lib/zstd/zstd_internal.h

   1 /**
   2  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under the BSD-style license found in the
   6  * LICENSE file in the root directory of https://github.com/facebook/zstd.
   7  * An additional grant of patent rights can be found in the PATENTS file in the
   8  * same directory.
   9  *
  10  * This program is free software; you can redistribute it and/or modify it under
  11  * the terms of the GNU General Public License version 2 as published by the
  12  * Free Software Foundation. This program is dual-licensed; you may select
  13  * either version 2 of the GNU General Public License ("GPL") or BSD license
  14  * ("BSD").
  15  */
  16
  17 #ifndef ZSTD_CCOMMON_H_MODULE
  18 #define ZSTD_CCOMMON_H_MODULE
  19
  20 /*-*******************************************************
  21 *  Compiler specifics
  22 *********************************************************/
  23 #define FORCE_INLINE static __always_inline
  24 #define FORCE_NOINLINE static noinline
  25
  26 /*-*************************************
  27 *  Dependencies
  28 ***************************************/
  29 #include "error_private.h"
  30 #include "mem.h"
  31 #include <linux/compiler.h>
  32 #include <linux/kernel.h>
  33 #include <linux/xxhash.h>
  34 #include <linux/zstd.h>
  35
  36 /*-*************************************
  37 *  shared macros
  38 ***************************************/
  39 #define MIN(a, b) ((a) < (b) ? (a) : (b))
  40 #define MAX(a, b) ((a) > (b) ? (a) : (b))
  41 #define CHECK_F(f)                       \
  42         {                                \
  43                 size_t const errcod = f; \
  44                 if (ERR_isError(errcod)) \
  45                         return errcod;   \
  46         } /* check and Forward error code */
  47 #define CHECK_E(f, e)                    \
  48         {                                \
  49                 size_t const errcod = f; \
  50                 if (ERR_isError(errcod)) \
  51                         return ERROR(e); \
  52         } /* check and send Error code */
  53 #define ZSTD_STATIC_ASSERT(c)                                   \
  54         {                                                       \
  55                 enum { ZSTD_static_assert = 1 / (int)(!!(c)) }; \
  56         }
  57
  58 /*-*************************************
  59 *  Common constants
  60 ***************************************/
  61 #define ZSTD_OPT_NUM (1 << 12)
  62 #define ZSTD_DICT_MAGIC 0xEC30A437 /* v0.7+ */
  63
  64 #define ZSTD_REP_NUM 3                /* number of repcodes */
  65 #define ZSTD_REP_CHECK (ZSTD_REP_NUM) /* number of repcodes to check by the optimal parser */
  66 #define ZSTD_REP_MOVE (ZSTD_REP_NUM - 1)
  67 #define ZSTD_REP_MOVE_OPT (ZSTD_REP_NUM)
  68 static const U32 repStartValue[ZSTD_REP_NUM] = {1, 4, 8};
  69
  70 #define KB *(1 << 10)
  71 #define MB *(1 << 20)
  72 #define GB *(1U << 30)
  73
  74 #define BIT7 128
  75 #define BIT6 64
  76 #define BIT5 32
  77 #define BIT4 16
  78 #define BIT1 2
  79 #define BIT0 1
  80
  81 #define ZSTD_WINDOWLOG_ABSOLUTEMIN 10
  82 static const size_t ZSTD_fcs_fieldSize[4] = {0, 2, 4, 8};
  83 static const size_t ZSTD_did_fieldSize[4] = {0, 1, 2, 4};
  84
  85 #define ZSTD_BLOCKHEADERSIZE 3 /* C standard doesn't allow `static const` variable to be init using another `static const` variable */
  86 static const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;
  87 typedef enum { bt_raw, bt_rle, bt_compressed, bt_reserved } blockType_e;
  88
  89 #define MIN_SEQUENCES_SIZE 1                                                                      /* nbSeq==0 */
  90 #define MIN_CBLOCK_SIZE (1 /*litCSize*/ + 1 /* RLE or RAW */ + MIN_SEQUENCES_SIZE /* nbSeq==0 */) /* for a non-null block */
  91
  92 #define HufLog 12
  93 typedef enum { set_basic, set_rle, set_compressed, set_repeat } symbolEncodingType_e;
  94
  95 #define LONGNBSEQ 0x7F00
  96
  97 #define MINMATCH 3
  98 #define EQUAL_READ32 4
  99
 100 #define Litbits 8
 101 #define MaxLit ((1 << Litbits) - 1)
 102 #define MaxML 52
 103 #define MaxLL 35
 104 #define MaxOff 28
 105 #define MaxSeq MAX(MaxLL, MaxML) /* Assumption : MaxOff < MaxLL,MaxML */
 106 #define MLFSELog 9
 107 #define LLFSELog 9
 108 #define OffFSELog 8
 109
 110 static const U32 LL_bits[MaxLL + 1] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
 111 static const S16 LL_defaultNorm[MaxLL + 1] = {4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1, -1, -1, -1, -1};
 112 #define LL_DEFAULTNORMLOG 6 /* for static allocation */
 113 static const U32 LL_defaultNormLog = LL_DEFAULTNORMLOG;
 114
 115 static const U32 ML_bits[MaxML + 1] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0,  0,  0,  0,  0,  0, 0,
 116                                        0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
 117 static const S16 ML_defaultNorm[MaxML + 1] = {1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1,  1,  1,  1,  1, 1,
 118                                               1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1};
 119 #define ML_DEFAULTNORMLOG 6 /* for static allocation */
 120 static const U32 ML_defaultNormLog = ML_DEFAULTNORMLOG;
 121
 122 static const S16 OF_defaultNorm[MaxOff + 1] = {1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1};
 123 #define OF_DEFAULTNORMLOG 5 /* for static allocation */
 124 static const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG;
 125
 126 /*-*******************************************
 127 *  Shared functions to include for inlining
 128 *********************************************/
 129 ZSTD_STATIC void ZSTD_copy8(void *dst, const void *src) {
 130         memcpy(dst, src, 8);
 131 }
 132 /*! ZSTD_wildcopy() :
 133 *   custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */
 134 #define WILDCOPY_OVERLENGTH 8
 135 ZSTD_STATIC void ZSTD_wildcopy(void *dst, const void *src, ptrdiff_t length)
 136 {
 137         const BYTE* ip = (const BYTE*)src;
 138         BYTE* op = (BYTE*)dst;
 139         BYTE* const oend = op + length;
 140         /* Work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388.
 141          * Avoid the bad case where the loop only runs once by handling the
 142          * special case separately. This doesn't trigger the bug because it
 143          * doesn't involve pointer/integer overflow.
 144          */
 145         if (length <= 8)
 146                 return ZSTD_copy8(dst, src);
 147         do {
 148                 ZSTD_copy8(op, ip);
 149                 op += 8;
 150                 ip += 8;
 151         } while (op < oend);
 152 }
 153
 154 /*-*******************************************
 155 *  Private interfaces
 156 *********************************************/
 157 typedef struct ZSTD_stats_s ZSTD_stats_t;
 158
 159 typedef struct {
 160         U32 off;
 161         U32 len;
 162 } ZSTD_match_t;
 163
 164 typedef struct {
 165         U32 price;
 166         U32 off;
 167         U32 mlen;
 168         U32 litlen;
 169         U32 rep[ZSTD_REP_NUM];
 170 } ZSTD_optimal_t;
 171
 172 typedef struct seqDef_s {
 173         U32 offset;
 174         U16 litLength;
 175         U16 matchLength;
 176 } seqDef;
 177
 178 typedef struct {
 179         seqDef *sequencesStart;
 180         seqDef *sequences;
 181         BYTE *litStart;
 182         BYTE *lit;
 183         BYTE *llCode;
 184         BYTE *mlCode;
 185         BYTE *ofCode;
 186         U32 longLengthID; /* 0 == no longLength; 1 == Lit.longLength; 2 == Match.longLength; */
 187         U32 longLengthPos;
 188         /* opt */
 189         ZSTD_optimal_t *priceTable;
 190         ZSTD_match_t *matchTable;
 191         U32 *matchLengthFreq;
 192         U32 *litLengthFreq;
 193         U32 *litFreq;
 194         U32 *offCodeFreq;
 195         U32 matchLengthSum;
 196         U32 matchSum;
 197         U32 litLengthSum;
 198         U32 litSum;
 199         U32 offCodeSum;
 200         U32 log2matchLengthSum;
 201         U32 log2matchSum;
 202         U32 log2litLengthSum;
 203         U32 log2litSum;
 204         U32 log2offCodeSum;
 205         U32 factor;
 206         U32 staticPrices;
 207         U32 cachedPrice;
 208         U32 cachedLitLength;
 209         const BYTE *cachedLiterals;
 210 } seqStore_t;
 211
 212 const seqStore_t *ZSTD_getSeqStore(const ZSTD_CCtx *ctx);
 213 void ZSTD_seqToCodes(const seqStore_t *seqStorePtr);
 214 int ZSTD_isSkipFrame(ZSTD_DCtx *dctx);
 215
 216 /*= Custom memory allocation functions */
 217 typedef void *(*ZSTD_allocFunction)(void *opaque, size_t size);
 218 typedef void (*ZSTD_freeFunction)(void *opaque, void *address);
 219 typedef struct {
 220         ZSTD_allocFunction customAlloc;
 221         ZSTD_freeFunction customFree;
 222         void *opaque;
 223 } ZSTD_customMem;
 224
 225 void *ZSTD_malloc(size_t size, ZSTD_customMem customMem);
 226 void ZSTD_free(void *ptr, ZSTD_customMem customMem);
 227
 228 /*====== stack allocation  ======*/
 229
 230 typedef struct {
 231         void *ptr;
 232         const void *end;
 233 } ZSTD_stack;
 234
 235 #define ZSTD_ALIGN(x) ALIGN(x, sizeof(size_t))
 236 #define ZSTD_PTR_ALIGN(p) PTR_ALIGN(p, sizeof(size_t))
 237
 238 ZSTD_customMem ZSTD_initStack(void *workspace, size_t workspaceSize);
 239
 240 void *ZSTD_stackAllocAll(void *opaque, size_t *size);
 241 void *ZSTD_stackAlloc(void *opaque, size_t size);
 242 void ZSTD_stackFree(void *opaque, void *address);
 243
 244 /*======  common function  ======*/
 245
 246 ZSTD_STATIC U32 ZSTD_highbit32(U32 val) { return 31 - __builtin_clz(val); }
 247
 248 /* hidden functions */
 249
 250 /* ZSTD_invalidateRepCodes() :
 251  * ensures next compression will not use repcodes from previous block.
 252  * Note : only works with regular variant;
 253  *        do not use with extDict variant ! */
 254 void ZSTD_invalidateRepCodes(ZSTD_CCtx *cctx);
 255
 256 size_t ZSTD_freeCCtx(ZSTD_CCtx *cctx);
 257 size_t ZSTD_freeDCtx(ZSTD_DCtx *dctx);
 258 size_t ZSTD_freeCDict(ZSTD_CDict *cdict);
 259 size_t ZSTD_freeDDict(ZSTD_DDict *cdict);
 260 size_t ZSTD_freeCStream(ZSTD_CStream *zcs);
 261 size_t ZSTD_freeDStream(ZSTD_DStream *zds);
 262
 263 #endif /* ZSTD_CCOMMON_H_MODULE */