44 lines
1.2 KiB
Go
44 lines
1.2 KiB
Go
/*
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* Minio Cloud 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 md5
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import (
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"crypto/md5"
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"io"
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)
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// Sum - low memory footprint io.Reader based md5sum helper
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func Sum(reader io.Reader) ([]byte, error) {
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hash := md5.New()
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var err error
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var length int
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for err == nil {
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byteBuffer := make([]byte, 1024*1024)
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length, err = reader.Read(byteBuffer)
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// While hash.Write() wouldn't mind a Nil byteBuffer
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// It is necessary for us to verify this and break
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if length == 0 {
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break
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}
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byteBuffer = byteBuffer[0:length]
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hash.Write(byteBuffer)
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}
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if err != io.EOF {
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return nil, err
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}
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return hash.Sum(nil), nil
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}
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