Line data Source code
1 : /*
2 : LZ4 - Fast LZ compression algorithm
3 : Copyright (C) 2011-2014, Yann Collet.
4 : BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
5 :
6 : Redistribution and use in source and binary forms, with or without
7 : modification, are permitted provided that the following conditions are
8 : met:
9 :
10 : * Redistributions of source code must retain the above copyright
11 : notice, this list of conditions and the following disclaimer.
12 : * Redistributions in binary form must reproduce the above
13 : copyright notice, this list of conditions and the following disclaimer
14 : in the documentation and/or other materials provided with the
15 : distribution.
16 :
17 : THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 : "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 : LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 : A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 : OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 : SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 : LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 : DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 : THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 : (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 : OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 :
29 : You can contact the author at :
30 : - LZ4 source repository : http://code.google.com/p/lz4/
31 : - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
32 : */
33 :
34 : /**************************************
35 : Tuning parameters
36 : **************************************/
37 : /*
38 : * HEAPMODE :
39 : * Select how default compression functions will allocate memory for their hash table,
40 : * in memory stack (0:default, fastest), or in memory heap (1:requires memory allocation (malloc)).
41 : */
42 : #define HEAPMODE 0
43 :
44 :
45 : /**************************************
46 : CPU Feature Detection
47 : **************************************/
48 : /* 32 or 64 bits ? */
49 : #if (defined(__x86_64__) || defined(_M_X64) || defined(_WIN64) \
50 : || defined(__powerpc64__) || defined(__powerpc64le__) \
51 : || defined(__ppc64__) || defined(__ppc64le__) \
52 : || defined(__PPC64__) || defined(__PPC64LE__) \
53 : || defined(__ia64) || defined(__itanium__) || defined(_M_IA64) \
54 : || (defined(__mips64) && defined(_ABI64))) /* Detects 64 bits mode */
55 : # define LZ4_ARCH64 1
56 : #else
57 : # define LZ4_ARCH64 0
58 : #endif
59 :
60 : /*
61 : * Little Endian or Big Endian ?
62 : * Overwrite the #define below if you know your architecture endianess
63 : */
64 : #include <stdlib.h> /* Apparently required to detect endianess */
65 : #if defined (__GLIBC__)
66 : # include <endian.h>
67 : # if (__BYTE_ORDER == __BIG_ENDIAN)
68 : # define LZ4_BIG_ENDIAN 1
69 : # endif
70 : #elif (defined(__BIG_ENDIAN__) || defined(__BIG_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(__LITTLE_ENDIAN__) || defined(__LITTLE_ENDIAN) || defined(_LITTLE_ENDIAN))
71 : # define LZ4_BIG_ENDIAN 1
72 : #elif defined(__sparc) || defined(__sparc__) \
73 : || defined(__powerpc__) || defined(__ppc__) || defined(__PPC__) \
74 : || defined(__hpux) || defined(__hppa) \
75 : || defined(_MIPSEB) || defined(__s390__)
76 : # define LZ4_BIG_ENDIAN 1
77 : #else
78 : /* Little Endian assumed. PDP Endian and other very rare endian format are unsupported. */
79 : #endif
80 :
81 : /*
82 : * Unaligned memory access is automatically enabled for "common" CPU, such as x86.
83 : * For others CPU, such as ARM, the compiler may be more cautious, inserting unnecessary extra code to ensure aligned access property
84 : * If you know your target CPU supports unaligned memory access, you want to force this option manually to improve performance
85 : */
86 : #if defined(__ARM_FEATURE_UNALIGNED)
87 : # define LZ4_FORCE_UNALIGNED_ACCESS 1
88 : #endif
89 :
90 : /* Define this parameter if your target system or compiler does not support hardware bit count */
91 : #if defined(_MSC_VER) && defined(_WIN32_WCE) /* Visual Studio for Windows CE does not support Hardware bit count */
92 : # define LZ4_FORCE_SW_BITCOUNT
93 : #endif
94 :
95 : /*
96 : * BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE :
97 : * This option may provide a small boost to performance for some big endian cpu, although probably modest.
98 : * You may set this option to 1 if data will remain within closed environment.
99 : * This option is useless on Little_Endian CPU (such as x86)
100 : */
101 :
102 : /* #define BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE 1 */
103 :
104 :
105 : /**************************************
106 : Compiler Options
107 : **************************************/
108 : #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */
109 : /* "restrict" is a known keyword */
110 : #else
111 : # define restrict /* Disable restrict */
112 : #endif
113 :
114 : #ifdef _MSC_VER /* Visual Studio */
115 : # define FORCE_INLINE static __forceinline
116 : # include <intrin.h> /* For Visual 2005 */
117 : # if LZ4_ARCH64 /* 64-bits */
118 : # pragma intrinsic(_BitScanForward64) /* For Visual 2005 */
119 : # pragma intrinsic(_BitScanReverse64) /* For Visual 2005 */
120 : # else /* 32-bits */
121 : # pragma intrinsic(_BitScanForward) /* For Visual 2005 */
122 : # pragma intrinsic(_BitScanReverse) /* For Visual 2005 */
123 : # endif
124 : # pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
125 : #else
126 : # ifdef __GNUC__
127 : # define FORCE_INLINE static inline __attribute__((always_inline))
128 : # else
129 : # define FORCE_INLINE static inline
130 : # endif
131 : #endif
132 :
133 : #ifdef _MSC_VER /* Visual Studio */
134 : # define lz4_bswap16(x) _byteswap_ushort(x)
135 : #else
136 : # define lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))
137 : #endif
138 :
139 : #define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
140 :
141 : #if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
142 : # define expect(expr,value) (__builtin_expect ((expr),(value)) )
143 : #else
144 : # define expect(expr,value) (expr)
145 : #endif
146 :
147 : #define likely(expr) expect((expr) != 0, 1)
148 : #define unlikely(expr) expect((expr) != 0, 0)
149 :
150 :
151 : /**************************************
152 : Memory routines
153 : **************************************/
154 : #include <stdlib.h> /* malloc, calloc, free */
155 : #define ALLOCATOR(n,s) calloc(n,s)
156 : #define FREEMEM free
157 : #include <string.h> /* memset, memcpy */
158 : #define MEM_INIT memset
159 :
160 :
161 : /**************************************
162 : Includes
163 : **************************************/
164 : #include "lz4.h"
165 :
166 :
167 : /**************************************
168 : Basic Types
169 : **************************************/
170 : #if defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */
171 : # include <stdint.h>
172 : typedef uint8_t BYTE;
173 : typedef uint16_t U16;
174 : typedef uint32_t U32;
175 : typedef int32_t S32;
176 : typedef uint64_t U64;
177 : #else
178 : typedef unsigned char BYTE;
179 : typedef unsigned short U16;
180 : typedef unsigned int U32;
181 : typedef signed int S32;
182 : typedef unsigned long long U64;
183 : #endif
184 :
185 : #if defined(__GNUC__) && !defined(LZ4_FORCE_UNALIGNED_ACCESS)
186 : # define _PACKED __attribute__ ((packed))
187 : #else
188 : # define _PACKED
189 : #endif
190 :
191 : #if !defined(LZ4_FORCE_UNALIGNED_ACCESS) && !defined(__GNUC__)
192 : # if defined(__IBMC__) || defined(__SUNPRO_C) || defined(__SUNPRO_CC)
193 : # pragma pack(1)
194 : # else
195 : # pragma pack(push, 1)
196 : # endif
197 : #endif
198 :
199 : typedef struct { U16 v; } _PACKED U16_S;
200 : typedef struct { U32 v; } _PACKED U32_S;
201 : typedef struct { U64 v; } _PACKED U64_S;
202 : typedef struct {size_t v;} _PACKED size_t_S;
203 :
204 : #if !defined(LZ4_FORCE_UNALIGNED_ACCESS) && !defined(__GNUC__)
205 : # if defined(__SUNPRO_C) || defined(__SUNPRO_CC)
206 : # pragma pack(0)
207 : # else
208 : # pragma pack(pop)
209 : # endif
210 : #endif
211 :
212 : #define A16(x) (((U16_S *)(x))->v)
213 : #define A32(x) (((U32_S *)(x))->v)
214 : #define A64(x) (((U64_S *)(x))->v)
215 : #define AARCH(x) (((size_t_S *)(x))->v)
216 :
217 :
218 : /**************************************
219 : Constants
220 : **************************************/
221 : #define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2)
222 : #define HASHTABLESIZE (1 << LZ4_MEMORY_USAGE)
223 : #define HASH_SIZE_U32 (1 << LZ4_HASHLOG)
224 :
225 : #define MINMATCH 4
226 :
227 : #define COPYLENGTH 8
228 : #define LASTLITERALS 5
229 : #define MFLIMIT (COPYLENGTH+MINMATCH)
230 : static const int LZ4_minLength = (MFLIMIT+1);
231 :
232 : #define KB *(1U<<10)
233 : #define MB *(1U<<20)
234 : #define GB *(1U<<30)
235 :
236 : #define LZ4_64KLIMIT ((64 KB) + (MFLIMIT-1))
237 : #define SKIPSTRENGTH 6 /* Increasing this value will make the compression run slower on incompressible data */
238 :
239 : #define MAXD_LOG 16
240 : #define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
241 :
242 : #define ML_BITS 4
243 : #define ML_MASK ((1U<<ML_BITS)-1)
244 : #define RUN_BITS (8-ML_BITS)
245 : #define RUN_MASK ((1U<<RUN_BITS)-1)
246 :
247 :
248 : /**************************************
249 : Structures and local types
250 : **************************************/
251 : typedef struct {
252 : U32 hashTable[HASH_SIZE_U32];
253 : U32 currentOffset;
254 : U32 initCheck;
255 : const BYTE* dictionary;
256 : const BYTE* bufferStart;
257 : U32 dictSize;
258 : } LZ4_stream_t_internal;
259 :
260 : typedef enum { notLimited = 0, limitedOutput = 1 } limitedOutput_directive;
261 : typedef enum { byPtr, byU32, byU16 } tableType_t;
262 :
263 : typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
264 : typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
265 :
266 : typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
267 : typedef enum { full = 0, partial = 1 } earlyEnd_directive;
268 :
269 :
270 : /**************************************
271 : Architecture-specific macros
272 : **************************************/
273 : #define STEPSIZE sizeof(size_t)
274 : #define LZ4_COPYSTEP(d,s) { AARCH(d) = AARCH(s); d+=STEPSIZE; s+=STEPSIZE; }
275 : #define LZ4_COPY8(d,s) { LZ4_COPYSTEP(d,s); if (STEPSIZE<8) LZ4_COPYSTEP(d,s); }
276 :
277 : #if (defined(LZ4_BIG_ENDIAN) && !defined(BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE))
278 : # define LZ4_READ_LITTLEENDIAN_16(d,s,p) { U16 v = A16(p); v = lz4_bswap16(v); d = (s) - v; }
279 : # define LZ4_WRITE_LITTLEENDIAN_16(p,i) { U16 v = (U16)(i); v = lz4_bswap16(v); A16(p) = v; p+=2; }
280 : #else /* Little Endian */
281 : # define LZ4_READ_LITTLEENDIAN_16(d,s,p) { d = (s) - A16(p); }
282 : # define LZ4_WRITE_LITTLEENDIAN_16(p,v) { A16(p) = v; p+=2; }
283 : #endif
284 :
285 :
286 : /**************************************
287 : Macros
288 : **************************************/
289 : #define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1/(!!(c)) }; } /* use only *after* variable declarations */
290 : #if LZ4_ARCH64 || !defined(__GNUC__)
291 : # define LZ4_WILDCOPY(d,s,e) { do { LZ4_COPY8(d,s) } while (d<e); } /* at the end, d>=e; */
292 : #else
293 : # define LZ4_WILDCOPY(d,s,e) { if (likely(e-d <= 8)) LZ4_COPY8(d,s) else do { LZ4_COPY8(d,s) } while (d<e); }
294 : #endif
295 :
296 :
297 : /****************************
298 : Private local functions
299 : ****************************/
300 : #if LZ4_ARCH64
301 :
302 0 : int LZ4_NbCommonBytes (register U64 val)
303 : {
304 : # if defined(LZ4_BIG_ENDIAN)
305 : # if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
306 : unsigned long r = 0;
307 : _BitScanReverse64( &r, val );
308 : return (int)(r>>3);
309 : # elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
310 : return (__builtin_clzll(val) >> 3);
311 : # else
312 : int r;
313 : if (!(val>>32)) { r=4; } else { r=0; val>>=32; }
314 : if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
315 : r += (!val);
316 : return r;
317 : # endif
318 : # else
319 : # if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
320 : unsigned long r = 0;
321 : _BitScanForward64( &r, val );
322 : return (int)(r>>3);
323 : # elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
324 0 : return (__builtin_ctzll(val) >> 3);
325 : # else
326 : static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 };
327 : return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
328 : # endif
329 : # endif
330 : }
331 :
332 : #else
333 :
334 : int LZ4_NbCommonBytes (register U32 val)
335 : {
336 : # if defined(LZ4_BIG_ENDIAN)
337 : # if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
338 : unsigned long r = 0;
339 : _BitScanReverse( &r, val );
340 : return (int)(r>>3);
341 : # elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
342 : return (__builtin_clz(val) >> 3);
343 : # else
344 : int r;
345 : if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
346 : r += (!val);
347 : return r;
348 : # endif
349 : # else
350 : # if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
351 : unsigned long r;
352 : _BitScanForward( &r, val );
353 : return (int)(r>>3);
354 : # elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
355 : return (__builtin_ctz(val) >> 3);
356 : # else
357 : static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 };
358 : return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
359 : # endif
360 : # endif
361 : }
362 :
363 : #endif
364 :
365 :
366 : /********************************
367 : Compression functions
368 : ********************************/
369 0 : int LZ4_compressBound(int isize) { return LZ4_COMPRESSBOUND(isize); }
370 :
371 0 : static int LZ4_hashSequence(U32 sequence, tableType_t tableType)
372 : {
373 0 : if (tableType == byU16)
374 0 : return (((sequence) * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
375 : else
376 0 : return (((sequence) * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
377 : }
378 :
379 0 : static int LZ4_hashPosition(const BYTE* p, tableType_t tableType) { return LZ4_hashSequence(A32(p), tableType); }
380 :
381 0 : static void LZ4_putPositionOnHash(const BYTE* p, U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
382 : {
383 0 : switch (tableType)
384 : {
385 0 : case byPtr: { const BYTE** hashTable = (const BYTE**) tableBase; hashTable[h] = p; break; }
386 0 : case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = (U32)(p-srcBase); break; }
387 0 : case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = (U16)(p-srcBase); break; }
388 : }
389 0 : }
390 :
391 0 : static void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
392 : {
393 0 : U32 h = LZ4_hashPosition(p, tableType);
394 0 : LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
395 0 : }
396 :
397 0 : static const BYTE* LZ4_getPositionOnHash(U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
398 : {
399 0 : if (tableType == byPtr) { const BYTE** hashTable = (const BYTE**) tableBase; return hashTable[h]; }
400 0 : if (tableType == byU32) { U32* hashTable = (U32*) tableBase; return hashTable[h] + srcBase; }
401 0 : { U16* hashTable = (U16*) tableBase; return hashTable[h] + srcBase; } /* default, to ensure a return */
402 : }
403 :
404 0 : static const BYTE* LZ4_getPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
405 : {
406 0 : U32 h = LZ4_hashPosition(p, tableType);
407 0 : return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
408 : }
409 :
410 0 : static unsigned LZ4_count(const BYTE* pIn, const BYTE* pRef, const BYTE* pInLimit)
411 : {
412 0 : const BYTE* const pStart = pIn;
413 :
414 0 : while (likely(pIn<pInLimit-(STEPSIZE-1)))
415 : {
416 0 : size_t diff = AARCH(pRef) ^ AARCH(pIn);
417 0 : if (!diff) { pIn+=STEPSIZE; pRef+=STEPSIZE; continue; }
418 0 : pIn += LZ4_NbCommonBytes(diff);
419 0 : return (unsigned)(pIn - pStart);
420 : }
421 0 : if (sizeof(void*)==8) if ((pIn<(pInLimit-3)) && (A32(pRef) == A32(pIn))) { pIn+=4; pRef+=4; }
422 0 : if ((pIn<(pInLimit-1)) && (A16(pRef) == A16(pIn))) { pIn+=2; pRef+=2; }
423 0 : if ((pIn<pInLimit) && (*pRef == *pIn)) pIn++;
424 :
425 0 : return (unsigned)(pIn - pStart);
426 : }
427 :
428 :
429 0 : static int LZ4_compress_generic(
430 : void* ctx,
431 : const char* source,
432 : char* dest,
433 : int inputSize,
434 : int maxOutputSize,
435 :
436 : limitedOutput_directive outputLimited,
437 : tableType_t tableType,
438 : dict_directive dict,
439 : dictIssue_directive dictIssue)
440 : {
441 0 : LZ4_stream_t_internal* const dictPtr = (LZ4_stream_t_internal*)ctx;
442 :
443 0 : const BYTE* ip = (const BYTE*) source;
444 : const BYTE* base;
445 : const BYTE* lowLimit;
446 0 : const BYTE* const lowRefLimit = ip - dictPtr->dictSize;
447 0 : const BYTE* const dictionary = dictPtr->dictionary;
448 0 : const BYTE* const dictEnd = dictionary + dictPtr->dictSize;
449 0 : const size_t dictDelta = dictEnd - (const BYTE*)source;
450 0 : const BYTE* anchor = (const BYTE*) source;
451 0 : const BYTE* const iend = ip + inputSize;
452 0 : const BYTE* const mflimit = iend - MFLIMIT;
453 0 : const BYTE* const matchlimit = iend - LASTLITERALS;
454 :
455 0 : BYTE* op = (BYTE*) dest;
456 0 : BYTE* const olimit = op + maxOutputSize;
457 :
458 0 : const int skipStrength = SKIPSTRENGTH;
459 : U32 forwardH;
460 0 : size_t refDelta=0;
461 :
462 : /* Init conditions */
463 0 : if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size, too large (or negative) */
464 0 : switch(dict)
465 : {
466 : case noDict:
467 : default:
468 0 : base = (const BYTE*)source;
469 0 : lowLimit = (const BYTE*)source;
470 0 : break;
471 : case withPrefix64k:
472 0 : base = (const BYTE*)source - dictPtr->currentOffset;
473 0 : lowLimit = (const BYTE*)source - dictPtr->dictSize;
474 0 : break;
475 : case usingExtDict:
476 0 : base = (const BYTE*)source - dictPtr->currentOffset;
477 0 : lowLimit = (const BYTE*)source;
478 0 : break;
479 : }
480 0 : if ((tableType == byU16) && (inputSize>=(int)LZ4_64KLIMIT)) return 0; /* Size too large (not within 64K limit) */
481 0 : if (inputSize<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
482 :
483 : /* First Byte */
484 0 : LZ4_putPosition(ip, ctx, tableType, base);
485 0 : ip++; forwardH = LZ4_hashPosition(ip, tableType);
486 :
487 : /* Main Loop */
488 : for ( ; ; )
489 : {
490 : const BYTE* ref;
491 : BYTE* token;
492 : {
493 0 : const BYTE* forwardIp = ip;
494 0 : unsigned step=1;
495 0 : unsigned searchMatchNb = (1U << skipStrength);
496 :
497 : /* Find a match */
498 0 : do {
499 0 : U32 h = forwardH;
500 0 : ip = forwardIp;
501 0 : forwardIp += step;
502 0 : step = searchMatchNb++ >> skipStrength;
503 : //if (step>8) step=8; // required for valid forwardIp ; slows down uncompressible data a bit
504 :
505 0 : if (unlikely(forwardIp > mflimit)) goto _last_literals;
506 :
507 0 : ref = LZ4_getPositionOnHash(h, ctx, tableType, base);
508 0 : if (dict==usingExtDict)
509 : {
510 0 : if (ref<(const BYTE*)source)
511 : {
512 0 : refDelta = dictDelta;
513 0 : lowLimit = dictionary;
514 : }
515 : else
516 : {
517 0 : refDelta = 0;
518 0 : lowLimit = (const BYTE*)source;
519 : }
520 : }
521 0 : forwardH = LZ4_hashPosition(forwardIp, tableType);
522 0 : LZ4_putPositionOnHash(ip, h, ctx, tableType, base);
523 :
524 : } while ( ((dictIssue==dictSmall) ? (ref < lowRefLimit) : 0)
525 0 : || ((tableType==byU16) ? 0 : (ref + MAX_DISTANCE < ip))
526 0 : || (A32(ref+refDelta) != A32(ip)) );
527 : }
528 :
529 : /* Catch up */
530 0 : while ((ip>anchor) && (ref+refDelta > lowLimit) && (unlikely(ip[-1]==ref[refDelta-1]))) { ip--; ref--; }
531 :
532 : {
533 : /* Encode Literal length */
534 0 : unsigned litLength = (unsigned)(ip - anchor);
535 0 : token = op++;
536 0 : if ((outputLimited) && (unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit)))
537 0 : return 0; /* Check output limit */
538 0 : if (litLength>=RUN_MASK)
539 : {
540 0 : int len = (int)litLength-RUN_MASK;
541 0 : *token=(RUN_MASK<<ML_BITS);
542 0 : for(; len >= 255 ; len-=255) *op++ = 255;
543 0 : *op++ = (BYTE)len;
544 : }
545 0 : else *token = (BYTE)(litLength<<ML_BITS);
546 :
547 : /* Copy Literals */
548 0 : { BYTE* end = op+litLength; LZ4_WILDCOPY(op,anchor,end); op=end; }
549 : }
550 :
551 : _next_match:
552 : /* Encode Offset */
553 0 : LZ4_WRITE_LITTLEENDIAN_16(op, (U16)(ip-ref));
554 :
555 : /* Encode MatchLength */
556 : {
557 : unsigned matchLength;
558 :
559 0 : if ((dict==usingExtDict) && (lowLimit==dictionary))
560 : {
561 : const BYTE* limit;
562 0 : ref += refDelta;
563 0 : limit = ip + (dictEnd-ref);
564 0 : if (limit > matchlimit) limit = matchlimit;
565 0 : matchLength = LZ4_count(ip+MINMATCH, ref+MINMATCH, limit);
566 0 : ip += MINMATCH + matchLength;
567 0 : if (ip==limit)
568 : {
569 0 : unsigned more = LZ4_count(ip, (const BYTE*)source, matchlimit);
570 0 : matchLength += more;
571 0 : ip += more;
572 0 : }
573 : }
574 : else
575 : {
576 0 : matchLength = LZ4_count(ip+MINMATCH, ref+MINMATCH, matchlimit);
577 0 : ip += MINMATCH + matchLength;
578 : }
579 :
580 0 : if (matchLength>=ML_MASK)
581 : {
582 0 : if ((outputLimited) && (unlikely(op + (1 + LASTLITERALS) + (matchLength>>8) > olimit)))
583 0 : return 0; /* Check output limit */
584 0 : *token += ML_MASK;
585 0 : matchLength -= ML_MASK;
586 0 : for (; matchLength >= 510 ; matchLength-=510) { *op++ = 255; *op++ = 255; }
587 0 : if (matchLength >= 255) { matchLength-=255; *op++ = 255; }
588 0 : *op++ = (BYTE)matchLength;
589 : }
590 0 : else *token += (BYTE)(matchLength);
591 : }
592 :
593 0 : anchor = ip;
594 :
595 : /* Test end of chunk */
596 0 : if (ip > mflimit) break;
597 :
598 : /* Fill table */
599 0 : LZ4_putPosition(ip-2, ctx, tableType, base);
600 :
601 : /* Test next position */
602 0 : ref = LZ4_getPosition(ip, ctx, tableType, base);
603 0 : if (dict==usingExtDict)
604 : {
605 0 : if (ref<(const BYTE*)source)
606 : {
607 0 : refDelta = dictDelta;
608 0 : lowLimit = dictionary;
609 : }
610 : else
611 : {
612 0 : refDelta = 0;
613 0 : lowLimit = (const BYTE*)source;
614 : }
615 : }
616 0 : LZ4_putPosition(ip, ctx, tableType, base);
617 0 : if ( ((dictIssue==dictSmall) ? (ref>=lowRefLimit) : 1)
618 0 : && (ref+MAX_DISTANCE>=ip)
619 0 : && (A32(ref+refDelta)==A32(ip)) )
620 0 : { token=op++; *token=0; goto _next_match; }
621 :
622 : /* Prepare next loop */
623 0 : forwardH = LZ4_hashPosition(++ip, tableType);
624 0 : }
625 :
626 : _last_literals:
627 : /* Encode Last Literals */
628 : {
629 0 : int lastRun = (int)(iend - anchor);
630 0 : if ((outputLimited) && (((char*)op - dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize))
631 0 : return 0; /* Check output limit */
632 0 : if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun >= 255 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; }
633 0 : else *op++ = (BYTE)(lastRun<<ML_BITS);
634 0 : memcpy(op, anchor, iend - anchor);
635 0 : op += iend-anchor;
636 : }
637 :
638 : /* End */
639 0 : return (int) (((char*)op)-dest);
640 : }
641 :
642 :
643 0 : int LZ4_compress(const char* source, char* dest, int inputSize)
644 : {
645 : #if (HEAPMODE)
646 : void* ctx = ALLOCATOR(LZ4_STREAMSIZE_U32, 4); /* Aligned on 4-bytes boundaries */
647 : #else
648 0 : U32 ctx[LZ4_STREAMSIZE_U32] = {0}; /* Ensure data is aligned on 4-bytes boundaries */
649 : #endif
650 : int result;
651 :
652 0 : if (inputSize < (int)LZ4_64KLIMIT)
653 0 : result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, 0, notLimited, byU16, noDict, noDictIssue);
654 : else
655 0 : result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, 0, notLimited, (sizeof(void*)==8) ? byU32 : byPtr, noDict, noDictIssue);
656 :
657 : #if (HEAPMODE)
658 : FREEMEM(ctx);
659 : #endif
660 0 : return result;
661 : }
662 :
663 0 : int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize)
664 : {
665 : #if (HEAPMODE)
666 : void* ctx = ALLOCATOR(LZ4_STREAMSIZE_U32, 4); /* Aligned on 4-bytes boundaries */
667 : #else
668 0 : U32 ctx[LZ4_STREAMSIZE_U32] = {0}; /* Ensure data is aligned on 4-bytes boundaries */
669 : #endif
670 : int result;
671 :
672 0 : if (inputSize < (int)LZ4_64KLIMIT)
673 0 : result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue);
674 : else
675 0 : result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, maxOutputSize, limitedOutput, (sizeof(void*)==8) ? byU32 : byPtr, noDict, noDictIssue);
676 :
677 : #if (HEAPMODE)
678 : FREEMEM(ctx);
679 : #endif
680 0 : return result;
681 : }
682 :
683 :
684 : /*****************************************
685 : Experimental : Streaming functions
686 : *****************************************/
687 :
688 0 : void* LZ4_createStream()
689 : {
690 0 : void* lz4s = ALLOCATOR(4, LZ4_STREAMSIZE_U32);
691 0 : MEM_INIT(lz4s, 0, LZ4_STREAMSIZE);
692 0 : return lz4s;
693 : }
694 :
695 0 : int LZ4_free (void* LZ4_stream)
696 : {
697 0 : FREEMEM(LZ4_stream);
698 0 : return (0);
699 : }
700 :
701 :
702 0 : int LZ4_loadDict (void* LZ4_dict, const char* dictionary, int dictSize)
703 : {
704 0 : LZ4_stream_t_internal* dict = (LZ4_stream_t_internal*) LZ4_dict;
705 0 : const BYTE* p = (const BYTE*)dictionary;
706 0 : const BYTE* const dictEnd = p + dictSize;
707 : const BYTE* base;
708 :
709 : LZ4_STATIC_ASSERT(LZ4_STREAMSIZE >= sizeof(LZ4_stream_t_internal)); /* A compilation error here means LZ4_STREAMSIZE is not large enough */
710 0 : if (dict->initCheck) MEM_INIT(dict, 0, sizeof(LZ4_stream_t_internal)); /* Uninitialized structure detected */
711 :
712 0 : if (dictSize < MINMATCH)
713 : {
714 0 : dict->dictionary = NULL;
715 0 : dict->dictSize = 0;
716 0 : return 1;
717 : }
718 :
719 0 : if (p <= dictEnd - 64 KB) p = dictEnd - 64 KB;
720 0 : base = p - dict->currentOffset;
721 0 : dict->dictionary = p;
722 0 : dict->dictSize = (U32)(dictEnd - p);
723 0 : dict->currentOffset += dict->dictSize;
724 :
725 0 : while (p <= dictEnd-MINMATCH)
726 : {
727 0 : LZ4_putPosition(p, dict, byU32, base);
728 0 : p+=3;
729 : }
730 :
731 0 : return 1;
732 : }
733 :
734 :
735 0 : void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, const BYTE* src)
736 : {
737 0 : if ((LZ4_dict->currentOffset > 0x80000000) ||
738 0 : ((size_t)LZ4_dict->currentOffset > (size_t)src)) /* address space overflow */
739 : {
740 : /* rescale hash table */
741 0 : U32 delta = LZ4_dict->currentOffset - 64 KB;
742 0 : const BYTE* dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize;
743 : int i;
744 0 : for (i=0; i<HASH_SIZE_U32; i++)
745 : {
746 0 : if (LZ4_dict->hashTable[i] < delta) LZ4_dict->hashTable[i]=0;
747 0 : else LZ4_dict->hashTable[i] -= delta;
748 : }
749 0 : LZ4_dict->currentOffset = 64 KB;
750 0 : if (LZ4_dict->dictSize > 64 KB) LZ4_dict->dictSize = 64 KB;
751 0 : LZ4_dict->dictionary = dictEnd - LZ4_dict->dictSize;
752 : }
753 0 : }
754 :
755 :
756 : FORCE_INLINE int LZ4_compress_continue_generic (void* LZ4_stream, const char* source, char* dest, int inputSize,
757 : int maxOutputSize, limitedOutput_directive limit)
758 : {
759 0 : LZ4_stream_t_internal* streamPtr = (LZ4_stream_t_internal*)LZ4_stream;
760 0 : const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
761 :
762 0 : const BYTE* smallest = (const BYTE*) source;
763 0 : if (streamPtr->initCheck) return 0; /* Uninitialized structure detected */
764 0 : if ((streamPtr->dictSize>0) && (smallest>dictEnd)) smallest = dictEnd;
765 0 : LZ4_renormDictT(streamPtr, smallest);
766 :
767 : /* Check overlapping input/dictionary space */
768 : {
769 0 : const BYTE* sourceEnd = (const BYTE*) source + inputSize;
770 0 : if ((sourceEnd > streamPtr->dictionary) && (sourceEnd < dictEnd))
771 : {
772 0 : streamPtr->dictSize = (U32)(dictEnd - sourceEnd);
773 0 : if (streamPtr->dictSize > 64 KB) streamPtr->dictSize = 64 KB;
774 0 : if (streamPtr->dictSize < 4) streamPtr->dictSize = 0;
775 0 : streamPtr->dictionary = dictEnd - streamPtr->dictSize;
776 : }
777 : }
778 :
779 : /* prefix mode : source data follows dictionary */
780 0 : if (dictEnd == (const BYTE*)source)
781 : {
782 : int result;
783 0 : if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
784 0 : result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, withPrefix64k, dictSmall);
785 : else
786 0 : result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, withPrefix64k, noDictIssue);
787 0 : streamPtr->dictSize += (U32)inputSize;
788 0 : streamPtr->currentOffset += (U32)inputSize;
789 0 : return result;
790 : }
791 :
792 : /* external dictionary mode */
793 : {
794 : int result;
795 0 : if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
796 0 : result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, usingExtDict, dictSmall);
797 : else
798 0 : result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, usingExtDict, noDictIssue);
799 0 : streamPtr->dictionary = (const BYTE*)source;
800 0 : streamPtr->dictSize = (U32)inputSize;
801 0 : streamPtr->currentOffset += (U32)inputSize;
802 0 : return result;
803 : }
804 : }
805 :
806 :
807 0 : int LZ4_compress_continue (void* LZ4_stream, const char* source, char* dest, int inputSize)
808 : {
809 0 : return LZ4_compress_continue_generic(LZ4_stream, source, dest, inputSize, 0, notLimited);
810 : }
811 :
812 0 : int LZ4_compress_limitedOutput_continue (void* LZ4_stream, const char* source, char* dest, int inputSize, int maxOutputSize)
813 : {
814 0 : return LZ4_compress_continue_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limitedOutput);
815 : }
816 :
817 :
818 : // Hidden debug function, to force separate dictionary mode
819 0 : int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int inputSize)
820 : {
821 0 : LZ4_stream_t_internal* streamPtr = (LZ4_stream_t_internal*)LZ4_dict;
822 : int result;
823 0 : const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
824 :
825 0 : const BYTE* smallest = dictEnd;
826 0 : if (smallest > (const BYTE*) source) smallest = (const BYTE*) source;
827 0 : LZ4_renormDictT((LZ4_stream_t_internal*)LZ4_dict, smallest);
828 :
829 0 : result = LZ4_compress_generic(LZ4_dict, source, dest, inputSize, 0, notLimited, byU32, usingExtDict, noDictIssue);
830 :
831 0 : streamPtr->dictionary = (const BYTE*)source;
832 0 : streamPtr->dictSize = (U32)inputSize;
833 0 : streamPtr->currentOffset += (U32)inputSize;
834 :
835 0 : return result;
836 : }
837 :
838 :
839 0 : int LZ4_saveDict (void* LZ4_dict, char* safeBuffer, int dictSize)
840 : {
841 0 : LZ4_stream_t_internal* dict = (LZ4_stream_t_internal*) LZ4_dict;
842 0 : const BYTE* previousDictEnd = dict->dictionary + dict->dictSize;
843 :
844 0 : if ((U32)dictSize > 64 KB) dictSize = 64 KB; /* useless to define a dictionary > 64 KB */
845 0 : if ((U32)dictSize > dict->dictSize) dictSize = dict->dictSize;
846 :
847 0 : memcpy(safeBuffer, previousDictEnd - dictSize, dictSize);
848 :
849 0 : dict->dictionary = (const BYTE*)safeBuffer;
850 0 : dict->dictSize = (U32)dictSize;
851 :
852 0 : return 1;
853 : }
854 :
855 :
856 :
857 : /****************************
858 : Decompression functions
859 : ****************************/
860 : /*
861 : * This generic decompression function cover all use cases.
862 : * It shall be instanciated several times, using different sets of directives
863 : * Note that it is essential this generic function is really inlined,
864 : * in order to remove useless branches during compilation optimisation.
865 : */
866 : FORCE_INLINE int LZ4_decompress_generic(
867 : const char* source,
868 : char* dest,
869 : int inputSize,
870 : int outputSize, /* If endOnInput==endOnInputSize, this value is the max size of Output Buffer. */
871 :
872 : int endOnInput, /* endOnOutputSize, endOnInputSize */
873 : int partialDecoding, /* full, partial */
874 : int targetOutputSize, /* only used if partialDecoding==partial */
875 : int dict, /* noDict, withPrefix64k, usingExtDict */
876 : const char* dictStart, /* only if dict==usingExtDict */
877 : int dictSize /* note : = 0 if noDict */
878 : )
879 : {
880 : /* Local Variables */
881 1 : const BYTE* restrict ip = (const BYTE*) source;
882 : const BYTE* ref;
883 1 : const BYTE* const iend = ip + inputSize;
884 :
885 1 : BYTE* op = (BYTE*) dest;
886 1 : BYTE* const oend = op + outputSize;
887 : BYTE* cpy;
888 1 : BYTE* oexit = op + targetOutputSize;
889 1 : const BYTE* const lowLimit = (const BYTE*)dest - dictSize;
890 :
891 1 : const BYTE* const dictEnd = (const BYTE*)dictStart + dictSize;
892 : //#define OLD
893 : #ifdef OLD
894 : const size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0}; /* static reduces speed for LZ4_decompress_safe() on GCC64 */
895 : #else
896 1 : const size_t dec32table[] = {4-0, 4-3, 4-2, 4-3, 4-0, 4-0, 4-0, 4-0}; /* static reduces speed for LZ4_decompress_safe() on GCC64 */
897 : #endif
898 : static const size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};
899 :
900 1 : const int checkOffset = (endOnInput) && (dictSize < (int)(64 KB));
901 :
902 :
903 : /* Special cases */
904 1 : if ((partialDecoding) && (oexit> oend-MFLIMIT)) oexit = oend-MFLIMIT; /* targetOutputSize too high => decode everything */
905 1 : if ((endOnInput) && (unlikely(outputSize==0))) return ((inputSize==1) && (*ip==0)) ? 0 : -1; /* Empty output buffer */
906 1 : if ((!endOnInput) && (unlikely(outputSize==0))) return (*ip==0?1:-1);
907 :
908 :
909 : /* Main Loop */
910 : while (1)
911 : {
912 : unsigned token;
913 : size_t length;
914 :
915 : /* get runlength */
916 109 : token = *ip++;
917 109 : if ((length=(token>>ML_BITS)) == RUN_MASK)
918 : {
919 : unsigned s;
920 : do
921 : {
922 14 : s = *ip++;
923 14 : length += s;
924 : }
925 14 : while (likely((endOnInput)?ip<iend-RUN_MASK:1) && (s==255));
926 : //if ((sizeof(void*)==4) && unlikely(length>LZ4_MAX_INPUT_SIZE)) goto _output_error; /* overflow detection */
927 : if ((sizeof(void*)==4) && unlikely((size_t)(op+length)<(size_t)(op))) goto _output_error; /* quickfix issue 134 */
928 : if ((endOnInput) && (sizeof(void*)==4) && unlikely((size_t)(ip+length)<(size_t)(ip))) goto _output_error; /* quickfix issue 134 */
929 : }
930 :
931 : /* copy literals */
932 109 : cpy = op+length;
933 109 : if (((endOnInput) && ((cpy>(partialDecoding?oexit:oend-MFLIMIT)) || (ip+length>iend-(2+1+LASTLITERALS))) )
934 109 : || ((!endOnInput) && (cpy>oend-COPYLENGTH)))
935 : {
936 1 : if (partialDecoding)
937 : {
938 0 : if (cpy > oend) goto _output_error; /* Error : write attempt beyond end of output buffer */
939 0 : if ((endOnInput) && (ip+length > iend)) goto _output_error; /* Error : read attempt beyond end of input buffer */
940 : }
941 : else
942 : {
943 1 : if ((!endOnInput) && (cpy != oend)) goto _output_error; /* Error : block decoding must stop exactly there */
944 1 : if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) goto _output_error; /* Error : input must be consumed */
945 : }
946 1 : memcpy(op, ip, length);
947 1 : ip += length;
948 1 : op += length;
949 : break; /* Necessarily EOF, due to parsing restrictions */
950 : }
951 151 : LZ4_WILDCOPY(op, ip, cpy); ip -= (op-cpy); op = cpy;
952 :
953 : /* get offset */
954 108 : LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2;
955 108 : if ((checkOffset) && (unlikely(ref < lowLimit))) goto _output_error; /* Error : offset outside destination buffer */
956 :
957 : /* get matchlength */
958 108 : if ((length=(token&ML_MASK)) == ML_MASK)
959 : {
960 : unsigned s;
961 : do
962 : {
963 48 : if ((endOnInput) && (ip > iend-LASTLITERALS)) goto _output_error;
964 48 : s = *ip++;
965 48 : length += s;
966 48 : } while (s==255);
967 : //if ((sizeof(void*)==4) && unlikely(length>LZ4_MAX_INPUT_SIZE)) goto _output_error; /* overflow detection */
968 : if ((sizeof(void*)==4) && unlikely((size_t)(op+length)<(size_t)op)) goto _output_error; /* quickfix issue 134 */
969 : }
970 :
971 : /* check external dictionary */
972 108 : if ((dict==usingExtDict) && (ref < (BYTE* const)dest))
973 : {
974 0 : if (unlikely(op+length+MINMATCH > oend-LASTLITERALS)) goto _output_error;
975 :
976 0 : if (length+MINMATCH <= (size_t)(dest-(char*)ref))
977 : {
978 0 : ref = dictEnd - (dest-(char*)ref);
979 0 : memcpy(op, ref, length+MINMATCH);
980 0 : op += length+MINMATCH;
981 : }
982 : else
983 : {
984 0 : size_t copySize = (size_t)(dest-(char*)ref);
985 0 : memcpy(op, dictEnd - copySize, copySize);
986 0 : op += copySize;
987 0 : copySize = length+MINMATCH - copySize;
988 0 : if (copySize > (size_t)((char*)op-dest)) /* overlap */
989 : {
990 0 : BYTE* const cpy = op + copySize;
991 0 : const BYTE* ref = (BYTE*)dest;
992 0 : while (op < cpy) *op++ = *ref++;
993 : }
994 : else
995 : {
996 0 : memcpy(op, dest, copySize);
997 0 : op += copySize;
998 : }
999 : }
1000 : continue;
1001 : }
1002 :
1003 : /* copy repeated sequence */
1004 108 : if (unlikely((op-ref)<(int)STEPSIZE))
1005 : {
1006 1 : const size_t dec64 = dec64table[(sizeof(void*)==4) ? 0 : op-ref];
1007 1 : op[0] = ref[0];
1008 1 : op[1] = ref[1];
1009 1 : op[2] = ref[2];
1010 1 : op[3] = ref[3];
1011 : #ifdef OLD
1012 : op += 4, ref += 4; ref -= dec32table[op-ref];
1013 : A32(op) = A32(ref);
1014 : op += STEPSIZE-4; ref -= dec64;
1015 : #else
1016 1 : ref += dec32table[op-ref];
1017 1 : A32(op+4) = A32(ref);
1018 1 : op += STEPSIZE; ref -= dec64;
1019 : #endif
1020 107 : } else { LZ4_COPYSTEP(op,ref); }
1021 108 : cpy = op + length - (STEPSIZE-4);
1022 :
1023 108 : if (unlikely(cpy>oend-COPYLENGTH-(STEPSIZE-4)))
1024 : {
1025 1 : if (cpy > oend-LASTLITERALS) goto _output_error; /* Error : last 5 bytes must be literals */
1026 1 : if (op<oend-COPYLENGTH) LZ4_WILDCOPY(op, ref, (oend-COPYLENGTH));
1027 1 : while(op<cpy) *op++=*ref++;
1028 1 : op=cpy;
1029 : continue;
1030 : }
1031 381 : LZ4_WILDCOPY(op, ref, cpy);
1032 107 : op=cpy; /* correction */
1033 : }
1034 :
1035 : /* end of decoding */
1036 1 : if (endOnInput)
1037 0 : return (int) (((char*)op)-dest); /* Nb of output bytes decoded */
1038 : else
1039 1 : return (int) (((char*)ip)-source); /* Nb of input bytes read */
1040 :
1041 : /* Overflow error detected */
1042 : _output_error:
1043 0 : return (int) (-(((char*)ip)-source))-1;
1044 : }
1045 :
1046 :
1047 0 : int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxOutputSize)
1048 : {
1049 0 : return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, noDict, NULL, 0);
1050 : }
1051 :
1052 0 : int LZ4_decompress_safe_partial(const char* source, char* dest, int compressedSize, int targetOutputSize, int maxOutputSize)
1053 : {
1054 0 : return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, partial, targetOutputSize, noDict, NULL, 0);
1055 : }
1056 :
1057 1 : int LZ4_decompress_fast(const char* source, char* dest, int originalSize)
1058 : {
1059 1 : return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, withPrefix64k, NULL, 0);
1060 : }
1061 :
1062 : /* streaming decompression functions */
1063 :
1064 : //#define LZ4_STREAMDECODESIZE_U32 4
1065 : //#define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U32 * sizeof(unsigned int))
1066 : //typedef struct { unsigned int table[LZ4_STREAMDECODESIZE_U32]; } LZ4_streamDecode_t;
1067 : typedef struct
1068 : {
1069 : const char* dictionary;
1070 : int dictSize;
1071 : } LZ4_streamDecode_t_internal;
1072 :
1073 : /*
1074 : * If you prefer dynamic allocation methods,
1075 : * LZ4_createStreamDecode()
1076 : * provides a pointer (void*) towards an initialized LZ4_streamDecode_t structure.
1077 : */
1078 0 : void* LZ4_createStreamDecode()
1079 : {
1080 0 : void* lz4s = ALLOCATOR(sizeof(U32), LZ4_STREAMDECODESIZE_U32);
1081 0 : MEM_INIT(lz4s, 0, LZ4_STREAMDECODESIZE);
1082 0 : return lz4s;
1083 : }
1084 :
1085 : /*
1086 : * LZ4_setDictDecode
1087 : * Use this function to instruct where to find the dictionary
1088 : * This function is not necessary if previous data is still available where it was decoded.
1089 : * Loading a size of 0 is allowed (same effect as no dictionary).
1090 : * Return : 1 if OK, 0 if error
1091 : */
1092 0 : int LZ4_setDictDecode (void* LZ4_streamDecode, const char* dictionary, int dictSize)
1093 : {
1094 0 : LZ4_streamDecode_t_internal* lz4sd = (LZ4_streamDecode_t_internal*) LZ4_streamDecode;
1095 0 : lz4sd->dictionary = dictionary;
1096 0 : lz4sd->dictSize = dictSize;
1097 0 : return 1;
1098 : }
1099 :
1100 : /*
1101 : *_continue() :
1102 : These decoding functions allow decompression of multiple blocks in "streaming" mode.
1103 : Previously decoded blocks must still be available at the memory position where they were decoded.
1104 : If it's not possible, save the relevant part of decoded data into a safe buffer,
1105 : and indicate where it stands using LZ4_setDictDecode()
1106 : */
1107 0 : int LZ4_decompress_safe_continue (void* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxOutputSize)
1108 : {
1109 0 : LZ4_streamDecode_t_internal* lz4sd = (LZ4_streamDecode_t_internal*) LZ4_streamDecode;
1110 : int result;
1111 :
1112 0 : result = LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, usingExtDict, lz4sd->dictionary, lz4sd->dictSize);
1113 0 : if (result <= 0) return result;
1114 0 : if (lz4sd->dictionary + lz4sd->dictSize == dest)
1115 : {
1116 0 : lz4sd->dictSize += result;
1117 : }
1118 : else
1119 : {
1120 0 : lz4sd->dictionary = dest;
1121 0 : lz4sd->dictSize = result;
1122 : }
1123 :
1124 0 : return result;
1125 : }
1126 :
1127 0 : int LZ4_decompress_fast_continue (void* LZ4_streamDecode, const char* source, char* dest, int originalSize)
1128 : {
1129 0 : LZ4_streamDecode_t_internal* lz4sd = (LZ4_streamDecode_t_internal*) LZ4_streamDecode;
1130 : int result;
1131 :
1132 0 : result = LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, usingExtDict, lz4sd->dictionary, lz4sd->dictSize);
1133 0 : if (result <= 0) return result;
1134 0 : if (lz4sd->dictionary + lz4sd->dictSize == dest)
1135 : {
1136 0 : lz4sd->dictSize += result;
1137 : }
1138 : else
1139 : {
1140 0 : lz4sd->dictionary = dest;
1141 0 : lz4sd->dictSize = result;
1142 : }
1143 :
1144 0 : return result;
1145 : }
1146 :
1147 :
1148 : /*
1149 : Advanced decoding functions :
1150 : *_usingDict() :
1151 : These decoding functions work the same as "_continue" ones,
1152 : the dictionary must be explicitly provided within parameters
1153 : */
1154 :
1155 0 : int LZ4_decompress_safe_usingDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
1156 : {
1157 0 : return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, usingExtDict, dictStart, dictSize);
1158 : }
1159 :
1160 0 : int LZ4_decompress_fast_usingDict(const char* source, char* dest, int originalSize, const char* dictStart, int dictSize)
1161 : {
1162 0 : return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, usingExtDict, dictStart, dictSize);
1163 : }
|
