s->save_gMinlen     = 0;
20278556Sobrien      s->save_gLimit      = NULL;
20378556Sobrien      s->save_gBase       = NULL;
20478556Sobrien      s->save_gPerm       = NULL;
20578556Sobrien   }
20678556Sobrien
20778556Sobrien   /*restore from the save area*/
20878556Sobrien   i           = s->save_i;
20978556Sobrien   j           = s->save_j;
21078556Sobrien   t           = s->save_t;
21178556Sobrien   alphaSize   = s->save_alphaSize;
21278556Sobrien   nGroups     = s->save_nGroups;
21378556Sobrien   nSelectors  = s->save_nSelectors;
21478556Sobrien   EOB         = s->save_EOB;
21578556Sobrien   groupNo     = s->save_groupNo;
21678556Sobrien   groupPos    = s->save_groupPos;
21778556Sobrien   nextSym     = s->save_nextSym;
21878556Sobrien   nblockMAX   = s->save_nblockMAX;
21978556Sobrien   nblock      = s->save_nblock;
22078556Sobrien   es          = s->save_es;
22178556Sobrien   N           = s->save_N;
22278556Sobrien   curr        = s->save_curr;
22378556Sobrien   zt          = s->save_zt;
22478556Sobrien   zn          = s->save_zn;
22578556Sobrien   zvec        = s->save_zvec;
22678556Sobrien   zj          = s->save_zj;
22778556Sobrien   gSel        = s->save_gSel;
22878556Sobrien   gMinlen     = s->save_gMinlen;
22978556Sobrien   gLimit      = s->save_gLimit;
23078556Sobrien   gBase       = s->save_gBase;
23178556Sobrien   gPerm       = s->save_gPerm;
23278556Sobrien
23378556Sobrien   retVal = BZ_OK;
23478556Sobrien
23578556Sobrien   switch (s->state) {
23678556Sobrien
23778556Sobrien      GET_UCHAR(BZ_X_MAGIC_1, uc);
23878556Sobrien      if (uc != 'B') RETURN(BZ_DATA_ERROR_MAGIC);
23978556Sobrien
24078556Sobrien      GET_UCHAR(BZ_X_MAGIC_2, uc);
24178556Sobrien      if (uc != 'Z') RETURN(BZ_DATA_ERROR_MAGIC);
24278556Sobrien
24378556Sobrien      GET_UCHAR(BZ_X_MAGIC_3, uc)
24478556Sobrien      if (uc != 'h') RETURN(BZ_DATA_ERROR_MAGIC);
24578556Sobrien
24678556Sobrien      GET_BITS(BZ_X_MAGIC_4, s->blockSize100k, 8)
24778556Sobrien      if (s->blockSize100k < '1' ||
24878556Sobrien          s->blockSize100k > '9') RETURN(BZ_DATA_ERROR_MAGIC);
24978556Sobrien      s->blockSize100k -= '0';
25078556Sobrien
25178556Sobrien      if (s->smallDecompress) {
25278556Sobrien         s->ll16 = BZALLOC( s->blockSize100k * 100000 * sizeof(UInt16) );
25378556Sobrien         s->ll4  = BZALLOC(
25478556Sobrien                      ((1 + s->blockSize100k * 100000) >> 1) * sizeof(UChar)
25578556Sobrien                   );
25678556Sobrien         if (s->ll16 == NULL || s->ll4 == NULL) RETURN(BZ_MEM_ERROR);
25778556Sobrien      } else {
25878556Sobrien         s->tt  = BZALLOC( s->blockSize100k * 100000 * sizeof(Int32) );
25978556Sobrien         if (s->tt == NULL) RETURN(BZ_MEM_ERROR);
26078556Sobrien      }
26178556Sobrien
26278556Sobrien      GET_UCHAR(BZ_X_BLKHDR_1, uc);
26378556Sobrien
26478556Sobrien      if (uc == 0x17) goto endhdr_2;
26578556Sobrien      if (uc != 0x31) RETURN(BZ_DATA_ERROR);
26678556Sobrien      GET_UCHAR(BZ_X_BLKHDR_2, uc);
26778556Sobrien      if (uc != 0x41) RETURN(BZ_DATA_ERROR);
26878556Sobrien      GET_UCHAR(BZ_X_BLKHDR_3, uc);
26978556Sobrien      if (uc != 0x59) RETURN(BZ_DATA_ERROR);
27078556Sobrien      GET_UCHAR(BZ_X_BLKHDR_4, uc);
27178556Sobrien      if (uc != 0x26) RETURN(BZ_DATA_ERROR);
27278556Sobrien      GET_UCHAR(BZ_X_BLKHDR_5, uc);
27378556Sobrien      if (uc != 0x53) RETURN(BZ_DATA_ERROR);
27478556Sobrien      GET_UCHAR(BZ_X_BLKHDR_6, uc);
27578556Sobrien      if (uc != 0x59) RETURN(BZ_DATA_ERROR);
27678556Sobrien
27778556Sobrien      s->currBlockNo++;
27878556Sobrien      if (s->verbosity >= 2)
27978556Sobrien         VPrintf1 ( "\n    [%d: huff+mtf ", s->currBlockNo );
28078556Sobrien
28178556Sobrien      s->storedBlockCRC = 0;
28278556Sobrien      GET_UCHAR(BZ_X_BCRC_1, uc);
28378556Sobrien      s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc);
28478556Sobrien      GET_UCHAR(BZ_X_BCRC_2, uc);
28578556Sobrien      s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc);
28678556Sobrien      GET_UCHAR(BZ_X_BCRC_3, uc);
28778556Sobrien      s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc);
28878556Sobrien      GET_UCHAR(BZ_X_BCRC_4, uc);
28978556Sobrien      s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc);
29078556Sobrien
29178556Sobrien      GET_BITS(BZ_X_RANDBIT, s->blockRandomised, 1);
29278556Sobrien
29378556Sobrien      s->origPtr = 0;
29478556Sobrien      GET_UCHAR(BZ_X_ORIGPTR_1, uc);
29578556Sobrien      s->origPtr = (s->origPtr << 8) | ((Int32)uc);
29678556Sobrien      GET_UCHAR(BZ_X_ORIGPTR_2, uc);
29778556Sobrien      s->origPtr = (s->origPtr << 8) | ((Int32)uc);
29878556Sobrien      GET_UCHAR(BZ_X_ORIGPTR_3, uc);
29978556Sobrien      s->origPtr = (s->origPtr << 8) | ((Int32)uc);
30078556Sobrien
30178556Sobrien      if (s->origPtr < 0)
30278556Sobrien         RETURN(BZ_DATA_ERROR);
30378556Sobrien      if (s->origPtr > 10 + 100000*s->blockSize100k)
30478556Sobrien         RETURN(BZ_DATA_ERROR);
30578556Sobrien
30678556Sobrien      /*--- Receive the mapping table ---*/
30778556Sobrien      for (i = 0; i < 16; i++) {
30878556Sobrien         GET_BIT(BZ_X_MAPPING_1, uc);
30978556Sobrien         if (uc == 1)
31078556Sobrien            s->inUse16[i] = True; else
31178556Sobrien            s->inUse16[i] = False;
31278556Sobrien      }
31378556Sobrien
31478556Sobrien      for (i = 0; i < 256; i++) s->inUse[i] = False;
31578556Sobrien
31678556Sobrien      for (i = 0; i < 16; i++)
31778556Sobrien         if (s->inUse16[i])
31878556Sobrien            for (j = 0; j < 16; j++) {
31978556Sobrien               GET_BIT(BZ_X_MAPPING_2, uc);
32078556Sobrien               if (uc == 1) s->inUse[i * 16 + j] = True;
32178556Sobrien            }
32278556Sobrien      makeMaps_d ( s );
32378556Sobrien      if (s->nInUse == 0) RETURN(BZ_DATA_ERROR);
32478556Sobrien      alphaSize = s->nInUse+2;
32578556Sobrien
32678556Sobrien      /*--- Now the selectors ---*/
32778556Sobrien      GET_BITS(BZ_X_SELECTOR_1, nGroups, 3);
32878556Sobrien      if (nGroups < 2 || nGroups > 6) RETURN(BZ_DATA_ERROR);
32978556Sobrien      GET_BITS(BZ_X_SELECTOR_2, nSelectors, 15);
33078556Sobrien      if (nSelectors < 1) RETURN(BZ_DATA_ERROR);
33178556Sobrien      for (i = 0; i < nSelectors; i++) {
33278556Sobrien         j = 0;
33378556Sobrien         while (True) {
33478556Sobrien            GET_BIT(BZ_X_SELECTOR_3, uc);
33578556Sobrien            if (uc == 0) break;
33678556Sobrien            j++;
33778556Sobrien            if (j >= nGroups) RETURN(BZ_DATA_ERROR);
33878556Sobrien         }
33978556Sobrien         s->selectorMtf[i] = j;
34078556Sobrien      }
34178556Sobrien
34278556Sobrien      /*--- Undo the MTF values for the selectors. ---*/
34378556Sobrien      {
34478556Sobrien         UChar pos[BZ_N_GROUPS], tmp, v;
34578556Sobrien         for (v = 0; v < nGroups; v++) pos[v] = v;
34678556Sobrien
34778556Sobrien         for (i = 0; i < nSelectors; i++) {
34878556Sobrien            v = s->selectorMtf[i];
34978556Sobrien            tmp = pos[v];
35078556Sobrien            while (v > 0) { pos[v] = pos[v-1]; v--; }
35178556Sobrien            pos[0] = tmp;
35278556Sobrien            s->selector[i] = tmp;
35378556Sobrien         }
35478556Sobrien      }
35578556Sobrien
35678556Sobrien      /*--- Now the coding tables ---*/
35778556Sobrien      for (t = 0; t < nGroups; t++) {
35878556Sobrien         GET_BITS(BZ_X_CODING_1, curr, 5);
35978556Sobrien         for (i = 0; i < alphaSize; i++) {
36078556Sobrien            while (True) {
36178556Sobrien               if (curr < 1 || curr > 20) RETURN(BZ_DATA_ERROR);
36278556Sobrien               GET_BIT(BZ_X_CODING_2, uc);
36378556Sobrien               if (uc == 0) break;
36478556Sobrien               GET_BIT(BZ_X_CODING_3, uc);
36578556Sobrien               if (uc == 0) curr++; else curr--;
36678556Sobrien            }
36778556Sobrien            s->len[t][i] = curr;
36878556Sobrien         }
36978556Sobrien      }
37078556Sobrien
37178556Sobrien      /*--- Create the Huffman decoding tables ---*/
37278556Sobrien      for (t = 0; t < nGroups; t++) {
37378556Sobrien         minLen = 32;
37478556Sobrien         maxLen = 0;
37578556Sobrien         for (i = 0; i < alphaSize; i++) {
37678556Sobrien            if (s->len[t][i] > maxLen) maxLen = s->len[t][i];
37778556Sobrien            if (s->len[t][i] < minLen) minLen = s->len[t][i];
37878556Sobrien         }
37978556Sobrien         BZ2_hbCreateDecodeTables (
38078556Sobrien            &(s->limit[t][0]),
38178556Sobrien            &(s->base[t][0]),
38278556Sobrien            &(s->perm[t][0]),
38378556Sobrien            &(s->len[t][0]),
38478556Sobrien            minLen, maxLen, alphaSize
38578556Sobrien         );
38678556Sobrien         s->minLens[t] = minLen;
38778556Sobrien      }
38878556Sobrien
38978556Sobrien      /*--- Now the MTF values ---*/
39078556Sobrien
39178556Sobrien      EOB      = s->nInUse+1;
39278556Sobrien      nblockMAX = 100000 * s->blockSize100k;
39378556Sobrien      groupNo  = -1;
39478556Sobrien      groupPos = 0;
39578556Sobrien
39678556Sobrien      for (i = 0; i <= 255; i++) s->unzftab[i] = 0;
39778556Sobrien
39878556Sobrien      /*-- MTF init --*/
39978556Sobrien      {
40078556Sobrien         Int32 ii, jj, kk;
40178556Sobrien         kk = MTFA_SIZE-1;
40278556Sobrien         for (ii = 256 / MTFL_SIZE - 1; ii >= 0; ii--) {
40378556Sobrien            for (jj = MTFL_SIZE-1; jj >= 0; jj--) {
40478556Sobrien               s->mtfa[kk] = (UChar)(ii * MTFL_SIZE + jj);
40578556Sobrien               kk--;
40678556Sobrien            }
40778556Sobrien            s->mtfbase[ii] = kk + 1;
40878556Sobrien         }
40978556Sobrien      }
41078556Sobrien      /*-- end MTF init --*/
41178556Sobrien
41278556Sobrien      nblock = 0;
41378556Sobrien      GET_MTF_VAL(BZ_X_MTF_1, BZ_X_MTF_2, nextSym);
41478556Sobrien
41578556Sobrien      while (True) {
41678556Sobrien
41778556Sobrien         if (nextSym == EOB) break;
41878556Sobrien
41978556Sobrien         if (nextSym == BZ_RUNA || nextSym == BZ_RUNB) {
42078556Sobrien
42178556Sobrien            es = -1;
42278556Sobrien            N = 1;
42378556Sobrien            do {
42478556Sobrien               if (nextSym == BZ_RUNA) es = es + (0+1) * N; else
42578556Sobrien               if (nextSym == BZ_RUNB) es = es + (1+1) * N;
42678556Sobrien               N = N * 2;
42778556Sobrien               GET_MTF_VAL(BZ_X_MTF_3, BZ_X_MTF_4, nextSym);
42878556Sobrien            }
42978556Sobrien               while (nextSym == BZ_RUNA || nextSym == BZ_RUNB);
43078556Sobrien
43178556Sobrien            es++;
43278556Sobrien            uc = s->seqToUnseq[ s->mtfa[s->mtfbase[0]] ];
43378556Sobrien            s->unzftab[uc] += es;
43478556Sobrien
43578556Sobrien            if (s->smallDecompress)
43678556Sobrien               while (es > 0) {
43778556Sobrien                  if (nblock >= nblockMAX) RETURN(BZ_DATA_ERROR);
43878556Sobrien                  s->ll16[nblock] = (UInt16)uc;
43978556Sobrien                  nblock++;
44078556Sobrien                  es--;
44178556Sobrien               }
44278556Sobrien            else
44378556Sobrien               while (es > 0) {
44478556Sobrien                  if (nblock >= nblockMAX) RETURN(BZ_DATA_ERROR);
44578556Sobrien                  s->tt[nblock] = (UInt32)uc;
44678556Sobrien                  nblock++;
44778556Sobrien                  es--;
44878556Sobrien               };
44978556Sobrien
45078556Sobrien            continue;
45178556Sobrien
45278556Sobrien         } else {
45378556Sobrien
45478556Sobrien            if (nblock >= nblockMAX) RETURN(BZ_DATA_ERROR);
45578556Sobrien
45678556Sobrien            /*-- uc = MTF ( nextSym-1 ) --*/
45778556Sobrien            {
45878556Sobrien               Int32 ii, jj, kk, pp, lno, off;
45978556Sobrien               UInt32 nn;
46078556Sobrien               nn = (UInt32)(nextSym - 1);
46178556Sobrien
46278556Sobrien               if (nn < MTFL_SIZE) {
46378556Sobrien                  /* avoid general-case expense */
46478556Sobrien                  pp = s->mtfbase[0];
46578556Sobrien                  uc = s->mtfa[pp+nn];
46678556Sobrien                  while (nn > 3) {
46778556Sobrien                     Int32 z = pp+nn;
46878556Sobrien                     s->mtfa[(z)  ] = s->mtfa[(z)-1];
46978556Sobrien                     s->mtfa[(z)-1] = s->mtfa[(z)-2];
47078556Sobrien                     s->mtfa[(z)-2] = s->mtfa[(z)-3];
47178556Sobrien                     s->mtfa[(z)-3] = s->mtfa[(z)-4];
47278556Sobrien                     nn -= 4;
47378556Sobrien                  }
47478556Sobrien                  while (nn > 0) {
47578556Sobrien                     s->mtfa[(pp+nn)] = s->mtfa[(pp+nn)-1]; nn--;
47678556Sobrien                  };
47778556Sobrien                  s->mtfa[pp] = uc;
47878556Sobrien               } else {
47978556Sobrien                  /* general case */
48078556Sobrien                  lno = nn / MTFL_SIZE;
48178556Sobrien                  off = nn % MTFL_SIZE;
48278556Sobrien                  pp = s->mtfbase[lno] + off;
48378556Sobrien                  uc = s->mtfa[pp];
48478556Sobrien                  while (pp > s->mtfbase[lno]) {
48578556Sobrien                     s->mtfa[pp] = s->mtfa[pp-1]; pp--;
48678556Sobrien                  };
48778556Sobrien                  s->mtfbase[lno]++;
48878556Sobrien                  while (lno > 0) {
48978556Sobrien                     s->mtfbase[lno]--;
49078556Sobrien                     s->mtfa[s->mtfbase[lno]]
49178556Sobrien                        = s->mtfa[s->mtfbase[lno-1] + MTFL_SIZE - 1];
49278556Sobrien                     lno--;
49378556Sobrien                  }
49478556Sobrien                  s->mtfbase[0]--;
49578556Sobrien                  s->mtfa[s->mtfbase[0]] = uc;
49678556Sobrien                  if (s->mtfbase[0] == 0) {
49778556Sobrien                     kk = MTFA_SIZE-1;
49878556Sobrien                     for (ii = 256 / MTFL_SIZE-1; ii >= 0; ii--) {
49978556Sobrien                        for (jj = MTFL_SIZE-1; jj >= 0; jj--) {
50078556Sobrien                           s->mtfa[kk] = s->mtfa[s->mtfbase[ii] + jj];
50178556Sobrien                           kk--;
50278556Sobrien                        }
50378556Sobrien                        s->mtfbase[ii] = kk + 1;
50478556Sobrien                     }
50578556Sobrien                  }
50678556Sobrien               }
50778556Sobrien            }
50878556Sobrien            /*-- end uc = MTF ( nextSym-1 ) --*/
50978556Sobrien
51078556Sobrien            s->unzftab[s->seqToUnseq[uc]]++;
51178556Sobrien            if (s->smallDecompress)
51278556Sobrien               s->ll16[nblock] = (UInt16)(s->seqToUnseq[uc]); else
51378556Sobrien               s->tt[nblock]   = (UInt32)(s->seqToUnseq[uc]);
51478556Sobrien            nblock++;
51578556Sobrien
51678556Sobrien            GET_MTF_VAL(BZ_X_MTF_5, BZ_X_MTF_6, nextSym);
51778556Sobrien            continue;
51878556Sobrien         }
51978556Sobrien      }
52078556Sobrien
52178556Sobrien      /* Now we know what nblock is, we can do a better sanity
52278556Sobrien         check on s->origPtr.
52378556Sobrien      */
52478556Sobrien      if (s->origPtr < 0 || s->origPtr >= nblock)
52578556Sobrien         RETURN(BZ_DATA_ERROR);
52678556Sobrien
52778556Sobrien      s->state_out_len = 0;
52878556Sobrien      s->state_out_ch  = 0;
52978556Sobrien      BZ_INITIALISE_CRC ( s->calculatedBlockCRC );
53078556Sobrien      s->state = BZ_X_OUTPUT;
53178556Sobrien      if (s->verbosity >= 2) VPrintf0 ( "rt+rld" );
53278556Sobrien
53378556Sobrien      /*-- Set up cftab to facilitate generation of T^(-1) --*/
53478556Sobrien      s->cftab[0] = 0;
53578556Sobrien      for (i = 1; i <= 256; i++) s->cftab[i] = s->unzftab[i-1];
53678556Sobrien      for (i = 1; i <= 256; i++) s->cftab[i] += s->cftab[i-1];
53778556Sobrien
53878556Sobrien      if (s->smallDecompress) {
53978556Sobrien
54078556Sobrien         /*-- Make a copy of cftab, used in generation of T --*/
54178556Sobrien         for (i = 0; i <= 256; i++) s->cftabCopy[i] = s->cftab[i];
54278556Sobrien
54378556Sobrien         /*-- compute the T vector --*/
54478556Sobrien         for (i = 0; i < nblock; i++) {
54578556Sobrien            uc = (UChar)(s->ll16[i]);
54678556Sobrien            SET_LL(i, s->cftabCopy[uc]);
54778556Sobrien            s->cftabCopy[uc]++;
54878556Sobrien         }
54978556Sobrien
55078556Sobrien         /*-- Compute T^(-1) by pointer reversal on T --*/
55178556Sobrien         i = s->origPtr;
55278556Sobrien         j = GET_LL(i);
55378556Sobrien         do {
55478556Sobrien            Int32 tmp = GET_LL(j);
55578556Sobrien            SET_LL(j, i);
55678556Sobrien            i = j;
55778556Sobrien            j = tmp;
55878556Sobrien         }
55978556Sobrien            while (i != s->origPtr);
56078556Sobrien
56178556Sobrien         s->tPos = s->origPtr;
56278556Sobrien         s->nblock_used = 0;
56378556Sobrien         if (s->blockRandomised) {
56478556Sobrien            BZ_RAND_INIT_MASK;
56578556Sobrien            BZ_GET_SMALL(s->k0); s->nblock_used++;
56678556Sobrien            BZ_RAND_UPD_MASK; s->k0 ^= BZ_RAND_MASK;
56778556Sobrien         } else {
56878556Sobrien            BZ_GET_SMALL(s->k0); s->nblock_used++;
56978556Sobrien         }
57078556Sobrien
57178556Sobrien      } else {
57278556Sobrien
57378556Sobrien         /*-- compute the T^(-1) vector --*/
57478556Sobrien         for (i = 0; i < nblock; i++) {
57578556Sobrien            uc = (UChar)(s->tt[i] & 0xff);
57678556Sobrien            s->tt[s->cftab[uc]] |= (i << 8);
57778556Sobrien            s->cftab[uc]++;
57878556Sobrien         }
57978556Sobrien
58078556Sobrien         s->tPos = s->tt[s->origPtr] >> 8;
58178556Sobrien         s->nblock_used = 0;
58278556Sobrien         if (s->blockRandomised) {
58378556Sobrien            BZ_RAND_INIT_MASK;
58478556Sobrien            BZ_GET_FAST(s->k0); s->nblock_used++;
58578556Sobrien            BZ_RAND_UPD_MASK; s->k0 ^= BZ_RAND_MASK;
58678556Sobrien         } else {
58778556Sobrien            BZ_GET_FAST(s->k0); s->nblock_used++;
58878556Sobrien         }
58978556Sobrien
59078556Sobrien      }
59178556Sobrien
59278556Sobrien      RETURN(BZ_OK);
59378556Sobrien
59478556Sobrien
59578556Sobrien
59678556Sobrien    endhdr_2:
59778556Sobrien
59878556Sobrien      GET_UCHAR(BZ_X_ENDHDR_2, uc);
59978556Sobrien      if (uc != 0x72) RETURN(BZ_DATA_ERROR);
60078556Sobrien      GET_UCHAR(BZ_X_ENDHDR_3, uc);
60178556Sobrien      if (uc != 0x45) RETURN(BZ_DATA_ERROR);
60278556Sobrien      GET_UCHAR(BZ_X_ENDHDR_4, uc);
60378556Sobrien      if (uc != 0x38) RETURN(BZ_DATA_ERROR);
60478556Sobrien      GET_UCHAR(BZ_X_ENDHDR_5, uc);
60578556Sobrien      if (uc != 0x50) RETURN(BZ_DATA_ERROR);
60678556Sobrien      GET_UCHAR(BZ_X_ENDHDR_6, uc);
60778556Sobrien      if (uc != 0x90) RETURN(BZ_DATA_ERROR);
60878556Sobrien
60978556Sobrien      s->storedCombinedCRC = 0;
61078556Sobrien      GET_UCHAR(BZ_X_CCRC_1, uc);
61178556Sobrien      s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
61278556Sobrien      GET_UCHAR(BZ_X_CCRC_2, uc);
61378556Sobrien      s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
61478556Sobrien      GET_UCHAR(BZ_X_CCRC_3, uc);
61578556Sobrien      s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
61678556Sobrien      GET_UCHAR(BZ_X_CCRC_4, uc);
61778556Sobrien      s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((UInt32)uc);
61878556Sobrien
61978556Sobrien      s->state = BZ_X_IDLE;
62078556Sobrien      RETURN(BZ_STREAM_END);
62178556Sobrien
62278556Sobrien      default: AssertH ( False, 4001 );
62378556Sobrien   }
62478556Sobrien
62578556Sobrien   AssertH ( False, 4002 );
62678556Sobrien
62778556Sobrien   save_state_and_return:
62878556Sobrien
62978556Sobrien   s->save_i           = i;
63078556Sobrien   s->save_j           = j;
63178556Sobrien   s->save_t           = t;
63278556Sobrien   s->save_alphaSize   = alphaSize;
63378556Sobrien   s->save_nGroups     = nGroups;
63478556Sobrien   s->save_nSelectors  = nSelectors;
63578556Sobrien   s->save_EOB         = EOB;
63678556Sobrien   s->save_groupNo     = groupNo;
63778556Sobrien   s->save_groupPos    = groupPos;
63878556Sobrien   s->save_nextSym     = nextSym;
63978556Sobrien   s->save_nblockMAX   = nblockMAX;
64078556Sobrien   s->save_nblock      = nblock;
64178556Sobrien   s->save_es          = es;
64278556Sobrien   s->save_N           = N;
64378556Sobrien   s->save_curr        = curr;
64478556Sobrien   s->save_zt          = zt;
64578556Sobrien   s->save_zn          = zn;
64678556Sobrien   s->save_zvec        = zvec;
64778556Sobrien   s->save_zj          = zj;
64878556Sobrien   s->save_gSel        = gSel;
64978556Sobrien   s->save_gMinlen     = gMinlen;
65078556Sobrien   s->save_gLimit      = gLimit;
65178556Sobrien   s->save_gBase       = gBase;
65278556Sobrien   s->save_gPerm       = gPerm;
65378556Sobrien
65478556Sobrien   return retVal;
65578556Sobrien}
65678556Sobrien
65778556Sobrien
65878556Sobrien/*-------------------------------------------------------------*/
65978556Sobrien/*--- end                                      decompress.c ---*/
66078556Sobrien/*-------------------------------------------------------------*/
661