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30 lines
691 B
30 lines
691 B
// Copyright 2011 The LevelDB-Go Authors. 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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"hash/crc32" |
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) |
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var table = crc32.MakeTable(crc32.Castagnoli) |
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// CRC is a CRC-32 checksum computed using Castagnoli's polynomial. |
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type CRC uint32 |
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// NewCRC creates a new crc based on the given bytes. |
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func NewCRC(b []byte) CRC { |
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return CRC(0).Update(b) |
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} |
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// Update updates the crc with the given bytes. |
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func (c CRC) Update(b []byte) CRC { |
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return CRC(crc32.Update(uint32(c), table, b)) |
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} |
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// Value returns a masked crc. |
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func (c CRC) Value() uint32 { |
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return uint32(c>>15|c<<17) + 0xa282ead8 |
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}
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