diff options
-rw-r--r-- | THIRD-PARTY-NOTICES.TXT | 28 | ||||
-rw-r--r-- | src/mscorlib/Resources/Strings.resx | 6 | ||||
-rw-r--r-- | src/mscorlib/shared/System.Private.CoreLib.Shared.projitems | 1 | ||||
-rw-r--r-- | src/mscorlib/shared/System/HashCode.cs | 430 |
4 files changed, 465 insertions, 0 deletions
diff --git a/THIRD-PARTY-NOTICES.TXT b/THIRD-PARTY-NOTICES.TXT index 30502be142..4a8002db25 100644 --- a/THIRD-PARTY-NOTICES.TXT +++ b/THIRD-PARTY-NOTICES.TXT @@ -221,3 +221,31 @@ License notice for the Printing Floating-Point Numbers 3. This notice may not be removed or altered from any source distribution. ******************************************************************************/ + +License notice for xxHash +------------------------- + +xxHash Library +Copyright (c) 2012-2014, Yann Collet +All rights reserved. + +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 HOLDER 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. diff --git a/src/mscorlib/Resources/Strings.resx b/src/mscorlib/Resources/Strings.resx index 0ded8ea294..ef3821abf1 100644 --- a/src/mscorlib/Resources/Strings.resx +++ b/src/mscorlib/Resources/Strings.resx @@ -3691,4 +3691,10 @@ <data name="Memory_OutstandingReferences" xml:space="preserve"> <value>Release all references before disposing this instance.</value> </data> + <data name="HashCode_HashCodeNotSupported" xml:space="preserve"> + <value>HashCode is a mutable struct and should not be compared with other HashCodes. Use ToHashCode to retrieve the computed hash code.</value> + </data> + <data name="HashCode_EqualityNotSupported" xml:space="preserve"> + <value>HashCode is a mutable struct and should not be compared with other HashCodes.</value> + </data> </root> diff --git a/src/mscorlib/shared/System.Private.CoreLib.Shared.projitems b/src/mscorlib/shared/System.Private.CoreLib.Shared.projitems index 4ab5924094..8cfd499edb 100644 --- a/src/mscorlib/shared/System.Private.CoreLib.Shared.projitems +++ b/src/mscorlib/shared/System.Private.CoreLib.Shared.projitems @@ -159,6 +159,7 @@ <Compile Include="$(MSBuildThisFileDirectory)System\Globalization\UmAlQuraCalendar.cs" /> <Compile Include="$(MSBuildThisFileDirectory)System\Globalization\UnicodeCategory.cs" /> <Compile Include="$(MSBuildThisFileDirectory)System\Guid.cs" /> + <Compile Include="$(MSBuildThisFileDirectory)System\HashCode.cs" /> <Compile Include="$(MSBuildThisFileDirectory)System\HResults.cs" /> <Compile Include="$(MSBuildThisFileDirectory)System\IAsyncResult.cs" /> <Compile Include="$(MSBuildThisFileDirectory)System\ICloneable.cs" /> diff --git a/src/mscorlib/shared/System/HashCode.cs b/src/mscorlib/shared/System/HashCode.cs new file mode 100644 index 0000000000..4be57be02a --- /dev/null +++ b/src/mscorlib/shared/System/HashCode.cs @@ -0,0 +1,430 @@ +// Licensed to the .NET Foundation under one or more agreements. +// The .NET Foundation licenses this file to you under the MIT license. +// See the LICENSE file in the project root for more information. + +/* + +The xxHash32 implementation is based on the code published by Yann Collet: +https://raw.githubusercontent.com/Cyan4973/xxHash/5c174cfa4e45a42f94082dc0d4539b39696afea1/xxhash.c + + xxHash - Fast Hash algorithm + Copyright (C) 2012-2016, Yann Collet + + 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 homepage: http://www.xxhash.com + - xxHash source repository : https://github.com/Cyan4973/xxHash + +*/ + +using System.Collections.Generic; +using System.ComponentModel; +using System.Runtime.CompilerServices; + +namespace System +{ + // xxHash32 is used for the hash code. + // https://github.com/Cyan4973/xxHash + + public struct HashCode + { + private static readonly uint s_seed = GenerateGlobalSeed(); + + private const uint Prime1 = 2654435761U; + private const uint Prime2 = 2246822519U; + private const uint Prime3 = 3266489917U; + private const uint Prime4 = 668265263U; + private const uint Prime5 = 374761393U; + + private uint _v1, _v2, _v3, _v4; + private uint _queue1, _queue2, _queue3; + private uint _length; + + private static unsafe uint GenerateGlobalSeed() + { + uint result; + Interop.GetRandomBytes((byte*)&result, sizeof(uint)); + return result; + } + + public static int Combine<T1>(T1 value1) + { + // Provide a way of diffusing bits from something with a limited + // input hash space. For example, many enums only have a few + // possible hashes, only using the bottom few bits of the code. Some + // collections are built on the assumption that hashes are spread + // over a larger space, so diffusing the bits may help the + // collection work more efficiently. + + var hc1 = (uint)(value1?.GetHashCode() ?? 0); + + uint hash = MixEmptyState(); + hash += 4; + + hash = QueueRound(hash, hc1); + + hash = MixFinal(hash); + return (int)hash; + } + + public static int Combine<T1, T2>(T1 value1, T2 value2) + { + var hc1 = (uint)(value1?.GetHashCode() ?? 0); + var hc2 = (uint)(value2?.GetHashCode() ?? 0); + + uint hash = MixEmptyState(); + hash += 8; + + hash = QueueRound(hash, hc1); + hash = QueueRound(hash, hc2); + + hash = MixFinal(hash); + return (int)hash; + } + + public static int Combine<T1, T2, T3>(T1 value1, T2 value2, T3 value3) + { + var hc1 = (uint)(value1?.GetHashCode() ?? 0); + var hc2 = (uint)(value2?.GetHashCode() ?? 0); + var hc3 = (uint)(value3?.GetHashCode() ?? 0); + + uint hash = MixEmptyState(); + hash += 12; + + hash = QueueRound(hash, hc1); + hash = QueueRound(hash, hc2); + hash = QueueRound(hash, hc3); + + hash = MixFinal(hash); + return (int)hash; + } + + public static int Combine<T1, T2, T3, T4>(T1 value1, T2 value2, T3 value3, T4 value4) + { + var hc1 = (uint)(value1?.GetHashCode() ?? 0); + var hc2 = (uint)(value2?.GetHashCode() ?? 0); + var hc3 = (uint)(value3?.GetHashCode() ?? 0); + var hc4 = (uint)(value4?.GetHashCode() ?? 0); + + Initialize(out uint v1, out uint v2, out uint v3, out uint v4); + + v1 = Round(v1, hc1); + v2 = Round(v2, hc2); + v3 = Round(v3, hc3); + v4 = Round(v4, hc4); + + uint hash = MixState(v1, v2, v3, v4); + hash += 16; + + hash = MixFinal(hash); + return (int)hash; + } + + public static int Combine<T1, T2, T3, T4, T5>(T1 value1, T2 value2, T3 value3, T4 value4, T5 value5) + { + var hc1 = (uint)(value1?.GetHashCode() ?? 0); + var hc2 = (uint)(value2?.GetHashCode() ?? 0); + var hc3 = (uint)(value3?.GetHashCode() ?? 0); + var hc4 = (uint)(value4?.GetHashCode() ?? 0); + var hc5 = (uint)(value5?.GetHashCode() ?? 0); + + Initialize(out uint v1, out uint v2, out uint v3, out uint v4); + + v1 = Round(v1, hc1); + v2 = Round(v2, hc2); + v3 = Round(v3, hc3); + v4 = Round(v4, hc4); + + uint hash = MixState(v1, v2, v3, v4); + hash += 20; + + hash = QueueRound(hash, hc5); + + hash = MixFinal(hash); + return (int)hash; + } + + public static int Combine<T1, T2, T3, T4, T5, T6>(T1 value1, T2 value2, T3 value3, T4 value4, T5 value5, T6 value6) + { + var hc1 = (uint)(value1?.GetHashCode() ?? 0); + var hc2 = (uint)(value2?.GetHashCode() ?? 0); + var hc3 = (uint)(value3?.GetHashCode() ?? 0); + var hc4 = (uint)(value4?.GetHashCode() ?? 0); + var hc5 = (uint)(value5?.GetHashCode() ?? 0); + var hc6 = (uint)(value6?.GetHashCode() ?? 0); + + Initialize(out uint v1, out uint v2, out uint v3, out uint v4); + + v1 = Round(v1, hc1); + v2 = Round(v2, hc2); + v3 = Round(v3, hc3); + v4 = Round(v4, hc4); + + uint hash = MixState(v1, v2, v3, v4); + hash += 24; + + hash = QueueRound(hash, hc5); + hash = QueueRound(hash, hc6); + + hash = MixFinal(hash); + return (int)hash; + } + + public static int Combine<T1, T2, T3, T4, T5, T6, T7>(T1 value1, T2 value2, T3 value3, T4 value4, T5 value5, T6 value6, T7 value7) + { + var hc1 = (uint)(value1?.GetHashCode() ?? 0); + var hc2 = (uint)(value2?.GetHashCode() ?? 0); + var hc3 = (uint)(value3?.GetHashCode() ?? 0); + var hc4 = (uint)(value4?.GetHashCode() ?? 0); + var hc5 = (uint)(value5?.GetHashCode() ?? 0); + var hc6 = (uint)(value6?.GetHashCode() ?? 0); + var hc7 = (uint)(value7?.GetHashCode() ?? 0); + + Initialize(out uint v1, out uint v2, out uint v3, out uint v4); + + v1 = Round(v1, hc1); + v2 = Round(v2, hc2); + v3 = Round(v3, hc3); + v4 = Round(v4, hc4); + + uint hash = MixState(v1, v2, v3, v4); + hash += 28; + + hash = QueueRound(hash, hc5); + hash = QueueRound(hash, hc6); + hash = QueueRound(hash, hc7); + + hash = MixFinal(hash); + return (int)hash; + } + + public static int Combine<T1, T2, T3, T4, T5, T6, T7, T8>(T1 value1, T2 value2, T3 value3, T4 value4, T5 value5, T6 value6, T7 value7, T8 value8) + { + var hc1 = (uint)(value1?.GetHashCode() ?? 0); + var hc2 = (uint)(value2?.GetHashCode() ?? 0); + var hc3 = (uint)(value3?.GetHashCode() ?? 0); + var hc4 = (uint)(value4?.GetHashCode() ?? 0); + var hc5 = (uint)(value5?.GetHashCode() ?? 0); + var hc6 = (uint)(value6?.GetHashCode() ?? 0); + var hc7 = (uint)(value7?.GetHashCode() ?? 0); + var hc8 = (uint)(value8?.GetHashCode() ?? 0); + + Initialize(out uint v1, out uint v2, out uint v3, out uint v4); + + v1 = Round(v1, hc1); + v2 = Round(v2, hc2); + v3 = Round(v3, hc3); + v4 = Round(v4, hc4); + + v1 = Round(v1, hc5); + v2 = Round(v2, hc6); + v3 = Round(v3, hc7); + v4 = Round(v4, hc8); + + uint hash = MixState(v1, v2, v3, v4); + hash += 32; + + hash = MixFinal(hash); + return (int)hash; + } + + [MethodImpl(MethodImplOptions.AggressiveInlining)] + private static uint Rol(uint value, int count) + => (value << count) | (value >> (32 - count)); + + [MethodImpl(MethodImplOptions.AggressiveInlining)] + private static void Initialize(out uint v1, out uint v2, out uint v3, out uint v4) + { + v1 = s_seed + Prime1 + Prime2; + v2 = s_seed + Prime2; + v3 = s_seed; + v4 = s_seed - Prime1; + } + + [MethodImpl(MethodImplOptions.AggressiveInlining)] + private static uint Round(uint hash, uint input) + { + hash += input * Prime2; + hash = Rol(hash, 13); + hash *= Prime1; + return hash; + } + + [MethodImpl(MethodImplOptions.AggressiveInlining)] + private static uint QueueRound(uint hash, uint queuedValue) + { + hash += queuedValue * Prime3; + return Rol(hash, 17) * Prime4; + } + + [MethodImpl(MethodImplOptions.AggressiveInlining)] + private static uint MixState(uint v1, uint v2, uint v3, uint v4) + { + return Rol(v1, 1) + Rol(v2, 7) + Rol(v3, 12) + Rol(v4, 18); + } + + private static uint MixEmptyState() + { + return s_seed + Prime5; + } + + [MethodImpl(MethodImplOptions.AggressiveInlining)] + private static uint MixFinal(uint hash) + { + hash ^= hash >> 15; + hash *= Prime2; + hash ^= hash >> 13; + hash *= Prime3; + hash ^= hash >> 16; + return hash; + } + + public void Add<T>(T value) + { + Add(value?.GetHashCode() ?? 0); + } + + public void Add<T>(T value, IEqualityComparer<T> comparer) + { + Add(comparer != null ? comparer.GetHashCode(value) : (value?.GetHashCode() ?? 0)); + } + + private void Add(int value) + { + // The original xxHash works as follows: + // 0. Initialize immediately. We can't do this in a struct (no + // default ctor). + // 1. Accumulate blocks of length 16 (4 uints) into 4 accumulators. + // 2. Accumulate remaining blocks of length 4 (1 uint) into the + // hash. + // 3. Accumulate remaining blocks of length 1 into the hash. + + // There is no need for #3 as this type only accepts ints. _queue1, + // _queue2 and _queue3 are basically a buffer so that when + // ToHashCode is called we can execute #2 correctly. + + // We need to initialize the xxHash32 state (_v1 to _v4) lazily (see + // #0) nd the last place that can be done if you look at the + // original code is just before the first block of 16 bytes is mixed + // in. The xxHash32 state is never used for streams containing fewer + // than 16 bytes. + + // To see what's really going on here, have a look at the Combine + // methods. + + var val = (uint)value; + + // Storing the value of _length locally shaves of quite a few bytes + // in the resulting machine code. + uint previousLength = _length++; + uint position = previousLength % 4; + + // Switch can't be inlined. + + if (position == 0) + _queue1 = val; + else if (position == 1) + _queue2 = val; + else if (position == 2) + _queue3 = val; + else // position == 3 + { + if (previousLength == 3) + Initialize(out _v1, out _v2, out _v3, out _v4); + + _v1 = Round(_v1, _queue1); + _v2 = Round(_v2, _queue2); + _v3 = Round(_v3, _queue3); + _v4 = Round(_v4, val); + } + } + + public int ToHashCode() + { + // Storing the value of _length locally shaves of quite a few bytes + // in the resulting machine code. + uint length = _length; + + // position refers to the *next* queue position in this method, so + // position == 1 means that _queue1 is populated; _queue2 would have + // been populated on the next call to Add. + uint position = length % 4; + + // If the length is less than 4, _v1 to _v4 don't contain anything + // yet. xxHash32 treats this differently. + + uint hash = length < 4 ? MixEmptyState() : MixState(_v1, _v2, _v3, _v4); + + // _length is incremented once per Add(Int32) and is therefore 4 + // times too small (xxHash length is in bytes, not ints). + + hash += length * 4; + + // Mix what remains in the queue + + // Switch can't be inlined right now, so use as few branches as + // possible by manually excluding impossible scenarios (position > 1 + // is always false if position is not > 0). + if (position > 0) + { + hash = QueueRound(hash, _queue1); + if (position > 1) + { + hash = QueueRound(hash, _queue2); + if (position > 2) + hash = QueueRound(hash, _queue3); + } + } + + hash = MixFinal(hash); + return (int)hash; + } + +#pragma warning disable 0809 + // Obsolete member 'memberA' overrides non-obsolete member 'memberB'. + // Disallowing GetHashCode and Equals is by design + + // * We decided to not override GetHashCode() to produce the hash code + // as this would be weird, both naming-wise as well as from a + // behavioral standpoint (GetHashCode() should return the object's + // hash code, not the one being computed). + + // * Even though ToHashCode() can be called safely multiple times on + // this implementation, it is not part of the contract. If the + // implementation has to change in the future we don't want to worry + // about people who might have incorrectly used this type. + + [Obsolete("HashCode is a mutable struct and should not be compared with other HashCodes. Use ToHashCode to retrieve the computed hash code.", error: true)] + [EditorBrowsable(EditorBrowsableState.Never)] + public override int GetHashCode() => throw new NotSupportedException(SR.HashCode_HashCodeNotSupported); + + [Obsolete("HashCode is a mutable struct and should not be compared with other HashCodes.", error: true)] + [EditorBrowsable(EditorBrowsableState.Never)] + public override bool Equals(object obj) => throw new NotSupportedException(SR.HashCode_EqualityNotSupported); +#pragma warning restore 0809 + } +} |