LXR linux/lib/zstd/zstd

   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)
  68static 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
  82static const size_t ZSTD_fcs_fieldSize[4] = {0, 2, 4, 8};
  83static 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 */
  86static const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;
  87typedef 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
  93typedef 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
 110static 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};
 111static 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 */
 113static const U32 LL_defaultNormLog = LL_DEFAULTNORMLOG;
 114
 115static 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};
 117static 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 */
 120static const U32 ML_defaultNormLog = ML_DEFAULTNORMLOG;
 121
 122static 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 */
 124static const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG;
 125
 126/*-*******************************************
 127*  Shared functions to include for inlining
 128*********************************************/
 129ZSTD_STATIC void ZSTD_copy8(void *dst, const void *src) {
 130        /*
 131         * zstd relies heavily on gcc being able to analyze and inline this
 132         * memcpy() call, since it is called in a tight loop. Preboot mode
 133         * is compiled in freestanding mode, which stops gcc from analyzing
 134         * memcpy(). Use __builtin_memcpy() to tell gcc to analyze this as a
 135         * regular memcpy().
 136         */
 137        __builtin_memcpy(dst, src, 8);
 138}
 139/*! ZSTD_wildcopy() :
 140*   custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */
 141#define WILDCOPY_OVERLENGTH 8
 142ZSTD_STATIC void ZSTD_wildcopy(void *dst, const void *src, ptrdiff_t length)
 143{
 144        const BYTE* ip = (const BYTE*)src;
 145        BYTE* op = (BYTE*)dst;
 146        BYTE* const oend = op + length;
 147#if defined(GCC_VERSION) && GCC_VERSION >= 70000 && GCC_VERSION < 70200
 148        /*
 149         * Work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388.
 150         * Avoid the bad case where the loop only runs once by handling the
 151         * special case separately. This doesn't trigger the bug because it
 152         * doesn't involve pointer/integer overflow.
 153         */
 154        if (length <= 8)
 155                return ZSTD_copy8(dst, src);
 156#endif
 157        do {
 158                ZSTD_copy8(op, ip);
 159                op += 8;
 160                ip += 8;
 161        } while (op < oend);
 162}
 163
 164/*-*******************************************
 165*  Private interfaces
 166*********************************************/
 167typedef struct ZSTD_stats_s ZSTD_stats_t;
 168
 169typedef struct {
 170        U32 off;
 171        U32 len;
 172} ZSTD_match_t;
 173
 174typedef struct {
 175        U32 price;
 176        U32 off;
 177        U32 mlen;
 178        U32 litlen;
 179        U32 rep[ZSTD_REP_NUM];
 180} ZSTD_optimal_t;
 181
 182typedef struct seqDef_s {
 183        U32 offset;
 184        U16 litLength;
 185        U16 matchLength;
 186} seqDef;
 187
 188typedef struct {
 189        seqDef *sequencesStart;
 190        seqDef *sequences;
 191        BYTE *litStart;
 192        BYTE *lit;
 193        BYTE *llCode;
 194        BYTE *mlCode;
 195        BYTE *ofCode;
 196        U32 longLengthID; /* 0 == no longLength; 1 == Lit.longLength; 2 == Match.longLength; */
 197        U32 longLengthPos;
 198        /* opt */
 199        ZSTD_optimal_t *priceTable;
 200        ZSTD_match_t *matchTable;
 201        U32 *matchLengthFreq;
 202        U32 *litLengthFreq;
 203        U32 *litFreq;
 204        U32 *offCodeFreq;
 205        U32 matchLengthSum;
 206        U32 matchSum;
 207        U32 litLengthSum;
 208        U32 litSum;
 209        U32 offCodeSum;
 210        U32 log2matchLengthSum;
 211        U32 log2matchSum;
 212        U32 log2litLengthSum;
 213        U32 log2litSum;
 214        U32 log2offCodeSum;
 215        U32 factor;
 216        U32 staticPrices;
 217        U32 cachedPrice;
 218        U32 cachedLitLength;
 219        const BYTE *cachedLiterals;
 220} seqStore_t;
 221
 222const seqStore_t *ZSTD_getSeqStore(const ZSTD_CCtx *ctx);
 223void ZSTD_seqToCodes(const seqStore_t *seqStorePtr);
 224int ZSTD_isSkipFrame(ZSTD_DCtx *dctx);
 225
 226/*= Custom memory allocation functions */
 227typedef void *(*ZSTD_allocFunction)(void *opaque, size_t size);
 228typedef void (*ZSTD_freeFunction)(void *opaque, void *address);
 229typedef struct {
 230        ZSTD_allocFunction customAlloc;
 231        ZSTD_freeFunction customFree;
 232        void *opaque;
 233} ZSTD_customMem;
 234
 235void *ZSTD_malloc(size_t size, ZSTD_customMem customMem);
 236void ZSTD_free(void *ptr, ZSTD_customMem customMem);
 237
 238/*====== stack allocation  ======*/
 239
 240typedef struct {
 241        void *ptr;
 242        const void *end;
 243} ZSTD_stack;
 244
 245#define ZSTD_ALIGN(x) ALIGN(x, sizeof(size_t))
 246#define ZSTD_PTR_ALIGN(p) PTR_ALIGN(p, sizeof(size_t))
 247
 248ZSTD_customMem ZSTD_initStack(void *workspace, size_t workspaceSize);
 249
 250void *ZSTD_stackAllocAll(void *opaque, size_t *size);
 251void *ZSTD_stackAlloc(void *opaque, size_t size);
 252void ZSTD_stackFree(void *opaque, void *address);
 253
 254/*======  common function  ======*/
 255
 256ZSTD_STATIC U32 ZSTD_highbit32(U32 val) { return 31 - __builtin_clz(val); }
 257
 258/* hidden functions */
 259
 260/* ZSTD_invalidateRepCodes() :
 261 * ensures next compression will not use repcodes from previous block.
 262 * Note : only works with regular variant;
 263 *        do not use with extDict variant ! */
 264void ZSTD_invalidateRepCodes(ZSTD_CCtx *cctx);
 265
 266size_t ZSTD_freeCCtx(ZSTD_CCtx *cctx);
 267size_t ZSTD_freeDCtx(ZSTD_DCtx *dctx);
 268size_t ZSTD_freeCDict(ZSTD_CDict *cdict);
 269size_t ZSTD_freeDDict(ZSTD_DDict *cdict);
 270size_t ZSTD_freeCStream(ZSTD_CStream *zcs);
 271size_t ZSTD_freeDStream(ZSTD_DStream *zds);
 272
 273#endif /* ZSTD_CCOMMON_H_MODULE */
 274