--- /dev/null
+#pragma once
+#include <cstdint>
+#include <cstring>
+#include <array>
+#include <type_traits>
+#include <cstdint>
+#include <vector>
+#include <string>
+
+#include <iostream>
+
+/*
+xxHash - Extremely Fast Hash algorithm
+Header File
+Copyright (C) 2012-2018, Yann Collet.
+Copyright (C) 2017-2018, Piotr Pliszka.
+All rights reserved.
+
+BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+* Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+* 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
+OWNER 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.
+You can contact the author at :
+- xxHash source repository : https://github.com/Cyan4973/xxHash
+- xxHash C++ port repository : https://github.com/RedSpah/xxhash_cpp
+*/
+
+/* *************************************
+* Tuning parameters
+***************************************/
+/*!XXH_FORCE_MEMORY_ACCESS :
+* By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
+* Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
+* The below switch allow to select different access method for improved performance.
+* Method 0 (default) : use `memcpy()`. Safe and portable.
+* Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
+* This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
+* Method 2 : direct access. This method doesn't depend on compiler but violate C standard.
+* It can generate buggy code on targets which do not support unaligned memory accesses.
+* But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
+* See http://stackoverflow.com/a/32095106/646947 for details.
+* Prefer these methods in priority order (0 > 1 > 2)
+*/
+#ifndef XXH_FORCE_MEMORY_ACCESS /* can be defined externally, on command line for example */
+# if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
+# define XXH_FORCE_MEMORY_ACCESS 2
+# elif defined(__INTEL_COMPILER) || (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
+# define XXH_FORCE_MEMORY_ACCESS 1
+# endif
+#endif
+
+
+/*!XXH_FORCE_NATIVE_FORMAT :
+* By default, xxHash library provides endian-independent Hash values, based on little-endian convention.
+* Results are therefore identical for little-endian and big-endian CPU.
+* This comes at a performance cost for big-endian CPU, since some swapping is required to emulate little-endian format.
+* Should endian-independence be of no importance for your application, you may set the #define below to 1,
+* to improve speed for Big-endian CPU.
+* This option has no impact on Little_Endian CPU.
+*/
+#if !defined(XXH_FORCE_NATIVE_FORMAT) || (XXH_FORCE_NATIVE_FORMAT == 0) /* can be defined externally */
+# define XXH_FORCE_NATIVE_FORMAT 0
+# define XXH_CPU_LITTLE_ENDIAN 1
+#endif
+
+
+/*!XXH_FORCE_ALIGN_CHECK :
+* This is a minor performance trick, only useful with lots of very small keys.
+* It means : check for aligned/unaligned input.
+* The check costs one initial branch per hash;
+* set it to 0 when the input is guaranteed to be aligned,
+* or when alignment doesn't matter for performance.
+*/
+#ifndef XXH_FORCE_ALIGN_CHECK /* can be defined externally */
+# if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64)
+# define XXH_FORCE_ALIGN_CHECK 0
+# else
+# define XXH_FORCE_ALIGN_CHECK 1
+# endif
+#endif
+
+/*!XXH_CPU_LITTLE_ENDIAN :
+* This is a CPU endian detection macro, will be
+* automatically set to 1 (little endian) if XXH_FORCE_NATIVE_FORMAT
+* is left undefined, XXH_FORCE_NATIVE_FORMAT is defined to 0, or if an x86/x86_64 compiler macro is defined.
+* If left undefined, endianness will be determined at runtime, at the cost of a slight one-time overhead
+* and a larger overhead due to get_endian() not being constexpr.
+*/
+#ifndef XXH_CPU_LITTLE_ENDIAN
+# if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64)
+# define XXH_CPU_LITTLE_ENDIAN 1
+# endif
+#endif
+
+/* *************************************
+* Compiler Specific Options
+***************************************/
+#define XXH_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
+
+namespace xxh
+{
+ /* *************************************
+ * Version
+ ***************************************/
+ constexpr int cpp_version_major = 0;
+ constexpr int cpp_version_minor = 6;
+ constexpr int cpp_version_release = 5;
+ constexpr uint32_t version_number() { return cpp_version_major * 10000 + cpp_version_minor * 100 + cpp_version_release; }
+
+ namespace hash_t_impl
+ {
+ /* *************************************
+ * Basic Types - Detail
+ ***************************************/
+
+ using _hash32_underlying = uint32_t;
+ using _hash64_underlying = uint64_t;
+
+ template <size_t N>
+ struct hash_type { using type = void; };
+ template <>
+ struct hash_type<32> { using type = _hash32_underlying; };
+ template <>
+ struct hash_type<64> { using type = _hash64_underlying; };
+ }
+
+ /* *************************************
+ * Basic Types - Public
+ ***************************************/
+
+ template <size_t N>
+ using hash_t = typename hash_t_impl::hash_type<N>::type;
+ using hash32_t = hash_t<32>;
+ using hash64_t = hash_t<64>;
+
+ /* *************************************
+ * Bit Functions - Public
+ ***************************************/
+
+ namespace bit_ops
+ {
+ /* ****************************************
+ * Intrinsics and Bit Operations
+ ******************************************/
+
+#if defined(_MSC_VER)
+ inline uint32_t rotl32(uint32_t x, int32_t r) { return _rotl(x, r); }
+ inline uint64_t rotl64(uint64_t x, int32_t r) { return _rotl64(x, r); }
+#else
+ inline uint32_t rotl32(uint32_t x, int32_t r) { return ((x << r) | (x >> (32 - r))); }
+ inline uint64_t rotl64(uint64_t x, int32_t r) { return ((x << r) | (x >> (64 - r))); }
+#endif
+
+#if defined(_MSC_VER) /* Visual Studio */
+ inline uint32_t swap32(uint32_t x) { return _byteswap_ulong(x); }
+ inline uint64_t swap64(uint64_t x) { return _byteswap_uint64(x); }
+#elif XXH_GCC_VERSION >= 403
+ inline uint32_t swap32(uint32_t x) { return __builtin_bswap32(x); }
+ inline uint64_t swap64(uint64_t x) { return __builtin_bswap64(x); }
+#else
+ inline uint32_t swap32(uint32_t x) { return ((x << 24) & 0xff000000) | ((x << 8) & 0x00ff0000) | ((x >> 8) & 0x0000ff00) | ((x >> 24) & 0x000000ff); }
+ inline uint64_t swap64(uint64_t x) { return ((x << 56) & 0xff00000000000000ULL) | ((x << 40) & 0x00ff000000000000ULL) | ((x << 24) & 0x0000ff0000000000ULL) | ((x << 8) & 0x000000ff00000000ULL) | ((x >> 8) & 0x00000000ff000000ULL) | ((x >> 24) & 0x0000000000ff0000ULL) | ((x >> 40) & 0x000000000000ff00ULL) | ((x >> 56) & 0x00000000000000ffULL); }
+#endif
+ template <size_t N>
+ inline hash_t<N> rotl(hash_t<N> n, int32_t r) {};
+
+ template <>
+ inline hash_t<32> rotl<32>(hash_t<32> n, int32_t r)
+ {
+ return rotl32(n, r);
+ };
+
+ template <>
+ inline hash_t<64> rotl<64>(hash_t<64> n, int32_t r)
+ {
+ return rotl64(n, r);
+ };
+
+ template <size_t N>
+ inline hash_t<N> swap(hash_t<N> n) {};
+
+ template <>
+ inline hash_t<32> swap<32>(hash_t<32> n)
+ {
+ return swap32(n);
+ };
+
+ template <>
+ inline hash_t<64> swap<64>(hash_t<64> n)
+ {
+ return swap64(n);
+ };
+ }
+
+ /* *************************************
+ * Memory Functions - Public
+ ***************************************/
+
+ enum class alignment : uint8_t { aligned, unaligned };
+ enum class endianness : uint8_t { big_endian = 0, little_endian = 1, unspecified = 2 };
+
+ namespace mem_ops
+ {
+ /* *************************************
+ * Memory Access
+ ***************************************/
+#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
+
+ /* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
+ template <size_t N>
+ inline hash_t<N> read_unaligned(const void* memPtr) { return *(const hash_t<N>*)memPtr; }
+
+#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
+
+ /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
+ /* currently only defined for gcc and icc */
+ template <size_t N>
+ using unalign = union { hash_t<N> uval; } __attribute((packed));
+
+ template <size_t N>
+ inline hash_t<N> read_unaligned(const void* memPtr) { return ((const unalign*)memPtr)->uval; }
+#else
+
+ /* portable and safe solution. Generally efficient.
+ * see : http://stackoverflow.com/a/32095106/646947
+ */
+ template <size_t N>
+ inline hash_t<N> read_unaligned(const void* memPtr)
+ {
+ hash_t<N> val;
+ memcpy(&val, memPtr, sizeof(val));
+ return val;
+ }
+
+#endif /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
+
+ inline hash_t<32> read32(const void* memPtr) { return read_unaligned<32>(memPtr); }
+ inline hash_t<64> read64(const void* memPtr) { return read_unaligned<64>(memPtr); }
+
+ /* *************************************
+ * Architecture Macros
+ ***************************************/
+
+ /* XXH_CPU_LITTLE_ENDIAN can be defined externally, for example on the compiler command line */
+
+#ifndef XXH_CPU_LITTLE_ENDIAN
+
+ inline endianness get_endian(endianness endian)
+ {
+ static struct _dummy_t
+ {
+ std::array<endianness, 3> endian_lookup = { endianness::big_endian, endianness::little_endian, endianness::unspecified };
+ const int g_one = 1;
+ _dummy_t()
+ {
+ endian_lookup[2] = static_cast<endianness>(*(const char*)(&g_one));
+ }
+ } _dummy;
+
+ return _dummy.endian_lookup[(uint8_t)endian];
+ }
+
+ inline bool is_little_endian()
+ {
+ return get_endian(endianness::unspecified) == endianness::little_endian;
+ }
+
+#else
+ constexpr endianness get_endian(endianness endian)
+ {
+ constexpr std::array<endianness, 3> endian_lookup = { endianness::big_endian, endianness::little_endian, (XXH_CPU_LITTLE_ENDIAN) ? endianness::little_endian : endianness::big_endian };
+ return endian_lookup[static_cast<uint8_t>(endian)];
+ }
+
+ constexpr bool is_little_endian()
+ {
+ return get_endian(endianness::unspecified) == endianness::little_endian;
+ }
+
+#endif
+
+
+
+ /* ***************************
+ * Memory reads
+ *****************************/
+
+
+ template <size_t N>
+ inline hash_t<N> readLE_align(const void* ptr, endianness endian, alignment align)
+ {
+ if (align == alignment::unaligned)
+ {
+ return endian == endianness::little_endian ? read_unaligned<N>(ptr) : bit_ops::swap<N>(read_unaligned<N>(ptr));
+ }
+ else
+ {
+ return endian == endianness::little_endian ? *reinterpret_cast<const hash_t<N>*>(ptr) : bit_ops::swap<N>(*reinterpret_cast<const hash_t<N>*>(ptr));
+ }
+ }
+
+ template <size_t N>
+ inline hash_t<N> readLE(const void* ptr, endianness endian)
+ {
+ return readLE_align<N>(ptr, endian, alignment::unaligned);
+ }
+
+ template <size_t N>
+ inline hash_t<N> readBE(const void* ptr)
+ {
+ return is_little_endian() ? bit_ops::swap<N>(read_unaligned<N>(ptr)) : read_unaligned<N>(ptr);
+ }
+
+ template <size_t N>
+ inline alignment get_alignment(const void* input)
+ {
+ return ((XXH_FORCE_ALIGN_CHECK) && ((reinterpret_cast<uintptr_t>(input) & ((N / 8) - 1)) == 0)) ? xxh::alignment::aligned : xxh::alignment::unaligned;
+ }
+ }
+
+ /* *******************************************************************
+ * Hash functions
+ *********************************************************************/
+
+ namespace detail
+ {
+ /* *******************************************************************
+ * Hash functions - Implementation
+ *********************************************************************/
+
+ constexpr static std::array<hash32_t, 5> primes32 = { 2654435761U, 2246822519U, 3266489917U, 668265263U, 374761393U };
+ constexpr static std::array<hash64_t, 5> primes64 = { 11400714785074694791ULL, 14029467366897019727ULL, 1609587929392839161ULL, 9650029242287828579ULL, 2870177450012600261ULL };
+
+ template <size_t N>
+ constexpr hash_t<N> PRIME(int32_t n) {};
+
+ template <>
+ constexpr hash32_t PRIME<32>(int32_t n)
+ {
+ return primes32[n - 1];
+ }
+
+ template <>
+ constexpr hash64_t PRIME<64>(int32_t n)
+ {
+ return primes64[n - 1];
+ }
+
+ template <size_t N>
+ inline hash_t<N> round(hash_t<N> seed, hash_t<N> input)
+ {
+ seed += input * PRIME<N>(2);
+ seed = bit_ops::rotl<N>(seed, ((N == 32) ? 13 : 31));
+ seed *= PRIME<N>(1);
+ return seed;
+ }
+
+ inline hash64_t mergeRound64(hash64_t acc, hash64_t val)
+ {
+ val = round<64>(0, val);
+ acc ^= val;
+ acc = acc * PRIME<64>(1) + PRIME<64>(4);
+ return acc;
+ }
+
+ template <size_t N>
+ inline void endian_align_sub_mergeround([[maybe_unused]] hash_t<N>& hash_ret, hash_t<N> v1, hash_t<N> v2, hash_t<N> v3, hash_t<N> v4) {};
+
+ template <>
+ inline void endian_align_sub_mergeround<64>(hash_t<64>& hash_ret, hash_t<64> v1, hash_t<64> v2, hash_t<64> v3, hash_t<64> v4)
+ {
+ hash_ret = mergeRound64(hash_ret, v1);
+ hash_ret = mergeRound64(hash_ret, v2);
+ hash_ret = mergeRound64(hash_ret, v3);
+ hash_ret = mergeRound64(hash_ret, v4);
+ }
+
+ template <size_t N>
+ inline hash_t<N> endian_align_sub_ending(hash_t<N> hash_ret, const uint8_t* p, const uint8_t* bEnd, xxh::endianness endian, xxh::alignment align) {};
+
+ template <>
+ inline hash_t<32> endian_align_sub_ending<32>(hash_t<32> hash_ret, const uint8_t* p, const uint8_t* bEnd, xxh::endianness endian, xxh::alignment align)
+ {
+ while ((p + 4) <= bEnd)
+ {
+ hash_ret += mem_ops::readLE_align<32>(p, endian, align) * PRIME<32>(3);
+ hash_ret = bit_ops::rotl<32>(hash_ret, 17) * PRIME<32>(4);
+ p += 4;
+ }
+
+ while (p < bEnd)
+ {
+ hash_ret += (*p) * PRIME<32>(5);
+ hash_ret = bit_ops::rotl<32>(hash_ret, 11) * PRIME<32>(1);
+ p++;
+ }
+
+ hash_ret ^= hash_ret >> 15;
+ hash_ret *= PRIME<32>(2);
+ hash_ret ^= hash_ret >> 13;
+ hash_ret *= PRIME<32>(3);
+ hash_ret ^= hash_ret >> 16;
+
+ return hash_ret;
+ }
+
+ template <>
+ inline hash_t<64> endian_align_sub_ending<64>(hash_t<64> hash_ret, const uint8_t* p, const uint8_t* bEnd, xxh::endianness endian, xxh::alignment align)
+ {
+ while (p + 8 <= bEnd)
+ {
+ const hash64_t k1 = round<64>(0, mem_ops::readLE_align<64>(p, endian, align));
+ hash_ret ^= k1;
+ hash_ret = bit_ops::rotl<64>(hash_ret, 27) * PRIME<64>(1) + PRIME<64>(4);
+ p += 8;
+ }
+
+ if (p + 4 <= bEnd)
+ {
+ hash_ret ^= static_cast<hash64_t>(mem_ops::readLE_align<32>(p, endian, align)) * PRIME<64>(1);
+ hash_ret = bit_ops::rotl<64>(hash_ret, 23) * PRIME<64>(2) + PRIME<64>(3);
+ p += 4;
+ }
+
+ while (p < bEnd)
+ {
+ hash_ret ^= (*p) * PRIME<64>(5);
+ hash_ret = bit_ops::rotl<64>(hash_ret, 11) * PRIME<64>(1);
+ p++;
+ }
+
+ hash_ret ^= hash_ret >> 33;
+ hash_ret *= PRIME<64>(2);
+ hash_ret ^= hash_ret >> 29;
+ hash_ret *= PRIME<64>(3);
+ hash_ret ^= hash_ret >> 32;
+
+ return hash_ret;
+ }
+
+ template <size_t N>
+ inline hash_t<N> endian_align(const void* input, size_t len, hash_t<N> seed, xxh::endianness endian, xxh::alignment align)
+ {
+ static_assert(!(N != 32 && N != 64), "You can only call endian_align in 32 or 64 bit mode.");
+
+ const uint8_t* p = static_cast<const uint8_t*>(input);
+ const uint8_t* bEnd = p + len;
+ hash_t<N> hash_ret;
+
+ if (len >= (N / 2))
+ {
+ const uint8_t* const limit = bEnd - (N / 2);
+ hash_t<N> v1 = seed + PRIME<N>(1) + PRIME<N>(2);
+ hash_t<N> v2 = seed + PRIME<N>(2);
+ hash_t<N> v3 = seed + 0;
+ hash_t<N> v4 = seed - PRIME<N>(1);
+
+ do
+ {
+ v1 = round<N>(v1, mem_ops::readLE_align<N>(p, endian, align)); p += (N / 8);
+ v2 = round<N>(v2, mem_ops::readLE_align<N>(p, endian, align)); p += (N / 8);
+ v3 = round<N>(v3, mem_ops::readLE_align<N>(p, endian, align)); p += (N / 8);
+ v4 = round<N>(v4, mem_ops::readLE_align<N>(p, endian, align)); p += (N / 8);
+ } while (p <= limit);
+
+ hash_ret = bit_ops::rotl<N>(v1, 1) + bit_ops::rotl<N>(v2, 7) + bit_ops::rotl<N>(v3, 12) + bit_ops::rotl<N>(v4, 18);
+
+ endian_align_sub_mergeround<N>(hash_ret, v1, v2, v3, v4);
+ }
+ else { hash_ret = seed + PRIME<N>(5); }
+
+ hash_ret += static_cast<hash_t<N>>(len);
+
+ return endian_align_sub_ending<N>(hash_ret, p, bEnd, endian, align);
+ }
+ }
+
+ template <size_t N>
+ hash_t<N> xxhash(const void* input, size_t len, hash_t<N> seed = 0, endianness endian = endianness::unspecified)
+ {
+ static_assert(!(N != 32 && N != 64), "You can only call xxhash in 32 or 64 bit mode.");
+ return detail::endian_align<N>(input, len, seed, mem_ops::get_endian(endian), mem_ops::get_alignment<N>(input));
+ }
+
+ template <size_t N, typename T>
+ hash_t<N> xxhash(const std::basic_string<T>& input, hash_t<N> seed = 0, endianness endian = endianness::unspecified)
+ {
+ static_assert(!(N != 32 && N != 64), "You can only call xxhash in 32 or 64 bit mode.");
+ return detail::endian_align<N>(static_cast<const void*>(input.data()), input.length() * sizeof(T), seed, mem_ops::get_endian(endian), mem_ops::get_alignment<N>(static_cast<const void*>(input.data())));
+ }
+
+ template <size_t N, typename ContiguousIterator>
+ hash_t<N> xxhash(ContiguousIterator begin, ContiguousIterator end, hash_t<N> seed = 0, endianness endian = endianness::unspecified)
+ {
+ static_assert(!(N != 32 && N != 64), "You can only call xxhash in 32 or 64 bit mode.");
+ using T = typename std::decay_t<decltype(*end)>;
+ return detail::endian_align<N>(static_cast<const void*>(&*begin), (end - begin) * sizeof(T), seed, mem_ops::get_endian(endian), mem_ops::get_alignment<N>(static_cast<const void*>(&*begin)));
+ }
+
+ template <size_t N, typename T>
+ hash_t<N> xxhash(const std::vector<T>& input, hash_t<N> seed = 0, endianness endian = endianness::unspecified)
+ {
+ static_assert(!(N != 32 && N != 64), "You can only call xxhash in 32 or 64 bit mode.");
+ return detail::endian_align<N>(static_cast<const void*>(input.data()), input.size() * sizeof(T), seed, mem_ops::get_endian(endian), mem_ops::get_alignment<N>(static_cast<const void*>(input.data())));
+ }
+
+ template <size_t N, typename T, size_t AN>
+ hash_t<N> xxhash(const std::array<T, AN>& input, hash_t<N> seed = 0, endianness endian = endianness::unspecified)
+ {
+ static_assert(!(N != 32 && N != 64), "You can only call xxhash in 32 or 64 bit mode.");
+ return detail::endian_align<N>(static_cast<const void*>(input.data()), AN * sizeof(T), seed, mem_ops::get_endian(endian), mem_ops::get_alignment<N>(static_cast<const void*>(input.data())));
+ }
+
+ template <size_t N, typename T>
+ hash_t<N> xxhash(const std::initializer_list<T>& input, hash_t<N> seed = 0, endianness endian = endianness::unspecified)
+ {
+ static_assert(!(N != 32 && N != 64), "You can only call xxhash in 32 or 64 bit mode.");
+ return detail::endian_align<N>(static_cast<const void*>(input.begin()), input.size() * sizeof(T), seed, mem_ops::get_endian(endian), mem_ops::get_alignment<N>(static_cast<const void*>(input.begin())));
+ }
+
+
+ /* *******************************************************************
+ * Hash streaming
+ *********************************************************************/
+ enum class error_code : uint8_t { ok = 0, error };
+
+ template <size_t N>
+ class hash_state_t {
+
+ uint64_t total_len = 0;
+ hash_t<N> v1 = 0, v2 = 0, v3 = 0, v4 = 0;
+ std::array<hash_t<N>, 4> mem = {{ 0,0,0,0 }};
+ uint32_t memsize = 0;
+
+ inline error_code _update_impl(const void* input, size_t length, endianness endian)
+ {
+ const uint8_t* p = reinterpret_cast<const uint8_t*>(input);
+ const uint8_t* const bEnd = p + length;
+
+ if (!input) { return xxh::error_code::error; }
+
+ total_len += length;
+
+ if (memsize + length < (N / 2))
+ { /* fill in tmp buffer */
+ memcpy(reinterpret_cast<uint8_t*>(mem.data()) + memsize, input, length);
+ memsize += static_cast<uint32_t>(length);
+ return error_code::ok;
+ }
+
+ if (memsize)
+ { /* some data left from previous update */
+ memcpy(reinterpret_cast<uint8_t*>(mem.data()) + memsize, input, (N / 2) - memsize);
+
+ const hash_t<N>* ptr = mem.data();
+ v1 = detail::round<N>(v1, mem_ops::readLE<N>(ptr, endian)); ptr++;
+ v2 = detail::round<N>(v2, mem_ops::readLE<N>(ptr, endian)); ptr++;
+ v3 = detail::round<N>(v3, mem_ops::readLE<N>(ptr, endian)); ptr++;
+ v4 = detail::round<N>(v4, mem_ops::readLE<N>(ptr, endian));
+
+ p += (N / 2) - memsize;
+ memsize = 0;
+ }
+
+ if (p <= bEnd - (N / 2))
+ {
+ const uint8_t* const limit = bEnd - (N / 2);
+
+ do
+ {
+ v1 = detail::round<N>(v1, mem_ops::readLE<N>(p, endian)); p += (N / 8);
+ v2 = detail::round<N>(v2, mem_ops::readLE<N>(p, endian)); p += (N / 8);
+ v3 = detail::round<N>(v3, mem_ops::readLE<N>(p, endian)); p += (N / 8);
+ v4 = detail::round<N>(v4, mem_ops::readLE<N>(p, endian)); p += (N / 8);
+ } while (p <= limit);
+ }
+
+ if (p < bEnd)
+ {
+ memcpy(mem.data(), p, static_cast<size_t>(bEnd - p));
+ memsize = static_cast<uint32_t>(bEnd - p);
+ }
+
+ return error_code::ok;
+ }
+
+ inline hash_t<N> _digest_impl(endianness endian) const
+ {
+ const uint8_t* p = reinterpret_cast<const uint8_t*>(mem.data());
+ const uint8_t* const bEnd = reinterpret_cast<const uint8_t*>(mem.data()) + memsize;
+ hash_t<N> hash_ret;
+
+ if (total_len > (N / 2))
+ {
+ hash_ret = bit_ops::rotl<N>(v1, 1) + bit_ops::rotl<N>(v2, 7) + bit_ops::rotl<N>(v3, 12) + bit_ops::rotl<N>(v4, 18);
+
+ detail::endian_align_sub_mergeround<N>(hash_ret, v1, v2, v3, v4);
+ }
+ else { hash_ret = v3 + detail::PRIME<N>(5); }
+
+ hash_ret += static_cast<hash_t<N>>(total_len);
+
+ return detail::endian_align_sub_ending<N>(hash_ret, p, bEnd, endian, alignment::unaligned);
+ }
+
+ public:
+ hash_state_t(hash_t<N> seed = 0)
+ {
+ static_assert(!(N != 32 && N != 64), "You can only stream hashing in 32 or 64 bit mode.");
+ v1 = seed + detail::PRIME<N>(1) + detail::PRIME<N>(2);
+ v2 = seed + detail::PRIME<N>(2);
+ v3 = seed + 0;
+ v4 = seed - detail::PRIME<N>(1);
+ };
+
+ hash_state_t operator=(hash_state_t<N>& other)
+ {
+ memcpy(this, other, sizeof(hash_state_t<N>));
+ }
+
+ error_code reset(hash_t<N> seed = 0)
+ {
+ memset(this, 0, sizeof(hash_state_t<N>));
+ v1 = seed + detail::PRIME<N>(1) + detail::PRIME<N>(2);
+ v2 = seed + detail::PRIME<N>(2);
+ v3 = seed + 0;
+ v4 = seed - detail::PRIME<N>(1);
+ return error_code::ok;
+ }
+
+ error_code update(const void* input, size_t length, endianness endian = endianness::unspecified)
+ {
+ return _update_impl(input, length, mem_ops::get_endian(endian));
+ }
+
+ template <typename T>
+ error_code update(const std::basic_string<T>& input, endianness endian = endianness::unspecified)
+ {
+ return _update_impl(static_cast<const void*>(input.data()), input.length() * sizeof(T), mem_ops::get_endian(endian));
+ }
+
+ template <typename ContiguousIterator>
+ error_code update(ContiguousIterator begin, ContiguousIterator end, endianness endian = endianness::unspecified)
+ {
+ using T = typename std::decay_t<decltype(*end)>;
+ return _update_impl(static_cast<const void*>(&*begin), (end - begin) * sizeof(T), mem_ops::get_endian(endian));
+ }
+
+ template <typename T>
+ error_code update(const std::vector<T>& input, endianness endian = endianness::unspecified)
+ {
+ return _update_impl(static_cast<const void*>(input.data()), input.size() * sizeof(T), mem_ops::get_endian(endian));
+ }
+
+ template <typename T, size_t AN>
+ error_code update(const std::array<T, AN>& input, endianness endian = endianness::unspecified)
+ {
+ return _update_impl(static_cast<const void*>(input.data()), AN * sizeof(T), mem_ops::get_endian(endian));
+ }
+
+ template <typename T>
+ error_code update(const std::initializer_list<T>& input, endianness endian = endianness::unspecified)
+ {
+ return _update_impl(static_cast<const void*>(input.begin()), input.size() * sizeof(T), mem_ops::get_endian(endian));
+ }
+
+ hash_t<N> digest(endianness endian = endianness::unspecified)
+ {
+ return _digest_impl(mem_ops::get_endian(endian));
+ }
+ };
+
+ using hash_state32_t = hash_state_t<32>;
+ using hash_state64_t = hash_state_t<64>;
+
+
+ /* *******************************************************************
+ * Canonical
+ *********************************************************************/
+
+ template <size_t N>
+ struct canonical_t
+ {
+ std::array<uint8_t, N / 8> digest;\
+
+
+
+ canonical_t(hash_t<N> hash)
+ {
+ if (mem_ops::is_little_endian()) { hash = bit_ops::swap<N>(hash); }
+ memcpy(digest.data(), &hash, sizeof(canonical_t<N>));
+ }
+
+ hash_t<N> get_hash() const
+ {
+ return mem_ops::readBE<N>(&digest);
+ }
+ };
+
+ using canonical32_t = canonical_t<32>;
+ using canonical64_t = canonical_t<64>;
+}
