xxhash.c 文件参考

#include "../../../include/lammp/secret.h"

xxhash.c 的引用(Include)关系图:

浏览源代码.

宏定义
#define	PRIME64_1   0x9E3779B185EBCA87ULL
#define	PRIME64_2   0xC2B2AE3D27D4EB4FULL
#define	PRIME64_3   0x165667B19E3779F9ULL
#define	PRIME64_4   0x85EBCA77C2B2AE63ULL
#define	PRIME64_5   0x27D4EB2F165667C5ULL

函数
uint64_t	lmmp_xxhash_ (mp_srcptr in, mp_size_t inlen, srckey64_t key)
	xxhash 函数（非标准处理任意字节流的 xxhash）
static uint64_t	rotl64 (uint64_t x, int b)

宏定义说明

PRIME64_1

#define PRIME64_1   0x9E3779B185EBCA87ULL

在文件 xxhash.c 第 9 行定义.

PRIME64_2

#define PRIME64_2   0xC2B2AE3D27D4EB4FULL

在文件 xxhash.c 第 10 行定义.

PRIME64_3

#define PRIME64_3   0x165667B19E3779F9ULL

在文件 xxhash.c 第 11 行定义.

PRIME64_4

#define PRIME64_4   0x85EBCA77C2B2AE63ULL

在文件 xxhash.c 第 12 行定义.

PRIME64_5

#define PRIME64_5   0x27D4EB2F165667C5ULL

在文件 xxhash.c 第 13 行定义.

函数说明

lmmp_xxhash_()

uint64_t lmmp_xxhash_	(	mp_srcptr	in,
		mp_size_t	inlen,
		srckey64_t	key
	)

xxhash 函数（非标准处理任意字节流的 xxhash）

参数

in	输入数据，可以为 NULL
inlen	输入数据长度
key	64-bit 秘钥，可以为 NULL

警告

若 key 为 NULL，则使用全零秘钥

返回

64-bit hash 值

在文件 xxhash.c 第 20 行定义.

                                                                     {
    uint64_t seed = key == NULL ? 0 : key[0];
    if (in == NULL || inlen == 0) {
        seed += PRIME64_5;
        seed += 0;  // len = 0
        seed ^= seed >> 33;
        seed *= PRIME64_2;
        seed ^= seed >> 29;
        seed *= PRIME64_3;
        seed ^= seed >> 32;
        return seed;
    }
 
    const uint64_t* p = in;
    const uint64_t* const end = in + inlen;
    uint64_t h64;
 
    if (inlen >= 4) {
        const uint64_t* const limit = end - 4;
        uint64_t v1 = seed + PRIME64_1 + PRIME64_2;
        uint64_t v2 = seed + PRIME64_2;
        uint64_t v3 = seed + 0;
        uint64_t v4 = seed - PRIME64_1;
 
        do {
            v1 += *p * PRIME64_2;
            v1 = rotl64(v1, 31);
            v1 *= PRIME64_1;
            p++;
 
            v2 += *p * PRIME64_2;
            v2 = rotl64(v2, 31);
            v2 *= PRIME64_1;
            p++;
 
            v3 += *p * PRIME64_2;
            v3 = rotl64(v3, 31);
            v3 *= PRIME64_1;
            p++;
 
            v4 += *p * PRIME64_2;
            v4 = rotl64(v4, 31);
            v4 *= PRIME64_1;
            p++;
        } while (p <= limit);
 
        h64 = rotl64(v1, 1) + rotl64(v2, 7) + rotl64(v3, 12) + rotl64(v4, 18);
 
        v1 *= PRIME64_2;
        v1 = rotl64(v1, 31);
        v1 *= PRIME64_1;
        h64 ^= v1;
        h64 = h64 * PRIME64_1 + PRIME64_4;
 
        v2 *= PRIME64_2;
        v2 = rotl64(v2, 31);
        v2 *= PRIME64_1;
        h64 ^= v2;
        h64 = h64 * PRIME64_1 + PRIME64_4;
 
        v3 *= PRIME64_2;
        v3 = rotl64(v3, 31);
        v3 *= PRIME64_1;
        h64 ^= v3;
        h64 = h64 * PRIME64_1 + PRIME64_4;
 
        v4 *= PRIME64_2;
        v4 = rotl64(v4, 31);
        v4 *= PRIME64_1;
        h64 ^= v4;
        h64 = h64 * PRIME64_1 + PRIME64_4;
    } else {
        h64 = seed + PRIME64_5;
    }
 
    h64 += (uint64_t)(inlen * sizeof(mp_limb_t));
 
    while (p < end) {
        uint64_t k1 = *p;
        k1 *= PRIME64_2;
        k1 = rotl64(k1, 31);
        k1 *= PRIME64_1;
        h64 ^= k1;
        h64 = rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
        p++;
    }
 
    h64 ^= h64 >> 33;
    h64 *= PRIME64_2;
    h64 ^= h64 >> 29;
    h64 *= PRIME64_3;
    h64 ^= h64 >> 32;
 
    return h64;
}

引用了 PRIME64_1, PRIME64_2, PRIME64_3, PRIME64_4, PRIME64_5, rotl64(), v1 , 以及 v2.

函数调用图:

rotl64()

static uint64_t rotl64 ( uint64_t  x, int  b  )

inlinestatic

在文件 xxhash.c 第 15 行定义.

                                                 {
    b &= 63;
    return (x << b) | (x >> (64 - b));
}

被这些函数引用 lmmp_xxhash_().

这是这个函数的调用关系图: