1 /*
2 * Copyright (c) Yann Collet, Facebook, Inc.
3 * All rights reserved.
4 *
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
9 */
10
11 #ifndef ZSTD_CCOMMON_H_MODULE
12 #define ZSTD_CCOMMON_H_MODULE
13
14 /* this module contains definitions which must be identical
15 * across compression, decompression and dictBuilder.
16 * It also contains a few functions useful to at least 2 of them
17 * and which benefit from being inlined */
18
19 /*-*************************************
20 * Dependencies
21 ***************************************/
22 #include "compiler.h"
23 #include "cpu.h"
24 #include "mem.h"
25 #include "debug.h" /* assert, DEBUGLOG, RAWLOG, g_debuglevel */
26 #include "error_private.h"
27 #define ZSTD_STATIC_LINKING_ONLY
28 #include <linux/zstd.h>
29 #define FSE_STATIC_LINKING_ONLY
30 #include "fse.h"
31 #define HUF_STATIC_LINKING_ONLY
32 #include "huf.h"
33 #include <linux/xxhash.h> /* XXH_reset, update, digest */
34 #define ZSTD_TRACE 0
35
36
37 /* ---- static assert (debug) --- */
38 #define ZSTD_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)
39 #define ZSTD_isError ERR_isError /* for inlining */
40 #define FSE_isError ERR_isError
41 #define HUF_isError ERR_isError
42
43
44 /*-*************************************
45 * shared macros
46 ***************************************/
47 #undef MIN
48 #undef MAX
49 #define MIN(a,b) ((a)<(b) ? (a) : (b))
50 #define MAX(a,b) ((a)>(b) ? (a) : (b))
51 #define BOUNDED(min,val,max) (MAX(min,MIN(val,max)))
52
53
54 /*-*************************************
55 * Common constants
56 ***************************************/
57 #define ZSTD_OPT_NUM (1<<12)
58
59 #define ZSTD_REP_NUM 3 /* number of repcodes */
60 static UNUSED_ATTR const U32 repStartValue[ZSTD_REP_NUM] = { 1, 4, 8 };
61
62 #define KB *(1 <<10)
63 #define MB *(1 <<20)
64 #define GB *(1U<<30)
65
66 #define BIT7 128
67 #define BIT6 64
68 #define BIT5 32
69 #define BIT4 16
70 #define BIT1 2
71 #define BIT0 1
72
73 #define ZSTD_WINDOWLOG_ABSOLUTEMIN 10
74 static UNUSED_ATTR const size_t ZSTD_fcs_fieldSize[4] = { 0, 2, 4, 8 };
75 static UNUSED_ATTR const size_t ZSTD_did_fieldSize[4] = { 0, 1, 2, 4 };
76
77 #define ZSTD_FRAMEIDSIZE 4 /* magic number size */
78
79 #define ZSTD_BLOCKHEADERSIZE 3 /* C standard doesn't allow `static const` variable to be init using another `static const` variable */
80 static UNUSED_ATTR const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;
81 typedef enum { bt_raw, bt_rle, bt_compressed, bt_reserved } blockType_e;
82
83 #define ZSTD_FRAMECHECKSUMSIZE 4
84
85 #define MIN_SEQUENCES_SIZE 1 /* nbSeq==0 */
86 #define MIN_CBLOCK_SIZE (1 /*litCSize*/ + 1 /* RLE or RAW */ + MIN_SEQUENCES_SIZE /* nbSeq==0 */) /* for a non-null block */
87
88 #define HufLog 12
89 typedef enum { set_basic, set_rle, set_compressed, set_repeat } symbolEncodingType_e;
90
91 #define LONGNBSEQ 0x7F00
92
93 #define MINMATCH 3
94
95 #define Litbits 8
96 #define MaxLit ((1<<Litbits) - 1)
97 #define MaxML 52
98 #define MaxLL 35
99 #define DefaultMaxOff 28
100 #define MaxOff 31
101 #define MaxSeq MAX(MaxLL, MaxML) /* Assumption : MaxOff < MaxLL,MaxML */
102 #define MLFSELog 9
103 #define LLFSELog 9
104 #define OffFSELog 8
105 #define MaxFSELog MAX(MAX(MLFSELog, LLFSELog), OffFSELog)
106
107 #define ZSTD_MAX_HUF_HEADER_SIZE 128 /* header + <= 127 byte tree description */
108 /* Each table cannot take more than #symbols * FSELog bits */
109 #define ZSTD_MAX_FSE_HEADERS_SIZE (((MaxML + 1) * MLFSELog + (MaxLL + 1) * LLFSELog + (MaxOff + 1) * OffFSELog + 7) / 8)
110
111 static UNUSED_ATTR const U8 LL_bits[MaxLL+1] = {
112 0, 0, 0, 0, 0, 0, 0, 0,
113 0, 0, 0, 0, 0, 0, 0, 0,
114 1, 1, 1, 1, 2, 2, 3, 3,
115 4, 6, 7, 8, 9,10,11,12,
116 13,14,15,16
117 };
118 static UNUSED_ATTR const S16 LL_defaultNorm[MaxLL+1] = {
119 4, 3, 2, 2, 2, 2, 2, 2,
120 2, 2, 2, 2, 2, 1, 1, 1,
121 2, 2, 2, 2, 2, 2, 2, 2,
122 2, 3, 2, 1, 1, 1, 1, 1,
123 -1,-1,-1,-1
124 };
125 #define LL_DEFAULTNORMLOG 6 /* for static allocation */
126 static UNUSED_ATTR const U32 LL_defaultNormLog = LL_DEFAULTNORMLOG;
127
128 static UNUSED_ATTR const U8 ML_bits[MaxML+1] = {
129 0, 0, 0, 0, 0, 0, 0, 0,
130 0, 0, 0, 0, 0, 0, 0, 0,
131 0, 0, 0, 0, 0, 0, 0, 0,
132 0, 0, 0, 0, 0, 0, 0, 0,
133 1, 1, 1, 1, 2, 2, 3, 3,
134 4, 4, 5, 7, 8, 9,10,11,
135 12,13,14,15,16
136 };
137 static UNUSED_ATTR const S16 ML_defaultNorm[MaxML+1] = {
138 1, 4, 3, 2, 2, 2, 2, 2,
139 2, 1, 1, 1, 1, 1, 1, 1,
140 1, 1, 1, 1, 1, 1, 1, 1,
141 1, 1, 1, 1, 1, 1, 1, 1,
142 1, 1, 1, 1, 1, 1, 1, 1,
143 1, 1, 1, 1, 1, 1,-1,-1,
144 -1,-1,-1,-1,-1
145 };
146 #define ML_DEFAULTNORMLOG 6 /* for static allocation */
147 static UNUSED_ATTR const U32 ML_defaultNormLog = ML_DEFAULTNORMLOG;
148
149 static UNUSED_ATTR const S16 OF_defaultNorm[DefaultMaxOff+1] = {
150 1, 1, 1, 1, 1, 1, 2, 2,
151 2, 1, 1, 1, 1, 1, 1, 1,
152 1, 1, 1, 1, 1, 1, 1, 1,
153 -1,-1,-1,-1,-1
154 };
155 #define OF_DEFAULTNORMLOG 5 /* for static allocation */
156 static UNUSED_ATTR const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG;
157
158
159 /*-*******************************************
160 * Shared functions to include for inlining
161 *********************************************/
162 static void ZSTD_copy8(void* dst, const void* src) {
163 #if defined(ZSTD_ARCH_ARM_NEON)
164 vst1_u8((uint8_t*)dst, vld1_u8((const uint8_t*)src));
165 #else
166 ZSTD_memcpy(dst, src, 8);
167 #endif
168 }
169 #define COPY8(d,s) { ZSTD_copy8(d,s); d+=8; s+=8; }
170
171 /* Need to use memmove here since the literal buffer can now be located within
172 the dst buffer. In circumstances where the op "catches up" to where the
173 literal buffer is, there can be partial overlaps in this call on the final
174 copy if the literal is being shifted by less than 16 bytes. */
175 static void ZSTD_copy16(void* dst, const void* src) {
176 #if defined(ZSTD_ARCH_ARM_NEON)
177 vst1q_u8((uint8_t*)dst, vld1q_u8((const uint8_t*)src));
178 #elif defined(ZSTD_ARCH_X86_SSE2)
179 _mm_storeu_si128((__m128i*)dst, _mm_loadu_si128((const __m128i*)src));
180 #elif defined(__clang__)
181 ZSTD_memmove(dst, src, 16);
182 #else
183 /* ZSTD_memmove is not inlined properly by gcc */
184 BYTE copy16_buf[16];
185 ZSTD_memcpy(copy16_buf, src, 16);
186 ZSTD_memcpy(dst, copy16_buf, 16);
187 #endif
188 }
189 #define COPY16(d,s) { ZSTD_copy16(d,s); d+=16; s+=16; }
190
191 #define WILDCOPY_OVERLENGTH 32
192 #define WILDCOPY_VECLEN 16
193
194 typedef enum {
195 ZSTD_no_overlap,
196 ZSTD_overlap_src_before_dst
197 /* ZSTD_overlap_dst_before_src, */
198 } ZSTD_overlap_e;
199
200 /*! ZSTD_wildcopy() :
201 * Custom version of ZSTD_memcpy(), can over read/write up to WILDCOPY_OVERLENGTH bytes (if length==0)
202 * @param ovtype controls the overlap detection
203 * - ZSTD_no_overlap: The source and destination are guaranteed to be at least WILDCOPY_VECLEN bytes apart.
204 * - ZSTD_overlap_src_before_dst: The src and dst may overlap, but they MUST be at least 8 bytes apart.
205 * The src buffer must be before the dst buffer.
206 */
207 MEM_STATIC FORCE_INLINE_ATTR
208 void ZSTD_wildcopy(void* dst, const void* src, ptrdiff_t length, ZSTD_overlap_e const ovtype)
209 {
210 ptrdiff_t diff = (BYTE*)dst - (const BYTE*)src;
211 const BYTE* ip = (const BYTE*)src;
212 BYTE* op = (BYTE*)dst;
213 BYTE* const oend = op + length;
214
215 if (ovtype == ZSTD_overlap_src_before_dst && diff < WILDCOPY_VECLEN) {
216 /* Handle short offset copies. */
217 do {
218 COPY8(op, ip)
219 } while (op < oend);
220 } else {
221 assert(diff >= WILDCOPY_VECLEN || diff <= -WILDCOPY_VECLEN);
222 /* Separate out the first COPY16() call because the copy length is
223 * almost certain to be short, so the branches have different
224 * probabilities. Since it is almost certain to be short, only do
225 * one COPY16() in the first call. Then, do two calls per loop since
226 * at that point it is more likely to have a high trip count.
227 */
228 #ifdef __aarch64__
229 do {
230 COPY16(op, ip);
231 }
232 while (op < oend);
233 #else
234 ZSTD_copy16(op, ip);
235 if (16 >= length) return;
236 op += 16;
237 ip += 16;
238 do {
239 COPY16(op, ip);
240 COPY16(op, ip);
241 }
242 while (op < oend);
243 #endif
244 }
245 }
246
247 MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
248 {
249 size_t const length = MIN(dstCapacity, srcSize);
250 if (length > 0) {
251 ZSTD_memcpy(dst, src, length);
252 }
253 return length;
254 }
255
256 /* define "workspace is too large" as this number of times larger than needed */
257 #define ZSTD_WORKSPACETOOLARGE_FACTOR 3
258
259 /* when workspace is continuously too large
260 * during at least this number of times,
261 * context's memory usage is considered wasteful,
262 * because it's sized to handle a worst case scenario which rarely happens.
263 * In which case, resize it down to free some memory */
264 #define ZSTD_WORKSPACETOOLARGE_MAXDURATION 128
265
266 /* Controls whether the input/output buffer is buffered or stable. */
267 typedef enum {
268 ZSTD_bm_buffered = 0, /* Buffer the input/output */
269 ZSTD_bm_stable = 1 /* ZSTD_inBuffer/ZSTD_outBuffer is stable */
270 } ZSTD_bufferMode_e;
271
272
273 /*-*******************************************
274 * Private declarations
275 *********************************************/
276 typedef struct seqDef_s {
277 U32 offBase; /* offBase == Offset + ZSTD_REP_NUM, or repcode 1,2,3 */
278 U16 litLength;
279 U16 mlBase; /* mlBase == matchLength - MINMATCH */
280 } seqDef;
281
282 /* Controls whether seqStore has a single "long" litLength or matchLength. See seqStore_t. */
283 typedef enum {
284 ZSTD_llt_none = 0, /* no longLengthType */
285 ZSTD_llt_literalLength = 1, /* represents a long literal */
286 ZSTD_llt_matchLength = 2 /* represents a long match */
287 } ZSTD_longLengthType_e;
288
289 typedef struct {
290 seqDef* sequencesStart;
291 seqDef* sequences; /* ptr to end of sequences */
292 BYTE* litStart;
293 BYTE* lit; /* ptr to end of literals */
294 BYTE* llCode;
295 BYTE* mlCode;
296 BYTE* ofCode;
297 size_t maxNbSeq;
298 size_t maxNbLit;
299
300 /* longLengthPos and longLengthType to allow us to represent either a single litLength or matchLength
301 * in the seqStore that has a value larger than U16 (if it exists). To do so, we increment
302 * the existing value of the litLength or matchLength by 0x10000.
303 */
304 ZSTD_longLengthType_e longLengthType;
305 U32 longLengthPos; /* Index of the sequence to apply long length modification to */
306 } seqStore_t;
307
308 typedef struct {
309 U32 litLength;
310 U32 matchLength;
311 } ZSTD_sequenceLength;
312
313 /*
314 * Returns the ZSTD_sequenceLength for the given sequences. It handles the decoding of long sequences
315 * indicated by longLengthPos and longLengthType, and adds MINMATCH back to matchLength.
316 */
317 MEM_STATIC ZSTD_sequenceLength ZSTD_getSequenceLength(seqStore_t const* seqStore, seqDef const* seq)
318 {
319 ZSTD_sequenceLength seqLen;
320 seqLen.litLength = seq->litLength;
321 seqLen.matchLength = seq->mlBase + MINMATCH;
322 if (seqStore->longLengthPos == (U32)(seq - seqStore->sequencesStart)) {
323 if (seqStore->longLengthType == ZSTD_llt_literalLength) {
324 seqLen.litLength += 0xFFFF;
325 }
326 if (seqStore->longLengthType == ZSTD_llt_matchLength) {
327 seqLen.matchLength += 0xFFFF;
328 }
329 }
330 return seqLen;
331 }
332
333 /*
334 * Contains the compressed frame size and an upper-bound for the decompressed frame size.
335 * Note: before using `compressedSize`, check for errors using ZSTD_isError().
336 * similarly, before using `decompressedBound`, check for errors using:
337 * `decompressedBound != ZSTD_CONTENTSIZE_ERROR`
338 */
339 typedef struct {
340 size_t compressedSize;
341 unsigned long long decompressedBound;
342 } ZSTD_frameSizeInfo; /* decompress & legacy */
343
344 const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx); /* compress & dictBuilder */
345 void ZSTD_seqToCodes(const seqStore_t* seqStorePtr); /* compress, dictBuilder, decodeCorpus (shouldn't get its definition from here) */
346
347 /* custom memory allocation functions */
348 void* ZSTD_customMalloc(size_t size, ZSTD_customMem customMem);
349 void* ZSTD_customCalloc(size_t size, ZSTD_customMem customMem);
350 void ZSTD_customFree(void* ptr, ZSTD_customMem customMem);
351
352
353 MEM_STATIC U32 ZSTD_highbit32(U32 val) /* compress, dictBuilder, decodeCorpus */
354 {
355 assert(val != 0);
356 {
357 # if (__GNUC__ >= 3) /* GCC Intrinsic */
358 return __builtin_clz (val) ^ 31;
359 # else /* Software version */
360 static const U32 DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
361 U32 v = val;
362 v |= v >> 1;
363 v |= v >> 2;
364 v |= v >> 4;
365 v |= v >> 8;
366 v |= v >> 16;
367 return DeBruijnClz[(v * 0x07C4ACDDU) >> 27];
368 # endif
369 }
370 }
371
372 /*
373 * Counts the number of trailing zeros of a `size_t`.
374 * Most compilers should support CTZ as a builtin. A backup
375 * implementation is provided if the builtin isn't supported, but
376 * it may not be terribly efficient.
377 */
378 MEM_STATIC unsigned ZSTD_countTrailingZeros(size_t val)
379 {
380 if (MEM_64bits()) {
381 # if (__GNUC__ >= 4)
382 return __builtin_ctzll((U64)val);
383 # else
384 static const int DeBruijnBytePos[64] = { 0, 1, 2, 7, 3, 13, 8, 19,
385 4, 25, 14, 28, 9, 34, 20, 56,
386 5, 17, 26, 54, 15, 41, 29, 43,
387 10, 31, 38, 35, 21, 45, 49, 57,
388 63, 6, 12, 18, 24, 27, 33, 55,
389 16, 53, 40, 42, 30, 37, 44, 48,
390 62, 11, 23, 32, 52, 39, 36, 47,
391 61, 22, 51, 46, 60, 50, 59, 58 };
392 return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
393 # endif
394 } else { /* 32 bits */
395 # if (__GNUC__ >= 3)
396 return __builtin_ctz((U32)val);
397 # else
398 static const int DeBruijnBytePos[32] = { 0, 1, 28, 2, 29, 14, 24, 3,
399 30, 22, 20, 15, 25, 17, 4, 8,
400 31, 27, 13, 23, 21, 19, 16, 7,
401 26, 12, 18, 6, 11, 5, 10, 9 };
402 return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
403 # endif
404 }
405 }
406
407
408 /* ZSTD_invalidateRepCodes() :
409 * ensures next compression will not use repcodes from previous block.
410 * Note : only works with regular variant;
411 * do not use with extDict variant ! */
412 void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx); /* zstdmt, adaptive_compression (shouldn't get this definition from here) */
413
414
415 typedef struct {
416 blockType_e blockType;
417 U32 lastBlock;
418 U32 origSize;
419 } blockProperties_t; /* declared here for decompress and fullbench */
420
421 /*! ZSTD_getcBlockSize() :
422 * Provides the size of compressed block from block header `src` */
423 /* Used by: decompress, fullbench (does not get its definition from here) */
424 size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
425 blockProperties_t* bpPtr);
426
427 /*! ZSTD_decodeSeqHeaders() :
428 * decode sequence header from src */
429 /* Used by: decompress, fullbench (does not get its definition from here) */
430 size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
431 const void* src, size_t srcSize);
432
433 /*
434 * @returns true iff the CPU supports dynamic BMI2 dispatch.
435 */
436 MEM_STATIC int ZSTD_cpuSupportsBmi2(void)
437 {
438 ZSTD_cpuid_t cpuid = ZSTD_cpuid();
439 return ZSTD_cpuid_bmi1(cpuid) && ZSTD_cpuid_bmi2(cpuid);
440 }
441
442
443 #endif /* ZSTD_CCOMMON_H_MODULE */
444
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