1219354Spjd/* 2219354Spjd * Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp@schmorp.de> 3219354Spjd * 4219354Spjd * Redistribution and use in source and binary forms, with or without modifica- 5219354Spjd * tion, are permitted provided that the following conditions are met: 6219354Spjd * 7219354Spjd * 1. Redistributions of source code must retain the above copyright notice, 8219354Spjd * this list of conditions and the following disclaimer. 9219354Spjd * 10219354Spjd * 2. Redistributions in binary form must reproduce the above copyright 11219354Spjd * notice, this list of conditions and the following disclaimer in the 12219354Spjd * documentation and/or other materials provided with the distribution. 13219354Spjd * 14219354Spjd * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 15219354Spjd * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- 16219354Spjd * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 17219354Spjd * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- 18219354Spjd * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19219354Spjd * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 20219354Spjd * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 21219354Spjd * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- 22219354Spjd * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 23219354Spjd * OF THE POSSIBILITY OF SUCH DAMAGE. 24219354Spjd * 25219354Spjd * Alternatively, the contents of this file may be used under the terms of 26219354Spjd * the GNU General Public License ("GPL") version 2 or any later version, 27219354Spjd * in which case the provisions of the GPL are applicable instead of 28219354Spjd * the above. If you wish to allow the use of your version of this file 29219354Spjd * only under the terms of the GPL and not to allow others to use your 30219354Spjd * version of this file under the BSD license, indicate your decision 31219354Spjd * by deleting the provisions above and replace them with the notice 32219354Spjd * and other provisions required by the GPL. If you do not delete the 33219354Spjd * provisions above, a recipient may use your version of this file under 34219354Spjd * either the BSD or the GPL. 35219354Spjd */ 36219354Spjd 37219354Spjd#include "lzf.h" 38219354Spjd 39219354Spjd#define HSIZE (1 << (HLOG)) 40219354Spjd 41219354Spjd/* 42219354Spjd * don't play with this unless you benchmark! 43219354Spjd * decompression is not dependent on the hash function 44219354Spjd * the hashing function might seem strange, just believe me 45219354Spjd * it works ;) 46219354Spjd */ 47219354Spjd#ifndef FRST 48219354Spjd# define FRST(p) (((p[0]) << 8) | p[1]) 49219354Spjd# define NEXT(v,p) (((v) << 8) | p[2]) 50219354Spjd# if ULTRA_FAST 51219354Spjd# define IDX(h) ((( h >> (3*8 - HLOG)) - h ) & (HSIZE - 1)) 52219354Spjd# elif VERY_FAST 53219354Spjd# define IDX(h) ((( h >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) 54219354Spjd# else 55219354Spjd# define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) 56219354Spjd# endif 57219354Spjd#endif 58219354Spjd/* 59219354Spjd * IDX works because it is very similar to a multiplicative hash, e.g. 60219354Spjd * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) 61219354Spjd * the latter is also quite fast on newer CPUs, and compresses similarly. 62219354Spjd * 63219354Spjd * the next one is also quite good, albeit slow ;) 64219354Spjd * (int)(cos(h & 0xffffff) * 1e6) 65219354Spjd */ 66219354Spjd 67219354Spjd#if 0 68219354Spjd/* original lzv-like hash function, much worse and thus slower */ 69219354Spjd# define FRST(p) (p[0] << 5) ^ p[1] 70219354Spjd# define NEXT(v,p) ((v) << 5) ^ p[2] 71219354Spjd# define IDX(h) ((h) & (HSIZE - 1)) 72219354Spjd#endif 73219354Spjd 74219354Spjd#define MAX_LIT (1 << 5) 75219354Spjd#define MAX_OFF (1 << 13) 76219354Spjd#define MAX_REF ((1 << 8) + (1 << 3)) 77219354Spjd 78219354Spjd#if __GNUC__ >= 3 79219354Spjd# define expect(expr,value) __builtin_expect ((expr),(value)) 80219354Spjd# define inline inline 81219354Spjd#else 82219354Spjd# define expect(expr,value) (expr) 83219354Spjd# define inline static 84219354Spjd#endif 85219354Spjd 86219354Spjd#define expect_false(expr) expect ((expr) != 0, 0) 87219354Spjd#define expect_true(expr) expect ((expr) != 0, 1) 88219354Spjd 89219354Spjd/* 90219354Spjd * compressed format 91219354Spjd * 92219354Spjd * 000LLLLL <L+1> ; literal 93219354Spjd * LLLooooo oooooooo ; backref L 94219354Spjd * 111ooooo LLLLLLLL oooooooo ; backref L+7 95219354Spjd * 96219354Spjd */ 97219354Spjd 98219354Spjdunsigned int 99219354Spjdlzf_compress (const void *const in_data, unsigned int in_len, 100219354Spjd void *out_data, unsigned int out_len 101219354Spjd#if LZF_STATE_ARG 102219354Spjd , LZF_STATE htab 103219354Spjd#endif 104219354Spjd ) 105219354Spjd{ 106219354Spjd#if !LZF_STATE_ARG 107219354Spjd LZF_STATE htab; 108219354Spjd#endif 109219354Spjd const u8 **hslot; 110219354Spjd const u8 *ip = (const u8 *)in_data; 111219354Spjd u8 *op = (u8 *)out_data; 112219354Spjd const u8 *in_end = ip + in_len; 113219354Spjd u8 *out_end = op + out_len; 114219354Spjd const u8 *ref; 115219354Spjd 116219354Spjd /* off requires a type wide enough to hold a general pointer difference. 117219354Spjd * ISO C doesn't have that (size_t might not be enough and ptrdiff_t only 118219354Spjd * works for differences within a single object). We also assume that no 119219354Spjd * no bit pattern traps. Since the only platform that is both non-POSIX 120219354Spjd * and fails to support both assumptions is windows 64 bit, we make a 121219354Spjd * special workaround for it. 122219354Spjd */ 123219354Spjd#if defined (WIN32) && defined (_M_X64) 124219354Spjd unsigned _int64 off; /* workaround for missing POSIX compliance */ 125219354Spjd#else 126219354Spjd unsigned long off; 127219354Spjd#endif 128219354Spjd unsigned int hval; 129219354Spjd int lit; 130219354Spjd 131219354Spjd if (!in_len || !out_len) 132219354Spjd return 0; 133219354Spjd 134219354Spjd#if INIT_HTAB 135219354Spjd memset (htab, 0, sizeof (htab)); 136219354Spjd# if 0 137219354Spjd for (hslot = htab; hslot < htab + HSIZE; hslot++) 138219354Spjd *hslot++ = ip; 139219354Spjd# endif 140219354Spjd#endif 141219354Spjd 142219354Spjd lit = 0; op++; /* start run */ 143219354Spjd 144219354Spjd hval = FRST (ip); 145219354Spjd while (ip < in_end - 2) 146219354Spjd { 147219354Spjd hval = NEXT (hval, ip); 148219354Spjd hslot = htab + IDX (hval); 149219354Spjd ref = *hslot; *hslot = ip; 150219354Spjd 151219354Spjd if (1 152219354Spjd#if INIT_HTAB 153219354Spjd && ref < ip /* the next test will actually take care of this, but this is faster */ 154219354Spjd#endif 155219354Spjd && (off = ip - ref - 1) < MAX_OFF 156219354Spjd && ip + 4 < in_end 157219354Spjd && ref > (const u8 *)in_data 158219354Spjd#if STRICT_ALIGN 159219354Spjd && ref[0] == ip[0] 160219354Spjd && ref[1] == ip[1] 161219354Spjd && ref[2] == ip[2] 162219354Spjd#else 163219354Spjd && *(const u16 *)ref == *(const u16 *)ip 164219354Spjd && ref[2] == ip[2] 165219354Spjd#endif 166219354Spjd ) 167219354Spjd { 168219354Spjd /* match found at *ref++ */ 169219354Spjd unsigned int len = 2; 170219354Spjd unsigned int maxlen = in_end - ip - len; 171219354Spjd maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; 172219354Spjd 173219354Spjd if (expect_false (op + 3 + 1 >= out_end)) /* first a faster conservative test */ 174219354Spjd if (op - !lit + 3 + 1 >= out_end) /* second the exact but rare test */ 175219354Spjd return 0; 176219354Spjd 177219354Spjd op [- lit - 1] = lit - 1; /* stop run */ 178219354Spjd op -= !lit; /* undo run if length is zero */ 179219354Spjd 180219354Spjd for (;;) 181219354Spjd { 182219354Spjd if (expect_true (maxlen > 16)) 183219354Spjd { 184219354Spjd len++; if (ref [len] != ip [len]) break; 185219354Spjd len++; if (ref [len] != ip [len]) break; 186219354Spjd len++; if (ref [len] != ip [len]) break; 187219354Spjd len++; if (ref [len] != ip [len]) break; 188219354Spjd 189219354Spjd len++; if (ref [len] != ip [len]) break; 190219354Spjd len++; if (ref [len] != ip [len]) break; 191219354Spjd len++; if (ref [len] != ip [len]) break; 192219354Spjd len++; if (ref [len] != ip [len]) break; 193219354Spjd 194219354Spjd len++; if (ref [len] != ip [len]) break; 195219354Spjd len++; if (ref [len] != ip [len]) break; 196219354Spjd len++; if (ref [len] != ip [len]) break; 197219354Spjd len++; if (ref [len] != ip [len]) break; 198219354Spjd 199219354Spjd len++; if (ref [len] != ip [len]) break; 200219354Spjd len++; if (ref [len] != ip [len]) break; 201219354Spjd len++; if (ref [len] != ip [len]) break; 202219354Spjd len++; if (ref [len] != ip [len]) break; 203219354Spjd } 204219354Spjd 205219354Spjd do 206219354Spjd len++; 207219354Spjd while (len < maxlen && ref[len] == ip[len]); 208219354Spjd 209219354Spjd break; 210219354Spjd } 211219354Spjd 212219354Spjd len -= 2; /* len is now #octets - 1 */ 213219354Spjd ip++; 214219354Spjd 215219354Spjd if (len < 7) 216219354Spjd { 217219354Spjd *op++ = (off >> 8) + (len << 5); 218219354Spjd } 219219354Spjd else 220219354Spjd { 221219354Spjd *op++ = (off >> 8) + ( 7 << 5); 222219354Spjd *op++ = len - 7; 223219354Spjd } 224219354Spjd 225219354Spjd *op++ = off; 226219354Spjd lit = 0; op++; /* start run */ 227219354Spjd 228219354Spjd ip += len + 1; 229219354Spjd 230219354Spjd if (expect_false (ip >= in_end - 2)) 231219354Spjd break; 232219354Spjd 233219354Spjd#if ULTRA_FAST || VERY_FAST 234219354Spjd --ip; 235219354Spjd# if VERY_FAST && !ULTRA_FAST 236219354Spjd --ip; 237219354Spjd# endif 238219354Spjd hval = FRST (ip); 239219354Spjd 240219354Spjd hval = NEXT (hval, ip); 241219354Spjd htab[IDX (hval)] = ip; 242219354Spjd ip++; 243219354Spjd 244219354Spjd# if VERY_FAST && !ULTRA_FAST 245219354Spjd hval = NEXT (hval, ip); 246219354Spjd htab[IDX (hval)] = ip; 247219354Spjd ip++; 248219354Spjd# endif 249219354Spjd#else 250219354Spjd ip -= len + 1; 251219354Spjd 252219354Spjd do 253219354Spjd { 254219354Spjd hval = NEXT (hval, ip); 255219354Spjd htab[IDX (hval)] = ip; 256219354Spjd ip++; 257219354Spjd } 258219354Spjd while (len--); 259219354Spjd#endif 260219354Spjd } 261219354Spjd else 262219354Spjd { 263219354Spjd /* one more literal byte we must copy */ 264219354Spjd if (expect_false (op >= out_end)) 265219354Spjd return 0; 266219354Spjd 267219354Spjd lit++; *op++ = *ip++; 268219354Spjd 269219354Spjd if (expect_false (lit == MAX_LIT)) 270219354Spjd { 271219354Spjd op [- lit - 1] = lit - 1; /* stop run */ 272219354Spjd lit = 0; op++; /* start run */ 273219354Spjd } 274219354Spjd } 275219354Spjd } 276219354Spjd 277219354Spjd if (op + 3 > out_end) /* at most 3 bytes can be missing here */ 278219354Spjd return 0; 279219354Spjd 280219354Spjd while (ip < in_end) 281219354Spjd { 282219354Spjd lit++; *op++ = *ip++; 283219354Spjd 284219354Spjd if (expect_false (lit == MAX_LIT)) 285219354Spjd { 286219354Spjd op [- lit - 1] = lit - 1; /* stop run */ 287219354Spjd lit = 0; op++; /* start run */ 288219354Spjd } 289219354Spjd } 290219354Spjd 291219354Spjd op [- lit - 1] = lit - 1; /* end run */ 292219354Spjd op -= !lit; /* undo run if length is zero */ 293219354Spjd 294219354Spjd return op - (u8 *)out_data; 295219354Spjd} 296219354Spjd 297219354Spjd#if AVOID_ERRNO 298219354Spjd# define SET_ERRNO(n) 299219354Spjd#else 300219354Spjd# include <errno.h> 301219354Spjd# define SET_ERRNO(n) errno = (n) 302219354Spjd#endif 303219354Spjd 304219354Spjd#if (__i386 || __amd64) && __GNUC__ >= 3 305219354Spjd# define lzf_movsb(dst, src, len) \ 306219354Spjd asm ("rep movsb" \ 307219354Spjd : "=D" (dst), "=S" (src), "=c" (len) \ 308219354Spjd : "0" (dst), "1" (src), "2" (len)); 309219354Spjd#endif 310219354Spjd 311219354Spjdunsigned int 312219354Spjdlzf_decompress (const void *const in_data, unsigned int in_len, 313219354Spjd void *out_data, unsigned int out_len) 314219354Spjd{ 315219354Spjd u8 const *ip = (const u8 *)in_data; 316219354Spjd u8 *op = (u8 *)out_data; 317219354Spjd u8 const *const in_end = ip + in_len; 318219354Spjd u8 *const out_end = op + out_len; 319219354Spjd 320219354Spjd do 321219354Spjd { 322219354Spjd unsigned int ctrl = *ip++; 323219354Spjd 324219354Spjd if (ctrl < (1 << 5)) /* literal run */ 325219354Spjd { 326219354Spjd ctrl++; 327219354Spjd 328219354Spjd if (op + ctrl > out_end) 329219354Spjd { 330219354Spjd SET_ERRNO (E2BIG); 331219354Spjd return 0; 332219354Spjd } 333219354Spjd 334219354Spjd#if CHECK_INPUT 335219354Spjd if (ip + ctrl > in_end) 336219354Spjd { 337219354Spjd SET_ERRNO (EINVAL); 338219354Spjd return 0; 339219354Spjd } 340219354Spjd#endif 341219354Spjd 342219354Spjd#ifdef lzf_movsb 343219354Spjd lzf_movsb (op, ip, ctrl); 344219354Spjd#else 345219354Spjd do 346219354Spjd *op++ = *ip++; 347219354Spjd while (--ctrl); 348219354Spjd#endif 349219354Spjd } 350219354Spjd else /* back reference */ 351219354Spjd { 352219354Spjd unsigned int len = ctrl >> 5; 353219354Spjd 354219354Spjd u8 *ref = op - ((ctrl & 0x1f) << 8) - 1; 355219354Spjd 356219354Spjd#if CHECK_INPUT 357219354Spjd if (ip >= in_end) 358219354Spjd { 359219354Spjd SET_ERRNO (EINVAL); 360219354Spjd return 0; 361219354Spjd } 362219354Spjd#endif 363219354Spjd if (len == 7) 364219354Spjd { 365219354Spjd len += *ip++; 366219354Spjd#if CHECK_INPUT 367219354Spjd if (ip >= in_end) 368219354Spjd { 369219354Spjd SET_ERRNO (EINVAL); 370219354Spjd return 0; 371219354Spjd } 372219354Spjd#endif 373219354Spjd } 374219354Spjd 375219354Spjd ref -= *ip++; 376219354Spjd 377219354Spjd if (op + len + 2 > out_end) 378219354Spjd { 379219354Spjd SET_ERRNO (E2BIG); 380219354Spjd return 0; 381219354Spjd } 382219354Spjd 383219354Spjd if (ref < (u8 *)out_data) 384219354Spjd { 385219354Spjd SET_ERRNO (EINVAL); 386219354Spjd return 0; 387219354Spjd } 388219354Spjd 389219354Spjd#ifdef lzf_movsb 390219354Spjd len += 2; 391219354Spjd lzf_movsb (op, ref, len); 392219354Spjd#else 393219354Spjd *op++ = *ref++; 394219354Spjd *op++ = *ref++; 395219354Spjd 396219354Spjd do 397219354Spjd *op++ = *ref++; 398219354Spjd while (--len); 399219354Spjd#endif 400219354Spjd } 401219354Spjd } 402219354Spjd while (ip < in_end); 403219354Spjd 404219354Spjd return op - (u8 *)out_data; 405219354Spjd} 406219354Spjd 407