Move UID handling from Base

Also clean up some of the value creation code.

graph/iterator/all_iterator.go

@@ -32,6 +32,7 @@ import (
 // An All iterator across a range of int64 values, from `max` to `min`.
 type Int64 struct {
 	Base
+	uid      uint64
 	tags     graph.Tagger
 	max, min int64
 	at       int64
@@ -39,14 +40,20 @@ type Int64 struct {
 
 // Creates a new Int64 with the given range.
 func NewInt64(min, max int64) *Int64 {
-	var all Int64
+	all := Int64{
+		uid: NextUID(),
+		min: min,
+		max: max,
+		at:  min,
+	}
 	BaseInit(&all.Base)
-	all.max = max
-	all.min = min
-	all.at = min
 	return &all
 }
 
+func (it *Int64) UID() uint64 {
+	return it.uid
+}
+
 // Start back at the beginning
 func (it *Int64) Reset() {
 	it.at = it.min

graph/iterator/and_iterator.go

@@ -26,6 +26,7 @@ import (
 // be Next()ed if next is called.
 type And struct {
 	Base
+	uid               uint64
 	tags              graph.Tagger
 	internalIterators []graph.Iterator
 	itCount           int
@@ -35,13 +36,18 @@ type And struct {
 
 // Creates a new And iterator.
 func NewAnd() *And {
-	var and And
+	and := And{
+		uid:               NextUID(),
+		internalIterators: make([]graph.Iterator, 0, 20),
+	}
 	BaseInit(&and.Base)
-	and.internalIterators = make([]graph.Iterator, 0, 20)
-	and.checkList = nil
 	return &and
 }
 
+func (it *And) UID() uint64 {
+	return it.uid
+}
+
 // Reset all internal iterators
 func (it *And) Reset() {
 	it.primaryIt.Reset()

graph/iterator/fixed_iterator.go

@@ -31,6 +31,7 @@ import (
 // an equality function.
 type Fixed struct {
 	Base
+	uid       uint64
 	tags      graph.Tagger
 	values    []graph.Value
 	lastIndex int
@@ -55,14 +56,19 @@ func newFixed() *Fixed {
 
 // Creates a new Fixed iterator with a custom comparitor.
 func NewFixedIteratorWithCompare(compareFn Equality) *Fixed {
-	var it Fixed
+	it := Fixed{
+		uid:    NextUID(),
+		values: make([]graph.Value, 0, 20),
+		cmp:    compareFn,
+	}
 	BaseInit(&it.Base)
-	it.values = make([]graph.Value, 0, 20)
-	it.lastIndex = 0
-	it.cmp = compareFn
 	return &it
 }
 
+func (it *Fixed) UID() uint64 {
+	return it.uid
+}
+
 func (it *Fixed) Reset() {
 	it.lastIndex = 0
 }

graph/iterator/hasa_iterator.go

@@ -47,6 +47,7 @@ import (
 // and a temporary holder for the iterator generated on Check().
 type HasA struct {
 	Base
+	uid       uint64
 	tags      graph.Tagger
 	ts        graph.TripleStore
 	primaryIt graph.Iterator
@@ -57,14 +58,20 @@ type HasA struct {
 // Construct a new HasA iterator, given the triple subiterator, and the triple
 // direction for which it stands.
 func NewHasA(ts graph.TripleStore, subIt graph.Iterator, d graph.Direction) *HasA {
-	var hasa HasA
+	hasa := HasA{
+		uid:       NextUID(),
+		ts:        ts,
+		primaryIt: subIt,
+		dir:       d,
+	}
 	BaseInit(&hasa.Base)
-	hasa.ts = ts
-	hasa.primaryIt = subIt
-	hasa.dir = d
 	return &hasa
 }
 
+func (it *HasA) UID() uint64 {
+	return it.uid
+}
+
 // Return our sole subiterator.
 func (it *HasA) SubIterators() []graph.Iterator {
 	return []graph.Iterator{it.primaryIt}

graph/iterator/iterator.go

@@ -22,8 +22,6 @@ import (
 	"strings"
 	"sync/atomic"
 
-	"github.com/barakmich/glog"
-
 	"github.com/google/cayley/graph"
 )
 
@@ -38,20 +36,12 @@ func NextUID() uint64 {
 type Base struct {
 	Last    graph.Value
 	canNext bool
-	uid     uint64
 }
 
 // Called by subclases.
 func BaseInit(it *Base) {
 	// Your basic iterator is nextable
 	it.canNext = true
-	if glog.V(2) {
-		it.uid = NextUID()
-	}
-}
-
-func (it *Base) UID() uint64 {
-	return it.uid
 }
 
 // Prints a silly debug string. Most classes override.
@@ -115,12 +105,17 @@ func (it *Base) Reset() {}
 // so it's important to give it a special iterator.
 type Null struct {
 	Base
+	uid  uint64
 	tags graph.Tagger
 }
 
 // Fairly useless New function.
 func NewNull() *Null {
-	return &Null{}
+	return &Null{uid: NextUID()}
+}
+
+func (it *Null) UID() uint64 {
+	return it.uid
 }
 
 func (it *Null) Tagger() *graph.Tagger {

graph/iterator/linksto_iterator.go

@@ -41,6 +41,7 @@ import (
 // `next_it` is the tempoarary iterator held per result in `primary_it`.
 type LinksTo struct {
 	Base
+	uid       uint64
 	tags      graph.Tagger
 	ts        graph.TripleStore
 	primaryIt graph.Iterator
@@ -51,15 +52,21 @@ type LinksTo struct {
 // Construct a new LinksTo iterator around a direction and a subiterator of
 // nodes.
 func NewLinksTo(ts graph.TripleStore, it graph.Iterator, d graph.Direction) *LinksTo {
-	var lto LinksTo
+	lto := LinksTo{
+		uid:       NextUID(),
+		ts:        ts,
+		primaryIt: it,
+		dir:       d,
+		nextIt:    &Null{},
+	}
 	BaseInit(&lto.Base)
-	lto.ts = ts
-	lto.primaryIt = it
-	lto.dir = d
-	lto.nextIt = &Null{}
 	return &lto
 }
 
+func (it *LinksTo) UID() uint64 {
+	return it.uid
+}
+
 func (it *LinksTo) Reset() {
 	it.primaryIt.Reset()
 	if it.nextIt != nil {

graph/iterator/optional_iterator.go

@@ -39,6 +39,7 @@ import (
 // and whether the last check we received was true or false.
 type Optional struct {
 	Base
+	uid       uint64
 	tags      graph.Tagger
 	subIt     graph.Iterator
 	lastCheck bool
@@ -50,9 +51,14 @@ func NewOptional(it graph.Iterator) *Optional {
 	BaseInit(&o.Base)
 	o.canNext = false
 	o.subIt = it
+	o.uid = NextUID()
 	return &o
 }
 
+func (it *Optional) UID() uint64 {
+	return it.uid
+}
+
 func (it *Optional) Reset() {
 	it.subIt.Reset()
 	it.lastCheck = false

graph/iterator/or_iterator.go

@@ -30,6 +30,7 @@ import (
 
 type Or struct {
 	Base
+	uid               uint64
 	tags              graph.Tagger
 	isShortCircuiting bool
 	internalIterators []graph.Iterator
@@ -38,23 +39,30 @@ type Or struct {
 }
 
 func NewOr() *Or {
-	var or Or
+	or := Or{
+		uid:               NextUID(),
+		internalIterators: make([]graph.Iterator, 0, 20),
+		currentIterator:   -1,
+	}
 	BaseInit(&or.Base)
-	or.internalIterators = make([]graph.Iterator, 0, 20)
-	or.isShortCircuiting = false
-	or.currentIterator = -1
 	return &or
 }
 
 func NewShortCircuitOr() *Or {
-	var or Or
+	or := Or{
+		uid:               NextUID(),
+		internalIterators: make([]graph.Iterator, 0, 20),
+		isShortCircuiting: true,
+		currentIterator:   -1,
+	}
 	BaseInit(&or.Base)
-	or.internalIterators = make([]graph.Iterator, 0, 20)
-	or.isShortCircuiting = true
-	or.currentIterator = -1
 	return &or
 }
 
+func (it *Or) UID() uint64 {
+	return it.uid
+}
+
 // Reset all internal iterators
 func (it *Or) Reset() {
 	for _, sub := range it.internalIterators {

graph/iterator/value_comparison_iterator.go

@@ -47,6 +47,7 @@ const (
 
 type Comparison struct {
 	Base
+	uid   uint64
 	tags  graph.Tagger
 	subIt graph.Iterator
 	op    Operator
@@ -55,15 +56,21 @@ type Comparison struct {
 }
 
 func NewComparison(sub graph.Iterator, op Operator, val interface{}, ts graph.TripleStore) *Comparison {
-	var vc Comparison
+	vc := Comparison{
+		uid:   NextUID(),
+		subIt: sub,
+		op:    op,
+		val:   val,
+		ts:    ts,
+	}
 	BaseInit(&vc.Base)
-	vc.subIt = sub
-	vc.op = op
-	vc.val = val
-	vc.ts = ts
 	return &vc
 }
 
+func (it *Comparison) UID() uint64 {
+	return it.uid
+}
+
 // Here's the non-boilerplate part of the ValueComparison iterator. Given a value
 // and our operator, determine whether or not we meet the requirement.
 func (it *Comparison) doComparison(val graph.Value) bool {

graph/leveldb/all_iterator.go

@@ -28,6 +28,7 @@ import (
 
 type AllIterator struct {
 	iterator.Base
+	uid    uint64
 	tags   graph.Tagger
 	prefix []byte
 	dir    graph.Direction
@@ -38,23 +39,36 @@ type AllIterator struct {
 }
 
 func NewAllIterator(prefix string, d graph.Direction, ts *TripleStore) *AllIterator {
-	var it AllIterator
+	opts := &opt.ReadOptions{
+		DontFillCache: true,
+	}
+
+	it := AllIterator{
+		uid:    iterator.NextUID(),
+		ro:     opts,
+		iter:   ts.db.NewIterator(nil, opts),
+		prefix: []byte(prefix),
+		dir:    d,
+		open:   true,
+		ts:     ts,
+	}
 	iterator.BaseInit(&it.Base)
-	it.ro = &opt.ReadOptions{}
-	it.ro.DontFillCache = true
-	it.iter = ts.db.NewIterator(nil, it.ro)
-	it.prefix = []byte(prefix)
-	it.dir = d
-	it.open = true
-	it.ts = ts
+
 	it.iter.Seek(it.prefix)
 	if !it.iter.Valid() {
+		// FIXME(kortschak) What are the semantics here? Is this iterator usable?
+		// If not, we should return nil *Iterator and an error.
 		it.open = false
 		it.iter.Release()
 	}
+
 	return &it
 }
 
+func (it *AllIterator) UID() uint64 {
+	return it.uid
+}
+
 func (it *AllIterator) Reset() {
 	if !it.open {
 		it.iter = it.ts.db.NewIterator(nil, it.ro)

graph/leveldb/iterator.go

@@ -28,6 +28,7 @@ import (
 
 type Iterator struct {
 	iterator.Base
+	uid            uint64
 	tags           graph.Tagger
 	nextPrefix     []byte
 	checkId        []byte
@@ -40,27 +41,43 @@ type Iterator struct {
 }
 
 func NewIterator(prefix string, d graph.Direction, value graph.Value, ts *TripleStore) *Iterator {
-	var it Iterator
+	vb := value.([]byte)
+	p := make([]byte, 0, 2+ts.hasher.Size())
+	p = append(p, []byte(prefix)...)
+	p = append(p, []byte(vb[1:])...)
+
+	opts := &opt.ReadOptions{
+		DontFillCache: true,
+	}
+
+	it := Iterator{
+		uid:            iterator.NextUID(),
+		nextPrefix:     p,
+		checkId:        vb,
+		dir:            d,
+		originalPrefix: prefix,
+		ro:             opts,
+		iter:           ts.db.NewIterator(nil, opts),
+		open:           true,
+		ts:             ts,
+	}
 	iterator.BaseInit(&it.Base)
-	it.checkId = value.([]byte)
-	it.dir = d
-	it.originalPrefix = prefix
-	it.nextPrefix = make([]byte, 0, 2+ts.hasher.Size())
-	it.nextPrefix = append(it.nextPrefix, []byte(prefix)...)
-	it.nextPrefix = append(it.nextPrefix, []byte(it.checkId[1:])...)
-	it.ro = &opt.ReadOptions{}
-	it.ro.DontFillCache = true
-	it.iter = ts.db.NewIterator(nil, it.ro)
-	it.open = true
-	it.ts = ts
+
 	ok := it.iter.Seek(it.nextPrefix)
 	if !ok {
+		// FIXME(kortschak) What are the semantics here? Is this iterator usable?
+		// If not, we should return nil *Iterator and an error.
 		it.open = false
 		it.iter.Release()
 	}
+
 	return &it
 }
 
+func (it *Iterator) UID() uint64 {
+	return it.uid
+}
+
 func (it *Iterator) Reset() {
 	if !it.open {
 		it.iter = it.ts.db.NewIterator(nil, it.ro)

graph/memstore/iterator.go

@@ -27,6 +27,7 @@ import (
 
 type Iterator struct {
 	iterator.Base
+	uid       uint64
 	tags      graph.Tagger
 	tree      *llrb.LLRB
 	data      string
@@ -54,14 +55,20 @@ func IterateOne(tree *llrb.LLRB, last Int64) Int64 {
 }
 
 func NewLlrbIterator(tree *llrb.LLRB, data string) *Iterator {
-	var it Iterator
+	it := Iterator{
+		uid:      iterator.NextUID(),
+		tree:     tree,
+		iterLast: Int64(-1),
+		data:     data,
+	}
 	iterator.BaseInit(&it.Base)
-	it.tree = tree
-	it.iterLast = Int64(-1)
-	it.data = data
 	return &it
 }
 
+func (it *Iterator) UID() uint64 {
+	return it.uid
+}
+
 func (it *Iterator) Reset() {
 	it.iterLast = Int64(-1)
 }

graph/mongo/iterator.go

@@ -28,6 +28,7 @@ import (
 
 type Iterator struct {
 	iterator.Base
+	uid        uint64
 	tags       graph.Tagger
 	ts         *TripleStore
 	dir        graph.Direction
@@ -41,54 +42,72 @@ type Iterator struct {
 }
 
 func NewIterator(ts *TripleStore, collection string, d graph.Direction, val graph.Value) *Iterator {
-	var m Iterator
-	iterator.BaseInit(&m.Base)
+	name := ts.NameOf(val)
 
-	m.name = ts.NameOf(val)
-	m.collection = collection
+	var constraint bson.M
 	switch d {
 	case graph.Subject:
-		m.constraint = bson.M{"Subject": m.name}
+		constraint = bson.M{"Subject": name}
 	case graph.Predicate:
-		m.constraint = bson.M{"Predicate": m.name}
+		constraint = bson.M{"Predicate": name}
 	case graph.Object:
-		m.constraint = bson.M{"Object": m.name}
+		constraint = bson.M{"Object": name}
 	case graph.Provenance:
-		m.constraint = bson.M{"Provenance": m.name}
+		constraint = bson.M{"Provenance": name}
 	}
 
-	m.ts = ts
-	m.dir = d
-	m.iter = ts.db.C(collection).Find(m.constraint).Iter()
-	size, err := ts.db.C(collection).Find(m.constraint).Count()
+	size, err := ts.db.C(collection).Find(constraint).Count()
 	if err != nil {
+		// FIXME(kortschak) This should be passed back rather than just logging.
 		glog.Errorln("Trouble getting size for iterator! ", err)
 		return nil
 	}
-	m.size = int64(size)
-	m.hash = val.(string)
-	m.isAll = false
+
+	m := Iterator{
+		uid:        iterator.NextUID(),
+		name:       name,
+		constraint: constraint,
+		collection: collection,
+		ts:         ts,
+		dir:        d,
+		iter:       ts.db.C(collection).Find(constraint).Iter(),
+		size:       int64(size),
+		hash:       val.(string),
+		isAll:      false,
+	}
+	iterator.BaseInit(&m.Base)
+
 	return &m
 }
 
 func NewAllIterator(ts *TripleStore, collection string) *Iterator {
-	var m Iterator
-	m.ts = ts
-	m.dir = graph.Any
-	m.constraint = nil
-	m.collection = collection
-	m.iter = ts.db.C(collection).Find(nil).Iter()
 	size, err := ts.db.C(collection).Count()
 	if err != nil {
+		// FIXME(kortschak) This should be passed back rather than just logging.
 		glog.Errorln("Trouble getting size for iterator! ", err)
 		return nil
 	}
-	m.size = int64(size)
-	m.hash = ""
-	m.isAll = true
+
+	m := Iterator{
+		uid:        iterator.NextUID(),
+		ts:         ts,
+		dir:        graph.Any,
+		constraint: nil,
+		collection: collection,
+		iter:       ts.db.C(collection).Find(nil).Iter(),
+		size:       int64(size),
+		hash:       "",
+		isAll:      true,
+	}
+	// FIXME(kortschak) Was there supposed to be a BaseInit call here?
+
 	return &m
 }
 
+func (it *Iterator) UID() uint64 {
+	return it.uid
+}
+
 func (it *Iterator) Reset() {
 	it.iter.Close()
 	it.iter = it.ts.db.C(it.collection).Find(it.constraint).Iter()