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31 lines
691 B
Go
31 lines
691 B
Go
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// 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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