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.
115 lines
3.7 KiB
115 lines
3.7 KiB
/*
|
|
* Minio Cloud Storage, (C) 2017 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 cmd
|
|
|
|
import (
|
|
"crypto/subtle"
|
|
"hash"
|
|
|
|
"github.com/klauspost/reedsolomon"
|
|
)
|
|
|
|
// OfflineDisk represents an unavailable disk.
|
|
var OfflineDisk StorageAPI // zero value is nil
|
|
|
|
// ErasureFileInfo contains information about an erasure file operation (create, read, heal).
|
|
type ErasureFileInfo struct {
|
|
Size int64
|
|
Algorithm BitrotAlgorithm
|
|
Checksums [][]byte
|
|
}
|
|
|
|
// ErasureStorage represents an array of disks.
|
|
// The disks contain erasure coded and bitrot-protected data.
|
|
type ErasureStorage struct {
|
|
disks []StorageAPI
|
|
erasure reedsolomon.Encoder
|
|
dataBlocks, parityBlocks int
|
|
}
|
|
|
|
// NewErasureStorage creates a new ErasureStorage. The storage erasure codes and protects all data written to
|
|
// the disks.
|
|
func NewErasureStorage(disks []StorageAPI, dataBlocks, parityBlocks int) (s ErasureStorage, err error) {
|
|
erasure, err := reedsolomon.New(dataBlocks, parityBlocks)
|
|
if err != nil {
|
|
return s, traceErrorf("failed to create erasure coding: %v", err)
|
|
}
|
|
s = ErasureStorage{
|
|
disks: make([]StorageAPI, len(disks)),
|
|
erasure: erasure,
|
|
dataBlocks: dataBlocks,
|
|
parityBlocks: parityBlocks,
|
|
}
|
|
copy(s.disks, disks)
|
|
return
|
|
}
|
|
|
|
// ErasureEncode encodes the given data and returns the erasure-coded data.
|
|
// It returns an error if the erasure coding failed.
|
|
func (s *ErasureStorage) ErasureEncode(data []byte) ([][]byte, error) {
|
|
encoded, err := s.erasure.Split(data)
|
|
if err != nil {
|
|
return nil, traceErrorf("failed to split data: %v", err)
|
|
}
|
|
if err = s.erasure.Encode(encoded); err != nil {
|
|
return nil, traceErrorf("failed to encode data: %v", err)
|
|
}
|
|
return encoded, nil
|
|
}
|
|
|
|
// ErasureDecodeDataBlocks decodes the given erasure-coded data.
|
|
// It only decodes the data blocks but does not verify them.
|
|
// It returns an error if the decoding failed.
|
|
func (s *ErasureStorage) ErasureDecodeDataBlocks(data [][]byte) error {
|
|
if err := s.erasure.ReconstructData(data); err != nil {
|
|
return traceErrorf("failed to reconstruct data: %v", err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// ErasureDecodeDataAndParityBlocks decodes the given erasure-coded data and verifies it.
|
|
// It returns an error if the decoding failed.
|
|
func (s *ErasureStorage) ErasureDecodeDataAndParityBlocks(data [][]byte) error {
|
|
if err := s.erasure.Reconstruct(data); err != nil {
|
|
return traceErrorf("failed to reconstruct data: %v", err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// NewBitrotVerifier returns a new BitrotVerifier implementing the given algorithm.
|
|
func NewBitrotVerifier(algorithm BitrotAlgorithm, checksum []byte) *BitrotVerifier {
|
|
return &BitrotVerifier{algorithm.New(), algorithm, checksum, false}
|
|
}
|
|
|
|
// BitrotVerifier can be used to verify protected data.
|
|
type BitrotVerifier struct {
|
|
hash.Hash
|
|
|
|
algorithm BitrotAlgorithm
|
|
sum []byte
|
|
verified bool
|
|
}
|
|
|
|
// Verify returns true iff the computed checksum of the verifier matches the the checksum provided when the verifier
|
|
// was created.
|
|
func (v *BitrotVerifier) Verify() bool {
|
|
v.verified = true
|
|
return subtle.ConstantTimeCompare(v.Sum(nil), v.sum) == 1
|
|
}
|
|
|
|
// IsVerified returns true iff Verify was called at least once.
|
|
func (v *BitrotVerifier) IsVerified() bool { return v.verified }
|
|
|