/** * 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 MEM_H_MODULE#define MEM_H_MODULE /*-*****************************************  Dependencies******************************************/#include <asm/unaligned.h>#include <linux/string.h> /* memcpy */#include <linux/types.h>  /* size_t, ptrdiff_t */ /*-*****************************************  Compiler specifics******************************************/#define ZSTD_STATIC static inline /*-***************************************************************  Basic Types*****************************************************************/typedef uint8_t BYTE;typedef uint16_t U16;typedef int16_t S16;typedef uint32_t U32;typedef int32_t S32;typedef uint64_t U64;typedef int64_t S64;typedef ptrdiff_t iPtrDiff;typedef uintptr_t uPtrDiff; /*-***************************************************************  Memory I/O*****************************************************************/ZSTD_STATIC unsigned ZSTD_32bits(void) { return sizeof(size_t) == 4; }ZSTD_STATIC unsigned ZSTD_64bits(void) { return sizeof(size_t) == 8; } #if defined(__LITTLE_ENDIAN)#define ZSTD_LITTLE_ENDIAN 1#else#define ZSTD_LITTLE_ENDIAN 0#endif ZSTD_STATIC unsigned ZSTD_isLittleEndian(void) { return ZSTD_LITTLE_ENDIAN; } ZSTD_STATIC U16 ZSTD_read16(const void *memPtr) { return get_unaligned((const U16 *)memPtr); } ZSTD_STATIC U32 ZSTD_read32(const void *memPtr) { return get_unaligned((const U32 *)memPtr); } ZSTD_STATIC U64 ZSTD_read64(const void *memPtr) { return get_unaligned((const U64 *)memPtr); } ZSTD_STATIC size_t ZSTD_readST(const void *memPtr) { return get_unaligned((const size_t *)memPtr); } ZSTD_STATIC void ZSTD_write16(void *memPtr, U16 value) { put_unaligned(value, (U16 *)memPtr); } ZSTD_STATIC void ZSTD_write32(void *memPtr, U32 value) { put_unaligned(value, (U32 *)memPtr); } ZSTD_STATIC void ZSTD_write64(void *memPtr, U64 value) { put_unaligned(value, (U64 *)memPtr); } /*=== Little endian r/w ===*/ ZSTD_STATIC U16 ZSTD_readLE16(const void *memPtr) { return get_unaligned_le16(memPtr); } ZSTD_STATIC void ZSTD_writeLE16(void *memPtr, U16 val) { put_unaligned_le16(val, memPtr); } ZSTD_STATIC U32 ZSTD_readLE24(const void *memPtr) { return ZSTD_readLE16(memPtr) + (((const BYTE *)memPtr)[2] << 16); } ZSTD_STATIC void ZSTD_writeLE24(void *memPtr, U32 val){	ZSTD_writeLE16(memPtr, (U16)val);	((BYTE *)memPtr)[2] = (BYTE)(val >> 16);} ZSTD_STATIC U32 ZSTD_readLE32(const void *memPtr) { return get_unaligned_le32(memPtr); } ZSTD_STATIC void ZSTD_writeLE32(void *memPtr, U32 val32) { put_unaligned_le32(val32, memPtr); } ZSTD_STATIC U64 ZSTD_readLE64(const void *memPtr) { return get_unaligned_le64(memPtr); } ZSTD_STATIC void ZSTD_writeLE64(void *memPtr, U64 val64) { put_unaligned_le64(val64, memPtr); } ZSTD_STATIC size_t ZSTD_readLEST(const void *memPtr){	if (ZSTD_32bits())		return (size_t)ZSTD_readLE32(memPtr);	else		return (size_t)ZSTD_readLE64(memPtr);} ZSTD_STATIC void ZSTD_writeLEST(void *memPtr, size_t val){	if (ZSTD_32bits())		ZSTD_writeLE32(memPtr, (U32)val);	else		ZSTD_writeLE64(memPtr, (U64)val);} /*=== Big endian r/w ===*/ ZSTD_STATIC U32 ZSTD_readBE32(const void *memPtr) { return get_unaligned_be32(memPtr); } ZSTD_STATIC void ZSTD_writeBE32(void *memPtr, U32 val32) { put_unaligned_be32(val32, memPtr); } ZSTD_STATIC U64 ZSTD_readBE64(const void *memPtr) { return get_unaligned_be64(memPtr); } ZSTD_STATIC void ZSTD_writeBE64(void *memPtr, U64 val64) { put_unaligned_be64(val64, memPtr); } ZSTD_STATIC size_t ZSTD_readBEST(const void *memPtr){	if (ZSTD_32bits())		return (size_t)ZSTD_readBE32(memPtr);	else		return (size_t)ZSTD_readBE64(memPtr);} ZSTD_STATIC void ZSTD_writeBEST(void *memPtr, size_t val){	if (ZSTD_32bits())		ZSTD_writeBE32(memPtr, (U32)val);	else		ZSTD_writeBE64(memPtr, (U64)val);} /* function safe only for comparisons */ZSTD_STATIC U32 ZSTD_readMINMATCH(const void *memPtr, U32 length){	switch (length) {	default:	case 4: return ZSTD_read32(memPtr);	case 3:		if (ZSTD_isLittleEndian())			return ZSTD_read32(memPtr) << 8;		else			return ZSTD_read32(memPtr) >> 8;	}} #endif /* MEM_H_MODULE */