/*-------------------------------------------------------------*/ /*--- Decompression machinery ---*/ /*--- decompress.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. ------------------------------------------------------------------ */ #include "bzlib_private.h" /*---------------------------------------------------*/ static void makeMaps_d ( DState* s ) { Int32 i; s->nInUse = 0; for (i = 0; i < 256; i++) if (s->inUse[i]) { s->seqToUnseq[s->nInUse] = i; s->nInUse++; } } /*---------------------------------------------------*/ #define RETURN(rrr) \ { retVal = rrr; goto save_state_and_return; }; #define GET_BITS(lll,vvv,nnn) \ case lll: s->state = lll; \ while (True) { \ if (s->bsLive >= nnn) { \ UInt32 v; \ v = (s->bsBuff >> \ (s->bsLive-nnn)) & ((1 << nnn)-1); \ s->bsLive -= nnn; \ vvv = v; \ break; \ } \ if (s->strm->avail_in == 0) RETURN(BZ_OK); \ s->bsBuff \ = (s->bsBuff << 8) | \ ((UInt32) \ (*((UChar*)(s->strm->next_in)))); \ s->bsLive += 8; \ 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++; \ } #define GET_UCHAR(lll,uuu) \ GET_BITS(lll,uuu,8) #define GET_BIT(lll,uuu) \ GET_BITS(lll,uuu,1) /*---------------------------------------------------*/ #define GET_MTF_VAL(label1,label2,lval) \ { \ if (groupPos == 0) { \ groupNo++; \ if (groupNo >= nSelectors) \ RETURN(BZ_DATA_ERROR); \ groupPos = BZ_G_SIZE; \ gSel = s->selector[groupNo]; \ gMinlen = s->minLens[gSel]; \ gLimit = &(s->limit[gSel][0]); \ gPerm = &(s->perm[gSel][0]); \ gBase = &(s->base[gSel][0]); \ } \ groupPos--; \ zn = gMinlen; \ GET_BITS(label1, zvec, zn); \ while (1) { \ if (zn > 20 /* the longest code */) \ RETURN(BZ_DATA_ERROR); \ if (zvec <= gLimit[zn]) break; \ zn++; \ GET_BIT(label2, zj); \ zvec = (zvec << 1) | zj; \ }; \ if (zvec - gBase[zn] < 0 \ || zvec - gBase[zn] >= BZ_MAX_ALPHA_SIZE) \ RETURN(BZ_DATA_ERROR); \ lval = gPerm[zvec - gBase[zn]]; \ } /*---------------------------------------------------*/ Int32 BZ2_decompress ( DState* s ) { UChar uc; Int32 retVal; Int32 minLen, maxLen; bz_stream* strm = s->strm; /* stuff that needs to be saved/restored */ Int32 i; Int32 j; Int32 t; Int32 alphaSize; Int32 nGroups; Int32 nSelectors; Int32 EOB; Int32 groupNo; Int32 groupPos; Int32 nextSym; Int32 nblockMAX; Int32 nblock; Int32 es; Int32 N; Int32 curr; Int32 zt; Int32 zn; Int32 zvec; Int32 zj; Int32 gSel; Int32 gMinlen; Int32* gLimit; Int32* gBase; Int32* gPerm; if (s->state == BZ_X_MAGIC_1) { /*initialise the save area*/ s->save_i = 0; s->save_j = 0; s->save_t = 0; s->save_alphaSize = 0; s->save_nGroups = 0; s->save_nSelectors = 0; s->save_EOB = 0; s->save_groupNo = 0; s->save_groupPos = 0; s->save_nextSym = 0; s->save_nblockMAX = 0; s->save_nblock = 0; s->save_es = 0; s->save_N = 0; s->save_curr = 0; s->save_zt = 0; s->save_zn = 0; s->save_zvec = 0; s->save_zj = 0; s->save_gSel = 0; s->save_gMinlen = 0; s->save_gLimit = NULL; s->save_gBase = NULL; s->save_gPerm = NULL; } /*restore from the save area*/ i = s->save_i; j = s->save_j; t = s->save_t; alphaSize = s->save_alphaSize; nGroups = s->save_nGroups; nSelectors = s->save_nSelectors; EOB = s->save_EOB; groupNo = s->save_groupNo; groupPos = s->save_groupPos; nextSym = s->save_nextSym; nblockMAX = s->save_nblockMAX; nblock = s->save_nblock; es = s->save_es; N = s->save_N; curr = s->save_curr; zt = s->save_zt; zn = s->save_zn; zvec = s->save_zvec; zj = s->save_zj; gSel = s->save_gSel; gMinlen = s->save_gMinlen; gLimit = s->save_gLimit; gBase = s->save_gBase; gPerm = s->save_gPerm; retVal = BZ_OK; switch (s->state) { GET_UCHAR(BZ_X_MAGIC_1, uc); if (uc != BZ_HDR_B) RETURN(BZ_DATA_ERROR_MAGIC); GET_UCHAR(BZ_X_MAGIC_2, uc); if (uc != BZ_HDR_Z) RETURN(BZ_DATA_ERROR_MAGIC); GET_UCHAR(BZ_X_MAGIC_3, uc) if (uc != BZ_HDR_h) RETURN(BZ_DATA_ERROR_MAGIC); GET_BITS(BZ_X_MAGIC_4, s->blockSize100k, 8) if (s->blockSize100k < (BZ_HDR_0 + 1) || s->blockSize100k > (BZ_HDR_0 + 9)) RETURN(BZ_DATA_ERROR_MAGIC); s->blockSize100k -= BZ_HDR_0; if (s->smallDecompress) { s->ll16 = BZALLOC( s->blockSize100k * 100000 * sizeof(UInt16) ); s->ll4 = BZALLOC( ((1 + s->blockSize100k * 100000) >> 1) * sizeof(UChar) ); if (s->ll16 == NULL || s->ll4 == NULL) RETURN(BZ_MEM_ERROR); } else { s->tt = BZALLOC( s->blockSize100k * 100000 * sizeof(Int32) ); if (s->tt == NULL) RETURN(BZ_MEM_ERROR); } GET_UCHAR(BZ_X_BLKHDR_1, uc); if (uc == 0x17) goto endhdr_2; if (uc != 0x31) RETURN(BZ_DATA_ERROR); GET_UCHAR(BZ_X_BLKHDR_2, uc); if (uc != 0x41) RETURN(BZ_DATA_ERROR); GET_UCHAR(BZ_X_BLKHDR_3, uc); if (uc != 0x59) RETURN(BZ_DATA_ERROR); GET_UCHAR(BZ_X_BLKHDR_4, uc); if (uc != 0x26) RETURN(BZ_DATA_ERROR); GET_UCHAR(BZ_X_BLKHDR_5, uc); if (uc != 0x53) RETURN(BZ_DATA_ERROR); GET_UCHAR(BZ_X_BLKHDR_6, uc); if (uc != 0x59) RETURN(BZ_DATA_ERROR); s->currBlockNo++; if (s->verbosity >= 2) VPrintf1 ( "\n [%d: huff+mtf ", s->currBlockNo ); s->storedBlockCRC = 0; GET_UCHAR(BZ_X_BCRC_1, uc); s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc); GET_UCHAR(BZ_X_BCRC_2, uc); s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc); GET_UCHAR(BZ_X_BCRC_3, uc); s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc); GET_UCHAR(BZ_X_BCRC_4, uc); s->storedBlockCRC = (s->storedBlockCRC << 8) | ((UInt32)uc); GET_BITS(BZ_X_RANDBIT, s->blockRandomised, 1); s->origPtr = 0; GET_UCHAR(BZ_X_ORIGPTR_1, uc); s->origPtr = (s->origPtr << 8) | ((Int32)uc); GET_UCHAR(BZ_X_ORIGPTR_2, uc); s->origPtr = (s->origPtr << 8) | ((Int32)uc); GET_UCHAR(BZ_X_ORIGPTR_3, uc); s->origPtr = (s->origPtr << 8) | ((Int32)uc); if (s->origPtr < 0) RETURN(BZ_DATA_ERROR); if (s->origPtr > 10 + 100000*s->blockSize100k) RETURN(BZ_DATA_ERROR); /*--- Receive the mapping table ---*/ for (i = 0; i < 16; i++) { GET_BIT(BZ_X_MAPPING_1, uc); if (uc == 1) s->inUse16[i] = True; else s->inUse16[i] = False; } for (i = 0; i < 256; i++) s->inUse[i] = False; for (i = 0; i < 16; i++) if (s->inUse16[i]) for (j = 0; j < 16; j++) { GET_BIT(BZ_X_MAPPING_2, uc); if (uc == 1) s->inUse[i * 16 + j] = True; } makeMaps_d ( s ); if (s->nInUse == 0) RETURN(BZ_DATA_ERROR); alphaSize = s->nInUse+2; /*--- Now the selectors ---*/ GET_BITS(BZ_X_SELECTOR_1, nGroups, 3); if (nGroups < 2 || nGroups > 6) RETURN(BZ_DATA_ERROR); GET_BITS(BZ_X_SELECTOR_2, nSelectors, 15); if (nSelectors < 1) RETURN(BZ_DATA_ERROR); for (i = 0; i < nSelectors; i++) { j = 0; while (True) { GET_BIT(BZ_X_SELECTOR_3, uc); if (uc == 0) break; 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 (nextSym == EOB) break; if (nextSym == BZ_RUNA || nextSym == BZ_RUNB) { es = -1; N = 1; do { /* Check that N doesn't get too big, so that es doesn't go negative. The maximum value that can be RUNA/RUNB encoded is equal to the block size (post the initial RLE), viz, 900k, so bounding N at 2 million should guard against overflow without rejecting any legitimate inputs. */ if (N >= 2*1024*1024) RETURN(BZ_DATA_ERROR); 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--) { 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); /*-- Set up cftab to facilitate generation of T^(-1) --*/ /* Check: unzftab entries in range. */ for (i = 0; i <= 255; i++) { if (s->unzftab[i] < 0 || s->unzftab[i] > nblock) RETURN(BZ_DATA_ERROR); } /* Actually generate cftab. */ 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]; /* Check: cftab entries in range. */ for (i = 0; i <= 256; i++) { if (s->cftab[i] < 0 || s->cftab[i] > nblock) { /* s->cftab[i] can legitimately be == nblock */ RETURN(BZ_DATA_ERROR); } } /* Check: cftab entries non-descending. */ for (i = 1; i <= 256; i++) { if (s->cftab[i-1] > s->cftab[i]) { 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" ); 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); 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 { /*-- 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 ---*/ /*-------------------------------------------------------------*/