Simon Glass | cf20452 | 2016-01-05 09:31:00 -0700 | [diff] [blame] | 1 | |
| 2 | /*-------------------------------------------------------------*/ |
| 3 | /*--- Block sorting machinery ---*/ |
| 4 | /*--- blocksort.c ---*/ |
| 5 | /*-------------------------------------------------------------*/ |
| 6 | |
| 7 | /*-- |
| 8 | This file is a part of bzip2 and/or libbzip2, a program and |
| 9 | library for lossless, block-sorting data compression. |
| 10 | |
| 11 | Copyright (C) 1996-2002 Julian R Seward. All rights reserved. |
| 12 | |
| 13 | Redistribution and use in source and binary forms, with or without |
| 14 | modification, are permitted provided that the following conditions |
| 15 | are met: |
| 16 | |
| 17 | 1. Redistributions of source code must retain the above copyright |
| 18 | notice, this list of conditions and the following disclaimer. |
| 19 | |
| 20 | 2. The origin of this software must not be misrepresented; you must |
| 21 | not claim that you wrote the original software. If you use this |
| 22 | software in a product, an acknowledgment in the product |
| 23 | documentation would be appreciated but is not required. |
| 24 | |
| 25 | 3. Altered source versions must be plainly marked as such, and must |
| 26 | not be misrepresented as being the original software. |
| 27 | |
| 28 | 4. The name of the author may not be used to endorse or promote |
| 29 | products derived from this software without specific prior written |
| 30 | permission. |
| 31 | |
| 32 | THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS |
| 33 | OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| 34 | WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 35 | ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
| 36 | DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 37 | DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE |
| 38 | GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 39 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 40 | WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 41 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 42 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 43 | |
| 44 | Julian Seward, Cambridge, UK. |
| 45 | jseward@acm.org |
| 46 | bzip2/libbzip2 version 1.0.6 of 6 September 2010 |
| 47 | Copyright (C) 1996-2010 Julian Seward <jseward@bzip.org> |
| 48 | |
| 49 | This program is based on (at least) the work of: |
| 50 | Mike Burrows |
| 51 | David Wheeler |
| 52 | Peter Fenwick |
| 53 | Alistair Moffat |
| 54 | Radford Neal |
| 55 | Ian H. Witten |
| 56 | Robert Sedgewick |
| 57 | Jon L. Bentley |
| 58 | |
| 59 | For more information on these sources, see the manual. |
| 60 | --*/ |
| 61 | |
| 62 | #include "bzlib_private.h" |
Simon Glass | f7ae49f | 2020-05-10 11:40:05 -0600 | [diff] [blame] | 63 | #include <log.h> |
Simon Glass | cf20452 | 2016-01-05 09:31:00 -0700 | [diff] [blame] | 64 | |
| 65 | /*---------------------------------------------*/ |
| 66 | /*--- Fallback O(N log(N)^2) sorting ---*/ |
| 67 | /*--- algorithm, for repetitive blocks ---*/ |
| 68 | /*---------------------------------------------*/ |
| 69 | |
| 70 | /*---------------------------------------------*/ |
| 71 | static |
| 72 | __inline__ |
| 73 | void fallbackSimpleSort ( UInt32* fmap, |
| 74 | UInt32* eclass, |
| 75 | Int32 lo, |
| 76 | Int32 hi ) |
| 77 | { |
| 78 | Int32 i, j, tmp; |
| 79 | UInt32 ec_tmp; |
| 80 | |
| 81 | if (lo == hi) return; |
| 82 | |
| 83 | if (hi - lo > 3) { |
| 84 | for ( i = hi-4; i >= lo; i-- ) { |
| 85 | tmp = fmap[i]; |
| 86 | ec_tmp = eclass[tmp]; |
| 87 | for ( j = i+4; j <= hi && ec_tmp > eclass[fmap[j]]; j += 4 ) |
| 88 | fmap[j-4] = fmap[j]; |
| 89 | fmap[j-4] = tmp; |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | for ( i = hi-1; i >= lo; i-- ) { |
| 94 | tmp = fmap[i]; |
| 95 | ec_tmp = eclass[tmp]; |
| 96 | for ( j = i+1; j <= hi && ec_tmp > eclass[fmap[j]]; j++ ) |
| 97 | fmap[j-1] = fmap[j]; |
| 98 | fmap[j-1] = tmp; |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | |
| 103 | /*---------------------------------------------*/ |
| 104 | #define fswap(zz1, zz2) \ |
| 105 | { Int32 zztmp = zz1; zz1 = zz2; zz2 = zztmp; } |
| 106 | |
| 107 | #define fvswap(zzp1, zzp2, zzn) \ |
| 108 | { \ |
| 109 | Int32 yyp1 = (zzp1); \ |
| 110 | Int32 yyp2 = (zzp2); \ |
| 111 | Int32 yyn = (zzn); \ |
| 112 | while (yyn > 0) { \ |
| 113 | fswap(fmap[yyp1], fmap[yyp2]); \ |
| 114 | yyp1++; yyp2++; yyn--; \ |
| 115 | } \ |
| 116 | } |
| 117 | |
| 118 | |
| 119 | #define fmin(a,b) ((a) < (b)) ? (a) : (b) |
| 120 | |
| 121 | #define fpush(lz,hz) { stackLo[sp] = lz; \ |
| 122 | stackHi[sp] = hz; \ |
| 123 | sp++; } |
| 124 | |
| 125 | #define fpop(lz,hz) { sp--; \ |
| 126 | lz = stackLo[sp]; \ |
| 127 | hz = stackHi[sp]; } |
| 128 | |
| 129 | #define FALLBACK_QSORT_SMALL_THRESH 10 |
| 130 | #define FALLBACK_QSORT_STACK_SIZE 100 |
| 131 | |
| 132 | |
| 133 | static |
| 134 | void fallbackQSort3 ( UInt32* fmap, |
| 135 | UInt32* eclass, |
| 136 | Int32 loSt, |
| 137 | Int32 hiSt ) |
| 138 | { |
| 139 | Int32 unLo, unHi, ltLo, gtHi, n, m; |
| 140 | Int32 sp, lo, hi; |
| 141 | UInt32 med, r, r3; |
| 142 | Int32 stackLo[FALLBACK_QSORT_STACK_SIZE]; |
| 143 | Int32 stackHi[FALLBACK_QSORT_STACK_SIZE]; |
| 144 | |
| 145 | r = 0; |
| 146 | |
| 147 | sp = 0; |
| 148 | fpush ( loSt, hiSt ); |
| 149 | |
| 150 | while (sp > 0) { |
| 151 | |
| 152 | AssertH ( sp < FALLBACK_QSORT_STACK_SIZE - 1, 1004 ); |
| 153 | |
| 154 | fpop ( lo, hi ); |
| 155 | if (hi - lo < FALLBACK_QSORT_SMALL_THRESH) { |
| 156 | fallbackSimpleSort ( fmap, eclass, lo, hi ); |
| 157 | continue; |
| 158 | } |
| 159 | |
| 160 | /* Random partitioning. Median of 3 sometimes fails to |
| 161 | avoid bad cases. Median of 9 seems to help but |
| 162 | looks rather expensive. This too seems to work but |
| 163 | is cheaper. Guidance for the magic constants |
| 164 | 7621 and 32768 is taken from Sedgewick's algorithms |
| 165 | book, chapter 35. |
| 166 | */ |
| 167 | r = ((r * 7621) + 1) % 32768; |
| 168 | r3 = r % 3; |
| 169 | if (r3 == 0) med = eclass[fmap[lo]]; else |
| 170 | if (r3 == 1) med = eclass[fmap[(lo+hi)>>1]]; else |
| 171 | med = eclass[fmap[hi]]; |
| 172 | |
| 173 | unLo = ltLo = lo; |
| 174 | unHi = gtHi = hi; |
| 175 | |
| 176 | while (1) { |
| 177 | while (1) { |
| 178 | if (unLo > unHi) break; |
| 179 | n = (Int32)eclass[fmap[unLo]] - (Int32)med; |
| 180 | if (n == 0) { |
| 181 | fswap(fmap[unLo], fmap[ltLo]); |
| 182 | ltLo++; unLo++; |
| 183 | continue; |
| 184 | }; |
| 185 | if (n > 0) break; |
| 186 | unLo++; |
| 187 | } |
| 188 | while (1) { |
| 189 | if (unLo > unHi) break; |
| 190 | n = (Int32)eclass[fmap[unHi]] - (Int32)med; |
| 191 | if (n == 0) { |
| 192 | fswap(fmap[unHi], fmap[gtHi]); |
| 193 | gtHi--; unHi--; |
| 194 | continue; |
| 195 | }; |
| 196 | if (n < 0) break; |
| 197 | unHi--; |
| 198 | } |
| 199 | if (unLo > unHi) break; |
| 200 | fswap(fmap[unLo], fmap[unHi]); unLo++; unHi--; |
| 201 | } |
| 202 | |
| 203 | AssertD ( unHi == unLo-1, "fallbackQSort3(2)" ); |
| 204 | |
| 205 | if (gtHi < ltLo) continue; |
| 206 | |
| 207 | n = fmin(ltLo-lo, unLo-ltLo); fvswap(lo, unLo-n, n); |
| 208 | m = fmin(hi-gtHi, gtHi-unHi); fvswap(unLo, hi-m+1, m); |
| 209 | |
| 210 | n = lo + unLo - ltLo - 1; |
| 211 | m = hi - (gtHi - unHi) + 1; |
| 212 | |
| 213 | if (n - lo > hi - m) { |
| 214 | fpush ( lo, n ); |
| 215 | fpush ( m, hi ); |
| 216 | } else { |
| 217 | fpush ( m, hi ); |
| 218 | fpush ( lo, n ); |
| 219 | } |
| 220 | } |
| 221 | } |
| 222 | |
| 223 | #undef fmin |
| 224 | #undef fpush |
| 225 | #undef fpop |
| 226 | #undef fswap |
| 227 | #undef fvswap |
| 228 | #undef FALLBACK_QSORT_SMALL_THRESH |
| 229 | #undef FALLBACK_QSORT_STACK_SIZE |
| 230 | |
| 231 | |
| 232 | /*---------------------------------------------*/ |
| 233 | /* Pre: |
| 234 | nblock > 0 |
| 235 | eclass exists for [0 .. nblock-1] |
| 236 | ((UChar*)eclass) [0 .. nblock-1] holds block |
| 237 | ptr exists for [0 .. nblock-1] |
| 238 | |
| 239 | Post: |
| 240 | ((UChar*)eclass) [0 .. nblock-1] holds block |
| 241 | All other areas of eclass destroyed |
| 242 | fmap [0 .. nblock-1] holds sorted order |
| 243 | bhtab [ 0 .. 2+(nblock/32) ] destroyed |
| 244 | */ |
| 245 | |
| 246 | #define SET_BH(zz) bhtab[(zz) >> 5] |= (1 << ((zz) & 31)) |
| 247 | #define CLEAR_BH(zz) bhtab[(zz) >> 5] &= ~(1 << ((zz) & 31)) |
| 248 | #define ISSET_BH(zz) (bhtab[(zz) >> 5] & (1 << ((zz) & 31))) |
| 249 | #define WORD_BH(zz) bhtab[(zz) >> 5] |
| 250 | #define UNALIGNED_BH(zz) ((zz) & 0x01f) |
| 251 | |
| 252 | static |
| 253 | void fallbackSort ( UInt32* fmap, |
| 254 | UInt32* eclass, |
| 255 | UInt32* bhtab, |
| 256 | Int32 nblock, |
| 257 | Int32 verb ) |
| 258 | { |
| 259 | Int32 ftab[257]; |
| 260 | Int32 ftabCopy[256]; |
| 261 | Int32 H, i, j, k, l, r, cc, cc1; |
| 262 | Int32 nNotDone; |
| 263 | Int32 nBhtab; |
| 264 | UChar* eclass8 = (UChar*)eclass; |
| 265 | |
| 266 | /*-- |
| 267 | Initial 1-char radix sort to generate |
| 268 | initial fmap and initial BH bits. |
| 269 | --*/ |
| 270 | if (verb >= 4) |
| 271 | VPrintf0 ( " bucket sorting ...\n" ); |
| 272 | for (i = 0; i < 257; i++) ftab[i] = 0; |
| 273 | for (i = 0; i < nblock; i++) ftab[eclass8[i]]++; |
| 274 | for (i = 0; i < 256; i++) ftabCopy[i] = ftab[i]; |
| 275 | for (i = 1; i < 257; i++) ftab[i] += ftab[i-1]; |
| 276 | |
| 277 | for (i = 0; i < nblock; i++) { |
| 278 | j = eclass8[i]; |
| 279 | k = ftab[j] - 1; |
| 280 | ftab[j] = k; |
| 281 | fmap[k] = i; |
| 282 | } |
| 283 | |
| 284 | nBhtab = 2 + (nblock / 32); |
| 285 | for (i = 0; i < nBhtab; i++) bhtab[i] = 0; |
| 286 | for (i = 0; i < 256; i++) SET_BH(ftab[i]); |
| 287 | |
| 288 | /*-- |
| 289 | Inductively refine the buckets. Kind-of an |
| 290 | "exponential radix sort" (!), inspired by the |
| 291 | Manber-Myers suffix array construction algorithm. |
| 292 | --*/ |
| 293 | |
| 294 | /*-- set sentinel bits for block-end detection --*/ |
| 295 | for (i = 0; i < 32; i++) { |
| 296 | SET_BH(nblock + 2*i); |
| 297 | CLEAR_BH(nblock + 2*i + 1); |
| 298 | } |
| 299 | |
| 300 | /*-- the log(N) loop --*/ |
| 301 | H = 1; |
| 302 | while (1) { |
| 303 | |
| 304 | if (verb >= 4) |
| 305 | VPrintf1 ( " depth %6d has ", H ); |
| 306 | |
| 307 | j = 0; |
| 308 | for (i = 0; i < nblock; i++) { |
| 309 | if (ISSET_BH(i)) j = i; |
| 310 | k = fmap[i] - H; if (k < 0) k += nblock; |
| 311 | eclass[k] = j; |
| 312 | } |
| 313 | |
| 314 | nNotDone = 0; |
| 315 | r = -1; |
| 316 | while (1) { |
| 317 | |
| 318 | /*-- find the next non-singleton bucket --*/ |
| 319 | k = r + 1; |
| 320 | while (ISSET_BH(k) && UNALIGNED_BH(k)) k++; |
| 321 | if (ISSET_BH(k)) { |
| 322 | while (WORD_BH(k) == 0xffffffff) k += 32; |
| 323 | while (ISSET_BH(k)) k++; |
| 324 | } |
| 325 | l = k - 1; |
| 326 | if (l >= nblock) break; |
| 327 | while (!ISSET_BH(k) && UNALIGNED_BH(k)) k++; |
| 328 | if (!ISSET_BH(k)) { |
| 329 | while (WORD_BH(k) == 0x00000000) k += 32; |
| 330 | while (!ISSET_BH(k)) k++; |
| 331 | } |
| 332 | r = k - 1; |
| 333 | if (r >= nblock) break; |
| 334 | |
| 335 | /*-- now [l, r] bracket current bucket --*/ |
| 336 | if (r > l) { |
| 337 | nNotDone += (r - l + 1); |
| 338 | fallbackQSort3 ( fmap, eclass, l, r ); |
| 339 | |
| 340 | /*-- scan bucket and generate header bits-- */ |
| 341 | cc = -1; |
| 342 | for (i = l; i <= r; i++) { |
| 343 | cc1 = eclass[fmap[i]]; |
| 344 | if (cc != cc1) { SET_BH(i); cc = cc1; }; |
| 345 | } |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | if (verb >= 4) |
| 350 | VPrintf1 ( "%6d unresolved strings\n", nNotDone ); |
| 351 | |
| 352 | H *= 2; |
| 353 | if (H > nblock || nNotDone == 0) break; |
| 354 | } |
| 355 | |
| 356 | /*-- |
| 357 | Reconstruct the original block in |
| 358 | eclass8 [0 .. nblock-1], since the |
| 359 | previous phase destroyed it. |
| 360 | --*/ |
| 361 | if (verb >= 4) |
| 362 | VPrintf0 ( " reconstructing block ...\n" ); |
| 363 | j = 0; |
| 364 | for (i = 0; i < nblock; i++) { |
| 365 | while (ftabCopy[j] == 0) j++; |
| 366 | ftabCopy[j]--; |
| 367 | eclass8[fmap[i]] = (UChar)j; |
| 368 | } |
| 369 | AssertH ( j < 256, 1005 ); |
| 370 | } |
| 371 | |
| 372 | #undef SET_BH |
| 373 | #undef CLEAR_BH |
| 374 | #undef ISSET_BH |
| 375 | #undef WORD_BH |
| 376 | #undef UNALIGNED_BH |
| 377 | |
| 378 | |
| 379 | /*---------------------------------------------*/ |
| 380 | /*--- The main, O(N^2 log(N)) sorting ---*/ |
| 381 | /*--- algorithm. Faster for "normal" ---*/ |
| 382 | /*--- non-repetitive blocks. ---*/ |
| 383 | /*---------------------------------------------*/ |
| 384 | |
| 385 | /*---------------------------------------------*/ |
| 386 | static |
| 387 | __inline__ |
| 388 | Bool mainGtU ( UInt32 i1, |
| 389 | UInt32 i2, |
| 390 | UChar* block, |
| 391 | UInt16* quadrant, |
| 392 | UInt32 nblock, |
| 393 | Int32* budget ) |
| 394 | { |
| 395 | Int32 k; |
| 396 | UChar c1, c2; |
| 397 | UInt16 s1, s2; |
| 398 | |
| 399 | AssertD ( i1 != i2, "mainGtU" ); |
| 400 | /* 1 */ |
| 401 | c1 = block[i1]; c2 = block[i2]; |
| 402 | if (c1 != c2) return (c1 > c2); |
| 403 | i1++; i2++; |
| 404 | /* 2 */ |
| 405 | c1 = block[i1]; c2 = block[i2]; |
| 406 | if (c1 != c2) return (c1 > c2); |
| 407 | i1++; i2++; |
| 408 | /* 3 */ |
| 409 | c1 = block[i1]; c2 = block[i2]; |
| 410 | if (c1 != c2) return (c1 > c2); |
| 411 | i1++; i2++; |
| 412 | /* 4 */ |
| 413 | c1 = block[i1]; c2 = block[i2]; |
| 414 | if (c1 != c2) return (c1 > c2); |
| 415 | i1++; i2++; |
| 416 | /* 5 */ |
| 417 | c1 = block[i1]; c2 = block[i2]; |
| 418 | if (c1 != c2) return (c1 > c2); |
| 419 | i1++; i2++; |
| 420 | /* 6 */ |
| 421 | c1 = block[i1]; c2 = block[i2]; |
| 422 | if (c1 != c2) return (c1 > c2); |
| 423 | i1++; i2++; |
| 424 | /* 7 */ |
| 425 | c1 = block[i1]; c2 = block[i2]; |
| 426 | if (c1 != c2) return (c1 > c2); |
| 427 | i1++; i2++; |
| 428 | /* 8 */ |
| 429 | c1 = block[i1]; c2 = block[i2]; |
| 430 | if (c1 != c2) return (c1 > c2); |
| 431 | i1++; i2++; |
| 432 | /* 9 */ |
| 433 | c1 = block[i1]; c2 = block[i2]; |
| 434 | if (c1 != c2) return (c1 > c2); |
| 435 | i1++; i2++; |
| 436 | /* 10 */ |
| 437 | c1 = block[i1]; c2 = block[i2]; |
| 438 | if (c1 != c2) return (c1 > c2); |
| 439 | i1++; i2++; |
| 440 | /* 11 */ |
| 441 | c1 = block[i1]; c2 = block[i2]; |
| 442 | if (c1 != c2) return (c1 > c2); |
| 443 | i1++; i2++; |
| 444 | /* 12 */ |
| 445 | c1 = block[i1]; c2 = block[i2]; |
| 446 | if (c1 != c2) return (c1 > c2); |
| 447 | i1++; i2++; |
| 448 | |
| 449 | k = nblock + 8; |
| 450 | |
| 451 | do { |
| 452 | /* 1 */ |
| 453 | c1 = block[i1]; c2 = block[i2]; |
| 454 | if (c1 != c2) return (c1 > c2); |
| 455 | s1 = quadrant[i1]; s2 = quadrant[i2]; |
| 456 | if (s1 != s2) return (s1 > s2); |
| 457 | i1++; i2++; |
| 458 | /* 2 */ |
| 459 | c1 = block[i1]; c2 = block[i2]; |
| 460 | if (c1 != c2) return (c1 > c2); |
| 461 | s1 = quadrant[i1]; s2 = quadrant[i2]; |
| 462 | if (s1 != s2) return (s1 > s2); |
| 463 | i1++; i2++; |
| 464 | /* 3 */ |
| 465 | c1 = block[i1]; c2 = block[i2]; |
| 466 | if (c1 != c2) return (c1 > c2); |
| 467 | s1 = quadrant[i1]; s2 = quadrant[i2]; |
| 468 | if (s1 != s2) return (s1 > s2); |
| 469 | i1++; i2++; |
| 470 | /* 4 */ |
| 471 | c1 = block[i1]; c2 = block[i2]; |
| 472 | if (c1 != c2) return (c1 > c2); |
| 473 | s1 = quadrant[i1]; s2 = quadrant[i2]; |
| 474 | if (s1 != s2) return (s1 > s2); |
| 475 | i1++; i2++; |
| 476 | /* 5 */ |
| 477 | c1 = block[i1]; c2 = block[i2]; |
| 478 | if (c1 != c2) return (c1 > c2); |
| 479 | s1 = quadrant[i1]; s2 = quadrant[i2]; |
| 480 | if (s1 != s2) return (s1 > s2); |
| 481 | i1++; i2++; |
| 482 | /* 6 */ |
| 483 | c1 = block[i1]; c2 = block[i2]; |
| 484 | if (c1 != c2) return (c1 > c2); |
| 485 | s1 = quadrant[i1]; s2 = quadrant[i2]; |
| 486 | if (s1 != s2) return (s1 > s2); |
| 487 | i1++; i2++; |
| 488 | /* 7 */ |
| 489 | c1 = block[i1]; c2 = block[i2]; |
| 490 | if (c1 != c2) return (c1 > c2); |
| 491 | s1 = quadrant[i1]; s2 = quadrant[i2]; |
| 492 | if (s1 != s2) return (s1 > s2); |
| 493 | i1++; i2++; |
| 494 | /* 8 */ |
| 495 | c1 = block[i1]; c2 = block[i2]; |
| 496 | if (c1 != c2) return (c1 > c2); |
| 497 | s1 = quadrant[i1]; s2 = quadrant[i2]; |
| 498 | if (s1 != s2) return (s1 > s2); |
| 499 | i1++; i2++; |
| 500 | |
| 501 | if (i1 >= nblock) i1 -= nblock; |
| 502 | if (i2 >= nblock) i2 -= nblock; |
| 503 | |
| 504 | k -= 8; |
| 505 | (*budget)--; |
| 506 | } |
| 507 | while (k >= 0); |
| 508 | |
| 509 | return False; |
| 510 | } |
| 511 | |
| 512 | |
| 513 | /*---------------------------------------------*/ |
| 514 | /*-- |
| 515 | Knuth's increments seem to work better |
| 516 | than Incerpi-Sedgewick here. Possibly |
| 517 | because the number of elems to sort is |
| 518 | usually small, typically <= 20. |
| 519 | --*/ |
| 520 | static |
| 521 | Int32 incs[14] = { 1, 4, 13, 40, 121, 364, 1093, 3280, |
| 522 | 9841, 29524, 88573, 265720, |
| 523 | 797161, 2391484 }; |
| 524 | |
| 525 | static |
| 526 | void mainSimpleSort ( UInt32* ptr, |
| 527 | UChar* block, |
| 528 | UInt16* quadrant, |
| 529 | Int32 nblock, |
| 530 | Int32 lo, |
| 531 | Int32 hi, |
| 532 | Int32 d, |
| 533 | Int32* budget ) |
| 534 | { |
| 535 | Int32 i, j, h, bigN, hp; |
| 536 | UInt32 v; |
| 537 | |
| 538 | bigN = hi - lo + 1; |
| 539 | if (bigN < 2) return; |
| 540 | |
| 541 | hp = 0; |
| 542 | while (incs[hp] < bigN) hp++; |
| 543 | hp--; |
| 544 | |
| 545 | for (; hp >= 0; hp--) { |
| 546 | h = incs[hp]; |
| 547 | |
| 548 | i = lo + h; |
| 549 | while (True) { |
| 550 | |
| 551 | /*-- copy 1 --*/ |
| 552 | if (i > hi) break; |
| 553 | v = ptr[i]; |
| 554 | j = i; |
| 555 | while ( mainGtU ( |
| 556 | ptr[j-h]+d, v+d, block, quadrant, nblock, budget |
| 557 | ) ) { |
| 558 | ptr[j] = ptr[j-h]; |
| 559 | j = j - h; |
| 560 | if (j <= (lo + h - 1)) break; |
| 561 | } |
| 562 | ptr[j] = v; |
| 563 | i++; |
| 564 | |
| 565 | /*-- copy 2 --*/ |
| 566 | if (i > hi) break; |
| 567 | v = ptr[i]; |
| 568 | j = i; |
| 569 | while ( mainGtU ( |
| 570 | ptr[j-h]+d, v+d, block, quadrant, nblock, budget |
| 571 | ) ) { |
| 572 | ptr[j] = ptr[j-h]; |
| 573 | j = j - h; |
| 574 | if (j <= (lo + h - 1)) break; |
| 575 | } |
| 576 | ptr[j] = v; |
| 577 | i++; |
| 578 | |
| 579 | /*-- copy 3 --*/ |
| 580 | if (i > hi) break; |
| 581 | v = ptr[i]; |
| 582 | j = i; |
| 583 | while ( mainGtU ( |
| 584 | ptr[j-h]+d, v+d, block, quadrant, nblock, budget |
| 585 | ) ) { |
| 586 | ptr[j] = ptr[j-h]; |
| 587 | j = j - h; |
| 588 | if (j <= (lo + h - 1)) break; |
| 589 | } |
| 590 | ptr[j] = v; |
| 591 | i++; |
| 592 | |
| 593 | if (*budget < 0) return; |
| 594 | } |
| 595 | } |
| 596 | } |
| 597 | |
| 598 | |
| 599 | /*---------------------------------------------*/ |
| 600 | /*-- |
| 601 | The following is an implementation of |
| 602 | an elegant 3-way quicksort for strings, |
| 603 | described in a paper "Fast Algorithms for |
| 604 | Sorting and Searching Strings", by Robert |
| 605 | Sedgewick and Jon L. Bentley. |
| 606 | --*/ |
| 607 | |
| 608 | #define mswap(zz1, zz2) \ |
| 609 | { Int32 zztmp = zz1; zz1 = zz2; zz2 = zztmp; } |
| 610 | |
| 611 | #define mvswap(zzp1, zzp2, zzn) \ |
| 612 | { \ |
| 613 | Int32 yyp1 = (zzp1); \ |
| 614 | Int32 yyp2 = (zzp2); \ |
| 615 | Int32 yyn = (zzn); \ |
| 616 | while (yyn > 0) { \ |
| 617 | mswap(ptr[yyp1], ptr[yyp2]); \ |
| 618 | yyp1++; yyp2++; yyn--; \ |
| 619 | } \ |
| 620 | } |
| 621 | |
| 622 | static |
| 623 | __inline__ |
| 624 | UChar mmed3 ( UChar a, UChar b, UChar c ) |
| 625 | { |
| 626 | UChar t; |
| 627 | if (a > b) { t = a; a = b; b = t; }; |
| 628 | if (b > c) { |
| 629 | b = c; |
| 630 | if (a > b) b = a; |
| 631 | } |
| 632 | return b; |
| 633 | } |
| 634 | |
| 635 | #define mmin(a,b) ((a) < (b)) ? (a) : (b) |
| 636 | |
| 637 | #define mpush(lz,hz,dz) { stackLo[sp] = lz; \ |
| 638 | stackHi[sp] = hz; \ |
| 639 | stackD [sp] = dz; \ |
| 640 | sp++; } |
| 641 | |
| 642 | #define mpop(lz,hz,dz) { sp--; \ |
| 643 | lz = stackLo[sp]; \ |
| 644 | hz = stackHi[sp]; \ |
| 645 | dz = stackD [sp]; } |
| 646 | |
| 647 | |
| 648 | #define mnextsize(az) (nextHi[az]-nextLo[az]) |
| 649 | |
| 650 | #define mnextswap(az,bz) \ |
| 651 | { Int32 tz; \ |
| 652 | tz = nextLo[az]; nextLo[az] = nextLo[bz]; nextLo[bz] = tz; \ |
| 653 | tz = nextHi[az]; nextHi[az] = nextHi[bz]; nextHi[bz] = tz; \ |
| 654 | tz = nextD [az]; nextD [az] = nextD [bz]; nextD [bz] = tz; } |
| 655 | |
| 656 | |
| 657 | #define MAIN_QSORT_SMALL_THRESH 20 |
| 658 | #define MAIN_QSORT_DEPTH_THRESH (BZ_N_RADIX + BZ_N_QSORT) |
| 659 | #define MAIN_QSORT_STACK_SIZE 100 |
| 660 | |
| 661 | static |
| 662 | void mainQSort3 ( UInt32* ptr, |
| 663 | UChar* block, |
| 664 | UInt16* quadrant, |
| 665 | Int32 nblock, |
| 666 | Int32 loSt, |
| 667 | Int32 hiSt, |
| 668 | Int32 dSt, |
| 669 | Int32* budget ) |
| 670 | { |
| 671 | Int32 unLo, unHi, ltLo, gtHi, n, m, med; |
| 672 | Int32 sp, lo, hi, d; |
| 673 | |
| 674 | Int32 stackLo[MAIN_QSORT_STACK_SIZE]; |
| 675 | Int32 stackHi[MAIN_QSORT_STACK_SIZE]; |
| 676 | Int32 stackD [MAIN_QSORT_STACK_SIZE]; |
| 677 | |
| 678 | Int32 nextLo[3]; |
| 679 | Int32 nextHi[3]; |
| 680 | Int32 nextD [3]; |
| 681 | |
| 682 | sp = 0; |
| 683 | mpush ( loSt, hiSt, dSt ); |
| 684 | |
| 685 | while (sp > 0) { |
| 686 | |
| 687 | AssertH ( sp < MAIN_QSORT_STACK_SIZE - 2, 1001 ); |
| 688 | |
| 689 | mpop ( lo, hi, d ); |
| 690 | if (hi - lo < MAIN_QSORT_SMALL_THRESH || |
| 691 | d > MAIN_QSORT_DEPTH_THRESH) { |
| 692 | mainSimpleSort ( ptr, block, quadrant, nblock, lo, hi, d, budget ); |
| 693 | if (*budget < 0) return; |
| 694 | continue; |
| 695 | } |
| 696 | |
| 697 | med = (Int32) |
| 698 | mmed3 ( block[ptr[ lo ]+d], |
| 699 | block[ptr[ hi ]+d], |
| 700 | block[ptr[ (lo+hi)>>1 ]+d] ); |
| 701 | |
| 702 | unLo = ltLo = lo; |
| 703 | unHi = gtHi = hi; |
| 704 | |
| 705 | while (True) { |
| 706 | while (True) { |
| 707 | if (unLo > unHi) break; |
| 708 | n = ((Int32)block[ptr[unLo]+d]) - med; |
| 709 | if (n == 0) { |
| 710 | mswap(ptr[unLo], ptr[ltLo]); |
| 711 | ltLo++; unLo++; continue; |
| 712 | }; |
| 713 | if (n > 0) break; |
| 714 | unLo++; |
| 715 | } |
| 716 | while (True) { |
| 717 | if (unLo > unHi) break; |
| 718 | n = ((Int32)block[ptr[unHi]+d]) - med; |
| 719 | if (n == 0) { |
| 720 | mswap(ptr[unHi], ptr[gtHi]); |
| 721 | gtHi--; unHi--; continue; |
| 722 | }; |
| 723 | if (n < 0) break; |
| 724 | unHi--; |
| 725 | } |
| 726 | if (unLo > unHi) break; |
| 727 | mswap(ptr[unLo], ptr[unHi]); unLo++; unHi--; |
| 728 | } |
| 729 | |
| 730 | AssertD ( unHi == unLo-1, "mainQSort3(2)" ); |
| 731 | |
| 732 | if (gtHi < ltLo) { |
| 733 | mpush(lo, hi, d+1 ); |
| 734 | continue; |
| 735 | } |
| 736 | |
| 737 | n = mmin(ltLo-lo, unLo-ltLo); mvswap(lo, unLo-n, n); |
| 738 | m = mmin(hi-gtHi, gtHi-unHi); mvswap(unLo, hi-m+1, m); |
| 739 | |
| 740 | n = lo + unLo - ltLo - 1; |
| 741 | m = hi - (gtHi - unHi) + 1; |
| 742 | |
| 743 | nextLo[0] = lo; nextHi[0] = n; nextD[0] = d; |
| 744 | nextLo[1] = m; nextHi[1] = hi; nextD[1] = d; |
| 745 | nextLo[2] = n+1; nextHi[2] = m-1; nextD[2] = d+1; |
| 746 | |
| 747 | if (mnextsize(0) < mnextsize(1)) mnextswap(0,1); |
| 748 | if (mnextsize(1) < mnextsize(2)) mnextswap(1,2); |
| 749 | if (mnextsize(0) < mnextsize(1)) mnextswap(0,1); |
| 750 | |
| 751 | AssertD (mnextsize(0) >= mnextsize(1), "mainQSort3(8)" ); |
| 752 | AssertD (mnextsize(1) >= mnextsize(2), "mainQSort3(9)" ); |
| 753 | |
| 754 | mpush (nextLo[0], nextHi[0], nextD[0]); |
| 755 | mpush (nextLo[1], nextHi[1], nextD[1]); |
| 756 | mpush (nextLo[2], nextHi[2], nextD[2]); |
| 757 | } |
| 758 | } |
| 759 | |
| 760 | #undef mswap |
| 761 | #undef mvswap |
| 762 | #undef mpush |
| 763 | #undef mpop |
| 764 | #undef mmin |
| 765 | #undef mnextsize |
| 766 | #undef mnextswap |
| 767 | #undef MAIN_QSORT_SMALL_THRESH |
| 768 | #undef MAIN_QSORT_DEPTH_THRESH |
| 769 | #undef MAIN_QSORT_STACK_SIZE |
| 770 | |
| 771 | |
| 772 | /*---------------------------------------------*/ |
| 773 | /* Pre: |
| 774 | nblock > N_OVERSHOOT |
| 775 | block32 exists for [0 .. nblock-1 +N_OVERSHOOT] |
| 776 | ((UChar*)block32) [0 .. nblock-1] holds block |
| 777 | ptr exists for [0 .. nblock-1] |
| 778 | |
| 779 | Post: |
| 780 | ((UChar*)block32) [0 .. nblock-1] holds block |
| 781 | All other areas of block32 destroyed |
| 782 | ftab [0 .. 65536 ] destroyed |
| 783 | ptr [0 .. nblock-1] holds sorted order |
| 784 | if (*budget < 0), sorting was abandoned |
| 785 | */ |
| 786 | |
| 787 | #define BIGFREQ(b) (ftab[((b)+1) << 8] - ftab[(b) << 8]) |
| 788 | #define SETMASK (1 << 21) |
| 789 | #define CLEARMASK (~(SETMASK)) |
| 790 | |
| 791 | static |
| 792 | void mainSort ( UInt32* ptr, |
| 793 | UChar* block, |
| 794 | UInt16* quadrant, |
| 795 | UInt32* ftab, |
| 796 | Int32 nblock, |
| 797 | Int32 verb, |
| 798 | Int32* budget ) |
| 799 | { |
| 800 | Int32 i, j, k, ss, sb; |
| 801 | Int32 runningOrder[256]; |
| 802 | Bool bigDone[256]; |
| 803 | Int32 copyStart[256]; |
| 804 | Int32 copyEnd [256]; |
| 805 | UChar c1; |
| 806 | Int32 numQSorted; |
| 807 | UInt16 s; |
| 808 | if (verb >= 4) VPrintf0 ( " main sort initialise ...\n" ); |
| 809 | |
| 810 | /*-- set up the 2-byte frequency table --*/ |
| 811 | for (i = 65536; i >= 0; i--) ftab[i] = 0; |
| 812 | |
| 813 | j = block[0] << 8; |
| 814 | i = nblock-1; |
| 815 | for (; i >= 3; i -= 4) { |
| 816 | quadrant[i] = 0; |
| 817 | j = (j >> 8) | ( ((UInt16)block[i]) << 8); |
| 818 | ftab[j]++; |
| 819 | quadrant[i-1] = 0; |
| 820 | j = (j >> 8) | ( ((UInt16)block[i-1]) << 8); |
| 821 | ftab[j]++; |
| 822 | quadrant[i-2] = 0; |
| 823 | j = (j >> 8) | ( ((UInt16)block[i-2]) << 8); |
| 824 | ftab[j]++; |
| 825 | quadrant[i-3] = 0; |
| 826 | j = (j >> 8) | ( ((UInt16)block[i-3]) << 8); |
| 827 | ftab[j]++; |
| 828 | } |
| 829 | for (; i >= 0; i--) { |
| 830 | quadrant[i] = 0; |
| 831 | j = (j >> 8) | ( ((UInt16)block[i]) << 8); |
| 832 | ftab[j]++; |
| 833 | } |
| 834 | |
| 835 | /*-- (emphasises close relationship of block & quadrant) --*/ |
| 836 | for (i = 0; i < BZ_N_OVERSHOOT; i++) { |
| 837 | block [nblock+i] = block[i]; |
| 838 | quadrant[nblock+i] = 0; |
| 839 | } |
| 840 | |
| 841 | if (verb >= 4) VPrintf0 ( " bucket sorting ...\n" ); |
| 842 | |
| 843 | /*-- Complete the initial radix sort --*/ |
| 844 | for (i = 1; i <= 65536; i++) ftab[i] += ftab[i-1]; |
| 845 | |
| 846 | s = block[0] << 8; |
| 847 | i = nblock-1; |
| 848 | for (; i >= 3; i -= 4) { |
| 849 | s = (s >> 8) | (block[i] << 8); |
| 850 | j = ftab[s] -1; |
| 851 | ftab[s] = j; |
| 852 | ptr[j] = i; |
| 853 | s = (s >> 8) | (block[i-1] << 8); |
| 854 | j = ftab[s] -1; |
| 855 | ftab[s] = j; |
| 856 | ptr[j] = i-1; |
| 857 | s = (s >> 8) | (block[i-2] << 8); |
| 858 | j = ftab[s] -1; |
| 859 | ftab[s] = j; |
| 860 | ptr[j] = i-2; |
| 861 | s = (s >> 8) | (block[i-3] << 8); |
| 862 | j = ftab[s] -1; |
| 863 | ftab[s] = j; |
| 864 | ptr[j] = i-3; |
| 865 | } |
| 866 | for (; i >= 0; i--) { |
| 867 | s = (s >> 8) | (block[i] << 8); |
| 868 | j = ftab[s] -1; |
| 869 | ftab[s] = j; |
| 870 | ptr[j] = i; |
| 871 | } |
| 872 | |
| 873 | /*-- |
| 874 | Now ftab contains the first loc of every small bucket. |
| 875 | Calculate the running order, from smallest to largest |
| 876 | big bucket. |
| 877 | --*/ |
| 878 | for (i = 0; i <= 255; i++) { |
| 879 | bigDone [i] = False; |
| 880 | runningOrder[i] = i; |
| 881 | } |
| 882 | |
| 883 | { |
| 884 | Int32 vv; |
| 885 | Int32 h = 1; |
| 886 | do h = 3 * h + 1; while (h <= 256); |
| 887 | do { |
| 888 | h = h / 3; |
| 889 | for (i = h; i <= 255; i++) { |
| 890 | vv = runningOrder[i]; |
| 891 | j = i; |
| 892 | while ( BIGFREQ(runningOrder[j-h]) > BIGFREQ(vv) ) { |
| 893 | runningOrder[j] = runningOrder[j-h]; |
| 894 | j = j - h; |
| 895 | if (j <= (h - 1)) goto zero; |
| 896 | } |
| 897 | zero: |
| 898 | runningOrder[j] = vv; |
| 899 | } |
| 900 | } while (h != 1); |
| 901 | } |
| 902 | |
| 903 | /*-- |
| 904 | The main sorting loop. |
| 905 | --*/ |
| 906 | |
| 907 | numQSorted = 0; |
| 908 | |
| 909 | for (i = 0; i <= 255; i++) { |
| 910 | |
| 911 | /*-- |
| 912 | Process big buckets, starting with the least full. |
| 913 | Basically this is a 3-step process in which we call |
| 914 | mainQSort3 to sort the small buckets [ss, j], but |
| 915 | also make a big effort to avoid the calls if we can. |
| 916 | --*/ |
| 917 | ss = runningOrder[i]; |
| 918 | |
| 919 | /*-- |
| 920 | Step 1: |
| 921 | Complete the big bucket [ss] by quicksorting |
| 922 | any unsorted small buckets [ss, j], for j != ss. |
| 923 | Hopefully previous pointer-scanning phases have already |
| 924 | completed many of the small buckets [ss, j], so |
| 925 | we don't have to sort them at all. |
| 926 | --*/ |
| 927 | for (j = 0; j <= 255; j++) { |
| 928 | if (j != ss) { |
| 929 | sb = (ss << 8) + j; |
| 930 | if ( ! (ftab[sb] & SETMASK) ) { |
| 931 | Int32 lo = ftab[sb] & CLEARMASK; |
| 932 | Int32 hi = (ftab[sb+1] & CLEARMASK) - 1; |
| 933 | if (hi > lo) { |
| 934 | if (verb >= 4) |
| 935 | VPrintf4 ( " qsort [0x%x, 0x%x] " |
| 936 | "done %d this %d\n", |
| 937 | ss, j, numQSorted, hi - lo + 1 ); |
| 938 | mainQSort3 ( |
| 939 | ptr, block, quadrant, nblock, |
| 940 | lo, hi, BZ_N_RADIX, budget |
| 941 | ); |
| 942 | numQSorted += (hi - lo + 1); |
| 943 | if (*budget < 0) return; |
| 944 | } |
| 945 | } |
| 946 | ftab[sb] |= SETMASK; |
| 947 | } |
| 948 | } |
| 949 | |
| 950 | AssertH ( !bigDone[ss], 1006 ); |
| 951 | |
| 952 | /*-- |
| 953 | Step 2: |
| 954 | Now scan this big bucket [ss] so as to synthesise the |
| 955 | sorted order for small buckets [t, ss] for all t, |
| 956 | including, magically, the bucket [ss,ss] too. |
| 957 | This will avoid doing Real Work in subsequent Step 1's. |
| 958 | --*/ |
| 959 | { |
| 960 | for (j = 0; j <= 255; j++) { |
| 961 | copyStart[j] = ftab[(j << 8) + ss] & CLEARMASK; |
| 962 | copyEnd [j] = (ftab[(j << 8) + ss + 1] & CLEARMASK) - 1; |
| 963 | } |
| 964 | for (j = ftab[ss << 8] & CLEARMASK; j < copyStart[ss]; j++) { |
| 965 | k = ptr[j]-1; if (k < 0) k += nblock; |
| 966 | c1 = block[k]; |
| 967 | if (!bigDone[c1]) |
| 968 | ptr[ copyStart[c1]++ ] = k; |
| 969 | } |
| 970 | for (j = (ftab[(ss+1) << 8] & CLEARMASK) - 1; j > copyEnd[ss]; j--) { |
| 971 | k = ptr[j]-1; if (k < 0) k += nblock; |
| 972 | c1 = block[k]; |
| 973 | if (!bigDone[c1]) |
| 974 | ptr[ copyEnd[c1]-- ] = k; |
| 975 | } |
| 976 | } |
| 977 | |
| 978 | AssertH ( (copyStart[ss]-1 == copyEnd[ss]) |
| 979 | || |
| 980 | /* Extremely rare case missing in bzip2-1.0.0 and 1.0.1. |
| 981 | Necessity for this case is demonstrated by compressing |
| 982 | a sequence of approximately 48.5 million of character |
| 983 | 251; 1.0.0/1.0.1 will then die here. */ |
| 984 | (copyStart[ss] == 0 && copyEnd[ss] == nblock-1), |
| 985 | 1007 ) |
| 986 | |
| 987 | for (j = 0; j <= 255; j++) ftab[(j << 8) + ss] |= SETMASK; |
| 988 | |
| 989 | /*-- |
| 990 | Step 3: |
| 991 | The [ss] big bucket is now done. Record this fact, |
| 992 | and update the quadrant descriptors. Remember to |
| 993 | update quadrants in the overshoot area too, if |
| 994 | necessary. The "if (i < 255)" test merely skips |
| 995 | this updating for the last bucket processed, since |
| 996 | updating for the last bucket is pointless. |
| 997 | |
| 998 | The quadrant array provides a way to incrementally |
| 999 | cache sort orderings, as they appear, so as to |
| 1000 | make subsequent comparisons in fullGtU() complete |
| 1001 | faster. For repetitive blocks this makes a big |
| 1002 | difference (but not big enough to be able to avoid |
| 1003 | the fallback sorting mechanism, exponential radix sort). |
| 1004 | |
| 1005 | The precise meaning is: at all times: |
| 1006 | |
| 1007 | for 0 <= i < nblock and 0 <= j <= nblock |
| 1008 | |
| 1009 | if block[i] != block[j], |
| 1010 | |
| 1011 | then the relative values of quadrant[i] and |
| 1012 | quadrant[j] are meaningless. |
| 1013 | |
| 1014 | else { |
| 1015 | if quadrant[i] < quadrant[j] |
| 1016 | then the string starting at i lexicographically |
| 1017 | precedes the string starting at j |
| 1018 | |
| 1019 | else if quadrant[i] > quadrant[j] |
| 1020 | then the string starting at j lexicographically |
| 1021 | precedes the string starting at i |
| 1022 | |
| 1023 | else |
| 1024 | the relative ordering of the strings starting |
| 1025 | at i and j has not yet been determined. |
| 1026 | } |
| 1027 | --*/ |
| 1028 | bigDone[ss] = True; |
| 1029 | |
| 1030 | if (i < 255) { |
| 1031 | Int32 bbStart = ftab[ss << 8] & CLEARMASK; |
| 1032 | Int32 bbSize = (ftab[(ss+1) << 8] & CLEARMASK) - bbStart; |
| 1033 | Int32 shifts = 0; |
| 1034 | |
| 1035 | while ((bbSize >> shifts) > 65534) shifts++; |
| 1036 | |
| 1037 | for (j = bbSize-1; j >= 0; j--) { |
| 1038 | Int32 a2update = ptr[bbStart + j]; |
| 1039 | UInt16 qVal = (UInt16)(j >> shifts); |
| 1040 | quadrant[a2update] = qVal; |
| 1041 | if (a2update < BZ_N_OVERSHOOT) |
| 1042 | quadrant[a2update + nblock] = qVal; |
| 1043 | } |
| 1044 | AssertH ( ((bbSize-1) >> shifts) <= 65535, 1002 ); |
| 1045 | } |
| 1046 | |
| 1047 | } |
| 1048 | |
| 1049 | if (verb >= 4) |
| 1050 | VPrintf3 ( " %d pointers, %d sorted, %d scanned\n", |
| 1051 | nblock, numQSorted, nblock - numQSorted ); |
| 1052 | } |
| 1053 | |
| 1054 | #undef BIGFREQ |
| 1055 | #undef SETMASK |
| 1056 | #undef CLEARMASK |
| 1057 | |
| 1058 | |
| 1059 | /*---------------------------------------------*/ |
| 1060 | /* Pre: |
| 1061 | nblock > 0 |
| 1062 | arr2 exists for [0 .. nblock-1 +N_OVERSHOOT] |
| 1063 | ((UChar*)arr2) [0 .. nblock-1] holds block |
| 1064 | arr1 exists for [0 .. nblock-1] |
| 1065 | |
| 1066 | Post: |
| 1067 | ((UChar*)arr2) [0 .. nblock-1] holds block |
| 1068 | All other areas of block destroyed |
| 1069 | ftab [ 0 .. 65536 ] destroyed |
| 1070 | arr1 [0 .. nblock-1] holds sorted order |
| 1071 | */ |
| 1072 | void BZ2_blockSort ( EState* s ) |
| 1073 | { |
| 1074 | UInt32* ptr = s->ptr; |
| 1075 | UChar* block = s->block; |
| 1076 | UInt32* ftab = s->ftab; |
| 1077 | Int32 nblock = s->nblock; |
| 1078 | Int32 verb = s->verbosity; |
| 1079 | Int32 wfact = s->workFactor; |
| 1080 | UInt16* quadrant; |
| 1081 | Int32 budget; |
| 1082 | Int32 budgetInit; |
| 1083 | Int32 i; |
| 1084 | |
| 1085 | if (nblock < 10000) { |
| 1086 | fallbackSort ( s->arr1, s->arr2, ftab, nblock, verb ); |
| 1087 | } else { |
| 1088 | /* Calculate the location for quadrant, remembering to get |
| 1089 | the alignment right. Assumes that &(block[0]) is at least |
| 1090 | 2-byte aligned -- this should be ok since block is really |
| 1091 | the first section of arr2. |
| 1092 | */ |
| 1093 | i = nblock+BZ_N_OVERSHOOT; |
| 1094 | if (i & 1) i++; |
| 1095 | quadrant = (UInt16*)(&(block[i])); |
| 1096 | |
| 1097 | /* (wfact-1) / 3 puts the default-factor-30 |
| 1098 | transition point at very roughly the same place as |
| 1099 | with v0.1 and v0.9.0. |
| 1100 | Not that it particularly matters any more, since the |
| 1101 | resulting compressed stream is now the same regardless |
| 1102 | of whether or not we use the main sort or fallback sort. |
| 1103 | */ |
| 1104 | if (wfact < 1 ) wfact = 1; |
| 1105 | if (wfact > 100) wfact = 100; |
| 1106 | budgetInit = nblock * ((wfact-1) / 3); |
| 1107 | budget = budgetInit; |
| 1108 | |
| 1109 | mainSort ( ptr, block, quadrant, ftab, nblock, verb, &budget ); |
| 1110 | if (verb >= 3) |
| 1111 | VPrintf3 ( " %d work, %d block, ratio %5.2f\n", |
| 1112 | budgetInit - budget, |
| 1113 | nblock, |
| 1114 | (float)(budgetInit - budget) / |
| 1115 | (float)(nblock==0 ? 1 : nblock) ); |
| 1116 | if (budget < 0) { |
| 1117 | if (verb >= 2) |
| 1118 | VPrintf0 ( " too repetitive; using fallback" |
| 1119 | " sorting algorithm\n" ); |
| 1120 | fallbackSort ( s->arr1, s->arr2, ftab, nblock, verb ); |
| 1121 | } |
| 1122 | } |
| 1123 | |
| 1124 | s->origPtr = -1; |
| 1125 | for (i = 0; i < s->nblock; i++) |
| 1126 | if (ptr[i] == 0) |
| 1127 | { s->origPtr = i; break; }; |
| 1128 | |
| 1129 | AssertH( s->origPtr != -1, 1003 ); |
| 1130 | } |
| 1131 | |
| 1132 | |
| 1133 | /*-------------------------------------------------------------*/ |
| 1134 | /*--- end blocksort.c ---*/ |
| 1135 | /*-------------------------------------------------------------*/ |