suyu/src/common/hash.h
Lioncash c5c89a4d5c common/hash: Remove unused HashableStruct
This is unused, so it can be removed. There's better ways of ensuring
zeroed out padding bits, like using zero-initialization, anyhow.
2019-11-13 14:58:43 -05:00

48 lines
1.5 KiB
C++

// Copyright 2015 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <cstddef>
#include <cstring>
#include <utility>
#include <boost/functional/hash.hpp>
#include "common/cityhash.h"
#include "common/common_types.h"
namespace Common {
/**
* Computes a 64-bit hash over the specified block of data
* @param data Block of data to compute hash over
* @param len Length of data (in bytes) to compute hash over
* @returns 64-bit hash value that was computed over the data block
*/
static inline u64 ComputeHash64(const void* data, std::size_t len) {
return CityHash64(static_cast<const char*>(data), len);
}
/**
* Computes a 64-bit hash of a struct. In addition to being trivially copyable, it is also critical
* that either the struct includes no padding, or that any padding is initialized to a known value
* by memsetting the struct to 0 before filling it in.
*/
template <typename T>
static inline u64 ComputeStructHash64(const T& data) {
static_assert(std::is_trivially_copyable_v<T>,
"Type passed to ComputeStructHash64 must be trivially copyable");
return ComputeHash64(&data, sizeof(data));
}
struct PairHash {
template <class T1, class T2>
std::size_t operator()(const std::pair<T1, T2>& pair) const noexcept {
std::size_t seed = std::hash<T1>()(pair.first);
boost::hash_combine(seed, std::hash<T2>()(pair.second));
return seed;
}
};
} // namespace Common