/** * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. * All rights reserved. * * This source code is licensed under the BSD-style license found in the * LICENSE file in the root directory of https://github.com/facebook/zstd. * An additional grant of patent rights can be found in the PATENTS file in the * same directory. * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License version 2 as published by the * Free Software Foundation. This program is dual-licensed; you may select * either version 2 of the GNU General Public License ("GPL") or BSD license * ("BSD"). */ #ifndef ZSTD_CCOMMON_H_MODULE#define ZSTD_CCOMMON_H_MODULE /*-********************************************************  Compiler specifics*********************************************************/#define FORCE_INLINE static __always_inline#define FORCE_NOINLINE static noinline /*-**************************************  Dependencies***************************************/#include "error_private.h"#include "mem.h"#include <linux/compiler.h>#include <linux/kernel.h>#include <linux/xxhash.h>#include <linux/zstd.h> /*-**************************************  shared macros***************************************/#define MIN(a, b) ((a) < (b) ? (a) : (b))#define MAX(a, b) ((a) > (b) ? (a) : (b))#define CHECK_F(f)                       \	{                                \		size_t const errcod = f; \		if (ERR_isError(errcod)) \			return errcod;   \	} /* check and Forward error code */#define CHECK_E(f, e)                    \	{                                \		size_t const errcod = f; \		if (ERR_isError(errcod)) \			return ERROR(e); \	} /* check and send Error code */#define ZSTD_STATIC_ASSERT(c)                                   \	{                                                       \		enum { ZSTD_static_assert = 1 / (int)(!!(c)) }; \	} /*-**************************************  Common constants***************************************/#define ZSTD_OPT_NUM (1 << 12)#define ZSTD_DICT_MAGIC 0xEC30A437 /* v0.7+ */ #define ZSTD_REP_NUM 3		      /* number of repcodes */#define ZSTD_REP_CHECK (ZSTD_REP_NUM) /* number of repcodes to check by the optimal parser */#define ZSTD_REP_MOVE (ZSTD_REP_NUM - 1)#define ZSTD_REP_MOVE_OPT (ZSTD_REP_NUM)static const U32 repStartValue[ZSTD_REP_NUM] = {1, 4, 8}; #define KB *(1 << 10)#define MB *(1 << 20)#define GB *(1U << 30) #define BIT7 128#define BIT6 64#define BIT5 32#define BIT4 16#define BIT1 2#define BIT0 1 #define ZSTD_WINDOWLOG_ABSOLUTEMIN 10static const size_t ZSTD_fcs_fieldSize[4] = {0, 2, 4, 8};static const size_t ZSTD_did_fieldSize[4] = {0, 1, 2, 4}; #define ZSTD_BLOCKHEADERSIZE 3 /* C standard doesn't allow `static const` variable to be init using another `static const` variable */static const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;typedef enum { bt_raw, bt_rle, bt_compressed, bt_reserved } blockType_e; #define MIN_SEQUENCES_SIZE 1									  /* nbSeq==0 */#define MIN_CBLOCK_SIZE (1 /*litCSize*/ + 1 /* RLE or RAW */ + MIN_SEQUENCES_SIZE /* nbSeq==0 */) /* for a non-null block */ #define HufLog 12typedef enum { set_basic, set_rle, set_compressed, set_repeat } symbolEncodingType_e; #define LONGNBSEQ 0x7F00 #define MINMATCH 3#define EQUAL_READ32 4 #define Litbits 8#define MaxLit ((1 << Litbits) - 1)#define MaxML 52#define MaxLL 35#define MaxOff 28#define MaxSeq MAX(MaxLL, MaxML) /* Assumption : MaxOff < MaxLL,MaxML */#define MLFSELog 9#define LLFSELog 9#define OffFSELog 8 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};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};#define LL_DEFAULTNORMLOG 6 /* for static allocation */static const U32 LL_defaultNormLog = LL_DEFAULTNORMLOG; 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,				       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};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,					      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};#define ML_DEFAULTNORMLOG 6 /* for static allocation */static const U32 ML_defaultNormLog = ML_DEFAULTNORMLOG; 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};#define OF_DEFAULTNORMLOG 5 /* for static allocation */static const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG; /*-********************************************  Shared functions to include for inlining*********************************************/ZSTD_STATIC void ZSTD_copy8(void *dst, const void *src) {	/*	 * zstd relies heavily on gcc being able to analyze and inline this	 * memcpy() call, since it is called in a tight loop. Preboot mode	 * is compiled in freestanding mode, which stops gcc from analyzing	 * memcpy(). Use __builtin_memcpy() to tell gcc to analyze this as a	 * regular memcpy().	 */	__builtin_memcpy(dst, src, 8);}/*! ZSTD_wildcopy() :*   custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */#define WILDCOPY_OVERLENGTH 8ZSTD_STATIC void ZSTD_wildcopy(void *dst, const void *src, ptrdiff_t length){	const BYTE* ip = (const BYTE*)src;	BYTE* op = (BYTE*)dst;	BYTE* const oend = op + length;#if defined(GCC_VERSION) && GCC_VERSION >= 70000 && GCC_VERSION < 70200	/*	 * Work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388.	 * Avoid the bad case where the loop only runs once by handling the	 * special case separately. This doesn't trigger the bug because it	 * doesn't involve pointer/integer overflow.	 */	if (length <= 8)		return ZSTD_copy8(dst, src);#endif	do {		ZSTD_copy8(op, ip);		op += 8;		ip += 8;	} while (op < oend);} /*-********************************************  Private interfaces*********************************************/typedef struct ZSTD_stats_s ZSTD_stats_t; typedef struct {	U32 off;	U32 len;} ZSTD_match_t; typedef struct {	U32 price;	U32 off;	U32 mlen;	U32 litlen;	U32 rep[ZSTD_REP_NUM];} ZSTD_optimal_t; typedef struct seqDef_s {	U32 offset;	U16 litLength;	U16 matchLength;} seqDef; typedef struct {	seqDef *sequencesStart;	seqDef *sequences;	BYTE *litStart;	BYTE *lit;	BYTE *llCode;	BYTE *mlCode;	BYTE *ofCode;	U32 longLengthID; /* 0 == no longLength; 1 == Lit.longLength; 2 == Match.longLength; */	U32 longLengthPos;	/* opt */	ZSTD_optimal_t *priceTable;	ZSTD_match_t *matchTable;	U32 *matchLengthFreq;	U32 *litLengthFreq;	U32 *litFreq;	U32 *offCodeFreq;	U32 matchLengthSum;	U32 matchSum;	U32 litLengthSum;	U32 litSum;	U32 offCodeSum;	U32 log2matchLengthSum;	U32 log2matchSum;	U32 log2litLengthSum;	U32 log2litSum;	U32 log2offCodeSum;	U32 factor;	U32 staticPrices;	U32 cachedPrice;	U32 cachedLitLength;	const BYTE *cachedLiterals;} seqStore_t; const seqStore_t *ZSTD_getSeqStore(const ZSTD_CCtx *ctx);void ZSTD_seqToCodes(const seqStore_t *seqStorePtr);int ZSTD_isSkipFrame(ZSTD_DCtx *dctx); /*= Custom memory allocation functions */typedef void *(*ZSTD_allocFunction)(void *opaque, size_t size);typedef void (*ZSTD_freeFunction)(void *opaque, void *address);typedef struct {	ZSTD_allocFunction customAlloc;	ZSTD_freeFunction customFree;	void *opaque;} ZSTD_customMem; void *ZSTD_malloc(size_t size, ZSTD_customMem customMem);void ZSTD_free(void *ptr, ZSTD_customMem customMem); /*====== stack allocation  ======*/ typedef struct {	void *ptr;	const void *end;} ZSTD_stack; #define ZSTD_ALIGN(x) ALIGN(x, sizeof(size_t))#define ZSTD_PTR_ALIGN(p) PTR_ALIGN(p, sizeof(size_t)) ZSTD_customMem ZSTD_initStack(void *workspace, size_t workspaceSize); void *ZSTD_stackAllocAll(void *opaque, size_t *size);void *ZSTD_stackAlloc(void *opaque, size_t size);void ZSTD_stackFree(void *opaque, void *address); /*======  common function  ======*/ ZSTD_STATIC U32 ZSTD_highbit32(U32 val) { return 31 - __builtin_clz(val); } /* hidden functions */ /* ZSTD_invalidateRepCodes() : * ensures next compression will not use repcodes from previous block. * Note : only works with regular variant; *        do not use with extDict variant ! */void ZSTD_invalidateRepCodes(ZSTD_CCtx *cctx); size_t ZSTD_freeCCtx(ZSTD_CCtx *cctx);size_t ZSTD_freeDCtx(ZSTD_DCtx *dctx);size_t ZSTD_freeCDict(ZSTD_CDict *cdict);size_t ZSTD_freeDDict(ZSTD_DDict *cdict);size_t ZSTD_freeCStream(ZSTD_CStream *zcs);size_t ZSTD_freeDStream(ZSTD_DStream *zds); #endif /* ZSTD_CCOMMON_H_MODULE */