mirror of https://github.com/minio/minio.git
100 lines
2.2 KiB
Go
100 lines
2.2 KiB
Go
/*
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* Mini Object Storage, (C) 2015 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 data_v1
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import (
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"bytes"
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"encoding/binary"
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"encoding/gob"
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"fmt"
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"io"
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)
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type Metadata map[string]string
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type DataHeader struct {
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Key string
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Part uint8
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Metadata Metadata
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EncoderParams EncoderParams
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}
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type EncoderTechnique int
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const (
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VANDERMONDE EncoderTechnique = iota
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CAUCHY
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)
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type EncoderParams struct {
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Length uint32
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K uint8
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M uint8
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Technique EncoderTechnique
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}
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func NewHeader(key string, part uint8, metadata Metadata, encoderParams EncoderParams) DataHeader {
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header := DataHeader{}
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header.Key = key
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header.Part = part
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header.Metadata = metadata
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header.EncoderParams = EncoderParams{
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Length: encoderParams.Length,
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K: encoderParams.K,
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M: encoderParams.M,
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Technique: encoderParams.Technique,
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}
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return header
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}
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func ValidateHeader(header DataHeader) bool {
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if header.Key == "" || header.Part < 0 || len(header.Metadata) < 2 {
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return false
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}
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if header.EncoderParams.Length < 0 || header.EncoderParams.Technique > 1 {
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return false
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}
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return true
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}
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func WriteData(target io.Writer, header DataHeader, data io.Reader) error {
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if !ValidateHeader(header) {
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return fmt.Errorf("Invalid header")
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}
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var headerBuffer bytes.Buffer
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// encode header
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encoder := gob.NewEncoder(&headerBuffer)
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encoder.Encode(header)
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// write length of header
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if err := binary.Write(target, binary.LittleEndian, int64(headerBuffer.Len())); err != nil {
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return err
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}
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// write encoded header
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if _, err := io.Copy(target, &headerBuffer); err != nil {
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return err
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}
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// write data
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if _, err := io.Copy(target, data); err != nil {
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return err
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}
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return nil
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}
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