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/*
* Copyright (c) 2017 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "icnet_utils_hash.h"
namespace icnet {
namespace utils {
uint32_t Hash::hash32(const void *data, std::size_t len) {
const uint32_t fnv1a_offset = 0x811C9DC5;
return Hash::cumulativeHash32(data, len, fnv1a_offset);
}
uint32_t Hash::cumulativeHash32(const void *data, std::size_t len, uint32_t lastValue) {
// Standard FNV 32-bit prime: see http://www.isthe.com/chongo/tech/comp/fnv/#FNV-param
const uint32_t fnv1a_prime = 0x01000193;
uint32_t hash = lastValue;
const char *chardata = (char *) data;
for (std::size_t i = 0; i < len; i++) {
hash = hash ^ chardata[i];
hash = hash * fnv1a_prime;
}
return hash;
}
uint64_t Hash::hash64(const void *data, std::size_t len) {
// Standard FNV 64-bit offset: see http://www.isthe.com/chongo/tech/comp/fnv/#FNV-param
const uint64_t fnv1a_offset = 0xCBF29CE484222325ULL;
return cumulativeHash64(data, len, fnv1a_offset);
}
uint64_t Hash::cumulativeHash64(const void *data, std::size_t len, uint64_t lastValue) {
// Standard FNV 64-bit prime: see http://www.isthe.com/chongo/tech/comp/fnv/#FNV-param
const uint64_t fnv1a_prime = 0x00000100000001B3ULL;
uint64_t hash = lastValue;
const char *chardata = (char *) data;
for (std::size_t i = 0; i < len; i++) {
hash = hash ^ chardata[i];
hash = hash * fnv1a_prime;
}
return hash;
}
}
}
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