Lime3DS/src/common/hash.h
2018-01-15 13:43:37 -08:00

36 lines
1.2 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 "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, size_t len) {
return CityHash64(static_cast<const char*>(data), len);
}
/**
* Computes a 64-bit hash of a struct. In addition to being POD (trivially copyable and having
* standard layout), 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<T>::value && std::is_standard_layout<T>::value,
"Type passed to ComputeStructHash64 must be trivially copyable and standard layout");
return ComputeHash64(&data, sizeof(data));
}
} // namespace Common