/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "cx/hash_key.h"
#include "cx/compare.h"
#include <string.h>
void cx_hash_murmur(CxHashKey *key) {
const unsigned char *data = key->data;
if (data == NULL) {
// extension: special value for NULL
key->hash = 1574210520u;
return;
}
size_t len = key->len;
unsigned m = 0x5bd1e995;
unsigned r = 24;
unsigned h = 25 ^ (unsigned) len;
unsigned i = 0;
while (len >= 4) {
unsigned k = data[i + 0] & 0xFF;
k |= (data[i + 1] & 0xFF) << 8;
k |= (data[i + 2] & 0xFF) << 16;
k |= (data[i + 3] & 0xFF) << 24;
k *= m;
k ^= k >> r;
k *= m;
h *= m;
h ^= k;
i += 4;
len -= 4;
}
switch (len) {
case 3:
h ^= (data[i + 2] & 0xFF) << 16;
cx_attr_fallthrough;
case 2:
h ^= (data[i + 1] & 0xFF) << 8;
cx_attr_fallthrough;
case 1:
h ^= (data[i + 0] & 0xFF);
h *= m;
cx_attr_fallthrough;
default: // do nothing
;
}
h ^= h >> 13;
h *= m;
h ^= h >> 15;
key->hash = h;
}
uint32_t cx_hash_u32(uint32_t x) {
x = ((x >> 16) ^ x) * 0x45d9f3bu;
x = ((x >> 16) ^ x) * 0x45d9f3bu;
x = (x >> 16) ^ x;
return x;
}
uint64_t cx_hash_u64(uint64_t x) {
x = (x ^ (x >> 30)) * UINT64_C(0xbf58476d1ce4e5b9);
x = (x ^ (x >> 27)) * UINT64_C(0x94d049bb133111eb);
x = x ^ (x >> 31);
return x;
}
CxHashKey cx_hash_key_str(const char *str) {
CxHashKey key;
key.data = str;
key.len = str == NULL ? 0 : strlen(str);
cx_hash_murmur(&key);
return key;
}
CxHashKey cx_hash_key_ustr(unsigned const char *str) {
CxHashKey key;
key.data = str;
key.len = str == NULL ? 0 : strlen((const char*)str);
cx_hash_murmur(&key);
return key;
}
CxHashKey cx_hash_key_cxstr(cxstring str) {
return cx_hash_key(str.ptr, str.length);
}
CxHashKey cx_hash_key_mutstr(cxmutstr str) {
return cx_hash_key(str.ptr, str.length);
}
CxHashKey cx_hash_key_bytes(
const unsigned char *bytes,
size_t len
) {
CxHashKey key;
key.data = bytes;
key.len = len;
cx_hash_murmur(&key);
return key;
}
CxHashKey cx_hash_key(
const void *obj,
size_t len
) {
CxHashKey key;
key.data = obj;
key.len = len;
cx_hash_murmur(&key);
return key;
}
CxHashKey cx_hash_key_u32(uint32_t x) {
CxHashKey key;
key.data = NULL;
key.len = 0;
key.hash = cx_hash_u32(x);
return key;
}
CxHashKey cx_hash_key_u64(uint64_t x) {
CxHashKey key;
key.data = NULL;
key.len = 0;
key.hash = cx_hash_u64(x);
return key;
}
int cx_hash_key_cmp(const void *l, const void *r) {
const CxHashKey *left = l;
const CxHashKey *right = r;
int d;
d = cx_vcmp_uint64(left->hash, right->hash);
if (d != 0) return d;
d = cx_vcmp_size(left->len, right->len);
if (d != 0) return d;
if (left->len == 0) return 0;
return memcmp(left->data, right->data, left->len);
}