minio/erasure.go

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2016-05-20 23:48:47 -04:00
/*
* Minio Cloud Storage, (C) 2016 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package main
import (
"errors"
"github.com/klauspost/reedsolomon"
)
// erasure storage layer.
type erasure struct {
ReedSolomon reedsolomon.Encoder // Erasure encoder/decoder.
DataBlocks int
ParityBlocks int
storageDisks []StorageAPI
}
// errUnexpected - returned for any unexpected error.
var errUnexpected = errors.New("Unexpected error - please report at https://github.com/minio/minio/issues")
// newErasure instantiate a new erasure.
func newErasure(disks []StorageAPI) (*erasure, error) {
// Initialize E.
e := &erasure{}
// Calculate data and parity blocks.
dataBlocks, parityBlocks := len(disks)/2, len(disks)/2
// Initialize reed solomon encoding.
rs, err := reedsolomon.New(dataBlocks, parityBlocks)
if err != nil {
return nil, err
}
// Save the reedsolomon.
e.DataBlocks = dataBlocks
e.ParityBlocks = parityBlocks
e.ReedSolomon = rs
// Save all the initialized storage disks.
e.storageDisks = disks
// Return successfully initialized.
return e, nil
}