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48 lines
832 B
48 lines
832 B
// Copyright (c) 2012, Suryandaru Triandana <[email protected]> |
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// All rights reserved. |
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// |
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// Use of this source code is governed by a BSD-style license that can be |
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// found in the LICENSE file. |
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package util |
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import ( |
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"encoding/binary" |
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) |
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// Hash return hash of the given data. |
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func Hash(data []byte, seed uint32) uint32 { |
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// Similar to murmur hash |
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const ( |
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m = uint32(0xc6a4a793) |
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r = uint32(24) |
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) |
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var ( |
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h = seed ^ (uint32(len(data)) * m) |
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i int |
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) |
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for n := len(data) - len(data)%4; i < n; i += 4 { |
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h += binary.LittleEndian.Uint32(data[i:]) |
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h *= m |
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h ^= (h >> 16) |
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} |
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switch len(data) - i { |
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default: |
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panic("not reached") |
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case 3: |
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h += uint32(data[i+2]) << 16 |
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fallthrough |
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case 2: |
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h += uint32(data[i+1]) << 8 |
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fallthrough |
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case 1: |
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h += uint32(data[i]) |
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h *= m |
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h ^= (h >> r) |
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case 0: |
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} |
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return h |
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}
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