minio/cmd/erasure-decode_test.go
Harshavardhana 80ca120088
remove checkBucketExist check entirely to avoid fan-out calls (#18917)
Each Put, List, Multipart operations heavily rely on making
GetBucketInfo() call to verify if bucket exists or not on
a regular basis. This has a large performance cost when there
are tons of servers involved.

We did optimize this part by vectorizing the bucket calls,
however its not enough, beyond 100 nodes and this becomes
fairly visible in terms of performance.
2024-01-30 12:43:25 -08:00

387 lines
21 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package cmd
import (
"bytes"
"context"
crand "crypto/rand"
"io"
"math/rand"
"testing"
"github.com/dustin/go-humanize"
)
func (a badDisk) ReadFile(ctx context.Context, volume string, path string, offset int64, buf []byte, verifier *BitrotVerifier) (n int64, err error) {
return 0, errFaultyDisk
}
var erasureDecodeTests = []struct {
dataBlocks int
onDisks, offDisks int
blocksize, data int64
offset int64
length int64
algorithm BitrotAlgorithm
shouldFail, shouldFailQuorum bool
}{
{dataBlocks: 2, onDisks: 4, offDisks: 0, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: BLAKE2b512, shouldFail: false, shouldFailQuorum: false}, // 0
{dataBlocks: 3, onDisks: 6, offDisks: 0, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: SHA256, shouldFail: false, shouldFailQuorum: false}, // 1
{dataBlocks: 4, onDisks: 8, offDisks: 0, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 2
{dataBlocks: 5, onDisks: 10, offDisks: 0, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 1, length: oneMiByte - 1, algorithm: BLAKE2b512, shouldFail: false, shouldFailQuorum: false}, // 3
{dataBlocks: 6, onDisks: 12, offDisks: 0, blocksize: int64(oneMiByte), data: oneMiByte, offset: oneMiByte, length: 0, algorithm: BLAKE2b512, shouldFail: false, shouldFailQuorum: false},
// 4
{dataBlocks: 7, onDisks: 14, offDisks: 0, blocksize: int64(oneMiByte), data: oneMiByte, offset: 3, length: 1024, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 5
{dataBlocks: 8, onDisks: 16, offDisks: 0, blocksize: int64(oneMiByte), data: oneMiByte, offset: 4, length: 8 * 1024, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 6
{dataBlocks: 7, onDisks: 14, offDisks: 7, blocksize: int64(blockSizeV2), data: oneMiByte, offset: oneMiByte, length: 1, algorithm: DefaultBitrotAlgorithm, shouldFail: true, shouldFailQuorum: false}, // 7
{dataBlocks: 6, onDisks: 12, offDisks: 6, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 8
{dataBlocks: 5, onDisks: 10, offDisks: 5, blocksize: int64(oneMiByte), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: BLAKE2b512, shouldFail: false, shouldFailQuorum: false}, // 9
{dataBlocks: 4, onDisks: 8, offDisks: 4, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: SHA256, shouldFail: false, shouldFailQuorum: false}, // 10
{dataBlocks: 3, onDisks: 6, offDisks: 3, blocksize: int64(oneMiByte), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 11
{dataBlocks: 2, onDisks: 4, offDisks: 2, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 12
{dataBlocks: 2, onDisks: 4, offDisks: 1, blocksize: int64(oneMiByte), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 13
{dataBlocks: 3, onDisks: 6, offDisks: 2, blocksize: int64(oneMiByte), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 14
{dataBlocks: 4, onDisks: 8, offDisks: 3, blocksize: int64(2 * oneMiByte), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 15
{dataBlocks: 5, onDisks: 10, offDisks: 6, blocksize: int64(oneMiByte), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: true}, // 16
{dataBlocks: 5, onDisks: 10, offDisks: 2, blocksize: int64(blockSizeV2), data: 2 * oneMiByte, offset: oneMiByte, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 17
{dataBlocks: 5, onDisks: 10, offDisks: 1, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: BLAKE2b512, shouldFail: false, shouldFailQuorum: false}, // 18
{dataBlocks: 6, onDisks: 12, offDisks: 3, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: SHA256, shouldFail: false, shouldFailQuorum: false},
// 19
{dataBlocks: 6, onDisks: 12, offDisks: 7, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: true}, // 20
{dataBlocks: 8, onDisks: 16, offDisks: 8, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 21
{dataBlocks: 8, onDisks: 16, offDisks: 9, blocksize: int64(oneMiByte), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: true}, // 22
{dataBlocks: 8, onDisks: 16, offDisks: 7, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 23
{dataBlocks: 2, onDisks: 4, offDisks: 1, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 24
{dataBlocks: 2, onDisks: 4, offDisks: 0, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 0, length: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 25
{dataBlocks: 2, onDisks: 4, offDisks: 0, blocksize: int64(blockSizeV2), data: int64(blockSizeV2) + 1, offset: 0, length: int64(blockSizeV2) + 1, algorithm: BLAKE2b512, shouldFail: false, shouldFailQuorum: false}, // 26
{dataBlocks: 2, onDisks: 4, offDisks: 0, blocksize: int64(blockSizeV2), data: int64(2 * blockSizeV2), offset: 12, length: int64(blockSizeV2) + 17, algorithm: BLAKE2b512, shouldFail: false, shouldFailQuorum: false}, // 27
{dataBlocks: 3, onDisks: 6, offDisks: 0, blocksize: int64(blockSizeV2), data: int64(2 * blockSizeV2), offset: 1023, length: int64(blockSizeV2) + 1024, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 28
{dataBlocks: 4, onDisks: 8, offDisks: 0, blocksize: int64(blockSizeV2), data: int64(2 * blockSizeV2), offset: 11, length: int64(blockSizeV2) + 2*1024, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 29
{dataBlocks: 6, onDisks: 12, offDisks: 0, blocksize: int64(blockSizeV2), data: int64(2 * blockSizeV2), offset: 512, length: int64(blockSizeV2) + 8*1024, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 30
{dataBlocks: 8, onDisks: 16, offDisks: 0, blocksize: int64(blockSizeV2), data: int64(2 * blockSizeV2), offset: int64(blockSizeV2), length: int64(blockSizeV2) - 1, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 31
{dataBlocks: 2, onDisks: 4, offDisks: 0, blocksize: int64(blockSizeV2), data: int64(oneMiByte), offset: -1, length: 3, algorithm: DefaultBitrotAlgorithm, shouldFail: true, shouldFailQuorum: false}, // 32
{dataBlocks: 2, onDisks: 4, offDisks: 0, blocksize: int64(blockSizeV2), data: int64(oneMiByte), offset: 1024, length: -1, algorithm: DefaultBitrotAlgorithm, shouldFail: true, shouldFailQuorum: false}, // 33
{dataBlocks: 4, onDisks: 6, offDisks: 0, blocksize: int64(blockSizeV2), data: int64(blockSizeV2), offset: 0, length: int64(blockSizeV2), algorithm: BLAKE2b512, shouldFail: false, shouldFailQuorum: false}, // 34
{dataBlocks: 4, onDisks: 6, offDisks: 1, blocksize: int64(blockSizeV2), data: int64(2 * blockSizeV2), offset: 12, length: int64(blockSizeV2) + 17, algorithm: BLAKE2b512, shouldFail: false, shouldFailQuorum: false}, // 35
{dataBlocks: 4, onDisks: 6, offDisks: 3, blocksize: int64(blockSizeV2), data: int64(2 * blockSizeV2), offset: 1023, length: int64(blockSizeV2) + 1024, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: true}, // 36
{dataBlocks: 8, onDisks: 12, offDisks: 4, blocksize: int64(blockSizeV2), data: int64(2 * blockSizeV2), offset: 11, length: int64(blockSizeV2) + 2*1024, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false}, // 37
}
func TestErasureDecode(t *testing.T) {
for i, test := range erasureDecodeTests {
setup, err := newErasureTestSetup(t, test.dataBlocks, test.onDisks-test.dataBlocks, test.blocksize)
if err != nil {
t.Fatalf("Test %d: failed to create test setup: %v", i, err)
}
erasure, err := NewErasure(context.Background(), test.dataBlocks, test.onDisks-test.dataBlocks, test.blocksize)
if err != nil {
t.Fatalf("Test %d: failed to create ErasureStorage: %v", i, err)
}
disks := setup.disks
data := make([]byte, test.data)
if _, err = io.ReadFull(crand.Reader, data); err != nil {
t.Fatalf("Test %d: failed to generate random test data: %v", i, err)
}
writeAlgorithm := test.algorithm
if !test.algorithm.Available() {
writeAlgorithm = DefaultBitrotAlgorithm
}
buffer := make([]byte, test.blocksize, 2*test.blocksize)
writers := make([]io.Writer, len(disks))
for i, disk := range disks {
writers[i] = newBitrotWriter(disk, "", "testbucket", "object", erasure.ShardFileSize(test.data), writeAlgorithm, erasure.ShardSize())
}
n, err := erasure.Encode(context.Background(), bytes.NewReader(data), writers, buffer, erasure.dataBlocks+1)
closeBitrotWriters(writers)
if err != nil {
t.Fatalf("Test %d: failed to create erasure test file: %v", i, err)
}
if n != test.data {
t.Fatalf("Test %d: failed to create erasure test file", i)
}
for i, w := range writers {
if w == nil {
disks[i] = nil
}
}
// Get the checksums of the current part.
bitrotReaders := make([]io.ReaderAt, len(disks))
for index, disk := range disks {
if disk == OfflineDisk {
continue
}
tillOffset := erasure.ShardFileOffset(test.offset, test.length, test.data)
bitrotReaders[index] = newBitrotReader(disk, nil, "testbucket", "object", tillOffset, writeAlgorithm, bitrotWriterSum(writers[index]), erasure.ShardSize())
}
writer := bytes.NewBuffer(nil)
_, err = erasure.Decode(context.Background(), writer, bitrotReaders, test.offset, test.length, test.data, nil)
closeBitrotReaders(bitrotReaders)
if err != nil && !test.shouldFail {
t.Errorf("Test %d: should pass but failed with: %v", i, err)
}
if err == nil && test.shouldFail {
t.Errorf("Test %d: should fail but it passed", i)
}
if err == nil {
if content := writer.Bytes(); !bytes.Equal(content, data[test.offset:test.offset+test.length]) {
t.Errorf("Test %d: read returns wrong file content.", i)
}
}
for i, r := range bitrotReaders {
if r == nil {
disks[i] = OfflineDisk
}
}
if err == nil && !test.shouldFail {
bitrotReaders = make([]io.ReaderAt, len(disks))
for index, disk := range disks {
if disk == OfflineDisk {
continue
}
tillOffset := erasure.ShardFileOffset(test.offset, test.length, test.data)
bitrotReaders[index] = newBitrotReader(disk, nil, "testbucket", "object", tillOffset, writeAlgorithm, bitrotWriterSum(writers[index]), erasure.ShardSize())
}
for j := range disks[:test.offDisks] {
if bitrotReaders[j] == nil {
continue
}
switch r := bitrotReaders[j].(type) {
case *wholeBitrotReader:
r.disk = badDisk{nil}
case *streamingBitrotReader:
r.disk = badDisk{nil}
}
}
if test.offDisks > 0 {
bitrotReaders[0] = nil
}
writer.Reset()
_, err = erasure.Decode(context.Background(), writer, bitrotReaders, test.offset, test.length, test.data, nil)
closeBitrotReaders(bitrotReaders)
if err != nil && !test.shouldFailQuorum {
t.Errorf("Test %d: should pass but failed with: %v", i, err)
}
if err == nil && test.shouldFailQuorum {
t.Errorf("Test %d: should fail but it passed", i)
}
if !test.shouldFailQuorum {
if content := writer.Bytes(); !bytes.Equal(content, data[test.offset:test.offset+test.length]) {
t.Errorf("Test %d: read returns wrong file content", i)
}
}
}
}
}
// Test erasureDecode with random offset and lengths.
// This test is t.Skip()ed as it a long time to run, hence should be run
// explicitly after commenting out t.Skip()
func TestErasureDecodeRandomOffsetLength(t *testing.T) {
if testing.Short() {
t.Skip()
}
// Initialize environment needed for the test.
dataBlocks := 7
parityBlocks := 7
blockSize := int64(1 * humanize.MiByte)
setup, err := newErasureTestSetup(t, dataBlocks, parityBlocks, blockSize)
if err != nil {
t.Error(err)
return
}
disks := setup.disks
erasure, err := NewErasure(context.Background(), dataBlocks, parityBlocks, blockSize)
if err != nil {
t.Fatalf("failed to create ErasureStorage: %v", err)
}
// Prepare a slice of 5MiB with random data.
data := make([]byte, 5*humanize.MiByte)
length := int64(len(data))
_, err = rand.Read(data)
if err != nil {
t.Fatal(err)
}
writers := make([]io.Writer, len(disks))
for i, disk := range disks {
if disk == nil {
continue
}
writers[i] = newBitrotWriter(disk, "", "testbucket", "object", erasure.ShardFileSize(length), DefaultBitrotAlgorithm, erasure.ShardSize())
}
// 10000 iterations with random offsets and lengths.
iterations := 10000
// Create a test file to read from.
buffer := make([]byte, blockSize, 2*blockSize)
n, err := erasure.Encode(context.Background(), bytes.NewReader(data), writers, buffer, erasure.dataBlocks+1)
closeBitrotWriters(writers)
if err != nil {
t.Fatal(err)
}
if n != length {
t.Errorf("erasureCreateFile returned %d, expected %d", n, length)
}
// To generate random offset/length.
r := rand.New(rand.NewSource(UTCNow().UnixNano()))
buf := &bytes.Buffer{}
// Verify erasure.Decode() for random offsets and lengths.
for i := 0; i < iterations; i++ {
offset := r.Int63n(length)
readLen := r.Int63n(length - offset)
expected := data[offset : offset+readLen]
// Get the checksums of the current part.
bitrotReaders := make([]io.ReaderAt, len(disks))
for index, disk := range disks {
if disk == OfflineDisk {
continue
}
tillOffset := erasure.ShardFileOffset(offset, readLen, length)
bitrotReaders[index] = newStreamingBitrotReader(disk, nil, "testbucket", "object", tillOffset, DefaultBitrotAlgorithm, erasure.ShardSize())
}
_, err = erasure.Decode(context.Background(), buf, bitrotReaders, offset, readLen, length, nil)
closeBitrotReaders(bitrotReaders)
if err != nil {
t.Fatal(err, offset, readLen)
}
got := buf.Bytes()
if !bytes.Equal(expected, got) {
t.Fatalf("read data is different from what was expected, offset=%d length=%d", offset, readLen)
}
buf.Reset()
}
}
// Benchmarks
func benchmarkErasureDecode(data, parity, dataDown, parityDown int, size int64, b *testing.B) {
setup, err := newErasureTestSetup(b, data, parity, blockSizeV2)
if err != nil {
b.Fatalf("failed to create test setup: %v", err)
}
disks := setup.disks
erasure, err := NewErasure(context.Background(), data, parity, blockSizeV2)
if err != nil {
b.Fatalf("failed to create ErasureStorage: %v", err)
}
writers := make([]io.Writer, len(disks))
for i, disk := range disks {
if disk == nil {
continue
}
writers[i] = newBitrotWriter(disk, "", "testbucket", "object", erasure.ShardFileSize(size), DefaultBitrotAlgorithm, erasure.ShardSize())
}
content := make([]byte, size)
buffer := make([]byte, blockSizeV2, 2*blockSizeV2)
_, err = erasure.Encode(context.Background(), bytes.NewReader(content), writers, buffer, erasure.dataBlocks+1)
closeBitrotWriters(writers)
if err != nil {
b.Fatalf("failed to create erasure test file: %v", err)
}
for i := 0; i < dataDown; i++ {
writers[i] = nil
}
for i := data; i < data+parityDown; i++ {
writers[i] = nil
}
b.ResetTimer()
b.SetBytes(size)
b.ReportAllocs()
for i := 0; i < b.N; i++ {
bitrotReaders := make([]io.ReaderAt, len(disks))
for index, disk := range disks {
if writers[index] == nil {
continue
}
tillOffset := erasure.ShardFileOffset(0, size, size)
bitrotReaders[index] = newStreamingBitrotReader(disk, nil, "testbucket", "object", tillOffset, DefaultBitrotAlgorithm, erasure.ShardSize())
}
if _, err = erasure.Decode(context.Background(), bytes.NewBuffer(content[:0]), bitrotReaders, 0, size, size, nil); err != nil {
panic(err)
}
closeBitrotReaders(bitrotReaders)
}
}
func BenchmarkErasureDecodeQuick(b *testing.B) {
const size = 12 * 1024 * 1024
b.Run(" 00|00 ", func(b *testing.B) { benchmarkErasureDecode(2, 2, 0, 0, size, b) })
b.Run(" 00|X0 ", func(b *testing.B) { benchmarkErasureDecode(2, 2, 0, 1, size, b) })
b.Run(" X0|00 ", func(b *testing.B) { benchmarkErasureDecode(2, 2, 1, 0, size, b) })
b.Run(" X0|X0 ", func(b *testing.B) { benchmarkErasureDecode(2, 2, 1, 1, size, b) })
}
func BenchmarkErasureDecode_4_64KB(b *testing.B) {
const size = 64 * 1024
b.Run(" 00|00 ", func(b *testing.B) { benchmarkErasureDecode(2, 2, 0, 0, size, b) })
b.Run(" 00|X0 ", func(b *testing.B) { benchmarkErasureDecode(2, 2, 0, 1, size, b) })
b.Run(" X0|00 ", func(b *testing.B) { benchmarkErasureDecode(2, 2, 1, 0, size, b) })
b.Run(" X0|X0 ", func(b *testing.B) { benchmarkErasureDecode(2, 2, 1, 1, size, b) })
b.Run(" 00|XX ", func(b *testing.B) { benchmarkErasureDecode(2, 2, 0, 2, size, b) })
b.Run(" XX|00 ", func(b *testing.B) { benchmarkErasureDecode(2, 2, 2, 0, size, b) })
}
func BenchmarkErasureDecode_8_20MB(b *testing.B) {
const size = 20 * 1024 * 1024
b.Run(" 0000|0000 ", func(b *testing.B) { benchmarkErasureDecode(4, 4, 0, 0, size, b) })
b.Run(" 0000|X000 ", func(b *testing.B) { benchmarkErasureDecode(4, 4, 0, 1, size, b) })
b.Run(" X000|0000 ", func(b *testing.B) { benchmarkErasureDecode(4, 4, 1, 0, size, b) })
b.Run(" X000|X000 ", func(b *testing.B) { benchmarkErasureDecode(4, 4, 1, 1, size, b) })
b.Run(" 0000|XXXX ", func(b *testing.B) { benchmarkErasureDecode(4, 4, 0, 4, size, b) })
b.Run(" XX00|XX00 ", func(b *testing.B) { benchmarkErasureDecode(4, 4, 2, 2, size, b) })
b.Run(" XXXX|0000 ", func(b *testing.B) { benchmarkErasureDecode(4, 4, 4, 0, size, b) })
}
func BenchmarkErasureDecode_12_30MB(b *testing.B) {
const size = 30 * 1024 * 1024
b.Run(" 000000|000000 ", func(b *testing.B) { benchmarkErasureDecode(6, 6, 0, 0, size, b) })
b.Run(" 000000|X00000 ", func(b *testing.B) { benchmarkErasureDecode(6, 6, 0, 1, size, b) })
b.Run(" X00000|000000 ", func(b *testing.B) { benchmarkErasureDecode(6, 6, 1, 0, size, b) })
b.Run(" X00000|X00000 ", func(b *testing.B) { benchmarkErasureDecode(6, 6, 1, 1, size, b) })
b.Run(" 000000|XXXXXX ", func(b *testing.B) { benchmarkErasureDecode(6, 6, 0, 6, size, b) })
b.Run(" XXX000|XXX000 ", func(b *testing.B) { benchmarkErasureDecode(6, 6, 3, 3, size, b) })
b.Run(" XXXXXX|000000 ", func(b *testing.B) { benchmarkErasureDecode(6, 6, 6, 0, size, b) })
}
func BenchmarkErasureDecode_16_40MB(b *testing.B) {
const size = 40 * 1024 * 1024
b.Run(" 00000000|00000000 ", func(b *testing.B) { benchmarkErasureDecode(8, 8, 0, 0, size, b) })
b.Run(" 00000000|X0000000 ", func(b *testing.B) { benchmarkErasureDecode(8, 8, 0, 1, size, b) })
b.Run(" X0000000|00000000 ", func(b *testing.B) { benchmarkErasureDecode(8, 8, 1, 0, size, b) })
b.Run(" X0000000|X0000000 ", func(b *testing.B) { benchmarkErasureDecode(8, 8, 1, 1, size, b) })
b.Run(" 00000000|XXXXXXXX ", func(b *testing.B) { benchmarkErasureDecode(8, 8, 0, 8, size, b) })
b.Run(" XXXX0000|XXXX0000 ", func(b *testing.B) { benchmarkErasureDecode(8, 8, 4, 4, size, b) })
b.Run(" XXXXXXXX|00000000 ", func(b *testing.B) { benchmarkErasureDecode(8, 8, 8, 0, size, b) })
}