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Use hash function to generate stable table types (#943)
See: https://gaiaplatform.atlassian.net/browse/GAIAPLAT-1389 for details on this workitem. Some unit tests are updated due to the change of type generation algorithms. We can no longer assume type 1 or 2 always exists.
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,85 @@ | ||
| ///////////////////////////////////////////// | ||
| // Copyright (c) Gaia Platform LLC | ||
| // All rights reserved. | ||
| ///////////////////////////////////////////// | ||
| #pragma once | ||
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| #include <cstdint> | ||
| #include <cstring> | ||
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| // Adapted from the public domain murmur3 hash implementation at: | ||
| // https://github.com/aappleby/smhasher/blob/master/src/MurmurHash3.cpp | ||
| uint32_t murmurhash3_x86_32(const void* key, int len) | ||
| { | ||
| const auto* data = static_cast<const uint8_t*>(key); | ||
| const int nblocks = len / 4; | ||
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| uint32_t h1 = len; | ||
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| const uint32_t c1 = 0xcc9e2d51; | ||
| const uint32_t c2 = 0x1b873593; | ||
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| //---------- | ||
| // body | ||
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| const auto* blocks = reinterpret_cast<const uint32_t*>(data + nblocks * 4); | ||
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| for (int i = -nblocks; i; i++) | ||
| { | ||
| uint32_t k1; | ||
| std::memcpy(&k1, (blocks + i), sizeof(k1)); | ||
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| k1 *= c1; | ||
| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| k1 = (k1 << 15) | (k1 >> (32 - 15)); | ||
| k1 *= c2; | ||
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| h1 ^= k1; | ||
| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| h1 = (k1 << 13) | (k1 >> (32 - 13)); | ||
| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| h1 = h1 * 5 + 0xe6546b64; | ||
| } | ||
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| //---------- | ||
| // tail | ||
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| const auto* tail = static_cast<const uint8_t*>(data + nblocks * 4); | ||
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| uint32_t k1 = 0; | ||
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| switch (len & 3) | ||
| { | ||
| case 3: | ||
| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| k1 ^= tail[2] << 16; | ||
| case 2: | ||
| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| k1 ^= tail[1] << 8; | ||
| case 1: | ||
| k1 ^= tail[0]; | ||
| k1 *= c1; | ||
| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| k1 = (k1 << 15) | (k1 >> (32 - 15)); | ||
| k1 *= c2; | ||
| h1 ^= k1; | ||
| }; | ||
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| //---------- | ||
| // finalization | ||
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| h1 ^= len; | ||
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| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| h1 ^= h1 >> 16; | ||
| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| h1 *= 0x85ebca6b; | ||
| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| h1 ^= h1 >> 13; | ||
| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| h1 *= 0xc2b2ae35; | ||
| // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers) | ||
| h1 ^= h1 >> 16; | ||
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| return h1; | ||
| } |
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