You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 
minio/erasure.go

91 lines
2.6 KiB

/*
* 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 (
"encoding/hex"
"hash"
"github.com/klauspost/reedsolomon"
)
// erasure storage layer.
type erasureConfig struct {
reedSolomon reedsolomon.Encoder // Erasure encoder/decoder.
dataBlocks int // Calculated data disks.
storageDisks []StorageAPI // Initialized storage disks.
distribution []int // Erasure block distribution.
hashWriters []hash.Hash // Allocate hash writers.
// Carries hex checksums needed for validating Reads.
hashChecksums []string
checkSumAlgo string
}
// newErasure instantiate a new erasure.
func newErasure(disks []StorageAPI, distribution []int) *erasureConfig {
// Initialize E.
e := &erasureConfig{}
// Calculate data and parity blocks.
dataBlocks, parityBlocks := len(disks)/2, len(disks)/2
// Initialize reed solomon encoding.
rs, err := reedsolomon.New(dataBlocks, parityBlocks)
fatalIf(err, "Unable to initialize reedsolomon package.")
// Save the reedsolomon.
e.dataBlocks = dataBlocks
e.reedSolomon = rs
// Save all the initialized storage disks.
e.storageDisks = disks
// Save the distribution.
e.distribution = distribution
// Return successfully initialized.
return e
}
// SaveAlgo - FIXME.
func (e *erasureConfig) SaveAlgo(algo string) {
e.checkSumAlgo = algo
}
// Save hex encoded hashes - saves hashes that need to be validated
// during reads for each blocks.
func (e *erasureConfig) SaveHashes(hashes []string) {
e.hashChecksums = hashes
}
// InitHash - initializes new hash for all blocks.
func (e *erasureConfig) InitHash(algo string) {
e.hashWriters = make([]hash.Hash, len(e.storageDisks))
for index := range e.storageDisks {
e.hashWriters[index] = newHash(algo)
}
}
// GetHashes - returns a slice of hex encoded hash.
func (e erasureConfig) GetHashes() []string {
var hexHashes = make([]string, len(e.storageDisks))
for index, hashWriter := range e.hashWriters {
hexHashes[index] = hex.EncodeToString(hashWriter.Sum(nil))
}
return hexHashes
}