frostfs-node/pkg/local_object_storage/pilorama/boltdb.go
Evgenii Stratonikov d6d7e35454 [#1431] pilorama: Cache attributes in the index
Currently to find a node by path we iterate over all the children on
each level. This is far from optimal and scales badly with the number of
nodes on a single level. Thus we introduce "indexed attributes" for
which an additional information is stored and which can be use in
`*ByPath` operations. Currently this set only includes `FileName`
attribute but this may change in future.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-07-08 13:18:23 +03:00

647 lines
16 KiB
Go

package pilorama
import (
"bytes"
"encoding/binary"
"math/rand"
"os"
"path/filepath"
"github.com/nspcc-dev/neo-go/pkg/io"
cidSDK "github.com/nspcc-dev/neofs-sdk-go/container/id"
"go.etcd.io/bbolt"
)
type boltForest struct {
path string
db *bbolt.DB
}
var (
dataBucket = []byte{0}
logBucket = []byte{1}
)
// NewBoltForest returns storage wrapper for storing operations on CRDT trees.
//
// Each tree is stored in a separate bucket by `CID + treeID` key.
// All integers are stored in little-endian unless explicitly specified otherwise.
//
// DB schema (for a single tree):
// timestamp is 8-byte, id is 4-byte.
//
// log storage (logBucket):
// timestamp in big-endian -> log operation
//
// tree storage (dataBucket):
// 't' + node (id) -> timestamp when the node first appeared
// 'p' + node (id) -> parent (id)
// 'm' + node (id) -> serialized meta
// 'c' + parent (id) + child (id) -> 0/1
// 'i' + 0 + attrKey + 0 + attrValue + 0 + parent (id) + node (id) -> 0/1 (1 for automatically created nodes)
func NewBoltForest(path string) ForestStorage {
return &boltForest{path: path}
}
func (t *boltForest) Init() error { return nil }
func (t *boltForest) Open() error {
if err := os.MkdirAll(filepath.Dir(t.path), os.ModePerm); err != nil {
return err
}
db, err := bbolt.Open(t.path, os.ModePerm, bbolt.DefaultOptions)
if err != nil {
return err
}
t.db = db
return db.Update(func(tx *bbolt.Tx) error {
_, err := tx.CreateBucketIfNotExists(dataBucket)
if err != nil {
return err
}
_, err = tx.CreateBucketIfNotExists(logBucket)
if err != nil {
return err
}
return nil
})
}
func (t *boltForest) Close() error { return t.db.Close() }
// TreeMove implements the Forest interface.
func (t *boltForest) TreeMove(cid cidSDK.ID, treeID string, m *Move) (*LogMove, error) {
var lm *LogMove
return lm, t.db.Update(func(tx *bbolt.Tx) error {
bLog, bTree, err := t.getTreeBuckets(tx, cid, treeID)
if err != nil {
return err
}
m.Time = t.getLatestTimestamp(bLog)
if m.Child == RootID {
m.Child = t.findSpareID(bTree)
}
lm, err = t.applyOperation(bLog, bTree, m)
return err
})
}
// TreeAddByPath implements the Forest interface.
func (t *boltForest) TreeAddByPath(cid cidSDK.ID, treeID string, attr string, path []string, meta []KeyValue) ([]LogMove, error) {
if !isAttributeInternal(attr) {
return nil, ErrNotPathAttribute
}
var lm []LogMove
var key [17]byte
err := t.db.Update(func(tx *bbolt.Tx) error {
bLog, bTree, err := t.getTreeBuckets(tx, cid, treeID)
if err != nil {
return err
}
i, node, err := t.getPathPrefix(bTree, attr, path)
if err != nil {
return err
}
lm = make([]LogMove, len(path)-i+1)
for j := i; j < len(path); j++ {
lm[j-i].Move = Move{
Parent: node,
Meta: Meta{
Time: t.getLatestTimestamp(bLog),
Items: []KeyValue{{Key: attr, Value: []byte(path[j])}},
},
Child: t.findSpareID(bTree),
}
err := t.do(bLog, bTree, key[:], &lm[j-i])
if err != nil {
return err
}
node = lm[j-i].Child
}
lm[len(lm)-1].Move = Move{
Parent: node,
Meta: Meta{
Time: t.getLatestTimestamp(bLog),
Items: meta,
},
Child: t.findSpareID(bTree),
}
return t.do(bLog, bTree, key[:], &lm[len(lm)-1])
})
return lm, err
}
// getLatestTimestamp returns timestamp for a new operation which is guaranteed to be bigger than
// all timestamps corresponding to already stored operations.
// FIXME timestamp should be based on a node position in the container.
func (t *boltForest) getLatestTimestamp(bLog *bbolt.Bucket) uint64 {
c := bLog.Cursor()
key, _ := c.Last()
if len(key) == 0 {
return 1
}
return binary.BigEndian.Uint64(key) + 1
}
// findSpareID returns random unused ID.
func (t *boltForest) findSpareID(bTree *bbolt.Bucket) uint64 {
id := uint64(rand.Int63())
var key [9]byte
key[0] = 't'
binary.LittleEndian.PutUint64(key[1:], id)
for {
if bTree.Get(key[:]) == nil {
return id
}
id = uint64(rand.Int63())
binary.LittleEndian.PutUint64(key[1:], id)
}
}
// TreeApply implements the Forest interface.
func (t *boltForest) TreeApply(cid cidSDK.ID, treeID string, m *Move) error {
return t.db.Update(func(tx *bbolt.Tx) error {
bLog, bTree, err := t.getTreeBuckets(tx, cid, treeID)
if err != nil {
return err
}
_, err = t.applyOperation(bLog, bTree, m)
return err
})
}
func (t *boltForest) getTreeBuckets(tx *bbolt.Tx, cid cidSDK.ID, treeID string) (*bbolt.Bucket, *bbolt.Bucket, error) {
treeRoot := bucketName(cid, treeID)
child, err := tx.CreateBucket(treeRoot)
if err != nil && err != bbolt.ErrBucketExists {
return nil, nil, err
}
var bLog, bData *bbolt.Bucket
if err == nil {
if bLog, err = child.CreateBucket(logBucket); err != nil {
return nil, nil, err
}
if bData, err = child.CreateBucket(dataBucket); err != nil {
return nil, nil, err
}
} else {
child = tx.Bucket(treeRoot)
bLog = child.Bucket(logBucket)
bData = child.Bucket(dataBucket)
}
return bLog, bData, nil
}
func (t *boltForest) applyOperation(logBucket, treeBucket *bbolt.Bucket, m *Move) (*LogMove, error) {
var lm LogMove
var tmp LogMove
var cKey [17]byte
c := logBucket.Cursor()
key, value := c.Last()
// 1. Undo up until the desired timestamp is here.
for len(key) == 8 && binary.BigEndian.Uint64(key) > m.Time {
if err := t.logFromBytes(&tmp, value); err != nil {
return nil, err
}
if err := t.undo(&tmp.Move, &tmp, treeBucket, cKey[:]); err != nil {
return nil, err
}
key, value = c.Prev()
}
// 2. Insert the operation.
if len(key) != 8 || binary.BigEndian.Uint64(key) != m.Time {
lm.Move = *m
if err := t.do(logBucket, treeBucket, cKey[:], &lm); err != nil {
return nil, err
}
}
key, value = c.Next()
// 3. Re-apply all other operations.
for len(key) == 8 {
if err := t.logFromBytes(&tmp, value); err != nil {
return nil, err
}
if err := t.do(logBucket, treeBucket, cKey[:], &tmp); err != nil {
return nil, err
}
key, value = c.Next()
}
return &lm, nil
}
func (t *boltForest) do(lb *bbolt.Bucket, b *bbolt.Bucket, key []byte, op *LogMove) error {
shouldPut := !t.isAncestor(b, key, op.Child, op.Parent) &&
!(op.Parent != 0 && op.Parent != TrashID && b.Get(timestampKey(key, op.Parent)) == nil)
shouldRemove := op.Parent == TrashID
currParent := b.Get(parentKey(key, op.Child))
if currParent != nil { // node is already in tree
op.HasOld = true
op.Old.Parent = binary.LittleEndian.Uint64(currParent)
if err := op.Old.Meta.FromBytes(b.Get(metaKey(key, op.Child))); err != nil {
return err
}
}
binary.BigEndian.PutUint64(key, op.Time)
if err := lb.Put(key[:8], t.logToBytes(op)); err != nil {
return err
}
if !shouldPut {
return nil
}
if shouldRemove {
if currParent != nil {
p := binary.LittleEndian.Uint64(currParent)
if err := b.Delete(childrenKey(key, op.Child, p)); err != nil {
return err
}
}
return t.removeNode(b, key, op.Child, op.Parent)
}
if currParent == nil {
if err := b.Put(timestampKey(key, op.Child), toUint64(op.Time)); err != nil {
return err
}
} else {
parent := binary.LittleEndian.Uint64(currParent)
if err := b.Delete(childrenKey(key, op.Child, parent)); err != nil {
return err
}
var meta Meta
var k = metaKey(key, op.Child)
if err := meta.FromBytes(b.Get(k)); err == nil {
for i := range meta.Items {
if isAttributeInternal(meta.Items[i].Key) {
err := b.Delete(internalKey(nil, meta.Items[i].Key, string(meta.Items[i].Value), parent, op.Child))
if err != nil {
return err
}
}
}
}
}
return t.addNode(b, key, op.Child, op.Parent, op.Meta)
}
// removeNode removes node keys from the tree except the children key or its parent.
func (t *boltForest) removeNode(b *bbolt.Bucket, key []byte, node, parent Node) error {
if err := b.Delete(parentKey(key, node)); err != nil {
return err
}
var meta Meta
var k = metaKey(key, node)
if err := meta.FromBytes(b.Get(k)); err == nil {
for i := range meta.Items {
if isAttributeInternal(meta.Items[i].Key) {
err := b.Delete(internalKey(nil, meta.Items[i].Key, string(meta.Items[i].Value), parent, node))
if err != nil {
return err
}
}
}
}
if err := b.Delete(metaKey(key, node)); err != nil {
return err
}
return b.Delete(timestampKey(key, node))
}
// addNode adds node keys to the tree except the timestamp key.
func (t *boltForest) addNode(b *bbolt.Bucket, key []byte, child, parent Node, meta Meta) error {
err := b.Put(parentKey(key, child), toUint64(parent))
if err != nil {
return err
}
err = b.Put(childrenKey(key, child, parent), []byte{1})
if err != nil {
return err
}
err = b.Put(metaKey(key, child), meta.Bytes())
if err != nil {
return err
}
for i := range meta.Items {
if !isAttributeInternal(meta.Items[i].Key) {
continue
}
key = internalKey(key, meta.Items[i].Key, string(meta.Items[i].Value), parent, child)
if len(meta.Items) == 1 {
err = b.Put(key, []byte{1})
} else {
err = b.Put(key, []byte{0})
}
if err != nil {
return err
}
}
return nil
}
func (t *boltForest) undo(m *Move, lm *LogMove, b *bbolt.Bucket, key []byte) error {
if err := b.Delete(childrenKey(key, m.Child, m.Parent)); err != nil {
return err
}
if !lm.HasOld {
return t.removeNode(b, key, m.Child, m.Parent)
}
return t.addNode(b, key, m.Child, lm.Old.Parent, lm.Old.Meta)
}
func (t *boltForest) isAncestor(b *bbolt.Bucket, key []byte, parent, child Node) bool {
key[0] = 'p'
for c := child; c != parent; {
binary.LittleEndian.PutUint64(key[1:], c)
rawParent := b.Get(key[:9])
if len(rawParent) != 8 {
return false
}
c = binary.LittleEndian.Uint64(rawParent)
}
return true
}
// TreeGetByPath implements the Forest interface.
func (t *boltForest) TreeGetByPath(cid cidSDK.ID, treeID string, attr string, path []string, latest bool) ([]Node, error) {
if !isAttributeInternal(attr) {
return nil, ErrNotPathAttribute
}
if len(path) == 0 {
return nil, nil
}
var nodes []Node
return nodes, t.db.View(func(tx *bbolt.Tx) error {
treeRoot := tx.Bucket(bucketName(cid, treeID))
if treeRoot == nil {
return ErrTreeNotFound
}
b := treeRoot.Bucket(dataBucket)
i, curNode, err := t.getPathPrefix(b, attr, path[:len(path)-1])
if err != nil {
return err
}
if i < len(path)-1 {
return nil
}
var (
childID [9]byte
maxTimestamp uint64
)
c := b.Cursor()
attrKey := internalKey(nil, attr, path[len(path)-1], curNode, 0)
attrKey = attrKey[:len(attrKey)-8]
childKey, _ := c.Seek(attrKey)
for len(childKey) == len(attrKey)+8 && bytes.Equal(attrKey, childKey[:len(childKey)-8]) {
child := binary.LittleEndian.Uint64(childKey[len(childKey)-8:])
if latest {
ts := binary.LittleEndian.Uint64(b.Get(timestampKey(childID[:], child)))
if ts >= maxTimestamp {
nodes = append(nodes[:0], child)
maxTimestamp = ts
}
} else {
nodes = append(nodes, child)
}
childKey, _ = c.Next()
}
return nil
})
}
// TreeGetMeta implements the forest interface.
func (t *boltForest) TreeGetMeta(cid cidSDK.ID, treeID string, nodeID Node) (Meta, Node, error) {
key := parentKey(make([]byte, 9), nodeID)
var m Meta
var parentID uint64
err := t.db.View(func(tx *bbolt.Tx) error {
treeRoot := tx.Bucket(bucketName(cid, treeID))
if treeRoot == nil {
return ErrTreeNotFound
}
b := treeRoot.Bucket(dataBucket)
if data := b.Get(key); len(data) == 8 {
parentID = binary.LittleEndian.Uint64(data)
}
return m.FromBytes(b.Get(metaKey(key, nodeID)))
})
return m, parentID, err
}
// TreeGetChildren implements the Forest interface.
func (t *boltForest) TreeGetChildren(cid cidSDK.ID, treeID string, nodeID Node) ([]uint64, error) {
key := make([]byte, 9)
key[0] = 'c'
binary.LittleEndian.PutUint64(key[1:], nodeID)
var children []uint64
err := t.db.View(func(tx *bbolt.Tx) error {
treeRoot := tx.Bucket(bucketName(cid, treeID))
if treeRoot == nil {
return ErrTreeNotFound
}
b := treeRoot.Bucket(dataBucket)
c := b.Cursor()
for k, _ := c.Seek(key); len(k) == 17 && binary.LittleEndian.Uint64(k[1:]) == nodeID; k, _ = c.Next() {
children = append(children, binary.LittleEndian.Uint64(k[9:]))
}
return nil
})
return children, err
}
// TreeGetOpLog implements the pilorama.Forest interface.
func (t *boltForest) TreeGetOpLog(cid cidSDK.ID, treeID string, height uint64) (Move, error) {
key := make([]byte, 8)
binary.BigEndian.PutUint64(key, height)
var lm Move
err := t.db.View(func(tx *bbolt.Tx) error {
treeRoot := tx.Bucket(bucketName(cid, treeID))
if treeRoot == nil {
return ErrTreeNotFound
}
c := treeRoot.Bucket(logBucket).Cursor()
if _, data := c.Seek(key); data != nil {
return t.moveFromBytes(&lm, data)
}
return nil
})
return lm, err
}
func (t *boltForest) getPathPrefix(bTree *bbolt.Bucket, attr string, path []string) (int, Node, error) {
c := bTree.Cursor()
var curNode Node
var attrKey []byte
loop:
for i := range path {
attrKey = internalKey(attrKey, attr, path[i], curNode, 0)
attrKey = attrKey[:len(attrKey)-8]
childKey, value := c.Seek(attrKey)
for len(childKey) == len(attrKey)+8 && bytes.Equal(attrKey, childKey[:len(childKey)-8]) {
if len(value) == 1 && value[0] == 1 {
curNode = binary.LittleEndian.Uint64(childKey[len(childKey)-8:])
continue loop
}
childKey, value = c.Next()
}
return i, curNode, nil
}
return len(path), curNode, nil
}
func (t *boltForest) moveFromBytes(m *Move, data []byte) error {
r := io.NewBinReaderFromBuf(data)
m.Child = r.ReadU64LE()
m.Parent = r.ReadU64LE()
if err := m.Meta.FromBytes(r.ReadVarBytes()); err != nil {
return err
}
return r.Err
}
func (t *boltForest) logFromBytes(lm *LogMove, data []byte) error {
r := io.NewBinReaderFromBuf(data)
lm.Child = r.ReadU64LE()
lm.Parent = r.ReadU64LE()
if err := lm.Meta.FromBytes(r.ReadVarBytes()); err != nil {
return err
}
lm.HasOld = r.ReadBool()
if lm.HasOld {
lm.Old.Parent = r.ReadU64LE()
if err := lm.Old.Meta.FromBytes(r.ReadVarBytes()); err != nil {
return err
}
}
return r.Err
}
func (t *boltForest) logToBytes(lm *LogMove) []byte {
w := io.NewBufBinWriter()
w.WriteU64LE(lm.Child)
w.WriteU64LE(lm.Parent)
w.WriteVarBytes(lm.Meta.Bytes())
w.WriteBool(lm.HasOld)
if lm.HasOld {
w.WriteU64LE(lm.Old.Parent)
w.WriteVarBytes(lm.Old.Meta.Bytes())
}
return w.Bytes()
}
func bucketName(cid cidSDK.ID, treeID string) []byte {
return []byte(cid.String() + treeID)
}
// 't' + node (id) -> timestamp when the node first appeared
func timestampKey(key []byte, child Node) []byte {
key[0] = 't'
binary.LittleEndian.PutUint64(key[1:], child)
return key[:9]
}
// 'p' + node (id) -> parent (id)
func parentKey(key []byte, child Node) []byte {
key[0] = 'p'
binary.LittleEndian.PutUint64(key[1:], child)
return key[:9]
}
// 'm' + node (id) -> serialized meta
func metaKey(key []byte, child Node) []byte {
key[0] = 'm'
binary.LittleEndian.PutUint64(key[1:], child)
return key[:9]
}
// 'c' + parent (id) + child (id) -> 0/1
func childrenKey(key []byte, child, parent Node) []byte {
key[0] = 'c'
binary.LittleEndian.PutUint64(key[1:], parent)
binary.LittleEndian.PutUint64(key[9:], child)
return key[:17]
}
// 'i' + attribute name (string) + attribute value (string) + parent (id) + node (id) -> 0/1
func internalKey(key []byte, k, v string, parent, node Node) []byte {
size := 1 /* prefix */ + 2*2 /* len */ + 2*8 /* nodes */ + len(k) + len(v)
if cap(key) < size {
key = make([]byte, 0, size)
}
key = key[:0]
key = append(key, 'i')
l := len(k)
key = append(key, byte(l), byte(l>>8))
key = append(key, k...)
l = len(v)
key = append(key, byte(l), byte(l>>8))
key = append(key, v...)
var raw [8]byte
binary.LittleEndian.PutUint64(raw[:], parent)
key = append(key, raw[:]...)
binary.LittleEndian.PutUint64(raw[:], node)
key = append(key, raw[:]...)
return key
}
func toUint64(x uint64) []byte {
var a [8]byte
binary.LittleEndian.PutUint64(a[:], x)
return a[:]
}