lib/zstd/common/mem.h

Source file repositories/reference/linux-study-clean/lib/zstd/common/mem.h

File Facts

System
Linux kernel
Corpus path
lib/zstd/common/mem.h
Extension
.h
Size
6571 bytes
Lines
263
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: implementation source
Status
source implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef MEM_H_MODULE
#define MEM_H_MODULE

/*-****************************************
*  Dependencies
******************************************/
#include <linux/unaligned.h>  /* get_unaligned, put_unaligned* */
#include <linux/compiler.h>  /* inline */
#include <linux/swab.h>  /* swab32, swab64 */
#include <linux/types.h>  /* size_t, ptrdiff_t */
#include "debug.h"  /* DEBUG_STATIC_ASSERT */

/*-****************************************
*  Compiler specifics
******************************************/
#undef MEM_STATIC /* may be already defined from common/compiler.h */
#define MEM_STATIC static inline

/*-**************************************************************
*  Basic Types
*****************************************************************/
typedef uint8_t  BYTE;
typedef uint8_t  U8;
typedef int8_t   S8;
typedef uint16_t U16;
typedef int16_t  S16;
typedef uint32_t U32;
typedef int32_t  S32;
typedef uint64_t U64;
typedef int64_t  S64;

/*-**************************************************************
*  Memory I/O API
*****************************************************************/
/*=== Static platform detection ===*/
MEM_STATIC unsigned MEM_32bits(void);
MEM_STATIC unsigned MEM_64bits(void);
MEM_STATIC unsigned MEM_isLittleEndian(void);

/*=== Native unaligned read/write ===*/
MEM_STATIC U16 MEM_read16(const void* memPtr);
MEM_STATIC U32 MEM_read32(const void* memPtr);
MEM_STATIC U64 MEM_read64(const void* memPtr);
MEM_STATIC size_t MEM_readST(const void* memPtr);

MEM_STATIC void MEM_write16(void* memPtr, U16 value);
MEM_STATIC void MEM_write32(void* memPtr, U32 value);
MEM_STATIC void MEM_write64(void* memPtr, U64 value);

/*=== Little endian unaligned read/write ===*/
MEM_STATIC U16 MEM_readLE16(const void* memPtr);
MEM_STATIC U32 MEM_readLE24(const void* memPtr);
MEM_STATIC U32 MEM_readLE32(const void* memPtr);
MEM_STATIC U64 MEM_readLE64(const void* memPtr);
MEM_STATIC size_t MEM_readLEST(const void* memPtr);

MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val);
MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val);
MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32);
MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64);
MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val);

/*=== Big endian unaligned read/write ===*/
MEM_STATIC U32 MEM_readBE32(const void* memPtr);
MEM_STATIC U64 MEM_readBE64(const void* memPtr);
MEM_STATIC size_t MEM_readBEST(const void* memPtr);

MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32);
MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64);
MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val);

/*=== Byteswap ===*/
MEM_STATIC U32 MEM_swap32(U32 in);
MEM_STATIC U64 MEM_swap64(U64 in);
MEM_STATIC size_t MEM_swapST(size_t in);

/*-**************************************************************
*  Memory I/O Implementation
*****************************************************************/
MEM_STATIC unsigned MEM_32bits(void)
{
    return sizeof(size_t) == 4;
}

MEM_STATIC unsigned MEM_64bits(void)
{
    return sizeof(size_t) == 8;
}

#if defined(__LITTLE_ENDIAN)

Annotation

Implementation Notes