51 lines
1.2 KiB
Go
51 lines
1.2 KiB
Go
/*
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* Minimalist Object Storage, (C) 2014 Minio, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package crc32c
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import (
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"hash/crc32"
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"io"
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)
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var castanagoliTable = crc32.MakeTable(crc32.Castagnoli)
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/// Convenience functions
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// Sum32 - single caller crc helper
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func Sum32(buffer []byte) uint32 {
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crc := crc32.New(castanagoliTable)
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crc.Reset()
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crc.Write(buffer)
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return crc.Sum32()
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}
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// Sum - io.Reader based crc helper
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func Sum(reader io.Reader) (uint32, error) {
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h := crc32.New(castanagoliTable)
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var err error
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for err == nil {
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length := 0
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byteBuffer := make([]byte, 1024*1024)
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length, err = reader.Read(byteBuffer)
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byteBuffer = byteBuffer[0:length]
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h.Write(byteBuffer)
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}
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if err != io.EOF {
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return 0, err
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}
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return h.Sum32(), nil
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}
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