bzip2-0.9.0cbzip2-0.9.0c

1 files changed, 588 insertions, 0 deletions

diff --git a/compress.c b/compress.c
new file mode 100644
index 0000000..23abd43
--- /dev/null
+++ b/compress.c
@@ -0,0 +1,588 @@
+
+/*-------------------------------------------------------------*/
+/*--- 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 ---*/
+/*-------------------------------------------------------------*/