diff options
author | Denis Vlasenko <vda.linux@googlemail.com> | 2007-10-13 07:36:03 +0400 |
---|---|---|
committer | Denis Vlasenko <vda.linux@googlemail.com> | 2007-10-13 07:36:03 +0400 |
commit | 77f1ec1b9bf100e6c10aa0856c7156e321511785 (patch) | |
tree | f20e5a9062ecad82a43bde81e3041a19c4292733 /archival/bz/compress.c | |
parent | 11c23d7b990eae27357e5a41a97d62b9a214f7db (diff) |
bzip2: port bzip2 1.0.4 to busybox. note: bzip2 code resides
in separate directory (archival/bz/*)
and is covered by BSD-style license.
code size: 13k
Diffstat (limited to 'archival/bz/compress.c')
-rw-r--r-- | archival/bz/compress.c | 671 |
1 files changed, 671 insertions, 0 deletions
diff --git a/archival/bz/compress.c b/archival/bz/compress.c new file mode 100644 index 000000000..54426dcc7 --- /dev/null +++ b/archival/bz/compress.c @@ -0,0 +1,671 @@ +/* + * bzip2 is written by Julian Seward <jseward@bzip.org>. + * Adapted for busybox by Denys Vlasenko <vda.linux@googlemail.com>. + * See README and LICENSE files in this directory for more information. + */ + +/*-------------------------------------------------------------*/ +/*--- Compression machinery (not incl block sorting) ---*/ +/*--- compress.c ---*/ +/*-------------------------------------------------------------*/ + +/* ------------------------------------------------------------------ +This file is part of bzip2/libbzip2, a program and library for +lossless, block-sorting data compression. + +bzip2/libbzip2 version 1.0.4 of 20 December 2006 +Copyright (C) 1996-2006 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. +------------------------------------------------------------------ */ + +/* 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 ---*/ +/*---------------------------------------------------*/ + +/*---------------------------------------------------*/ +static +void BZ2_bsInitWrite(EState* s) +{ + s->bsLive = 0; + s->bsBuff = 0; +} + + +/*---------------------------------------------------*/ +static NOINLINE +void bsFinishWrite(EState* s) +{ + while (s->bsLive > 0) { + s->zbits[s->numZ] = (UChar)(s->bsBuff >> 24); + s->numZ++; + s->bsBuff <<= 8; + s->bsLive -= 8; + } +} + + +/*---------------------------------------------------*/ +static +/* Forced inlining results in +600 bytes code, + * 2% faster compression. Not worth it. */ +/*ALWAYS_INLINE*/ +void bsW(EState* s, int32_t n, uint32_t v) +{ + while (s->bsLive >= 8) { + s->zbits[s->numZ] = (UChar)(s->bsBuff >> 24); + s->numZ++; + s->bsBuff <<= 8; + s->bsLive -= 8; + } + s->bsBuff |= (v << (32 - s->bsLive - n)); + s->bsLive += n; +} + + +/*---------------------------------------------------*/ +static +void bsPutU32(EState* s, uint32_t u) +{ + bsW(s, 8, (u >> 24) & 0xff); + bsW(s, 8, (u >> 16) & 0xff); + bsW(s, 8, (u >> 8) & 0xff); + bsW(s, 8, u & 0xff); +} + + +/*---------------------------------------------------*/ +static +void bsPutUChar(EState* s, UChar c) +{ + bsW(s, 8, (uint32_t)c); +} + + +/*---------------------------------------------------*/ +/*--- The back end proper ---*/ +/*---------------------------------------------------*/ + +/*---------------------------------------------------*/ +static +void makeMaps_e(EState* s) +{ + int32_t i; + s->nInUse = 0; + for (i = 0; i < 256; i++) { + if (s->inUse[i]) { + s->unseqToSeq[i] = s->nInUse; + s->nInUse++; + } + } +} + + +/*---------------------------------------------------*/ +static NOINLINE +void generateMTFValues(EState* s) +{ + UChar yy[256]; + int32_t i, j; + int32_t zPend; + int32_t wr; + int32_t 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_t*)s->arr1)[0 .. s->nblock-1]. + * Because there are strictly fewer or equal MTF values + * than block values, ptr values in this area are overwritten + * with MTF values only when they are no longer needed. + * + * The final compressed bitstream is generated into the + * area starting at + * (UChar*) (&((UChar*)s->arr2)[s->nblock]) + * + * These storage aliases are set up in bzCompressInit(), + * except for the last one, which is arranged in + * compressBlock(). + */ + uint32_t* ptr = s->ptr; + UChar* block = s->block; + uint16_t* 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 (1) { + 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 (1) { + 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 15 + +static NOINLINE +void sendMTFValues(EState* s) +{ + int32_t v, t, i, j, gs, ge, totc, bt, bc, iter; + int32_t nSelectors, alphaSize, minLen, maxLen, selCtr; + int32_t nGroups, nBytes; + + /* + * UChar len [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; + * is a global since the decoder also needs it. + * + * int32_t code[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; + * int32_t 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_t cost[BZ_N_GROUPS]; + int32_t fave[BZ_N_GROUPS]; + + uint16_t* mtfv = s->mtfv; + + 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_t 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--; + } + + 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; + +#ifdef FAST_GROUP6 + /* + * Set up an auxiliary length table which is used to fast-track + * the 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]; + } + } +#endif + + nSelectors = 0; + totc = 0; + gs = 0; + while (1) { + /*--- 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; +#ifdef FAST_GROUP6 + if (nGroups == 6 && 50 == ge-gs+1) { + /*--- fast track the common case ---*/ + register uint32_t cost01, cost23, cost45; + register uint16_t 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_ITER + cost[0] = cost01 & 0xffff; cost[1] = cost01 >> 16; + cost[2] = cost23 & 0xffff; cost[3] = cost23 >> 16; + cost[4] = cost45 & 0xffff; cost[5] = cost45 >> 16; + + } else +#endif + { + /*--- slow version which correctly handles all situations ---*/ + for (i = gs; i <= ge; i++) { + uint16_t 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; + //bc = cost[0]; + //bt = 0; + 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. + */ +/* ~0.5% faster compress. +800 bytes */ +#if 0 + 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 + gs = ge+1; + } else +#endif + { + /*--- slow version which correctly handles all situations ---*/ + while (gs <= ge) { + s->rfreq[bt][mtfv[gs]]++; + gs++; + } + /* already is: gs = ge+1; */ + } + } + + /* + * Recompute the tables based on the accumulated frequencies. + */ + /* maxLen was changed from 20 to 17 in bzip2-1.0.3. See + * comment 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); + } + } + } + } + + /*--- 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); + } + + /*--- Now the coding tables. ---*/ + nBytes = s->numZ; + + for (t = 0; t < nGroups; t++) { + int32_t 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); + } + } + + /*--- And finally, the block data proper ---*/ + nBytes = s->numZ; + selCtr = 0; + gs = 0; + while (1) { + 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); + +/* Costs 1300 bytes and is _slower_ (on Intel Core 2) */ +#if 0 + if (nGroups == 6 && 50 == ge-gs+1) { + /*--- fast track the common case ---*/ + uint16_t mtfv_i; + UChar* s_len_sel_selCtr = &(s->len[s->selector[selCtr]][0]); + int32_t* 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 + gs = ge+1; + } else +#endif + { + /*--- slow version which correctly handles all situations ---*/ + /* code is bit bigger, but moves multiply out of the loop */ + UChar* s_len_sel_selCtr = &(s->len [s->selector[selCtr]][0]); + int32_t* s_code_sel_selCtr = &(s->code[s->selector[selCtr]][0]); + while (gs <= ge) { + bsW(s, + s_len_sel_selCtr[mtfv[gs]], + s_code_sel_selCtr[mtfv[gs]] + ); + gs++; + } + /* already is: gs = ge+1; */ + } + selCtr++; + } + AssertH(selCtr == nSelectors, 3007); +} + + +/*---------------------------------------------------*/ +static +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; + + 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));*/ + bsPutU32(s, BZ_HDR_BZh0 + s->blockSize100k); + } + + if (s->nblock > 0) { + /*bsPutUChar(s, 0x31);*/ + /*bsPutUChar(s, 0x41);*/ + /*bsPutUChar(s, 0x59);*/ + /*bsPutUChar(s, 0x26);*/ + bsPutU32(s, 0x31415926); + bsPutUChar(s, 0x53); + bsPutUChar(s, 0x59); + + /*-- Now the block's CRC, so it is in a known place. --*/ + bsPutU32(s, s->blockCRC); + + /* + * Now a single bit indicating (non-)randomisation. + * As of version 0.9.5, we use a better sorting algorithm + * which makes randomisation unnecessary. So always set + * the randomised bit to 'no'. Of course, the decoder + * still needs to be able to handle randomised blocks + * so as to maintain backwards compatibility with + * older 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);*/ + bsPutU32(s, 0x17724538); + bsPutUChar(s, 0x50); + bsPutUChar(s, 0x90); + bsPutU32(s, s->combinedCRC); + bsFinishWrite(s); + } +} + + +/*-------------------------------------------------------------*/ +/*--- end compress.c ---*/ +/*-------------------------------------------------------------*/ |