SpookyHashV1.h | Explore in Territory

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 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
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 *     http://www.apache.org/licenses/LICENSE-2.0
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// This is version 1 of SpookyHash, incompatible with version 2.
//
// SpookyHash: a 128-bit noncryptographic hash function
// By Bob Jenkins, public domain
//   Oct 31 2010: alpha, framework + SpookyHash::Mix appears right
//   Oct 31 2011: alpha again, Mix only good to 2^^69 but rest appears right
//   Dec 31 2011: beta, improved Mix, tested it for 2-bit deltas
//   Feb  2 2012: production, same bits as beta
//   Feb  5 2012: adjusted definitions of uint* to be more portable
//   Mar 30 2012: 3 bytes/cycle, not 4.  Alpha was 4 but wasn't thorough enough.
//
// Up to 3 bytes/cycle for long messages.  Reasonably fast for short messages.
// All 1 or 2 bit deltas achieve avalanche within 1% bias per output bit.
//
// This was developed for and tested on 64-bit x86-compatible processors.
// It assumes the processor is little-endian.  There is a macro
// controlling whether unaligned reads are allowed (by default they are).
// This should be an equally good hash on big-endian machines, but it will
// compute different results on them than on little-endian machines.
//
// Google's CityHash has similar specs to SpookyHash, and CityHash is faster
// on some platforms.  MD4 and MD5 also have similar specs, but they are orders
// of magnitude slower.  CRCs are two or more times slower, but unlike
// SpookyHash, they have nice math for combining the CRCs of pieces to form
// the CRCs of wholes.  There are also cryptographic hashes, but those are even
// slower than MD5.
//

#pragma once

#include <cstddef>
#include <cstdint>

namespace folly {
namespace hash {

// clang-format off

class SpookyHashV1
{ … };

// clang-format on

} // namespace hash
} // namespace folly
folly/folly/hash/SpookyHashV1.h
