From f528f24036698e2014f370f174abab286ef397b6 Mon Sep 17 00:00:00 2001 From: "Claudius \"keldu\" Holeksa" Date: Thu, 18 Jan 2024 13:03:38 +0100 Subject: codec: Changed hashing to crc32 and made the calculation constexpr --- modules/codec/c++/crc32.h | 114 ++++++++++++++++++++++++++++++++++++++++ modules/codec/c++/schema_hash.h | 60 +++++++++++++-------- modules/codec/tests/schema.cpp | 30 +++++------ 3 files changed, 166 insertions(+), 38 deletions(-) create mode 100644 modules/codec/c++/crc32.h diff --git a/modules/codec/c++/crc32.h b/modules/codec/c++/crc32.h new file mode 100644 index 0000000..c67c16e --- /dev/null +++ b/modules/codec/c++/crc32.h @@ -0,0 +1,114 @@ +#pragma once + +#include +#include "schema.h" +#include "data.h" + +namespace saw { +namespace algs { +struct crc32 { + using Schema = schema::UInt32; + using Type = typename native_data_type::type; +}; +} + +template +struct hash {}; + +template<> +struct hash { + using Type = typename algs::crc32::Type; + + template + static constexpr Type update(Type crc, const T* data, uint64_t len){ + static_assert(sizeof(T) == 1, "Only uint8_t and int8_t are allowed here"); + constexpr std::array table = { + 0x00000000U,0x04C11DB7U,0x09823B6EU,0x0D4326D9U, + 0x130476DCU,0x17C56B6BU,0x1A864DB2U,0x1E475005U, + 0x2608EDB8U,0x22C9F00FU,0x2F8AD6D6U,0x2B4BCB61U, + 0x350C9B64U,0x31CD86D3U,0x3C8EA00AU,0x384FBDBDU, + 0x4C11DB70U,0x48D0C6C7U,0x4593E01EU,0x4152FDA9U, + 0x5F15ADACU,0x5BD4B01BU,0x569796C2U,0x52568B75U, + 0x6A1936C8U,0x6ED82B7FU,0x639B0DA6U,0x675A1011U, + 0x791D4014U,0x7DDC5DA3U,0x709F7B7AU,0x745E66CDU, + 0x9823B6E0U,0x9CE2AB57U,0x91A18D8EU,0x95609039U, + 0x8B27C03CU,0x8FE6DD8BU,0x82A5FB52U,0x8664E6E5U, + 0xBE2B5B58U,0xBAEA46EFU,0xB7A96036U,0xB3687D81U, + 0xAD2F2D84U,0xA9EE3033U,0xA4AD16EAU,0xA06C0B5DU, + 0xD4326D90U,0xD0F37027U,0xDDB056FEU,0xD9714B49U, + 0xC7361B4CU,0xC3F706FBU,0xCEB42022U,0xCA753D95U, + 0xF23A8028U,0xF6FB9D9FU,0xFBB8BB46U,0xFF79A6F1U, + 0xE13EF6F4U,0xE5FFEB43U,0xE8BCCD9AU,0xEC7DD02DU, + 0x34867077U,0x30476DC0U,0x3D044B19U,0x39C556AEU, + 0x278206ABU,0x23431B1CU,0x2E003DC5U,0x2AC12072U, + 0x128E9DCFU,0x164F8078U,0x1B0CA6A1U,0x1FCDBB16U, + 0x018AEB13U,0x054BF6A4U,0x0808D07DU,0x0CC9CDCAU, + 0x7897AB07U,0x7C56B6B0U,0x71159069U,0x75D48DDEU, + 0x6B93DDDBU,0x6F52C06CU,0x6211E6B5U,0x66D0FB02U, + 0x5E9F46BFU,0x5A5E5B08U,0x571D7DD1U,0x53DC6066U, + 0x4D9B3063U,0x495A2DD4U,0x44190B0DU,0x40D816BAU, + 0xACA5C697U,0xA864DB20U,0xA527FDF9U,0xA1E6E04EU, + 0xBFA1B04BU,0xBB60ADFCU,0xB6238B25U,0xB2E29692U, + 0x8AAD2B2FU,0x8E6C3698U,0x832F1041U,0x87EE0DF6U, + 0x99A95DF3U,0x9D684044U,0x902B669DU,0x94EA7B2AU, + 0xE0B41DE7U,0xE4750050U,0xE9362689U,0xEDF73B3EU, + 0xF3B06B3BU,0xF771768CU,0xFA325055U,0xFEF34DE2U, + 0xC6BCF05FU,0xC27DEDE8U,0xCF3ECB31U,0xCBFFD686U, + 0xD5B88683U,0xD1799B34U,0xDC3ABDEDU,0xD8FBA05AU, + 0x690CE0EEU,0x6DCDFD59U,0x608EDB80U,0x644FC637U, + 0x7A089632U,0x7EC98B85U,0x738AAD5CU,0x774BB0EBU, + 0x4F040D56U,0x4BC510E1U,0x46863638U,0x42472B8FU, + 0x5C007B8AU,0x58C1663DU,0x558240E4U,0x51435D53U, + 0x251D3B9EU,0x21DC2629U,0x2C9F00F0U,0x285E1D47U, + 0x36194D42U,0x32D850F5U,0x3F9B762CU,0x3B5A6B9BU, + 0x0315D626U,0x07D4CB91U,0x0A97ED48U,0x0E56F0FFU, + 0x1011A0FAU,0x14D0BD4DU,0x19939B94U,0x1D528623U, + 0xF12F560EU,0xF5EE4BB9U,0xF8AD6D60U,0xFC6C70D7U, + 0xE22B20D2U,0xE6EA3D65U,0xEBA91BBCU,0xEF68060BU, + 0xD727BBB6U,0xD3E6A601U,0xDEA580D8U,0xDA649D6FU, + 0xC423CD6AU,0xC0E2D0DDU,0xCDA1F604U,0xC960EBB3U, + 0xBD3E8D7EU,0xB9FF90C9U,0xB4BCB610U,0xB07DABA7U, + 0xAE3AFBA2U,0xAAFBE615U,0xA7B8C0CCU,0xA379DD7BU, + 0x9B3660C6U,0x9FF77D71U,0x92B45BA8U,0x9675461FU, + 0x8832161AU,0x8CF30BADU,0x81B02D74U,0x857130C3U, + 0x5D8A9099U,0x594B8D2EU,0x5408ABF7U,0x50C9B640U, + 0x4E8EE645U,0x4A4FFBF2U,0x470CDD2BU,0x43CDC09CU, + 0x7B827D21U,0x7F436096U,0x7200464FU,0x76C15BF8U, + 0x68860BFDU,0x6C47164AU,0x61043093U,0x65C52D24U, + 0x119B4BE9U,0x155A565EU,0x18197087U,0x1CD86D30U, + 0x029F3D35U,0x065E2082U,0x0B1D065BU,0x0FDC1BECU, + 0x3793A651U,0x3352BBE6U,0x3E119D3FU,0x3AD08088U, + 0x2497D08DU,0x2056CD3AU,0x2D15EBE3U,0x29D4F654U, + 0xC5A92679U,0xC1683BCEU,0xCC2B1D17U,0xC8EA00A0U, + 0xD6AD50A5U,0xD26C4D12U,0xDF2F6BCBU,0xDBEE767CU, + 0xE3A1CBC1U,0xE760D676U,0xEA23F0AFU,0xEEE2ED18U, + 0xF0A5BD1DU,0xF464A0AAU,0xF9278673U,0xFDE69BC4U, + 0x89B8FD09U,0x8D79E0BEU,0x803AC667U,0x84FBDBD0U, + 0x9ABC8BD5U,0x9E7D9662U,0x933EB0BBU,0x97FFAD0CU, + 0xAFB010B1U,0xAB710D06U,0xA6322BDFU,0xA2F33668U, + 0xBCB4666DU,0xB8757BDAU,0xB5365D03U,0xB1F740B4U, + }; + + while(len > 0){ + uint8_t val = static_cast(*data); + crc = table[val ^ ((crc >> 24) & 0xff)] ^ (crc << 8); + ++data; + --len; + } + return crc; + } + + static constexpr Type update(Type crc, const std::string_view& s){ + return update(crc, s.data(), s.size()); + } + + template + static constexpr Type apply(const T* data, uint64_t len){ + return update(0xffffffff, data, len) ^ 0xffffffff; + } + + static constexpr Type apply(const std::string_view& s){ + return apply(s.data(), s.size()); + } +}; +} diff --git a/modules/codec/c++/schema_hash.h b/modules/codec/c++/schema_hash.h index d4312c4..48e8d6c 100644 --- a/modules/codec/c++/schema_hash.h +++ b/modules/codec/c++/schema_hash.h @@ -2,22 +2,14 @@ #include #include "schema.h" +#include "crc32.h" namespace saw { -struct schema_hash_combine { - static constexpr uint64_t apply(uint64_t seed, uint64_t v){ - return seed ^( std::hash{}(v) + 0x9e3779b9 + (seed<<6) + (seed >> 2)); - } -}; - template struct hash_literal { - static constexpr uint64_t apply(uint64_t seed){ + static constexpr uint32_t apply(uint32_t seed){ constexpr std::string_view view = lit.view(); - for(uint64_t i = 0; i < view.size(); ++i){ - seed = schema_hash_combine::apply(seed, static_cast(view[i])); - } - return seed; + return hash::update(seed, view); } }; @@ -30,7 +22,7 @@ template<> struct schema_hash_seed { using Schema = schema::SignedInteger; - static constexpr uint64_t apply(uint64_t seed){ + static constexpr uint32_t apply(uint32_t seed){ return hash_literal::apply(seed); } }; @@ -39,7 +31,7 @@ template<> struct schema_hash_seed { using Schema = schema::UnsignedInteger; - static constexpr uint64_t apply(uint64_t seed){ + static constexpr uint32_t apply(uint32_t seed){ return hash_literal::apply(seed); } }; @@ -48,7 +40,7 @@ template<> struct schema_hash_seed { using Schema = schema::FloatingPoint; - static constexpr uint64_t apply(uint64_t seed){ + static constexpr uint32_t apply(uint32_t seed){ return hash_literal::apply(seed); } }; @@ -57,7 +49,7 @@ template<> struct schema_hash_seed { using Schema = schema::String; - static constexpr uint64_t apply(uint64_t seed){ + static constexpr uint32_t apply(uint32_t seed){ return hash_literal::apply(seed); } }; @@ -66,10 +58,21 @@ template struct schema_hash_seed> { using Schema = schema::Primitive; - static constexpr uint64_t apply(uint64_t seed){ + static constexpr uint32_t apply(uint32_t seed){ seed = hash_literal::apply(seed); seed = schema_hash_seed

::apply(seed); - seed = schema_hash_combine::apply(seed, N); + uint64_t val = N; + std::array dat{ + static_cast(val >> 0), + static_cast(val >> 8), + static_cast(val >> 16), + static_cast(val >> 24), + static_cast(val >> 32), + static_cast(val >> 40), + static_cast(val >> 48), + static_cast(val >> 56) + }; + seed = hash::update(seed, &dat[0], dat.size()); return seed; } }; @@ -78,10 +81,21 @@ template struct schema_hash_seed> { using Schema = schema::Array; - static constexpr uint64_t apply(uint64_t seed){ + static constexpr uint32_t apply(uint32_t seed){ seed = hash_literal::apply(seed); seed = schema_hash_seed::apply(seed); - seed = schema_hash_combine::apply(seed, N); + uint64_t val = N; + std::array dat{ + static_cast(val >> 0), + static_cast(val >> 8), + static_cast(val >> 16), + static_cast(val >> 24), + static_cast(val >> 32), + static_cast(val >> 40), + static_cast(val >> 48), + static_cast(val >> 56) + }; + seed = hash::update(seed, &dat[0], dat.size()); return seed; } }; @@ -91,7 +105,7 @@ struct schema_hash_seed...>> { using Schema = schema::Struct...>; template - static constexpr uint64_t apply_ele(uint64_t seed){ + static constexpr uint32_t apply_ele(uint32_t seed){ using Type = typename parameter_pack_type::type; constexpr string_literal Lit = parameter_key_pack_type::literal; using MemberT = typename parameter_pack_type...>::type; @@ -106,7 +120,7 @@ struct schema_hash_seed...>> { return seed; } - static constexpr uint64_t apply(uint64_t seed){ + static constexpr uint32_t apply(uint32_t seed){ seed = hash_literal::apply(seed); if constexpr (sizeof...(V) > 0){ seed = apply_ele<0>(seed); @@ -117,8 +131,8 @@ struct schema_hash_seed...>> { template struct schema_hash { - static constexpr uint64_t apply() { - constexpr uint64_t seed = 0; + static constexpr uint32_t apply() { + constexpr uint32_t seed = 0; return schema_hash_seed::apply(seed); } }; diff --git a/modules/codec/tests/schema.cpp b/modules/codec/tests/schema.cpp index 871feb7..71e806d 100644 --- a/modules/codec/tests/schema.cpp +++ b/modules/codec/tests/schema.cpp @@ -17,7 +17,7 @@ template struct schema_hash_test> { static void check(){ using namespace saw; - uint64_t hash = schema_hash::apply(); + constexpr uint64_t hash = schema_hash::apply(); SAW_EXPECT( hash == expected, std::string{"Hash for "} + std::string{T::name.view()} + " is " + std::to_string(hash) +", but should be "+ std::to_string(expected) + "."); } }; @@ -49,20 +49,20 @@ using namespace saw::schema; SAW_TEST("Schema Hashes"){ using namespace saw; schema_hash_test_multi< - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair, - schema_test_pair + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair, + schema_test_pair >::check(); } } -- cgit v1.2.3