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/*-------------------------------------------------------------*//*--- Compression machinery (not incl block sorting) ---*//*--- compress.c ---*//*-------------------------------------------------------------*//*--This file is a part of bzip2 and/or libbzip2, a program andlibrary for lossless, block-sorting data compression.Copyright (C) 1996-2005 Julian R Seward. All rights reserved.Redistribution and use in source and binary forms, with or withoutmodification, are permitted provided that the following conditionsare met:1. Redistributions of source code must retain the above copyrightnotice, this list of conditions and the following disclaimer.2. The origin of this software must not be misrepresented; you mustnot claim that you wrote the original software. If you use thissoftware in a product, an acknowledgment in the productdocumentation would be appreciated but is not required.3. Altered source versions must be plainly marked as such, and mustnot be misrepresented as being the original software.4. The name of the author may not be used to endorse or promoteproducts derived from this software without specific prior writtenpermission.THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESSOR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIEDWARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSEARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANYDIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIALDAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTEGOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESSINTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDINGNEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THISSOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.Julian Seward, Cambridge, UK.jseward@bzip.orgbzip2/libbzip2 version 1.0 of 21 March 2000This program is based on (at least) the work of:Mike BurrowsDavid WheelerPeter FenwickAlistair MoffatRadford NealIan H. WittenRobert SedgewickJon L. BentleyFor 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 todo a bit better on small files--*/#include "bzlib_private.h"/*---------------------------------------------------*//*--- Bit stream I/O ---*//*---------------------------------------------------*//*---------------------------------------------------*/void BZ2_bsInitWrite ( EState* s ){s->bsLive = 0;s->bsBuff = 0;}/*---------------------------------------------------*/staticvoid bsFinishWrite ( EState* s ){while (s->bsLive > 0) {s->zbits[s->numZ] = (UChar)(s->bsBuff >> 24);s->numZ++;s->bsBuff <<= 8;s->bsLive -= 8;}}/*---------------------------------------------------*/#define bsNEEDW(nz) \{ \while (s->bsLive >= 8) { \s->zbits[s->numZ] \= (UChar)(s->bsBuff >> 24); \s->numZ++; \s->bsBuff <<= 8; \s->bsLive -= 8; \} \}/*---------------------------------------------------*/staticR_INLINEvoid bsW ( EState* s, Int32 n, UInt32 v ){bsNEEDW ( n );s->bsBuff |= (v << (32 - s->bsLive - n));s->bsLive += n;}/*---------------------------------------------------*/staticvoid 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 );}/*---------------------------------------------------*/staticvoid bsPutUChar ( EState* s, UChar c ){bsW( s, 8, (UInt32)c );}/*---------------------------------------------------*//*--- The back end proper ---*//*---------------------------------------------------*//*---------------------------------------------------*/staticvoid 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++;}}/*---------------------------------------------------*/staticvoid generateMTFValues ( EState* s ){UChar yy[256];Int32 i, j;Int32 zPend;Int32 wr;Int32 EOB;/*After sorting (eg, here),s->arr1 [ 0 .. s->nblock-1 ] holds sorted order,and((UChar*)s->arr2) [ 0 .. s->nblock-1 ]holds the original block data.The first thing to do is generate the MTF values,and put them in((UInt16*)s->arr1) [ 0 .. s->nblock-1 ].Because there are strictly fewer or equal MTF valuesthan block values, ptr values in this area are overwrittenwith MTF values only when they are no longer needed.The final compressed bitstream is generated into thearea starting at(UChar*) (&((UChar*)s->arr2)[s->nblock])These storage aliases are set up in bzCompressInit(),except for the last one, which is arranged incompressBlock().*/UInt32* ptr = s->ptr;UChar* block = s->block;UInt16* mtfv = s->mtfv;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 = ptr[i]-1; if (j < 0) j += s->nblock;ll_i = s->unseqToSeq[block[j]];AssertD ( ll_i < s->nInUse, "generateMTFValues(2a)" );if (yy[0] == ll_i) {zPend++;} else {if (zPend > 0) {zPend--;while (True) {if (zPend & 1) {mtfv[wr] = BZ_RUNB; wr++;s->mtfFreq[BZ_RUNB]++;} else {mtfv[wr] = BZ_RUNA; wr++;s->mtfFreq[BZ_RUNA]++;}if (zPend < 2) break;zPend = (zPend - 2) / 2;};zPend = 0;}{register UChar rtmp;register UChar* ryy_j;register UChar rll_i;rtmp = yy[1];yy[1] = yy[0];ryy_j = &(yy[1]);rll_i = ll_i;while ( rll_i != rtmp ) {register UChar rtmp2;ryy_j++;rtmp2 = rtmp;rtmp = *ryy_j;*ryy_j = rtmp2;};yy[0] = rtmp;j = ryy_j - &(yy[0]);mtfv[wr] = j+1; wr++; s->mtfFreq[j+1]++;}}}if (zPend > 0) {zPend--;while (True) {if (zPend & 1) {mtfv[wr] = BZ_RUNB; wr++;s->mtfFreq[BZ_RUNB]++;} else {mtfv[wr] = BZ_RUNA; wr++;s->mtfFreq[BZ_RUNA]++;}if (zPend < 2) break;zPend = (zPend - 2) / 2;};zPend = 0;}mtfv[wr] = EOB; wr++; s->mtfFreq[EOB]++;s->nMTF = wr;}/*---------------------------------------------------*/#define BZ_LESSER_ICOST 0#define BZ_GREATER_ICOST 15staticvoid 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];UInt16* mtfv = s->mtfv;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; elseif (s->nMTF < 600) nGroups = 3; elseif (s->nMTF < 1200) nGroups = 4; elseif (s->nMTF < 2400) nGroups = 5; elsenGroups = 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; elses->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;/*---Set up an auxiliary length table which is used to fast-trackthe common case (nGroups == 6).---*/if (nGroups == 6) {for (v = 0; v < alphaSize; v++) {s->len_pack[v][0] = (s->len[1][v] << 16) | s->len[0][v];s->len_pack[v][1] = (s->len[3][v] << 16) | s->len[2][v];s->len_pack[v][2] = (s->len[5][v] << 16) | s->len[4][v];}}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 codedby each of the coding tables.--*/for (t = 0; t < nGroups; t++) cost[t] = 0;if (nGroups == 6 && 50 == ge-gs+1) {/*--- fast track the common case ---*/register UInt32 cost01, cost23, cost45;register UInt16 icv;cost01 = cost23 = cost45 = 0;# define BZ_ITER(nn) \icv = mtfv[gs+(nn)]; \cost01 += s->len_pack[icv][0]; \cost23 += s->len_pack[icv][1]; \cost45 += s->len_pack[icv][2]; \BZ_ITER(0); BZ_ITER(1); BZ_ITER(2); BZ_ITER(3); BZ_ITER(4);BZ_ITER(5); BZ_ITER(6); BZ_ITER(7); BZ_ITER(8); BZ_ITER(9);BZ_ITER(10); BZ_ITER(11); BZ_ITER(12); BZ_ITER(13); BZ_ITER(14);BZ_ITER(15); BZ_ITER(16); BZ_ITER(17); BZ_ITER(18); BZ_ITER(19);BZ_ITER(20); BZ_ITER(21); BZ_ITER(22); BZ_ITER(23); BZ_ITER(24);BZ_ITER(25); BZ_ITER(26); BZ_ITER(27); BZ_ITER(28); BZ_ITER(29);BZ_ITER(30); BZ_ITER(31); BZ_ITER(32); BZ_ITER(33); BZ_ITER(34);BZ_ITER(35); BZ_ITER(36); BZ_ITER(37); BZ_ITER(38); BZ_ITER(39);BZ_ITER(40); BZ_ITER(41); BZ_ITER(42); BZ_ITER(43); BZ_ITER(44);BZ_ITER(45); BZ_ITER(46); BZ_ITER(47); BZ_ITER(48); BZ_ITER(49);# undef BZ_ITERcost[0] = cost01 & 0xffff; cost[1] = cost01 >> 16;cost[2] = cost23 & 0xffff; cost[3] = cost23 >> 16;cost[4] = cost45 & 0xffff; cost[5] = cost45 >> 16;} else {/*--- slow version which correctly handles all situations ---*/for (i = gs; i <= ge; i++) {UInt16 icv = mtfv[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.--*/if (nGroups == 6 && 50 == ge-gs+1) {/*--- fast track the common case ---*/# define BZ_ITUR(nn) s->rfreq[bt][ mtfv[gs+(nn)] ]++BZ_ITUR(0); BZ_ITUR(1); BZ_ITUR(2); BZ_ITUR(3); BZ_ITUR(4);BZ_ITUR(5); BZ_ITUR(6); BZ_ITUR(7); BZ_ITUR(8); BZ_ITUR(9);BZ_ITUR(10); BZ_ITUR(11); BZ_ITUR(12); BZ_ITUR(13); BZ_ITUR(14);BZ_ITUR(15); BZ_ITUR(16); BZ_ITUR(17); BZ_ITUR(18); BZ_ITUR(19);BZ_ITUR(20); BZ_ITUR(21); BZ_ITUR(22); BZ_ITUR(23); BZ_ITUR(24);BZ_ITUR(25); BZ_ITUR(26); BZ_ITUR(27); BZ_ITUR(28); BZ_ITUR(29);BZ_ITUR(30); BZ_ITUR(31); BZ_ITUR(32); BZ_ITUR(33); BZ_ITUR(34);BZ_ITUR(35); BZ_ITUR(36); BZ_ITUR(37); BZ_ITUR(38); BZ_ITUR(39);BZ_ITUR(40); BZ_ITUR(41); BZ_ITUR(42); BZ_ITUR(43); BZ_ITUR(44);BZ_ITUR(45); BZ_ITUR(46); BZ_ITUR(47); BZ_ITUR(48); BZ_ITUR(49);# undef BZ_ITUR} else {/*--- slow version which correctly handles all situations ---*/for (i = gs; i <= ge; i++)s->rfreq[bt][ mtfv[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.--*//* maxLen was changed from 20 to 17 in bzip2-1.0.3. Seecomment in huffman.c for details. */for (t = 0; t < nGroups; t++)BZ2_hbMakeCodeLengths ( &(s->len[t][0]), &(s->rfreq[t][0]),alphaSize, 17 /*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 > 17 /*20*/ ), 3004 );AssertH ( !(minLen < 1), 3005 );BZ2_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;AssertH ( s->selector[selCtr] < nGroups, 3006 );if (nGroups == 6 && 50 == ge-gs+1) {/*--- fast track the common case ---*/UInt16 mtfv_i;UChar* s_len_sel_selCtr= &(s->len[s->selector[selCtr]][0]);Int32* s_code_sel_selCtr= &(s->code[s->selector[selCtr]][0]);# define BZ_ITAH(nn) \mtfv_i = mtfv[gs+(nn)]; \bsW ( s, \s_len_sel_selCtr[mtfv_i], \s_code_sel_selCtr[mtfv_i] )BZ_ITAH(0); BZ_ITAH(1); BZ_ITAH(2); BZ_ITAH(3); BZ_ITAH(4);BZ_ITAH(5); BZ_ITAH(6); BZ_ITAH(7); BZ_ITAH(8); BZ_ITAH(9);BZ_ITAH(10); BZ_ITAH(11); BZ_ITAH(12); BZ_ITAH(13); BZ_ITAH(14);BZ_ITAH(15); BZ_ITAH(16); BZ_ITAH(17); BZ_ITAH(18); BZ_ITAH(19);BZ_ITAH(20); BZ_ITAH(21); BZ_ITAH(22); BZ_ITAH(23); BZ_ITAH(24);BZ_ITAH(25); BZ_ITAH(26); BZ_ITAH(27); BZ_ITAH(28); BZ_ITAH(29);BZ_ITAH(30); BZ_ITAH(31); BZ_ITAH(32); BZ_ITAH(33); BZ_ITAH(34);BZ_ITAH(35); BZ_ITAH(36); BZ_ITAH(37); BZ_ITAH(38); BZ_ITAH(39);BZ_ITAH(40); BZ_ITAH(41); BZ_ITAH(42); BZ_ITAH(43); BZ_ITAH(44);BZ_ITAH(45); BZ_ITAH(46); BZ_ITAH(47); BZ_ITAH(48); BZ_ITAH(49);# undef BZ_ITAH} else {/*--- slow version which correctly handles all situations ---*/for (i = gs; i <= ge; i++) {bsW ( s,s->len [s->selector[selCtr]] [mtfv[i]],s->code [s->selector[selCtr]] [mtfv[i]] );}}gs = ge+1;selCtr++;}AssertH( selCtr == nSelectors, 3007 );if (s->verbosity >= 3)VPrintf1( "codes %d\n", s->numZ-nBytes );}/*---------------------------------------------------*/void BZ2_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%08x, ""combined CRC = 0x%08x, size = %d\n",s->blockNo, s->blockCRC, s->combinedCRC, s->nblock );BZ2_blockSort ( s );}s->zbits = (UChar*) (&((UChar*)s->arr2)[s->nblock]);/*-- If this is the first block, create the stream header. --*/if (s->blockNo == 1) {BZ2_bsInitWrite ( s );bsPutUChar ( s, BZ_HDR_B );bsPutUChar ( s, BZ_HDR_Z );bsPutUChar ( s, BZ_HDR_h );bsPutUChar ( s, (UChar)(BZ_HDR_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 (non-)randomisation.As of version 0.9.5, we use a better sorting algorithmwhich makes randomisation unnecessary. So always setthe randomised bit to 'no'. Of course, the decoderstill needs to be able to handle randomised blocksso as to maintain backwards compatibility witholder versions of bzip2.--*/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) {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%08x\n ", s->combinedCRC );bsFinishWrite ( s );}}/*-------------------------------------------------------------*//*--- end compress.c ---*//*-------------------------------------------------------------*/