Merge pull request #103 from barakmich/materializer_iterator

Fix Materializer iterator

graph/iterator/materialize_iterator.go

@@ -32,6 +32,10 @@ type result struct {
 	tags map[string]graph.Value
 }
 
+type hashable interface {
+	Hashable() interface{}
+}
+
 type Materialize struct {
 	uid         uint64
 	tags        graph.Tagger
@@ -200,7 +204,11 @@ func (it *Materialize) Contains(v graph.Value) bool {
 	if it.aborted {
 		return it.subIt.Contains(v)
 	}
-	if i, ok := it.containsMap[v]; ok {
+	key := v
+	if h, ok := v.(hashable); ok {
+		key = h.Hashable()
+	}
+	if i, ok := it.containsMap[key]; ok {
 		it.index = i
 		it.subindex = 0
 		return graph.ContainsLogOut(it, v, true)
@@ -228,7 +236,7 @@ func (it *Materialize) NextResult() bool {
 func (it *Materialize) materializeSet() {
 	i := 0
 	for {
-		val, ok := graph.Next(it.subIt)
+		id, ok := graph.Next(it.subIt)
 		if !ok {
 			break
 		}
@@ -237,6 +245,10 @@ func (it *Materialize) materializeSet() {
 			it.aborted = true
 			break
 		}
+		val := id
+		if h, ok := id.(hashable); ok {
+			val = h.Hashable()
+		}
 		if _, ok := it.containsMap[val]; !ok {
 			it.containsMap[val] = len(it.values)
 			it.values = append(it.values, nil)
@@ -244,11 +256,11 @@ func (it *Materialize) materializeSet() {
 		index := it.containsMap[val]
 		tags := make(map[string]graph.Value)
 		it.subIt.TagResults(tags)
-		it.values[index] = append(it.values[index], result{id: val, tags: tags})
+		it.values[index] = append(it.values[index], result{id: id, tags: tags})
 		for it.subIt.NextResult() == true {
 			tags := make(map[string]graph.Value)
 			it.subIt.TagResults(tags)
-			it.values[index] = append(it.values[index], result{id: val, tags: tags})
+			it.values[index] = append(it.values[index], result{id: id, tags: tags})
 		}
 	}
 	if it.aborted {

graph/leveldb/all_iterator.go

@@ -117,8 +117,8 @@ func (it *AllIterator) Next() (graph.Value, bool) {
 		it.Close()
 		return nil, false
 	}
-	it.result = out
-	return out, true
+	it.result = Token(out)
+	return it.result, true
 }
 
 func (it *AllIterator) ResultTree() *graph.ResultTree {

graph/leveldb/iterator.go

@@ -42,7 +42,7 @@ type Iterator struct {
 }
 
 func NewIterator(prefix string, d quad.Direction, value graph.Value, qs *TripleStore) *Iterator {
-	vb := value.([]byte)
+	vb := value.(Token)
 	p := make([]byte, 0, 2+qs.hasher.Size())
 	p = append(p, []byte(prefix)...)
 	p = append(p, []byte(vb[1:])...)
@@ -105,7 +105,7 @@ func (it *Iterator) TagResults(dst map[string]graph.Value) {
 }
 
 func (it *Iterator) Clone() graph.Iterator {
-	out := NewIterator(it.originalPrefix, it.dir, it.checkId, it.qs)
+	out := NewIterator(it.originalPrefix, it.dir, Token(it.checkId), it.qs)
 	out.tags.CopyFrom(it)
 	return out
 }
@@ -134,12 +134,12 @@ func (it *Iterator) Next() (graph.Value, bool) {
 	if bytes.HasPrefix(it.iter.Key(), it.nextPrefix) {
 		out := make([]byte, len(it.iter.Key()))
 		copy(out, it.iter.Key())
-		it.result = out
+		it.result = Token(out)
 		ok := it.iter.Next()
 		if !ok {
 			it.Close()
 		}
-		return out, true
+		return Token(out), true
 	}
 	it.Close()
 	it.result = nil
@@ -216,7 +216,7 @@ func PositionOf(prefix []byte, d quad.Direction, qs *TripleStore) int {
 }
 
 func (it *Iterator) Contains(v graph.Value) bool {
-	val := v.([]byte)
+	val := v.(Token)
 	if val[0] == 'z' {
 		return false
 	}
@@ -227,7 +227,7 @@ func (it *Iterator) Contains(v graph.Value) bool {
 		}
 	} else {
 		nameForDir := it.qs.Quad(v).Get(it.dir)
-		hashForDir := it.qs.ValueOf(nameForDir).([]byte)
+		hashForDir := it.qs.ValueOf(nameForDir).(Token)
 		if bytes.Equal(hashForDir, it.checkId) {
 			return true
 		}
@@ -236,12 +236,20 @@ func (it *Iterator) Contains(v graph.Value) bool {
 }
 
 func (it *Iterator) Size() (int64, bool) {
-	return it.qs.SizeOf(it.checkId), true
+	return it.qs.SizeOf(Token(it.checkId)), 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(it.checkId))
+	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)),
+	)
 }
 
 var levelDBType graph.Type

graph/leveldb/triplestore.go

@@ -42,6 +42,12 @@ const (
 	DefaultWriteBufferSize = 20
 )
 
+type Token []byte
+
+func (t Token) Hashable() interface{} {
+	return string(t)
+}
+
 type TripleStore struct {
 	dbOpts    *opt.Options
 	db        *leveldb.DB
@@ -308,7 +314,7 @@ func (qs *TripleStore) Close() {
 
 func (qs *TripleStore) Quad(k graph.Value) quad.Quad {
 	var triple quad.Quad
-	b, err := qs.db.Get(k.([]byte), qs.readopts)
+	b, err := qs.db.Get(k.(Token), qs.readopts)
 	if err != nil && err != leveldb.ErrNotFound {
 		glog.Error("Error: couldn't get triple from DB.")
 		return quad.Quad{}
@@ -334,7 +340,7 @@ func (qs *TripleStore) convertStringToByteHash(s string) []byte {
 }
 
 func (qs *TripleStore) ValueOf(s string) graph.Value {
-	return qs.createValueKeyFor(s)
+	return Token(qs.createValueKeyFor(s))
 }
 
 func (qs *TripleStore) valueData(value_key []byte) ValueData {
@@ -362,14 +368,14 @@ func (qs *TripleStore) NameOf(k graph.Value) string {
 		glog.V(2).Info("k was nil")
 		return ""
 	}
-	return qs.valueData(k.([]byte)).Name
+	return qs.valueData(k.(Token)).Name
 }
 
 func (qs *TripleStore) SizeOf(k graph.Value) int64 {
 	if k == nil {
 		return 0
 	}
-	return int64(qs.valueData(k.([]byte)).Size)
+	return int64(qs.valueData(k.(Token)).Size)
 }
 
 func (qs *TripleStore) getSize() {
@@ -432,17 +438,17 @@ func (qs *TripleStore) TriplesAllIterator() graph.Iterator {
 }
 
 func (qs *TripleStore) TripleDirection(val graph.Value, d quad.Direction) graph.Value {
-	v := val.([]uint8)
+	v := val.(Token)
 	offset := PositionOf(v[0:2], d, qs)
 	if offset != -1 {
-		return append([]byte("z"), v[offset:offset+qs.hasher.Size()]...)
+		return Token(append([]byte("z"), v[offset:offset+qs.hasher.Size()]...))
 	} else {
-		return qs.Quad(val).Get(d)
+		return Token(qs.Quad(val).Get(d))
 	}
 }
 
 func compareBytes(a, b graph.Value) bool {
-	return bytes.Equal(a.([]uint8), b.([]uint8))
+	return bytes.Equal(a.(Token), b.(Token))
 }
 
 func (qs *TripleStore) FixedIterator() graph.FixedIterator {

graph/triplestore.go

@@ -37,8 +37,8 @@ import (
 // pointers to structs, or merely triples, or whatever works best for the
 // backing store.
 //
-// These must be comparable, ie, not arrays or maps, as they may be used as keys
-// for maps.
+// These must be comparable, or implement a	`Hashable() interface{}` function
+// so that they may be stored in maps.
 type Value interface{}
 
 type TripleStore interface {