bolt db works

This commit is contained in:
Barak Michener 2014-08-11 05:31:34 -04:00
parent d261e5d870
commit 82e4d122fc
5 changed files with 272 additions and 203 deletions

View file

@ -17,12 +17,12 @@ package bolt
import (
"bytes"
"encoding/json"
"errors"
"fmt"
"strings"
"github.com/barakmich/glog"
ldbit "github.com/syndtr/goleveldb/leveldb/iterator"
"github.com/syndtr/goleveldb/leveldb/opt"
"github.com/boltdb/bolt"
"github.com/google/cayley/graph"
"github.com/google/cayley/graph/iterator"
@ -30,48 +30,38 @@ import (
)
type Iterator struct {
uid uint64
tags graph.Tagger
nextPrefix []byte
checkId []byte
dir quad.Direction
open bool
iter ldbit.Iterator
qs *QuadStore
ro *opt.ReadOptions
originalPrefix string
result graph.Value
uid uint64
tags graph.Tagger
bucket []byte
checkId []byte
dir quad.Direction
qs *QuadStore
result *Token
buffer [][]byte
offset int
done bool
size int64
}
func NewIterator(prefix string, d quad.Direction, value graph.Value, qs *QuadStore) graph.Iterator {
vb := value.(Token)
p := make([]byte, 0, 2+qs.hasher.Size())
p = append(p, []byte(prefix)...)
p = append(p, []byte(vb[1:])...)
var bufferSize = 50
opts := &opt.ReadOptions{
DontFillCache: true,
func NewIterator(bucket []byte, d quad.Direction, value graph.Value, qs *QuadStore) graph.Iterator {
tok := value.(*Token)
if !bytes.Equal(tok.bucket, nodeBucket) {
glog.Error("Creating an iterator from a non-node value.")
return &iterator.Null{}
}
it := Iterator{
uid: iterator.NextUID(),
nextPrefix: p,
checkId: vb,
dir: d,
originalPrefix: prefix,
ro: opts,
iter: qs.db.NewIterator(nil, opts),
open: true,
qs: qs,
uid: iterator.NextUID(),
bucket: bucket,
dir: d,
qs: qs,
size: qs.SizeOf(value),
}
ok := it.iter.Seek(it.nextPrefix)
if !ok {
it.open = false
it.iter.Release()
glog.Error("Opening LevelDB iterator couldn't seek to location ", it.nextPrefix)
return &iterator.Null{}
}
it.checkId = make([]byte, len(tok.key))
copy(it.checkId, tok.key)
return &it
}
@ -81,15 +71,9 @@ func (it *Iterator) UID() uint64 {
}
func (it *Iterator) Reset() {
if !it.open {
it.iter = it.qs.db.NewIterator(nil, it.ro)
it.open = true
}
ok := it.iter.Seek(it.nextPrefix)
if !ok {
it.open = false
it.iter.Release()
}
it.buffer = nil
it.offset = 0
it.done = false
}
func (it *Iterator) Tagger() *graph.Tagger {
@ -107,16 +91,15 @@ func (it *Iterator) TagResults(dst map[string]graph.Value) {
}
func (it *Iterator) Clone() graph.Iterator {
out := NewIterator(it.originalPrefix, it.dir, Token(it.checkId), it.qs)
out := NewIterator(it.bucket, it.dir, &Token{nodeBucket, it.checkId}, it.qs)
out.Tagger().CopyFrom(it)
return out
}
func (it *Iterator) Close() {
if it.open {
it.iter.Release()
it.open = false
}
it.result = nil
it.buffer = nil
it.done = true
}
func (it *Iterator) isLiveValue(val []byte) bool {
@ -125,36 +108,73 @@ func (it *Iterator) isLiveValue(val []byte) bool {
return len(entry.History)%2 != 0
}
var errNotExist = errors.New("Triple doesn't exist")
func (it *Iterator) Next() bool {
if it.iter == nil {
it.result = nil
if it.done {
return false
}
if !it.open {
it.result = nil
return false
}
if !it.iter.Valid() {
it.result = nil
it.Close()
return false
}
if bytes.HasPrefix(it.iter.Key(), it.nextPrefix) {
if !it.isLiveValue(it.iter.Value()) {
return it.Next()
if len(it.buffer) <= it.offset+1 {
it.offset = 0
var last []byte
if it.buffer != nil {
last = it.buffer[len(it.buffer)-1]
}
out := make([]byte, len(it.iter.Key()))
copy(out, it.iter.Key())
it.result = Token(out)
ok := it.iter.Next()
if !ok {
it.Close()
it.buffer = make([][]byte, 0, bufferSize)
err := it.qs.db.View(func(tx *bolt.Tx) error {
i := 0
b := tx.Bucket(it.bucket)
cur := b.Cursor()
if last == nil {
k, _ := cur.Seek(it.checkId)
if bytes.HasPrefix(k, it.checkId) {
var out []byte
out = make([]byte, len(k))
copy(out, k)
it.buffer = append(it.buffer, out)
i++
} else {
it.buffer = append(it.buffer, nil)
return errNotExist
}
} else {
k, _ := cur.Seek(last)
if !bytes.Equal(k, last) {
return fmt.Errorf("Couldn't pick up after", k)
}
}
for i < bufferSize {
k, v := cur.Next()
if k == nil || !bytes.HasPrefix(k, it.checkId) {
it.buffer = append(it.buffer, nil)
break
}
if !it.isLiveValue(v) {
continue
}
var out []byte
out = make([]byte, len(k))
copy(out, k)
it.buffer = append(it.buffer, out)
i++
}
return nil
})
if err != nil {
if err != errNotExist {
glog.Error("Error nexting in database: ", err)
}
it.done = true
return false
}
return true
} else {
it.offset++
}
it.Close()
it.result = nil
return false
if it.Result() == nil {
it.done = true
return false
}
return true
}
func (it *Iterator) ResultTree() *graph.ResultTree {
@ -162,7 +182,19 @@ func (it *Iterator) ResultTree() *graph.ResultTree {
}
func (it *Iterator) Result() graph.Value {
return it.result
if it.done {
return nil
}
if it.result != nil {
return it.result
}
if it.offset >= len(it.buffer) {
return nil
}
if it.buffer[it.offset] == nil {
return nil
}
return &Token{bucket: it.bucket, key: it.buffer[it.offset]}
}
func (it *Iterator) NextPath() bool {
@ -174,65 +206,65 @@ func (it *Iterator) SubIterators() []graph.Iterator {
return nil
}
func PositionOf(prefix []byte, d quad.Direction, qs *QuadStore) int {
if bytes.Equal(prefix, []byte("sp")) {
func PositionOf(tok *Token, d quad.Direction, qs *QuadStore) int {
if bytes.Equal(tok.bucket, spoBucket) {
switch d {
case quad.Subject:
return 2
return 0
case quad.Predicate:
return qs.hasher.Size() + 2
return qs.hasher.Size()
case quad.Object:
return 2*qs.hasher.Size() + 2
return 2 * qs.hasher.Size()
case quad.Label:
return 3*qs.hasher.Size() + 2
return 3 * qs.hasher.Size()
}
}
if bytes.Equal(prefix, []byte("po")) {
if bytes.Equal(tok.bucket, posBucket) {
switch d {
case quad.Subject:
return 2*qs.hasher.Size() + 2
return 2 * qs.hasher.Size()
case quad.Predicate:
return 2
return 0
case quad.Object:
return qs.hasher.Size() + 2
return qs.hasher.Size()
case quad.Label:
return 3*qs.hasher.Size() + 2
return 3 * qs.hasher.Size()
}
}
if bytes.Equal(prefix, []byte("os")) {
if bytes.Equal(tok.bucket, ospBucket) {
switch d {
case quad.Subject:
return qs.hasher.Size() + 2
return qs.hasher.Size()
case quad.Predicate:
return 2*qs.hasher.Size() + 2
return 2 * qs.hasher.Size()
case quad.Object:
return 2
return 0
case quad.Label:
return 3*qs.hasher.Size() + 2
return 3 * qs.hasher.Size()
}
}
if bytes.Equal(prefix, []byte("cp")) {
if bytes.Equal(tok.bucket, cpsBucket) {
switch d {
case quad.Subject:
return 2*qs.hasher.Size() + 2
return 2 * qs.hasher.Size()
case quad.Predicate:
return qs.hasher.Size() + 2
return qs.hasher.Size()
case quad.Object:
return 3*qs.hasher.Size() + 2
return 3 * qs.hasher.Size()
case quad.Label:
return 2
return 0
}
}
panic("unreachable")
}
func (it *Iterator) Contains(v graph.Value) bool {
val := v.(Token)
if val[0] == 'z' {
val := v.(*Token)
if bytes.Equal(val.bucket, nodeBucket) {
return false
}
offset := PositionOf(val[0:2], it.dir, it.qs)
if bytes.HasPrefix(val[offset:], it.checkId[1:]) {
offset := PositionOf(val, it.dir, it.qs)
if bytes.HasPrefix(val.key[offset:], it.checkId) {
// You may ask, why don't we check to see if it's a valid (not deleted) triple
// again?
//
@ -248,31 +280,30 @@ func (it *Iterator) Contains(v graph.Value) bool {
}
func (it *Iterator) Size() (int64, bool) {
return it.qs.SizeOf(Token(it.checkId)), true
return it.size, true
}
func (it *Iterator) DebugString(indent int) string {
size, _ := it.Size()
return fmt.Sprintf("%s(%s %d tags: %v dir: %s size:%d %s)",
strings.Repeat(" ", indent),
it.Type(),
it.UID(),
it.tags.Tags(),
it.dir,
size,
it.qs.NameOf(Token(it.checkId)),
it.size,
it.qs.NameOf(&Token{it.bucket, it.checkId}),
)
}
var levelDBType graph.Type
var boltType graph.Type
func init() {
levelDBType = graph.RegisterIterator("leveldb")
boltType = graph.RegisterIterator("bolt")
}
func Type() graph.Type { return levelDBType }
func Type() graph.Type { return boltType }
func (it *Iterator) Type() graph.Type { return levelDBType }
func (it *Iterator) Type() graph.Type { return boltType }
func (it *Iterator) Sorted() bool { return false }
func (it *Iterator) Optimize() (graph.Iterator, bool) {