[#868] blobstor: allow to decompress objects on-the-fly

We should be able to read whatever we have written earlier.
Compression setting applies only to the new objects.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
This commit is contained in:
Evgenii Stratonikov 2021-10-07 17:50:36 +03:00 committed by Leonard Lyubich
parent cc377b34d2
commit dd678cd976
3 changed files with 105 additions and 10 deletions

View file

@ -1,6 +1,7 @@
package blobstor
import (
"bytes"
"errors"
"fmt"
"path"
@ -781,20 +782,33 @@ func (b *blobovniczas) updateAndGet(p string, old *uint64) (blobovniczaWithIndex
func (b *blobovniczas) init() error {
b.log.Debug("initializing Blobovnicza's")
zstdC, err := zstdCompressor()
if err != nil {
return fmt.Errorf("could not create zstd compressor: %v", err)
}
zstdD, err := zstdDecompressor()
if err != nil {
return fmt.Errorf("could not create zstd decompressor: %v", err)
}
// Compression is always done based on config settings.
if b.compressionEnabled {
zstdC, err := zstdCompressor()
if err != nil {
return fmt.Errorf("could not create zstd compressor: %v", err)
}
zstdD, err := zstdDecompressor()
if err != nil {
return fmt.Errorf("could not create zstd decompressor: %v", err)
}
b.compressor = zstdC
b.decompressor = zstdD
} else {
b.compressor = noOpCompressor
b.decompressor = noOpDecompressor
}
// However we should be able to read any object
// we have previously written.
b.decompressor = func(data []byte) ([]byte, error) {
// Fallback to reading decompressed objects.
// For normal objects data is always bigger than 4 bytes, the first check is here
// because function interface is rather generic (Go compiler inserts bound
// checks anyway).
if len(data) < 4 || !bytes.Equal(data[:4], zstdFrameMagic) {
return noOpDecompressor(data)
}
return zstdD(data)
}
return b.iterateBlobovniczas(func(p string, blz *blobovnicza.Blobovnicza) error {

View file

@ -0,0 +1,77 @@
package blobstor
import (
"os"
"testing"
"github.com/nspcc-dev/neofs-node/pkg/core/object"
"github.com/stretchr/testify/require"
)
func TestCompression(t *testing.T) {
dir, err := os.MkdirTemp("", "neofs*")
require.NoError(t, err)
t.Cleanup(func() { _ = os.RemoveAll(dir) })
const (
smallSizeLimit = 512
objCount = 4
)
newBlobStor := func(t *testing.T, compress bool) *BlobStor {
bs := New(WithCompressObjects(compress),
WithRootPath(dir),
WithSmallSizeLimit(smallSizeLimit))
require.NoError(t, bs.Open())
require.NoError(t, bs.Init())
return bs
}
bigObj := make([]*object.Object, objCount)
smallObj := make([]*object.Object, objCount)
for i := 0; i < objCount; i++ {
bigObj[i] = testObject(smallSizeLimit * 2)
smallObj[i] = testObject(smallSizeLimit / 2)
}
testGet := func(t *testing.T, b *BlobStor, i int) {
res1, err := b.GetSmall(&GetSmallPrm{address: address{smallObj[i].Address()}})
require.NoError(t, err)
require.Equal(t, smallObj[i], res1.Object())
res2, err := b.GetBig(&GetBigPrm{address: address{bigObj[i].Address()}})
require.NoError(t, err)
require.Equal(t, bigObj[i], res2.Object())
}
testPut := func(t *testing.T, b *BlobStor, i int) {
prm := new(PutPrm)
prm.SetObject(smallObj[i])
_, err = b.Put(prm)
require.NoError(t, err)
prm = new(PutPrm)
prm.SetObject(bigObj[i])
_, err = b.Put(prm)
require.NoError(t, err)
}
// Put and Get uncompressed object
blobStor := newBlobStor(t, false)
testPut(t, blobStor, 0)
testGet(t, blobStor, 0)
require.NoError(t, blobStor.Close())
blobStor = newBlobStor(t, true)
testGet(t, blobStor, 0) // get uncompressed object with compress enabled
testPut(t, blobStor, 1)
testGet(t, blobStor, 1)
require.NoError(t, blobStor.Close())
blobStor = newBlobStor(t, false)
testGet(t, blobStor, 0) // get old uncompressed object
testGet(t, blobStor, 1) // get compressed object with compression disabled
testPut(t, blobStor, 2)
testGet(t, blobStor, 2)
require.NoError(t, blobStor.Close())
}

View file

@ -4,6 +4,10 @@ import (
"github.com/klauspost/compress/zstd"
)
// zstdFrameMagic contains first 4 bytes of any compressed object
// https://github.com/klauspost/compress/blob/master/zstd/framedec.go#L58 .
var zstdFrameMagic = []byte{0x28, 0xb5, 0x2f, 0xfd}
func noOpCompressor(data []byte) []byte {
return data
}