contrib/linux-kernel/lib/zstd/zstd_internal.h

/**
 * 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 <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/xxhash.h>
#include <linux/zstd.h>
#include "mem.h"
#include "error_private.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 */


/*-*************************************
*  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 10
static 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 12
typedef 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
*********************************************/
static void ZSTD_copy8(void* dst, const void* src) { memcpy(dst, src, 8); }
#define COPY8(d,s) { ZSTD_copy8(d,s); d+=8; s+=8; }

/*! ZSTD_wildcopy() :
*   custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */
#define WILDCOPY_OVERLENGTH 8
ZSTD_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;
	do
		COPY8(op, ip)
	while (op < oend);
}

ZSTD_STATIC void ZSTD_wildcopy_e(void* dst, const void* src, void* dstEnd)   /* should be faster for decoding, but strangely, not verified on all platform */
{
	const BYTE* ip = (const BYTE*)src;
	BYTE* op = (BYTE*)dst;
	BYTE* const oend = (BYTE*)dstEnd;
	do
		COPY8(op, ip)
	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 */