1 /*
2 * Copyright (c) Meta Platforms, Inc. and affiliates.
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 "../zstd.h"
29 #define FSE_STATIC_LINKING_ONLY
30 #include "fse.h"
31 #include "huf.h"
32 #ifndef XXH_STATIC_LINKING_ONLY
33 # define XXH_STATIC_LINKING_ONLY /* XXH64_state_t */
34 #endif
35 #include "xxhash.h" /* XXH_reset, update, digest */
36 #ifndef ZSTD_NO_TRACE
37 # include "zstd_trace.h"
38 #else
39 # define ZSTD_TRACE 0
40 #endif
41
42 /* ---- static assert (debug) --- */
43 #define ZSTD_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)
44 #define ZSTD_isError ERR_isError /* for inlining */
45 #define FSE_isError ERR_isError
46 #define HUF_isError ERR_isError
47
48
49 /*-*************************************
50 * shared macros
51 ***************************************/
52 #undef MIN
53 #undef MAX
54 #define MIN(a,b) ((a)<(b) ? (a) : (b))
55 #define MAX(a,b) ((a)>(b) ? (a) : (b))
56 #define BOUNDED(min,val,max) (MAX(min,MIN(val,max)))
57
58
59 /*-*************************************
60 * Common constants
61 ***************************************/
62 #define ZSTD_OPT_NUM (1<<12)
63
64 #define ZSTD_REP_NUM 3 /* number of repcodes */
65 static UNUSED_ATTR const U32 repStartValue[ZSTD_REP_NUM] = { 1, 4, 8 };
66
67 #define KB *(1 <<10)
68 #define MB *(1 <<20)
69 #define GB *(1U<<30)
70
71 #define BIT7 128
72 #define BIT6 64
73 #define BIT5 32
74 #define BIT4 16
75 #define BIT1 2
76 #define BIT0 1
77
78 #define ZSTD_WINDOWLOG_ABSOLUTEMIN 10
79 static UNUSED_ATTR const size_t ZSTD_fcs_fieldSize[4] = { 0, 2, 4, 8 };
80 static UNUSED_ATTR const size_t ZSTD_did_fieldSize[4] = { 0, 1, 2, 4 };
81
82 #define ZSTD_FRAMEIDSIZE 4 /* magic number size */
83
84 #define ZSTD_BLOCKHEADERSIZE 3 /* C standard doesn't allow `static const` variable to be init using another `static const` variable */
85 static UNUSED_ATTR const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;
86 typedef enum { bt_raw, bt_rle, bt_compressed, bt_reserved } blockType_e;
87
88 #define ZSTD_FRAMECHECKSUMSIZE 4
89
90 #define MIN_SEQUENCES_SIZE 1 /* nbSeq==0 */
91 #define MIN_CBLOCK_SIZE (1 /*litCSize*/ + 1 /* RLE or RAW */) /* for a non-null block */
92 #define MIN_LITERALS_FOR_4_STREAMS 6
93
94 typedef enum { set_basic, set_rle, set_compressed, set_repeat } SymbolEncodingType_e;
95
96 #define LONGNBSEQ 0x7F00
97
98 #define MINMATCH 3
99
100 #define Litbits 8
101 #define LitHufLog 11
102 #define MaxLit ((1<<Litbits) - 1)
103 #define MaxML 52
104 #define MaxLL 35
105 #define DefaultMaxOff 28
106 #define MaxOff 31
107 #define MaxSeq MAX(MaxLL, MaxML) /* Assumption : MaxOff < MaxLL,MaxML */
108 #define MLFSELog 9
109 #define LLFSELog 9
110 #define OffFSELog 8
111 #define MaxFSELog MAX(MAX(MLFSELog, LLFSELog), OffFSELog)
112 #define MaxMLBits 16
113 #define MaxLLBits 16
114
115 #define ZSTD_MAX_HUF_HEADER_SIZE 128 /* header + <= 127 byte tree description */
116 /* Each table cannot take more than #symbols * FSELog bits */
117 #define ZSTD_MAX_FSE_HEADERS_SIZE (((MaxML + 1) * MLFSELog + (MaxLL + 1) * LLFSELog + (MaxOff + 1) * OffFSELog + 7) / 8)
118
119 static UNUSED_ATTR const U8 LL_bits[MaxLL+1] = {
120 0, 0, 0, 0, 0, 0, 0, 0,
121 0, 0, 0, 0, 0, 0, 0, 0,
122 1, 1, 1, 1, 2, 2, 3, 3,
123 4, 6, 7, 8, 9,10,11,12,
124 13,14,15,16
125 };
126 static UNUSED_ATTR const S16 LL_defaultNorm[MaxLL+1] = {
127 4, 3, 2, 2, 2, 2, 2, 2,
128 2, 2, 2, 2, 2, 1, 1, 1,
129 2, 2, 2, 2, 2, 2, 2, 2,
130 2, 3, 2, 1, 1, 1, 1, 1,
131 -1,-1,-1,-1
132 };
133 #define LL_DEFAULTNORMLOG 6 /* for static allocation */
134 static UNUSED_ATTR const U32 LL_defaultNormLog = LL_DEFAULTNORMLOG;
135
136 static UNUSED_ATTR const U8 ML_bits[MaxML+1] = {
137 0, 0, 0, 0, 0, 0, 0, 0,
138 0, 0, 0, 0, 0, 0, 0, 0,
139 0, 0, 0, 0, 0, 0, 0, 0,
140 0, 0, 0, 0, 0, 0, 0, 0,
141 1, 1, 1, 1, 2, 2, 3, 3,
142 4, 4, 5, 7, 8, 9,10,11,
143 12,13,14,15,16
144 };
145 static UNUSED_ATTR const S16 ML_defaultNorm[MaxML+1] = {
146 1, 4, 3, 2, 2, 2, 2, 2,
147 2, 1, 1, 1, 1, 1, 1, 1,
148 1, 1, 1, 1, 1, 1, 1, 1,
149 1, 1, 1, 1, 1, 1, 1, 1,
150 1, 1, 1, 1, 1, 1, 1, 1,
151 1, 1, 1, 1, 1, 1,-1,-1,
152 -1,-1,-1,-1,-1
153 };
154 #define ML_DEFAULTNORMLOG 6 /* for static allocation */
155 static UNUSED_ATTR const U32 ML_defaultNormLog = ML_DEFAULTNORMLOG;
156
157 static UNUSED_ATTR const S16 OF_defaultNorm[DefaultMaxOff+1] = {
158 1, 1, 1, 1, 1, 1, 2, 2,
159 2, 1, 1, 1, 1, 1, 1, 1,
160 1, 1, 1, 1, 1, 1, 1, 1,
161 -1,-1,-1,-1,-1
162 };
163 #define OF_DEFAULTNORMLOG 5 /* for static allocation */
164 static UNUSED_ATTR const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG;
165
166
167 /*-*******************************************
168 * Shared functions to include for inlining
169 *********************************************/
ZSTD_copy8(void * dst,const void * src)170 static void ZSTD_copy8(void* dst, const void* src) {
171 #if defined(ZSTD_ARCH_ARM_NEON)
172 vst1_u8((uint8_t*)dst, vld1_u8((const uint8_t*)src));
173 #else
174 ZSTD_memcpy(dst, src, 8);
175 #endif
176 }
177 #define COPY8(d,s) do { ZSTD_copy8(d,s); d+=8; s+=8; } while (0)
178
179 /* Need to use memmove here since the literal buffer can now be located within
180 the dst buffer. In circumstances where the op "catches up" to where the
181 literal buffer is, there can be partial overlaps in this call on the final
182 copy if the literal is being shifted by less than 16 bytes. */
ZSTD_copy16(void * dst,const void * src)183 static void ZSTD_copy16(void* dst, const void* src) {
184 #if defined(ZSTD_ARCH_ARM_NEON)
185 vst1q_u8((uint8_t*)dst, vld1q_u8((const uint8_t*)src));
186 #elif defined(ZSTD_ARCH_X86_SSE2)
187 _mm_storeu_si128((__m128i*)dst, _mm_loadu_si128((const __m128i*)src));
188 #elif defined(__clang__)
189 ZSTD_memmove(dst, src, 16);
190 #else
191 /* ZSTD_memmove is not inlined properly by gcc */
192 BYTE copy16_buf[16];
193 ZSTD_memcpy(copy16_buf, src, 16);
194 ZSTD_memcpy(dst, copy16_buf, 16);
195 #endif
196 }
197 #define COPY16(d,s) do { ZSTD_copy16(d,s); d+=16; s+=16; } while (0)
198
199 #define WILDCOPY_OVERLENGTH 32
200 #define WILDCOPY_VECLEN 16
201
202 typedef enum {
203 ZSTD_no_overlap,
204 ZSTD_overlap_src_before_dst
205 /* ZSTD_overlap_dst_before_src, */
206 } ZSTD_overlap_e;
207
208 /*! ZSTD_wildcopy() :
209 * Custom version of ZSTD_memcpy(), can over read/write up to WILDCOPY_OVERLENGTH bytes (if length==0)
210 * @param ovtype controls the overlap detection
211 * - ZSTD_no_overlap: The source and destination are guaranteed to be at least WILDCOPY_VECLEN bytes apart.
212 * - ZSTD_overlap_src_before_dst: The src and dst may overlap, but they MUST be at least 8 bytes apart.
213 * The src buffer must be before the dst buffer.
214 */
215 MEM_STATIC FORCE_INLINE_ATTR
ZSTD_wildcopy(void * dst,const void * src,ptrdiff_t length,ZSTD_overlap_e const ovtype)216 void ZSTD_wildcopy(void* dst, const void* src, ptrdiff_t length, ZSTD_overlap_e const ovtype)
217 {
218 ptrdiff_t diff = (BYTE*)dst - (const BYTE*)src;
219 const BYTE* ip = (const BYTE*)src;
220 BYTE* op = (BYTE*)dst;
221 BYTE* const oend = op + length;
222
223 if (ovtype == ZSTD_overlap_src_before_dst && diff < WILDCOPY_VECLEN) {
224 /* Handle short offset copies. */
225 do {
226 COPY8(op, ip);
227 } while (op < oend);
228 } else {
229 assert(diff >= WILDCOPY_VECLEN || diff <= -WILDCOPY_VECLEN);
230 /* Separate out the first COPY16() call because the copy length is
231 * almost certain to be short, so the branches have different
232 * probabilities. Since it is almost certain to be short, only do
233 * one COPY16() in the first call. Then, do two calls per loop since
234 * at that point it is more likely to have a high trip count.
235 */
236 ZSTD_copy16(op, ip);
237 if (16 >= length) return;
238 op += 16;
239 ip += 16;
240 do {
241 COPY16(op, ip);
242 COPY16(op, ip);
243 }
244 while (op < oend);
245 }
246 }
247
ZSTD_limitCopy(void * dst,size_t dstCapacity,const void * src,size_t srcSize)248 MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
249 {
250 size_t const length = MIN(dstCapacity, srcSize);
251 if (length > 0) {
252 ZSTD_memcpy(dst, src, length);
253 }
254 return length;
255 }
256
257 /* define "workspace is too large" as this number of times larger than needed */
258 #define ZSTD_WORKSPACETOOLARGE_FACTOR 3
259
260 /* when workspace is continuously too large
261 * during at least this number of times,
262 * context's memory usage is considered wasteful,
263 * because it's sized to handle a worst case scenario which rarely happens.
264 * In which case, resize it down to free some memory */
265 #define ZSTD_WORKSPACETOOLARGE_MAXDURATION 128
266
267 /* Controls whether the input/output buffer is buffered or stable. */
268 typedef enum {
269 ZSTD_bm_buffered = 0, /* Buffer the input/output */
270 ZSTD_bm_stable = 1 /* ZSTD_inBuffer/ZSTD_outBuffer is stable */
271 } ZSTD_bufferMode_e;
272
273
274 /*-*******************************************
275 * Private declarations
276 *********************************************/
277
278 /**
279 * Contains the compressed frame size and an upper-bound for the decompressed frame size.
280 * Note: before using `compressedSize`, check for errors using ZSTD_isError().
281 * similarly, before using `decompressedBound`, check for errors using:
282 * `decompressedBound != ZSTD_CONTENTSIZE_ERROR`
283 */
284 typedef struct {
285 size_t nbBlocks;
286 size_t compressedSize;
287 unsigned long long decompressedBound;
288 } ZSTD_frameSizeInfo; /* decompress & legacy */
289
290 /* ZSTD_invalidateRepCodes() :
291 * ensures next compression will not use repcodes from previous block.
292 * Note : only works with regular variant;
293 * do not use with extDict variant ! */
294 void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx); /* zstdmt, adaptive_compression (shouldn't get this definition from here) */
295
296
297 typedef struct {
298 blockType_e blockType;
299 U32 lastBlock;
300 U32 origSize;
301 } blockProperties_t; /* declared here for decompress and fullbench */
302
303 /*! ZSTD_getcBlockSize() :
304 * Provides the size of compressed block from block header `src` */
305 /* Used by: decompress, fullbench */
306 size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
307 blockProperties_t* bpPtr);
308
309 /*! ZSTD_decodeSeqHeaders() :
310 * decode sequence header from src */
311 /* Used by: zstd_decompress_block, fullbench */
312 size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
313 const void* src, size_t srcSize);
314
315 /**
316 * @returns true iff the CPU supports dynamic BMI2 dispatch.
317 */
ZSTD_cpuSupportsBmi2(void)318 MEM_STATIC int ZSTD_cpuSupportsBmi2(void)
319 {
320 ZSTD_cpuid_t cpuid = ZSTD_cpuid();
321 return ZSTD_cpuid_bmi1(cpuid) && ZSTD_cpuid_bmi2(cpuid);
322 }
323
324 #endif /* ZSTD_CCOMMON_H_MODULE */
325