| |
| /*-------------------------------------------------------------*/ |
| /*--- Compression machinery (not incl block sorting) ---*/ |
| /*--- compress.c ---*/ |
| /*-------------------------------------------------------------*/ |
| |
| /*-- |
| This file is a part of bzip2 and/or libbzip2, a program and |
| library for lossless, block-sorting data compression. |
| |
| Copyright (C) 1996-1998 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, Guildford, Surrey, UK. |
| jseward@acm.org |
| bzip2/libbzip2 version 0.9.0 of 28 June 1998 |
| |
| 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 |
| * changed setting of nGroups in sendMTFValues() so as to |
| do a bit better on small files |
| --*/ |
| |
| #include "bzlib_private.h" |
| |
| |
| /*---------------------------------------------------*/ |
| /*--- Bit stream I/O ---*/ |
| /*---------------------------------------------------*/ |
| |
| /*---------------------------------------------------*/ |
| void bsInitWrite ( EState* s ) |
| { |
| s->bsLive = 0; |
| s->bsBuff = 0; |
| } |
| |
| |
| /*---------------------------------------------------*/ |
| static |
| void bsFinishWrite ( EState* s ) |
| { |
| while (s->bsLive > 0) { |
| ((UChar*)(s->quadrant))[s->numZ] = (UChar)(s->bsBuff >> 24); |
| s->numZ++; |
| s->bsBuff <<= 8; |
| s->bsLive -= 8; |
| } |
| } |
| |
| |
| /*---------------------------------------------------*/ |
| #define bsNEEDW(nz) \ |
| { \ |
| while (s->bsLive >= 8) { \ |
| ((UChar*)(s->quadrant))[s->numZ] \ |
| = (UChar)(s->bsBuff >> 24); \ |
| s->numZ++; \ |
| s->bsBuff <<= 8; \ |
| s->bsLive -= 8; \ |
| } \ |
| } |
| |
| |
| /*---------------------------------------------------*/ |
| static |
| void bsW ( EState* s, Int32 n, UInt32 v ) |
| { |
| bsNEEDW ( n ); |
| s->bsBuff |= (v << (32 - s->bsLive - n)); |
| s->bsLive += n; |
| } |
| |
| |
| /*---------------------------------------------------*/ |
| static |
| void bsPutUInt32 ( EState* s, UInt32 u ) |
| { |
| bsW ( s, 8, (u >> 24) & 0xffL ); |
| bsW ( s, 8, (u >> 16) & 0xffL ); |
| bsW ( s, 8, (u >> 8) & 0xffL ); |
| bsW ( s, 8, u & 0xffL ); |
| } |
| |
| |
| /*---------------------------------------------------*/ |
| static |
| void bsPutUChar ( EState* s, UChar c ) |
| { |
| bsW( s, 8, (UInt32)c ); |
| } |
| |
| |
| /*---------------------------------------------------*/ |
| /*--- The back end proper ---*/ |
| /*---------------------------------------------------*/ |
| |
| /*---------------------------------------------------*/ |
| static |
| void makeMaps_e ( EState* s ) |
| { |
| Int32 i; |
| s->nInUse = 0; |
| for (i = 0; i < 256; i++) |
| if (s->inUse[i]) { |
| s->unseqToSeq[i] = s->nInUse; |
| s->nInUse++; |
| } |
| } |
| |
| |
| /*---------------------------------------------------*/ |
| static |
| void generateMTFValues ( EState* s ) |
| { |
| UChar yy[256]; |
| Int32 i, j; |
| UChar tmp; |
| UChar tmp2; |
| Int32 zPend; |
| Int32 wr; |
| Int32 EOB; |
| |
| makeMaps_e ( s ); |
| EOB = s->nInUse+1; |
| |
| for (i = 0; i <= EOB; i++) s->mtfFreq[i] = 0; |
| |
| wr = 0; |
| zPend = 0; |
| for (i = 0; i < s->nInUse; i++) yy[i] = (UChar) i; |
| |
| for (i = 0; i < s->nblock; i++) { |
| UChar ll_i; |
| |
| AssertD ( wr <= i, "generateMTFValues(1)" ); |
| j = s->zptr[i]-1; if (j < 0) j += s->nblock; |
| ll_i = s->unseqToSeq[s->block[j]]; |
| AssertD ( ll_i < s->nInUse, "generateMTFValues(2a)" ); |
| |
| j = 0; |
| tmp = yy[j]; |
| while ( ll_i != tmp ) { |
| j++; |
| tmp2 = tmp; |
| tmp = yy[j]; |
| yy[j] = tmp2; |
| }; |
| yy[0] = tmp; |
| |
| if (j == 0) { |
| zPend++; |
| } else { |
| if (zPend > 0) { |
| zPend--; |
| while (True) { |
| switch (zPend % 2) { |
| case 0: s->szptr[wr] = BZ_RUNA; wr++; s->mtfFreq[BZ_RUNA]++; break; |
| case 1: s->szptr[wr] = BZ_RUNB; wr++; s->mtfFreq[BZ_RUNB]++; break; |
| }; |
| if (zPend < 2) break; |
| zPend = (zPend - 2) / 2; |
| }; |
| zPend = 0; |
| } |
| s->szptr[wr] = j+1; wr++; s->mtfFreq[j+1]++; |
| } |
| } |
| |
| if (zPend > 0) { |
| zPend--; |
| while (True) { |
| switch (zPend % 2) { |
| case 0: s->szptr[wr] = BZ_RUNA; wr++; s->mtfFreq[BZ_RUNA]++; break; |
| case 1: s->szptr[wr] = BZ_RUNB; wr++; s->mtfFreq[BZ_RUNB]++; break; |
| }; |
| if (zPend < 2) break; |
| zPend = (zPend - 2) / 2; |
| }; |
| } |
| |
| s->szptr[wr] = EOB; wr++; s->mtfFreq[EOB]++; |
| |
| s->nMTF = wr; |
| } |
| |
| |
| /*---------------------------------------------------*/ |
| #define BZ_LESSER_ICOST 0 |
| #define BZ_GREATER_ICOST 15 |
| |
| static |
| void sendMTFValues ( EState* s ) |
| { |
| Int32 v, t, i, j, gs, ge, totc, bt, bc, iter; |
| Int32 nSelectors, alphaSize, minLen, maxLen, selCtr; |
| Int32 nGroups, nBytes; |
| |
| /*-- |
| UChar len [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; |
| is a global since the decoder also needs it. |
| |
| Int32 code[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; |
| Int32 rfreq[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; |
| are also globals only used in this proc. |
| Made global to keep stack frame size small. |
| --*/ |
| |
| |
| UInt16 cost[BZ_N_GROUPS]; |
| Int32 fave[BZ_N_GROUPS]; |
| |
| if (s->verbosity >= 3) |
| VPrintf3( " %d in block, %d after MTF & 1-2 coding, " |
| "%d+2 syms in use\n", |
| s->nblock, s->nMTF, s->nInUse ); |
| |
| alphaSize = s->nInUse+2; |
| for (t = 0; t < BZ_N_GROUPS; t++) |
| for (v = 0; v < alphaSize; v++) |
| s->len[t][v] = BZ_GREATER_ICOST; |
| |
| /*--- Decide how many coding tables to use ---*/ |
| AssertH ( s->nMTF > 0, 3001 ); |
| if (s->nMTF < 200) nGroups = 2; else |
| if (s->nMTF < 600) nGroups = 3; else |
| if (s->nMTF < 1200) nGroups = 4; else |
| if (s->nMTF < 2400) nGroups = 5; else |
| nGroups = 6; |
| |
| /*--- Generate an initial set of coding tables ---*/ |
| { |
| Int32 nPart, remF, tFreq, aFreq; |
| |
| nPart = nGroups; |
| remF = s->nMTF; |
| gs = 0; |
| while (nPart > 0) { |
| tFreq = remF / nPart; |
| ge = gs-1; |
| aFreq = 0; |
| while (aFreq < tFreq && ge < alphaSize-1) { |
| ge++; |
| aFreq += s->mtfFreq[ge]; |
| } |
| |
| if (ge > gs |
| && nPart != nGroups && nPart != 1 |
| && ((nGroups-nPart) % 2 == 1)) { |
| aFreq -= s->mtfFreq[ge]; |
| ge--; |
| } |
| |
| if (s->verbosity >= 3) |
| VPrintf5( " initial group %d, [%d .. %d], " |
| "has %d syms (%4.1f%%)\n", |
| nPart, gs, ge, aFreq, |
| (100.0 * (float)aFreq) / (float)(s->nMTF) ); |
| |
| for (v = 0; v < alphaSize; v++) |
| if (v >= gs && v <= ge) |
| s->len[nPart-1][v] = BZ_LESSER_ICOST; else |
| s->len[nPart-1][v] = BZ_GREATER_ICOST; |
| |
| nPart--; |
| gs = ge+1; |
| remF -= aFreq; |
| } |
| } |
| |
| /*--- |
| Iterate up to BZ_N_ITERS times to improve the tables. |
| ---*/ |
| for (iter = 0; iter < BZ_N_ITERS; iter++) { |
| |
| for (t = 0; t < nGroups; t++) fave[t] = 0; |
| |
| for (t = 0; t < nGroups; t++) |
| for (v = 0; v < alphaSize; v++) |
| s->rfreq[t][v] = 0; |
| |
| nSelectors = 0; |
| totc = 0; |
| gs = 0; |
| while (True) { |
| |
| /*--- Set group start & end marks. --*/ |
| if (gs >= s->nMTF) break; |
| ge = gs + BZ_G_SIZE - 1; |
| if (ge >= s->nMTF) ge = s->nMTF-1; |
| |
| /*-- |
| Calculate the cost of this group as coded |
| by each of the coding tables. |
| --*/ |
| for (t = 0; t < nGroups; t++) cost[t] = 0; |
| |
| if (nGroups == 6) { |
| register UInt16 cost0, cost1, cost2, cost3, cost4, cost5; |
| cost0 = cost1 = cost2 = cost3 = cost4 = cost5 = 0; |
| for (i = gs; i <= ge; i++) { |
| UInt16 icv = s->szptr[i]; |
| cost0 += s->len[0][icv]; |
| cost1 += s->len[1][icv]; |
| cost2 += s->len[2][icv]; |
| cost3 += s->len[3][icv]; |
| cost4 += s->len[4][icv]; |
| cost5 += s->len[5][icv]; |
| } |
| cost[0] = cost0; cost[1] = cost1; cost[2] = cost2; |
| cost[3] = cost3; cost[4] = cost4; cost[5] = cost5; |
| } else { |
| for (i = gs; i <= ge; i++) { |
| UInt16 icv = s->szptr[i]; |
| for (t = 0; t < nGroups; t++) cost[t] += s->len[t][icv]; |
| } |
| } |
| |
| /*-- |
| Find the coding table which is best for this group, |
| and record its identity in the selector table. |
| --*/ |
| bc = 999999999; bt = -1; |
| for (t = 0; t < nGroups; t++) |
| if (cost[t] < bc) { bc = cost[t]; bt = t; }; |
| totc += bc; |
| fave[bt]++; |
| s->selector[nSelectors] = bt; |
| nSelectors++; |
| |
| /*-- |
| Increment the symbol frequencies for the selected table. |
| --*/ |
| for (i = gs; i <= ge; i++) |
| s->rfreq[bt][ s->szptr[i] ]++; |
| |
| gs = ge+1; |
| } |
| if (s->verbosity >= 3) { |
| VPrintf2 ( " pass %d: size is %d, grp uses are ", |
| iter+1, totc/8 ); |
| for (t = 0; t < nGroups; t++) |
| VPrintf1 ( "%d ", fave[t] ); |
| VPrintf0 ( "\n" ); |
| } |
| |
| /*-- |
| Recompute the tables based on the accumulated frequencies. |
| --*/ |
| for (t = 0; t < nGroups; t++) |
| hbMakeCodeLengths ( &(s->len[t][0]), &(s->rfreq[t][0]), |
| alphaSize, 20 ); |
| } |
| |
| |
| AssertH( nGroups < 8, 3002 ); |
| AssertH( nSelectors < 32768 && |
| nSelectors <= (2 + (900000 / BZ_G_SIZE)), |
| 3003 ); |
| |
| |
| /*--- Compute MTF values for the selectors. ---*/ |
| { |
| UChar pos[BZ_N_GROUPS], ll_i, tmp2, tmp; |
| for (i = 0; i < nGroups; i++) pos[i] = i; |
| for (i = 0; i < nSelectors; i++) { |
| ll_i = s->selector[i]; |
| j = 0; |
| tmp = pos[j]; |
| while ( ll_i != tmp ) { |
| j++; |
| tmp2 = tmp; |
| tmp = pos[j]; |
| pos[j] = tmp2; |
| }; |
| pos[0] = tmp; |
| s->selectorMtf[i] = j; |
| } |
| }; |
| |
| /*--- Assign actual codes for the 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]; |
| } |
| AssertH ( !(maxLen > 20), 3004 ); |
| AssertH ( !(minLen < 1), 3005 ); |
| hbAssignCodes ( &(s->code[t][0]), &(s->len[t][0]), |
| minLen, maxLen, alphaSize ); |
| } |
| |
| /*--- Transmit the mapping table. ---*/ |
| { |
| Bool inUse16[16]; |
| for (i = 0; i < 16; i++) { |
| inUse16[i] = False; |
| for (j = 0; j < 16; j++) |
| if (s->inUse[i * 16 + j]) inUse16[i] = True; |
| } |
| |
| nBytes = s->numZ; |
| for (i = 0; i < 16; i++) |
| if (inUse16[i]) bsW(s,1,1); else bsW(s,1,0); |
| |
| for (i = 0; i < 16; i++) |
| if (inUse16[i]) |
| for (j = 0; j < 16; j++) { |
| if (s->inUse[i * 16 + j]) bsW(s,1,1); else bsW(s,1,0); |
| } |
| |
| if (s->verbosity >= 3) |
| VPrintf1( " bytes: mapping %d, ", s->numZ-nBytes ); |
| } |
| |
| /*--- Now the selectors. ---*/ |
| nBytes = s->numZ; |
| bsW ( s, 3, nGroups ); |
| bsW ( s, 15, nSelectors ); |
| for (i = 0; i < nSelectors; i++) { |
| for (j = 0; j < s->selectorMtf[i]; j++) bsW(s,1,1); |
| bsW(s,1,0); |
| } |
| if (s->verbosity >= 3) |
| VPrintf1( "selectors %d, ", s->numZ-nBytes ); |
| |
| /*--- Now the coding tables. ---*/ |
| nBytes = s->numZ; |
| |
| for (t = 0; t < nGroups; t++) { |
| Int32 curr = s->len[t][0]; |
| bsW ( s, 5, curr ); |
| for (i = 0; i < alphaSize; i++) { |
| while (curr < s->len[t][i]) { bsW(s,2,2); curr++; /* 10 */ }; |
| while (curr > s->len[t][i]) { bsW(s,2,3); curr--; /* 11 */ }; |
| bsW ( s, 1, 0 ); |
| } |
| } |
| |
| if (s->verbosity >= 3) |
| VPrintf1 ( "code lengths %d, ", s->numZ-nBytes ); |
| |
| /*--- And finally, the block data proper ---*/ |
| nBytes = s->numZ; |
| selCtr = 0; |
| gs = 0; |
| while (True) { |
| if (gs >= s->nMTF) break; |
| ge = gs + BZ_G_SIZE - 1; |
| if (ge >= s->nMTF) ge = s->nMTF-1; |
| for (i = gs; i <= ge; i++) { |
| AssertH ( s->selector[selCtr] < nGroups, 3006 ); |
| bsW ( s, |
| s->len [s->selector[selCtr]] [s->szptr[i]], |
| s->code [s->selector[selCtr]] [s->szptr[i]] ); |
| } |
| |
| gs = ge+1; |
| selCtr++; |
| } |
| AssertH( selCtr == nSelectors, 3007 ); |
| |
| if (s->verbosity >= 3) |
| VPrintf1( "codes %d\n", s->numZ-nBytes ); |
| } |
| |
| |
| /*---------------------------------------------------*/ |
| void compressBlock ( EState* s, Bool is_last_block ) |
| { |
| if (s->nblock > 0) { |
| |
| BZ_FINALISE_CRC ( s->blockCRC ); |
| s->combinedCRC = (s->combinedCRC << 1) | (s->combinedCRC >> 31); |
| s->combinedCRC ^= s->blockCRC; |
| if (s->blockNo > 1) s->numZ = 0; |
| |
| if (s->verbosity >= 2) |
| VPrintf4( " block %d: crc = 0x%8x, " |
| "combined CRC = 0x%8x, size = %d\n", |
| s->blockNo, s->blockCRC, s->combinedCRC, s->nblock ); |
| |
| blockSort ( s ); |
| } |
| |
| /*-- If this is the first block, create the stream header. --*/ |
| if (s->blockNo == 1) { |
| bsInitWrite ( s ); |
| bsPutUChar ( s, 'B' ); |
| bsPutUChar ( s, 'Z' ); |
| bsPutUChar ( s, 'h' ); |
| bsPutUChar ( s, '0' + s->blockSize100k ); |
| } |
| |
| if (s->nblock > 0) { |
| |
| bsPutUChar ( s, 0x31 ); bsPutUChar ( s, 0x41 ); |
| bsPutUChar ( s, 0x59 ); bsPutUChar ( s, 0x26 ); |
| bsPutUChar ( s, 0x53 ); bsPutUChar ( s, 0x59 ); |
| |
| /*-- Now the block's CRC, so it is in a known place. --*/ |
| bsPutUInt32 ( s, s->blockCRC ); |
| |
| /*-- Now a single bit indicating randomisation. --*/ |
| if (s->blockRandomised) { |
| bsW(s,1,1); s->nBlocksRandomised++; |
| } else |
| bsW(s,1,0); |
| |
| bsW ( s, 24, s->origPtr ); |
| generateMTFValues ( s ); |
| sendMTFValues ( s ); |
| } |
| |
| |
| /*-- If this is the last block, add the stream trailer. --*/ |
| if (is_last_block) { |
| |
| if (s->verbosity >= 2 && s->nBlocksRandomised > 0) |
| VPrintf2 ( " %d block%s needed randomisation\n", |
| s->nBlocksRandomised, |
| s->nBlocksRandomised == 1 ? "" : "s" ); |
| |
| bsPutUChar ( s, 0x17 ); bsPutUChar ( s, 0x72 ); |
| bsPutUChar ( s, 0x45 ); bsPutUChar ( s, 0x38 ); |
| bsPutUChar ( s, 0x50 ); bsPutUChar ( s, 0x90 ); |
| bsPutUInt32 ( s, s->combinedCRC ); |
| if (s->verbosity >= 2) |
| VPrintf1( " final combined CRC = 0x%x\n ", s->combinedCRC ); |
| bsFinishWrite ( s ); |
| } |
| } |
| |
| |
| /*-------------------------------------------------------------*/ |
| /*--- end compress.c ---*/ |
| /*-------------------------------------------------------------*/ |