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) )   /* Detects 64 bits mode */
54 #  define LZ4_ARCH64 1
55 #else
56 #  define LZ4_ARCH64 0
57 #endif
58 
59 /*
60  * Little Endian or Big Endian ?
61  * Overwrite the #define below if you know your architecture endianess
62  */
63 #include <stdlib.h>   /* Apparently required to detect endianess */
64 #if defined (__GLIBC__)
65 #  include <endian.h>
66 #  if (__BYTE_ORDER == __BIG_ENDIAN)
67 #     define LZ4_BIG_ENDIAN 1
68 #  endif
69 #elif (defined(__BIG_ENDIAN__) || defined(__BIG_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(__LITTLE_ENDIAN__) || defined(__LITTLE_ENDIAN) || defined(_LITTLE_ENDIAN))
70 #  define LZ4_BIG_ENDIAN 1
71 #elif defined(__sparc) || defined(__sparc__) \
72    || defined(__powerpc__) || defined(__ppc__) || defined(__PPC__) \
73    || defined(__hpux)  || defined(__hppa) \
74    || defined(_MIPSEB) || defined(__s390__)
75 #  define LZ4_BIG_ENDIAN 1
76 #else
77 /* Little Endian assumed. PDP Endian and other very rare endian format are unsupported. */
78 #endif
79 
80 /*
81  * Unaligned memory access is automatically enabled for "common" CPU, such as x86.
82  * For others CPU, such as ARM, the compiler may be more cautious, inserting unnecessary extra code to ensure aligned access property
83  * If you know your target CPU supports unaligned memory access, you want to force this option manually to improve performance
84  */
85 #if defined(__ARM_FEATURE_UNALIGNED)
86 #  define LZ4_FORCE_UNALIGNED_ACCESS 1
87 #endif
88 
89 /* Define this parameter if your target system or compiler does not support hardware bit count */
90 #if defined(_MSC_VER) && defined(_WIN32_WCE)   /* Visual Studio for Windows CE does not support Hardware bit count */
91 #  define LZ4_FORCE_SW_BITCOUNT
92 #endif
93 
94 /*
95  * BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE :
96  * This option may provide a small boost to performance for some big endian cpu, although probably modest.
97  * You may set this option to 1 if data will remain within closed environment.
98  * This option is useless on Little_Endian CPU (such as x86)
99  */
100 
101 /* #define BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE 1 */
102 
103 
104 /**************************************
105  Compiler Options
106 **************************************/
107 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)   /* C99 */
108 /* "restrict" is a known keyword */
109 #else
110 #  define restrict /* Disable restrict */
111 #endif
112 
113 #ifdef _MSC_VER    /* Visual Studio */
114 #  define FORCE_INLINE static __forceinline
115 #  include <intrin.h>                    /* For Visual 2005 */
116 #  if LZ4_ARCH64   /* 64-bits */
117 #    pragma intrinsic(_BitScanForward64) /* For Visual 2005 */
118 #    pragma intrinsic(_BitScanReverse64) /* For Visual 2005 */
119 #  else            /* 32-bits */
120 #    pragma intrinsic(_BitScanForward)   /* For Visual 2005 */
121 #    pragma intrinsic(_BitScanReverse)   /* For Visual 2005 */
122 #  endif
123 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
124 #else
125 #  ifdef __GNUC__
126 #    define FORCE_INLINE static inline __attribute__((always_inline))
127 #  else
128 #    define FORCE_INLINE static inline
129 #  endif
130 #endif
131 
132 #ifdef _MSC_VER  /* Visual Studio */
133 #  define lz4_bswap16(x) _byteswap_ushort(x)
134 #else
135 #  define lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))
136 #endif
137 
138 #define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
139 
140 #if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
141 #  define expect(expr,value)    (__builtin_expect ((expr),(value)) )
142 #else
143 #  define expect(expr,value)    (expr)
144 #endif
145 
146 #define likely(expr)     expect((expr) != 0, 1)
147 #define unlikely(expr)   expect((expr) != 0, 0)
148 
149 
150 /**************************************
151    Memory routines
152 **************************************/
153 #include <stdlib.h>   /* malloc, calloc, free */
154 #define ALLOCATOR(n,s) calloc(n,s)
155 #define FREEMEM        free
156 #include <string.h>   /* memset, memcpy */
157 #define MEM_INIT       memset
158 
159 
160 /**************************************
161    Includes
162 **************************************/
163 #include "lz4.h"
164 
165 
166 /**************************************
167    Basic Types
168 **************************************/
169 #if defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)   /* C99 */
170 # include <stdint.h>
171   typedef  uint8_t BYTE;
172   typedef uint16_t U16;
173   typedef uint32_t U32;
174   typedef  int32_t S32;
175   typedef uint64_t U64;
176 #else
177   typedef unsigned char       BYTE;
178   typedef unsigned short      U16;
179   typedef unsigned int        U32;
180   typedef   signed int        S32;
181   typedef unsigned long long  U64;
182 #endif
183 
184 #if defined(__GNUC__)  && !defined(LZ4_FORCE_UNALIGNED_ACCESS)
185 #  define _PACKED __attribute__ ((packed))
186 #else
187 #  define _PACKED
188 #endif
189 
190 #if !defined(LZ4_FORCE_UNALIGNED_ACCESS) && !defined(__GNUC__)
191 #  if defined(__IBMC__) || defined(__SUNPRO_C) || defined(__SUNPRO_CC)
192 #    pragma pack(1)
193 #  else
194 #    pragma pack(push, 1)
195 #  endif
196 #endif
197 
198 typedef struct { U16 v; }  _PACKED U16_S;
199 typedef struct { U32 v; }  _PACKED U32_S;
200 typedef struct { U64 v; }  _PACKED U64_S;
201 typedef struct {size_t v;} _PACKED size_t_S;
202 
203 #if !defined(LZ4_FORCE_UNALIGNED_ACCESS) && !defined(__GNUC__)
204 #  if defined(__SUNPRO_C) || defined(__SUNPRO_CC)
205 #    pragma pack(0)
206 #  else
207 #    pragma pack(pop)
208 #  endif
209 #endif
210 
211 #define A16(x)   (((U16_S *)(x))->v)
212 #define A32(x)   (((U32_S *)(x))->v)
213 #define A64(x)   (((U64_S *)(x))->v)
214 #define AARCH(x) (((size_t_S *)(x))->v)
215 
216 
217 /**************************************
218    Constants
219 **************************************/
220 #define LZ4_HASHLOG   (LZ4_MEMORY_USAGE-2)
221 #define HASHTABLESIZE (1 << LZ4_MEMORY_USAGE)
222 #define HASH_SIZE_U32 (1 << LZ4_HASHLOG)
223 
224 #define MINMATCH 4
225 
226 #define COPYLENGTH 8
227 #define LASTLITERALS 5
228 #define MFLIMIT (COPYLENGTH+MINMATCH)
229 static const int LZ4_minLength = (MFLIMIT+1);
230 
231 #define KB *(1U<<10)
232 #define MB *(1U<<20)
233 #define GB *(1U<<30)
234 
235 #define LZ4_64KLIMIT ((64 KB) + (MFLIMIT-1))
236 #define SKIPSTRENGTH 6   /* Increasing this value will make the compression run slower on incompressible data */
237 
238 #define MAXD_LOG 16
239 #define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
240 
241 #define ML_BITS  4
242 #define ML_MASK  ((1U<<ML_BITS)-1)
243 #define RUN_BITS (8-ML_BITS)
244 #define RUN_MASK ((1U<<RUN_BITS)-1)
245 
246 
247 /**************************************
248    Structures and local types
249 **************************************/
250 typedef struct {
251     U32  hashTable[HASH_SIZE_U32];
252     U32  currentOffset;
253     U32  initCheck;
254     const BYTE* dictionary;
255     const BYTE* bufferStart;
256     U32  dictSize;
257 } LZ4_stream_t_internal;
258 
259 typedef enum { notLimited = 0, limitedOutput = 1 } limitedOutput_directive;
260 typedef enum { byPtr, byU32, byU16 } tableType_t;
261 
262 typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
263 typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
264 
265 typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
266 typedef enum { full = 0, partial = 1 } earlyEnd_directive;
267 
268 
269 /**************************************
270    Architecture-specific macros
271 **************************************/
272 #define STEPSIZE                  sizeof(size_t)
273 #define LZ4_COPYSTEP(d,s)         { AARCH(d) = AARCH(s); d+=STEPSIZE; s+=STEPSIZE; }
274 #define LZ4_COPY8(d,s)            { LZ4_COPYSTEP(d,s); if (STEPSIZE<8) LZ4_COPYSTEP(d,s); }
275 
276 #if (defined(LZ4_BIG_ENDIAN) && !defined(BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE))
277 #  define LZ4_READ_LITTLEENDIAN_16(d,s,p) { U16 v = A16(p); v = lz4_bswap16(v); d = (s) - v; }
278 #  define LZ4_WRITE_LITTLEENDIAN_16(p,i)  { U16 v = (U16)(i); v = lz4_bswap16(v); A16(p) = v; p+=2; }
279 #else      /* Little Endian */
280 #  define LZ4_READ_LITTLEENDIAN_16(d,s,p) { d = (s) - A16(p); }
281 #  define LZ4_WRITE_LITTLEENDIAN_16(p,v)  { A16(p) = v; p+=2; }
282 #endif
283 
284 
285 /**************************************
286    Macros
287 **************************************/
288 #define LZ4_STATIC_ASSERT(c)    { enum { LZ4_static_assert = 1/(!!(c)) }; }   /* use only *after* variable declarations */
289 #if LZ4_ARCH64 || !defined(__GNUC__)
290 #  define LZ4_WILDCOPY(d,s,e)   { do { LZ4_COPY8(d,s) } while (d<e); }        /* at the end, d>=e; */
291 #else
292 #  define LZ4_WILDCOPY(d,s,e)   { if (likely(e-d <= 8)) LZ4_COPY8(d,s) else do { LZ4_COPY8(d,s) } while (d<e); }
293 #endif
294 
295 
296 /****************************
297    Private local functions
298 ****************************/
299 #if LZ4_ARCH64
300 
LZ4_NbCommonBytes(register U64 val)301 int LZ4_NbCommonBytes (register U64 val)
302 {
303 # if defined(LZ4_BIG_ENDIAN)
304 #   if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
305     unsigned long r = 0;
306     _BitScanReverse64( &r, val );
307     return (int)(r>>3);
308 #   elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
309     return (__builtin_clzll(val) >> 3);
310 #   else
311     int r;
312     if (!(val>>32)) { r=4; } else { r=0; val>>=32; }
313     if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
314     r += (!val);
315     return r;
316 #   endif
317 # else
318 #   if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
319     unsigned long r = 0;
320     _BitScanForward64( &r, val );
321     return (int)(r>>3);
322 #   elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
323     return (__builtin_ctzll(val) >> 3);
324 #   else
325     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 };
326     return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
327 #   endif
328 # endif
329 }
330 
331 #else
332 
LZ4_NbCommonBytes(register U32 val)333 int LZ4_NbCommonBytes (register U32 val)
334 {
335 # if defined(LZ4_BIG_ENDIAN)
336 #   if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
337     unsigned long r = 0;
338     _BitScanReverse( &r, val );
339     return (int)(r>>3);
340 #   elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
341     return (__builtin_clz(val) >> 3);
342 #   else
343     int r;
344     if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
345     r += (!val);
346     return r;
347 #   endif
348 # else
349 #   if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
350     unsigned long r;
351     _BitScanForward( &r, val );
352     return (int)(r>>3);
353 #   elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
354     return (__builtin_ctz(val) >> 3);
355 #   else
356     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 };
357     return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
358 #   endif
359 # endif
360 }
361 
362 #endif
363 
364 
365 /********************************
366    Compression functions
367 ********************************/
LZ4_compressBound(int isize)368 int LZ4_compressBound(int isize)  { return LZ4_COMPRESSBOUND(isize); }
369 
LZ4_hashSequence(U32 sequence,tableType_t tableType)370 static int LZ4_hashSequence(U32 sequence, tableType_t tableType)
371 {
372     if (tableType == byU16)
373         return (((sequence) * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
374     else
375         return (((sequence) * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
376 }
377 
LZ4_hashPosition(const BYTE * p,tableType_t tableType)378 static int LZ4_hashPosition(const BYTE* p, tableType_t tableType) { return LZ4_hashSequence(A32(p), tableType); }
379 
LZ4_putPositionOnHash(const BYTE * p,U32 h,void * tableBase,tableType_t tableType,const BYTE * srcBase)380 static void LZ4_putPositionOnHash(const BYTE* p, U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
381 {
382     switch (tableType)
383     {
384     case byPtr: { const BYTE** hashTable = (const BYTE**) tableBase; hashTable[h] = p; break; }
385     case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = (U32)(p-srcBase); break; }
386     case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = (U16)(p-srcBase); break; }
387     }
388 }
389 
LZ4_putPosition(const BYTE * p,void * tableBase,tableType_t tableType,const BYTE * srcBase)390 static void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
391 {
392     U32 h = LZ4_hashPosition(p, tableType);
393     LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
394 }
395 
LZ4_getPositionOnHash(U32 h,void * tableBase,tableType_t tableType,const BYTE * srcBase)396 static const BYTE* LZ4_getPositionOnHash(U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
397 {
398     if (tableType == byPtr) { const BYTE** hashTable = (const BYTE**) tableBase; return hashTable[h]; }
399     if (tableType == byU32) { U32* hashTable = (U32*) tableBase; return hashTable[h] + srcBase; }
400     { U16* hashTable = (U16*) tableBase; return hashTable[h] + srcBase; }   /* default, to ensure a return */
401 }
402 
LZ4_getPosition(const BYTE * p,void * tableBase,tableType_t tableType,const BYTE * srcBase)403 static const BYTE* LZ4_getPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
404 {
405     U32 h = LZ4_hashPosition(p, tableType);
406     return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
407 }
408 
LZ4_count(const BYTE * pIn,const BYTE * pRef,const BYTE * pInLimit)409 static unsigned LZ4_count(const BYTE* pIn, const BYTE* pRef, const BYTE* pInLimit)
410 {
411     const BYTE* const pStart = pIn;
412 
413     while (likely(pIn<pInLimit-(STEPSIZE-1)))
414     {
415         size_t diff = AARCH(pRef) ^ AARCH(pIn);
416         if (!diff) { pIn+=STEPSIZE; pRef+=STEPSIZE; continue; }
417         pIn += LZ4_NbCommonBytes(diff);
418         return (unsigned)(pIn - pStart);
419     }
420     if (sizeof(void*)==8) if ((pIn<(pInLimit-3)) && (A32(pRef) == A32(pIn))) { pIn+=4; pRef+=4; }
421     if ((pIn<(pInLimit-1)) && (A16(pRef) == A16(pIn))) { pIn+=2; pRef+=2; }
422     if ((pIn<pInLimit) && (*pRef == *pIn)) pIn++;
423 
424     return (unsigned)(pIn - pStart);
425 }
426 
427 
LZ4_compress_generic(void * ctx,const char * source,char * dest,int inputSize,int maxOutputSize,limitedOutput_directive outputLimited,tableType_t tableType,dict_directive dict,dictIssue_directive dictIssue)428 static int LZ4_compress_generic(
429                  void* ctx,
430                  const char* source,
431                  char* dest,
432                  int inputSize,
433                  int maxOutputSize,
434 
435                  limitedOutput_directive outputLimited,
436                  tableType_t tableType,
437                  dict_directive dict,
438                  dictIssue_directive dictIssue)
439 {
440     LZ4_stream_t_internal* const dictPtr = (LZ4_stream_t_internal*)ctx;
441 
442     const BYTE* ip = (const BYTE*) source;
443     const BYTE* base;
444     const BYTE* lowLimit;
445     const BYTE* const lowRefLimit = ip - dictPtr->dictSize;
446     const BYTE* const dictionary = dictPtr->dictionary;
447     const BYTE* const dictEnd = dictionary + dictPtr->dictSize;
448     const size_t dictDelta = dictEnd - (const BYTE*)source;
449     const BYTE* anchor = (const BYTE*) source;
450     const BYTE* const iend = ip + inputSize;
451     const BYTE* const mflimit = iend - MFLIMIT;
452     const BYTE* const matchlimit = iend - LASTLITERALS;
453 
454     BYTE* op = (BYTE*) dest;
455     BYTE* const olimit = op + maxOutputSize;
456 
457     const int skipStrength = SKIPSTRENGTH;
458     U32 forwardH;
459     size_t refDelta=0;
460 
461     /* Init conditions */
462     if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0;          /* Unsupported input size, too large (or negative) */
463     switch(dict)
464     {
465     case noDict:
466     default:
467         base = (const BYTE*)source;
468         lowLimit = (const BYTE*)source;
469         break;
470     case withPrefix64k:
471         base = (const BYTE*)source - dictPtr->currentOffset;
472         lowLimit = (const BYTE*)source - dictPtr->dictSize;
473         break;
474     case usingExtDict:
475         base = (const BYTE*)source - dictPtr->currentOffset;
476         lowLimit = (const BYTE*)source;
477         break;
478     }
479     if ((tableType == byU16) && (inputSize>=(int)LZ4_64KLIMIT)) return 0;   /* Size too large (not within 64K limit) */
480     if (inputSize<LZ4_minLength) goto _last_literals;                       /* Input too small, no compression (all literals) */
481 
482     /* First Byte */
483     LZ4_putPosition(ip, ctx, tableType, base);
484     ip++; forwardH = LZ4_hashPosition(ip, tableType);
485 
486     /* Main Loop */
487     for ( ; ; )
488     {
489         const BYTE* ref;
490         BYTE* token;
491         {
492             const BYTE* forwardIp = ip;
493             unsigned step=1;
494             unsigned searchMatchNb = (1U << skipStrength);
495 
496             /* Find a match */
497             do {
498                 U32 h = forwardH;
499                 ip = forwardIp;
500                 forwardIp += step;
501                 step = searchMatchNb++ >> skipStrength;
502                 //if (step>8) step=8;   // required for valid forwardIp ; slows down uncompressible data a bit
503 
504                 if (unlikely(forwardIp > mflimit)) goto _last_literals;
505 
506                 ref = LZ4_getPositionOnHash(h, ctx, tableType, base);
507                 if (dict==usingExtDict)
508                 {
509                     if (ref<(const BYTE*)source)
510                     {
511                         refDelta = dictDelta;
512                         lowLimit = dictionary;
513                     }
514                     else
515                     {
516                         refDelta = 0;
517                         lowLimit = (const BYTE*)source;
518                     }
519                 }
520                 forwardH = LZ4_hashPosition(forwardIp, tableType);
521                 LZ4_putPositionOnHash(ip, h, ctx, tableType, base);
522 
523             } while ( ((dictIssue==dictSmall) ? (ref < lowRefLimit) : 0)
524                 || ((tableType==byU16) ? 0 : (ref + MAX_DISTANCE < ip))
525                 || (A32(ref+refDelta) != A32(ip)) );
526         }
527 
528         /* Catch up */
529         while ((ip>anchor) && (ref+refDelta > lowLimit) && (unlikely(ip[-1]==ref[refDelta-1]))) { ip--; ref--; }
530 
531         {
532             /* Encode Literal length */
533             unsigned litLength = (unsigned)(ip - anchor);
534             token = op++;
535             if ((outputLimited) && (unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit)))
536                 return 0;   /* Check output limit */
537             if (litLength>=RUN_MASK)
538             {
539                 int len = (int)litLength-RUN_MASK;
540                 *token=(RUN_MASK<<ML_BITS);
541                 for(; len >= 255 ; len-=255) *op++ = 255;
542                 *op++ = (BYTE)len;
543             }
544             else *token = (BYTE)(litLength<<ML_BITS);
545 
546             /* Copy Literals */
547             { BYTE* end = op+litLength; LZ4_WILDCOPY(op,anchor,end); op=end; }
548         }
549 
550 _next_match:
551         /* Encode Offset */
552         LZ4_WRITE_LITTLEENDIAN_16(op, (U16)(ip-ref));
553 
554         /* Encode MatchLength */
555         {
556             unsigned matchLength;
557 
558             if ((dict==usingExtDict) && (lowLimit==dictionary))
559             {
560                 const BYTE* limit;
561                 ref += refDelta;
562                 limit = ip + (dictEnd-ref);
563                 if (limit > matchlimit) limit = matchlimit;
564                 matchLength = LZ4_count(ip+MINMATCH, ref+MINMATCH, limit);
565                 ip += MINMATCH + matchLength;
566                 if (ip==limit)
567                 {
568                     unsigned more = LZ4_count(ip, (const BYTE*)source, matchlimit);
569                     matchLength += more;
570                     ip += more;
571                 }
572             }
573             else
574             {
575                 matchLength = LZ4_count(ip+MINMATCH, ref+MINMATCH, matchlimit);
576                 ip += MINMATCH + matchLength;
577             }
578 
579             if (matchLength>=ML_MASK)
580             {
581                 if ((outputLimited) && (unlikely(op + (1 + LASTLITERALS) + (matchLength>>8) > olimit)))
582                     return 0;    /* Check output limit */
583                 *token += ML_MASK;
584                 matchLength -= ML_MASK;
585                 for (; matchLength >= 510 ; matchLength-=510) { *op++ = 255; *op++ = 255; }
586                 if (matchLength >= 255) { matchLength-=255; *op++ = 255; }
587                 *op++ = (BYTE)matchLength;
588             }
589             else *token += (BYTE)(matchLength);
590         }
591 
592         anchor = ip;
593 
594         /* Test end of chunk */
595         if (ip > mflimit) break;
596 
597         /* Fill table */
598         LZ4_putPosition(ip-2, ctx, tableType, base);
599 
600         /* Test next position */
601         ref = LZ4_getPosition(ip, ctx, tableType, base);
602         if (dict==usingExtDict)
603         {
604             if (ref<(const BYTE*)source)
605             {
606                 refDelta = dictDelta;
607                 lowLimit = dictionary;
608             }
609             else
610             {
611                 refDelta = 0;
612                 lowLimit = (const BYTE*)source;
613             }
614         }
615         LZ4_putPosition(ip, ctx, tableType, base);
616         if ( ((dictIssue==dictSmall) ? (ref>=lowRefLimit) : 1)
617             && (ref+MAX_DISTANCE>=ip)
618             && (A32(ref+refDelta)==A32(ip)) )
619         { token=op++; *token=0; goto _next_match; }
620 
621         /* Prepare next loop */
622         forwardH = LZ4_hashPosition(++ip, tableType);
623     }
624 
625 _last_literals:
626     /* Encode Last Literals */
627     {
628         int lastRun = (int)(iend - anchor);
629         if ((outputLimited) && (((char*)op - dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize))
630             return 0;   /* Check output limit */
631         if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun >= 255 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; }
632         else *op++ = (BYTE)(lastRun<<ML_BITS);
633         memcpy(op, anchor, iend - anchor);
634         op += iend-anchor;
635     }
636 
637     /* End */
638     return (int) (((char*)op)-dest);
639 }
640 
641 
LZ4_compress(const char * source,char * dest,int inputSize)642 int LZ4_compress(const char* source, char* dest, int inputSize)
643 {
644 #if (HEAPMODE)
645     void* ctx = ALLOCATOR(LZ4_STREAMSIZE_U32, 4);   /* Aligned on 4-bytes boundaries */
646 #else
647     U32 ctx[LZ4_STREAMSIZE_U32] = {0};      /* Ensure data is aligned on 4-bytes boundaries */
648 #endif
649     int result;
650 
651     if (inputSize < (int)LZ4_64KLIMIT)
652         result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, 0, notLimited, byU16, noDict, noDictIssue);
653     else
654         result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, 0, notLimited, (sizeof(void*)==8) ? byU32 : byPtr, noDict, noDictIssue);
655 
656 #if (HEAPMODE)
657     FREEMEM(ctx);
658 #endif
659     return result;
660 }
661 
LZ4_compress_limitedOutput(const char * source,char * dest,int inputSize,int maxOutputSize)662 int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize)
663 {
664 #if (HEAPMODE)
665     void* ctx = ALLOCATOR(LZ4_STREAMSIZE_U32, 4);   /* Aligned on 4-bytes boundaries */
666 #else
667     U32 ctx[LZ4_STREAMSIZE_U32] = {0};      /* Ensure data is aligned on 4-bytes boundaries */
668 #endif
669     int result;
670 
671     if (inputSize < (int)LZ4_64KLIMIT)
672         result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue);
673     else
674         result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, maxOutputSize, limitedOutput, (sizeof(void*)==8) ? byU32 : byPtr, noDict, noDictIssue);
675 
676 #if (HEAPMODE)
677     FREEMEM(ctx);
678 #endif
679     return result;
680 }
681 
682 
683 /*****************************************
684    Experimental : Streaming functions
685 *****************************************/
686 
LZ4_createStream()687 void* LZ4_createStream()
688 {
689     void* lz4s = ALLOCATOR(4, LZ4_STREAMSIZE_U32);
690     MEM_INIT(lz4s, 0, LZ4_STREAMSIZE);
691     return lz4s;
692 }
693 
LZ4_free(void * LZ4_stream)694 int LZ4_free (void* LZ4_stream)
695 {
696     FREEMEM(LZ4_stream);
697     return (0);
698 }
699 
700 
LZ4_loadDict(void * LZ4_dict,const char * dictionary,int dictSize)701 int LZ4_loadDict (void* LZ4_dict, const char* dictionary, int dictSize)
702 {
703     LZ4_stream_t_internal* dict = (LZ4_stream_t_internal*) LZ4_dict;
704     const BYTE* p = (const BYTE*)dictionary;
705     const BYTE* const dictEnd = p + dictSize;
706     const BYTE* base;
707 
708     LZ4_STATIC_ASSERT(LZ4_STREAMSIZE >= sizeof(LZ4_stream_t_internal));      /* A compilation error here means LZ4_STREAMSIZE is not large enough */
709     if (dict->initCheck) MEM_INIT(dict, 0, sizeof(LZ4_stream_t_internal));   /* Uninitialized structure detected */
710 
711     if (dictSize < MINMATCH)
712     {
713         dict->dictionary = NULL;
714         dict->dictSize = 0;
715         return 1;
716     }
717 
718     if (p <= dictEnd - 64 KB) p = dictEnd - 64 KB;
719     base = p - dict->currentOffset;
720     dict->dictionary = p;
721     dict->dictSize = (U32)(dictEnd - p);
722     dict->currentOffset += dict->dictSize;
723 
724     while (p <= dictEnd-MINMATCH)
725     {
726         LZ4_putPosition(p, dict, byU32, base);
727         p+=3;
728     }
729 
730     return 1;
731 }
732 
733 
LZ4_renormDictT(LZ4_stream_t_internal * LZ4_dict,const BYTE * src)734 void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, const BYTE* src)
735 {
736     if ((LZ4_dict->currentOffset > 0x80000000) ||
737         ((size_t)LZ4_dict->currentOffset > (size_t)src))   /* address space overflow */
738     {
739         /* rescale hash table */
740         U32 delta = LZ4_dict->currentOffset - 64 KB;
741         const BYTE* dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize;
742         int i;
743         for (i=0; i<HASH_SIZE_U32; i++)
744         {
745             if (LZ4_dict->hashTable[i] < delta) LZ4_dict->hashTable[i]=0;
746             else LZ4_dict->hashTable[i] -= delta;
747         }
748         LZ4_dict->currentOffset = 64 KB;
749         if (LZ4_dict->dictSize > 64 KB) LZ4_dict->dictSize = 64 KB;
750         LZ4_dict->dictionary = dictEnd - LZ4_dict->dictSize;
751     }
752 }
753 
754 
LZ4_compress_continue_generic(void * LZ4_stream,const char * source,char * dest,int inputSize,int maxOutputSize,limitedOutput_directive limit)755 FORCE_INLINE int LZ4_compress_continue_generic (void* LZ4_stream, const char* source, char* dest, int inputSize,
756                                                 int maxOutputSize, limitedOutput_directive limit)
757 {
758     LZ4_stream_t_internal* streamPtr = (LZ4_stream_t_internal*)LZ4_stream;
759     const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
760 
761     const BYTE* smallest = (const BYTE*) source;
762     if (streamPtr->initCheck) return 0;   /* Uninitialized structure detected */
763     if ((streamPtr->dictSize>0) && (smallest>dictEnd)) smallest = dictEnd;
764     LZ4_renormDictT(streamPtr, smallest);
765 
766     /* Check overlapping input/dictionary space */
767     {
768         const BYTE* sourceEnd = (const BYTE*) source + inputSize;
769         if ((sourceEnd > streamPtr->dictionary) && (sourceEnd < dictEnd))
770         {
771             streamPtr->dictSize = (U32)(dictEnd - sourceEnd);
772             if (streamPtr->dictSize > 64 KB) streamPtr->dictSize = 64 KB;
773             if (streamPtr->dictSize < 4) streamPtr->dictSize = 0;
774             streamPtr->dictionary = dictEnd - streamPtr->dictSize;
775         }
776     }
777 
778     /* prefix mode : source data follows dictionary */
779     if (dictEnd == (const BYTE*)source)
780     {
781         int result;
782         if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
783             result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, withPrefix64k, dictSmall);
784         else
785             result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, withPrefix64k, noDictIssue);
786         streamPtr->dictSize += (U32)inputSize;
787         streamPtr->currentOffset += (U32)inputSize;
788         return result;
789     }
790 
791     /* external dictionary mode */
792     {
793         int result;
794         if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
795             result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, usingExtDict, dictSmall);
796         else
797             result = LZ4_compress_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limit, byU32, usingExtDict, noDictIssue);
798         streamPtr->dictionary = (const BYTE*)source;
799         streamPtr->dictSize = (U32)inputSize;
800         streamPtr->currentOffset += (U32)inputSize;
801         return result;
802     }
803 }
804 
805 
LZ4_compress_continue(void * LZ4_stream,const char * source,char * dest,int inputSize)806 int LZ4_compress_continue (void* LZ4_stream, const char* source, char* dest, int inputSize)
807 {
808     return LZ4_compress_continue_generic(LZ4_stream, source, dest, inputSize, 0, notLimited);
809 }
810 
LZ4_compress_limitedOutput_continue(void * LZ4_stream,const char * source,char * dest,int inputSize,int maxOutputSize)811 int LZ4_compress_limitedOutput_continue (void* LZ4_stream, const char* source, char* dest, int inputSize, int maxOutputSize)
812 {
813     return LZ4_compress_continue_generic(LZ4_stream, source, dest, inputSize, maxOutputSize, limitedOutput);
814 }
815 
816 
817 // Hidden debug function, to force separate dictionary mode
LZ4_compress_forceExtDict(LZ4_stream_t * LZ4_dict,const char * source,char * dest,int inputSize)818 int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int inputSize)
819 {
820     LZ4_stream_t_internal* streamPtr = (LZ4_stream_t_internal*)LZ4_dict;
821     int result;
822     const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
823 
824     const BYTE* smallest = dictEnd;
825     if (smallest > (const BYTE*) source) smallest = (const BYTE*) source;
826     LZ4_renormDictT((LZ4_stream_t_internal*)LZ4_dict, smallest);
827 
828     result = LZ4_compress_generic(LZ4_dict, source, dest, inputSize, 0, notLimited, byU32, usingExtDict, noDictIssue);
829 
830     streamPtr->dictionary = (const BYTE*)source;
831     streamPtr->dictSize = (U32)inputSize;
832     streamPtr->currentOffset += (U32)inputSize;
833 
834     return result;
835 }
836 
837 
LZ4_saveDict(void * LZ4_dict,char * safeBuffer,int dictSize)838 int LZ4_saveDict (void* LZ4_dict, char* safeBuffer, int dictSize)
839 {
840     LZ4_stream_t_internal* dict = (LZ4_stream_t_internal*) LZ4_dict;
841     const BYTE* previousDictEnd = dict->dictionary + dict->dictSize;
842 
843     if ((U32)dictSize > 64 KB) dictSize = 64 KB;   /* useless to define a dictionary > 64 KB */
844     if ((U32)dictSize > dict->dictSize) dictSize = dict->dictSize;
845 
846     memcpy(safeBuffer, previousDictEnd - dictSize, dictSize);
847 
848     dict->dictionary = (const BYTE*)safeBuffer;
849     dict->dictSize = (U32)dictSize;
850 
851     return 1;
852 }
853 
854 
855 
856 /****************************
857    Decompression functions
858 ****************************/
859 /*
860  * This generic decompression function cover all use cases.
861  * It shall be instanciated several times, using different sets of directives
862  * Note that it is essential this generic function is really inlined,
863  * in order to remove useless branches during compilation optimisation.
864  */
LZ4_decompress_generic(const char * source,char * dest,int inputSize,int outputSize,int endOnInput,int partialDecoding,int targetOutputSize,int dict,const char * dictStart,int dictSize)865 FORCE_INLINE int LZ4_decompress_generic(
866                  const char* source,
867                  char* dest,
868                  int inputSize,
869                  int outputSize,         /* If endOnInput==endOnInputSize, this value is the max size of Output Buffer. */
870 
871                  int endOnInput,         /* endOnOutputSize, endOnInputSize */
872                  int partialDecoding,    /* full, partial */
873                  int targetOutputSize,   /* only used if partialDecoding==partial */
874                  int dict,               /* noDict, withPrefix64k, usingExtDict */
875                  const char* dictStart,  /* only if dict==usingExtDict */
876                  int dictSize            /* note : = 0 if noDict */
877                  )
878 {
879     /* Local Variables */
880     const BYTE* restrict ip = (const BYTE*) source;
881     const BYTE* ref;
882     const BYTE* const iend = ip + inputSize;
883 
884     BYTE* op = (BYTE*) dest;
885     BYTE* const oend = op + outputSize;
886     BYTE* cpy;
887     BYTE* oexit = op + targetOutputSize;
888     const BYTE* const lowLimit = (const BYTE*)dest - dictSize;
889 
890     const BYTE* const dictEnd = (const BYTE*)dictStart + dictSize;
891 //#define OLD
892 #ifdef OLD
893     const size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};   /* static reduces speed for LZ4_decompress_safe() on GCC64 */
894 #else
895     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 */
896 #endif
897     static const size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};
898 
899     const int checkOffset = (endOnInput) && (dictSize < (int)(64 KB));
900 
901 
902     /* Special cases */
903     if ((partialDecoding) && (oexit> oend-MFLIMIT)) oexit = oend-MFLIMIT;                        /* targetOutputSize too high => decode everything */
904     if ((endOnInput) && (unlikely(outputSize==0))) return ((inputSize==1) && (*ip==0)) ? 0 : -1;   /* Empty output buffer */
905     if ((!endOnInput) && (unlikely(outputSize==0))) return (*ip==0?1:-1);
906 
907 
908     /* Main Loop */
909     while (1)
910     {
911         unsigned token;
912         size_t length;
913 
914         /* get runlength */
915         token = *ip++;
916         if ((length=(token>>ML_BITS)) == RUN_MASK)
917         {
918             unsigned s;
919             do
920             {
921                 s = *ip++;
922                 length += s;
923             }
924             while (likely((endOnInput)?ip<iend-RUN_MASK:1) && (s==255));
925             //if ((sizeof(void*)==4) && unlikely(length>LZ4_MAX_INPUT_SIZE)) goto _output_error;   /* overflow detection */
926             if ((sizeof(void*)==4) && unlikely((size_t)(op+length)<(size_t)(op))) goto _output_error;   /* quickfix issue 134 */
927             if ((endOnInput) && (sizeof(void*)==4) && unlikely((size_t)(ip+length)<(size_t)(ip))) goto _output_error;   /* quickfix issue 134 */
928         }
929 
930         /* copy literals */
931         cpy = op+length;
932         if (((endOnInput) && ((cpy>(partialDecoding?oexit:oend-MFLIMIT)) || (ip+length>iend-(2+1+LASTLITERALS))) )
933             || ((!endOnInput) && (cpy>oend-COPYLENGTH)))
934         {
935             if (partialDecoding)
936             {
937                 if (cpy > oend) goto _output_error;                           /* Error : write attempt beyond end of output buffer */
938                 if ((endOnInput) && (ip+length > iend)) goto _output_error;   /* Error : read attempt beyond end of input buffer */
939             }
940             else
941             {
942                 if ((!endOnInput) && (cpy != oend)) goto _output_error;       /* Error : block decoding must stop exactly there */
943                 if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) goto _output_error;   /* Error : input must be consumed */
944             }
945             memcpy(op, ip, length);
946             ip += length;
947             op += length;
948             break;                                       /* Necessarily EOF, due to parsing restrictions */
949         }
950         LZ4_WILDCOPY(op, ip, cpy); ip -= (op-cpy); op = cpy;
951 
952         /* get offset */
953         LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2;
954         if ((checkOffset) && (unlikely(ref < lowLimit))) goto _output_error;   /* Error : offset outside destination buffer */
955 
956         /* get matchlength */
957         if ((length=(token&ML_MASK)) == ML_MASK)
958         {
959             unsigned s;
960             do
961             {
962                 if ((endOnInput) && (ip > iend-LASTLITERALS)) goto _output_error;
963                 s = *ip++;
964                 length += s;
965             } while (s==255);
966             //if ((sizeof(void*)==4) && unlikely(length>LZ4_MAX_INPUT_SIZE)) goto _output_error;   /* overflow detection */
967             if ((sizeof(void*)==4) && unlikely((size_t)(op+length)<(size_t)op)) goto _output_error;   /* quickfix issue 134 */
968         }
969 
970         /* check external dictionary */
971         if ((dict==usingExtDict) && (ref < (BYTE* const)dest))
972         {
973             if (unlikely(op+length+MINMATCH > oend-LASTLITERALS)) goto _output_error;
974 
975             if (length+MINMATCH <= (size_t)(dest-(char*)ref))
976             {
977                 ref = dictEnd - (dest-(char*)ref);
978                 memcpy(op, ref, length+MINMATCH);
979                 op += length+MINMATCH;
980             }
981             else
982             {
983                 size_t copySize = (size_t)(dest-(char*)ref);
984                 memcpy(op, dictEnd - copySize, copySize);
985                 op += copySize;
986                 copySize = length+MINMATCH - copySize;
987                 if (copySize > (size_t)((char*)op-dest))   /* overlap */
988                 {
989                     BYTE* const cpy = op + copySize;
990                     const BYTE* ref = (BYTE*)dest;
991                     while (op < cpy) *op++ = *ref++;
992                 }
993                 else
994                 {
995                     memcpy(op, dest, copySize);
996                     op += copySize;
997                 }
998             }
999             continue;
1000         }
1001 
1002         /* copy repeated sequence */
1003         if (unlikely((op-ref)<(int)STEPSIZE))
1004         {
1005             const size_t dec64 = dec64table[(sizeof(void*)==4) ? 0 : op-ref];
1006             op[0] = ref[0];
1007             op[1] = ref[1];
1008             op[2] = ref[2];
1009             op[3] = ref[3];
1010 #ifdef OLD
1011             op += 4, ref += 4; ref -= dec32table[op-ref];
1012             A32(op) = A32(ref);
1013             op += STEPSIZE-4; ref -= dec64;
1014 #else
1015             ref += dec32table[op-ref];
1016             A32(op+4) = A32(ref);
1017             op += STEPSIZE; ref -= dec64;
1018 #endif
1019         } else { LZ4_COPYSTEP(op,ref); }
1020         cpy = op + length - (STEPSIZE-4);
1021 
1022         if (unlikely(cpy>oend-COPYLENGTH-(STEPSIZE-4)))
1023         {
1024             if (cpy > oend-LASTLITERALS) goto _output_error;    /* Error : last 5 bytes must be literals */
1025             if (op<oend-COPYLENGTH) LZ4_WILDCOPY(op, ref, (oend-COPYLENGTH));
1026             while(op<cpy) *op++=*ref++;
1027             op=cpy;
1028             continue;
1029         }
1030         LZ4_WILDCOPY(op, ref, cpy);
1031         op=cpy;   /* correction */
1032     }
1033 
1034     /* end of decoding */
1035     if (endOnInput)
1036        return (int) (((char*)op)-dest);     /* Nb of output bytes decoded */
1037     else
1038        return (int) (((char*)ip)-source);   /* Nb of input bytes read */
1039 
1040     /* Overflow error detected */
1041 _output_error:
1042     return (int) (-(((char*)ip)-source))-1;
1043 }
1044 
1045 
LZ4_decompress_safe(const char * source,char * dest,int compressedSize,int maxOutputSize)1046 int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxOutputSize)
1047 {
1048     return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, noDict, NULL, 0);
1049 }
1050 
LZ4_decompress_safe_partial(const char * source,char * dest,int compressedSize,int targetOutputSize,int maxOutputSize)1051 int LZ4_decompress_safe_partial(const char* source, char* dest, int compressedSize, int targetOutputSize, int maxOutputSize)
1052 {
1053     return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, partial, targetOutputSize, noDict, NULL, 0);
1054 }
1055 
LZ4_decompress_fast(const char * source,char * dest,int originalSize)1056 int LZ4_decompress_fast(const char* source, char* dest, int originalSize)
1057 {
1058     return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, withPrefix64k, NULL, 0);
1059 }
1060 
1061 /* streaming decompression functions */
1062 
1063 //#define LZ4_STREAMDECODESIZE_U32 4
1064 //#define LZ4_STREAMDECODESIZE     (LZ4_STREAMDECODESIZE_U32 * sizeof(unsigned int))
1065 //typedef struct { unsigned int table[LZ4_STREAMDECODESIZE_U32]; } LZ4_streamDecode_t;
1066 typedef struct
1067 {
1068     const char* dictionary;
1069     int dictSize;
1070 } LZ4_streamDecode_t_internal;
1071 
1072 /*
1073  * If you prefer dynamic allocation methods,
1074  * LZ4_createStreamDecode()
1075  * provides a pointer (void*) towards an initialized LZ4_streamDecode_t structure.
1076  */
LZ4_createStreamDecode()1077 void* LZ4_createStreamDecode()
1078 {
1079     void* lz4s = ALLOCATOR(sizeof(U32), LZ4_STREAMDECODESIZE_U32);
1080     MEM_INIT(lz4s, 0, LZ4_STREAMDECODESIZE);
1081     return lz4s;
1082 }
1083 
1084 /*
1085  * LZ4_setDictDecode
1086  * Use this function to instruct where to find the dictionary
1087  * This function is not necessary if previous data is still available where it was decoded.
1088  * Loading a size of 0 is allowed (same effect as no dictionary).
1089  * Return : 1 if OK, 0 if error
1090  */
LZ4_setDictDecode(void * LZ4_streamDecode,const char * dictionary,int dictSize)1091 int LZ4_setDictDecode (void* LZ4_streamDecode, const char* dictionary, int dictSize)
1092 {
1093     LZ4_streamDecode_t_internal* lz4sd = (LZ4_streamDecode_t_internal*) LZ4_streamDecode;
1094     lz4sd->dictionary = dictionary;
1095     lz4sd->dictSize = dictSize;
1096     return 1;
1097 }
1098 
1099 /*
1100 *_continue() :
1101     These decoding functions allow decompression of multiple blocks in "streaming" mode.
1102     Previously decoded blocks must still be available at the memory position where they were decoded.
1103     If it's not possible, save the relevant part of decoded data into a safe buffer,
1104     and indicate where it stands using LZ4_setDictDecode()
1105 */
LZ4_decompress_safe_continue(void * LZ4_streamDecode,const char * source,char * dest,int compressedSize,int maxOutputSize)1106 int LZ4_decompress_safe_continue (void* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxOutputSize)
1107 {
1108     LZ4_streamDecode_t_internal* lz4sd = (LZ4_streamDecode_t_internal*) LZ4_streamDecode;
1109     int result;
1110 
1111     result = LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, usingExtDict, lz4sd->dictionary, lz4sd->dictSize);
1112     if (result <= 0) return result;
1113     if (lz4sd->dictionary + lz4sd->dictSize == dest)
1114     {
1115         lz4sd->dictSize += result;
1116     }
1117     else
1118     {
1119         lz4sd->dictionary = dest;
1120         lz4sd->dictSize = result;
1121     }
1122 
1123     return result;
1124 }
1125 
LZ4_decompress_fast_continue(void * LZ4_streamDecode,const char * source,char * dest,int originalSize)1126 int LZ4_decompress_fast_continue (void* LZ4_streamDecode, const char* source, char* dest, int originalSize)
1127 {
1128     LZ4_streamDecode_t_internal* lz4sd = (LZ4_streamDecode_t_internal*) LZ4_streamDecode;
1129     int result;
1130 
1131     result = LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, usingExtDict, lz4sd->dictionary, lz4sd->dictSize);
1132     if (result <= 0) return result;
1133     if (lz4sd->dictionary + lz4sd->dictSize == dest)
1134     {
1135         lz4sd->dictSize += result;
1136     }
1137     else
1138     {
1139         lz4sd->dictionary = dest;
1140         lz4sd->dictSize = result;
1141     }
1142 
1143     return result;
1144 }
1145 
1146 
1147 /*
1148 Advanced decoding functions :
1149 *_usingDict() :
1150     These decoding functions work the same as "_continue" ones,
1151     the dictionary must be explicitly provided within parameters
1152 */
1153 
LZ4_decompress_safe_usingDict(const char * source,char * dest,int compressedSize,int maxOutputSize,const char * dictStart,int dictSize)1154 int LZ4_decompress_safe_usingDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
1155 {
1156     return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, usingExtDict, dictStart, dictSize);
1157 }
1158 
LZ4_decompress_fast_usingDict(const char * source,char * dest,int originalSize,const char * dictStart,int dictSize)1159 int LZ4_decompress_fast_usingDict(const char* source, char* dest, int originalSize, const char* dictStart, int dictSize)
1160 {
1161     return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, usingExtDict, dictStart, dictSize);
1162 }
1163 
1164 
1165 /***************************************************
1166     Obsolete Functions
1167 ***************************************************/
1168 /*
1169 These function names are deprecated and should no longer be used.
1170 They are only provided here for compatibility with older user programs.
1171 - LZ4_uncompress is totally equivalent to LZ4_decompress_fast
1172 - LZ4_uncompress_unknownOutputSize is totally equivalent to LZ4_decompress_safe
1173 */
LZ4_uncompress(const char * source,char * dest,int outputSize)1174 int LZ4_uncompress (const char* source, char* dest, int outputSize) { return LZ4_decompress_fast(source, dest, outputSize); }
LZ4_uncompress_unknownOutputSize(const char * source,char * dest,int isize,int maxOutputSize)1175 int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize) { return LZ4_decompress_safe(source, dest, isize, maxOutputSize); }
1176 
1177 
1178 /* Obsolete Streaming functions */
1179 
LZ4_sizeofStreamState()1180 int LZ4_sizeofStreamState() { return LZ4_STREAMSIZE; }
1181 
LZ4_init(LZ4_stream_t_internal * lz4ds,const BYTE * base)1182 void LZ4_init(LZ4_stream_t_internal* lz4ds, const BYTE* base)
1183 {
1184     MEM_INIT(lz4ds, 0, LZ4_STREAMSIZE);
1185     lz4ds->bufferStart = base;
1186 }
1187 
LZ4_resetStreamState(void * state,const char * inputBuffer)1188 int LZ4_resetStreamState(void* state, const char* inputBuffer)
1189 {
1190     if ((((size_t)state) & 3) != 0) return 1;   /* Error : pointer is not aligned on 4-bytes boundary */
1191     LZ4_init((LZ4_stream_t_internal*)state, (const BYTE*)inputBuffer);
1192     return 0;
1193 }
1194 
LZ4_create(const char * inputBuffer)1195 void* LZ4_create (const char* inputBuffer)
1196 {
1197     void* lz4ds = ALLOCATOR(4, LZ4_STREAMSIZE_U32);
1198     LZ4_init ((LZ4_stream_t_internal*)lz4ds, (const BYTE*)inputBuffer);
1199     return lz4ds;
1200 }
1201 
LZ4_slideInputBuffer(void * LZ4_Data)1202 char* LZ4_slideInputBuffer (void* LZ4_Data)
1203 {
1204     LZ4_stream_t_internal* lz4ds = (LZ4_stream_t_internal*)LZ4_Data;
1205 
1206     LZ4_saveDict((LZ4_stream_t*)LZ4_Data, (char*)lz4ds->bufferStart, 64 KB);
1207 
1208     return (char*)(lz4ds->bufferStart + 64 KB);
1209 }
1210 
1211 /*  Obsolete compresson functions using User-allocated state */
1212 
LZ4_sizeofState()1213 int LZ4_sizeofState() { return LZ4_STREAMSIZE; }
1214 
LZ4_compress_withState(void * state,const char * source,char * dest,int inputSize)1215 int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize)
1216 {
1217     if (((size_t)(state)&3) != 0) return 0;   /* Error : state is not aligned on 4-bytes boundary */
1218     MEM_INIT(state, 0, LZ4_STREAMSIZE);
1219 
1220     if (inputSize < (int)LZ4_64KLIMIT)
1221         return LZ4_compress_generic(state, source, dest, inputSize, 0, notLimited, byU16, noDict, noDictIssue);
1222     else
1223         return LZ4_compress_generic(state, source, dest, inputSize, 0, notLimited, (sizeof(void*)==8) ? byU32 : byPtr, noDict, noDictIssue);
1224 }
1225 
LZ4_compress_limitedOutput_withState(void * state,const char * source,char * dest,int inputSize,int maxOutputSize)1226 int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize)
1227 {
1228     if (((size_t)(state)&3) != 0) return 0;   /* Error : state is not aligned on 4-bytes boundary */
1229     MEM_INIT(state, 0, LZ4_STREAMSIZE);
1230 
1231     if (inputSize < (int)LZ4_64KLIMIT)
1232         return LZ4_compress_generic(state, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue);
1233     else
1234         return LZ4_compress_generic(state, source, dest, inputSize, maxOutputSize, limitedOutput, (sizeof(void*)==8) ? byU32 : byPtr, noDict, noDictIssue);
1235 }
1236 
1237 /* Obsolete streaming decompression functions */
1238 
LZ4_decompress_safe_withPrefix64k(const char * source,char * dest,int compressedSize,int maxOutputSize)1239 int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize)
1240 {
1241     return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, withPrefix64k, NULL, 64 KB);
1242 }
1243 
LZ4_decompress_fast_withPrefix64k(const char * source,char * dest,int originalSize)1244 int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int originalSize)
1245 {
1246     return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, withPrefix64k, NULL, 64 KB);
1247 }
1248