func NewIterator(prefix string, d quad.Direction, value graph.Value, qs *QuadStore) *Iterator {
vb := value.(Token)
p := make([]byte, 0, 2+quad.HashSize)
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: qs.db.NewIterator(nil, opts),
open: true,
qs: qs,
}
ok := it.iter.Seek(it.nextPrefix)
if !ok {
it.open = false
it.iter.Release()
clog.Errorf("Opening LevelDB iterator couldn't seek to location %v", it.nextPrefix)
}
return &it
}
func NewAllIterator(prefix string, d quad.Direction, qs *QuadStore) *AllIterator {
opts := &opt.ReadOptions{
DontFillCache: true,
}
it := AllIterator{
nodes: prefix == "z",
uid: iterator.NextUID(),
ro: opts,
iter: qs.db.NewIterator(nil, opts),
prefix: []byte(prefix),
dir: d,
open: true,
qs: qs,
}
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 NewAllIterator(qs *QuadStore, kind string) *Iterator {
if kind != nodeKind && kind != quadKind {
clog.Errorf("Cannot create iterator for an unknown kind")
return &Iterator{done: true}
}
if qs.context == nil {
clog.Errorf("Cannot create iterator without a valid context")
return &Iterator{done: true}
}
var size int64
if kind == nodeKind {
size = qs.NodeSize()
} else {
size = qs.Size()
}
return &Iterator{
uid: iterator.NextUID(),
qs: qs,
size: size,
dir: quad.Any,
isAll: true,
kind: kind,
done: false,
}
}
func (it *Iterator) Clone() graph.Iterator {
var iter *b.Enumerator
if it.result != nil {
var ok bool
iter, ok = it.tree.Seek(it.result.(int64))
if !ok {
panic("value unexpectedly missing")
}
} else {
var err error
iter, err = it.tree.SeekFirst()
if err != nil {
iter = nil
}
}
m := &Iterator{
uid: iterator.NextUID(),
qs: it.qs,
tree: it.tree,
iter: iter,
d: it.d,
value: it.value,
}
m.tags.CopyFrom(it)
return m
}
func TestSQLNodeIteration(t *testing.T) {
if *postgres_path == "" {
t.SkipNow()
}
db, err := newQuadStore(*postgres_path, nil)
if err != nil {
t.Fatal(err)
}
link := NewSQLLinkIterator(db.(*QuadStore), quad.Object, quad.Raw("/en/humphrey_bogart"))
it := &SQLIterator{
uid: iterator.NextUID(),
qs: db.(*QuadStore),
sql: &SQLNodeIterator{
tableName: newTableName(),
linkIt: sqlItDir{
it: link.sql,
dir: quad.Subject,
},
},
}
s, v := it.sql.buildSQL(true, nil)
t.Log(s, v)
c := 0
for it.Next() {
t.Log(it.Result())
c += 1
}
if c != 56 {
t.Errorf("Not enough results, got %d expected 56", c)
}
}
func (it *SQLIterator) Clone() graph.Iterator {
m := &SQLIterator{
uid: iterator.NextUID(),
qs: it.qs,
sql: it.sql.sqlClone(),
}
return m
}
func NewSQLIterator(qs *QuadStore, sql sqlIterator) *SQLIterator {
l := &SQLIterator{
uid: iterator.NextUID(),
qs: qs,
sql: sql,
}
return l
}
func NewAllIterator(qs *QuadStore, table string) *AllIterator {
it := &AllIterator{
uid: iterator.NextUID(),
qs: qs,
table: table,
}
return it
}
func NewAllIterator(bucket []byte, d quad.Direction, qs *QuadStore) *AllIterator {
return &AllIterator{
uid: iterator.NextUID(),
bucket: bucket,
dir: d,
qs: qs,
}
}
// NewLinksTo constructs a new indexed LinksTo iterator for Mongo around a direction
// and a subiterator of nodes.
func NewLinksTo(qs *QuadStore, it graph.Iterator, collection string, d quad.Direction, lset []graph.Linkage) *LinksTo {
return &LinksTo{
uid: iterator.NextUID(),
qs: qs,
primaryIt: it,
dir: d,
nextIt: nil,
lset: lset,
collection: collection,
}
}
func NewIteratorWithConstraints(qs *QuadStore, collection string, constraint bson.M) *Iterator {
return &Iterator{
uid: iterator.NextUID(),
qs: qs,
dir: quad.Any,
constraint: constraint,
collection: collection,
iter: nil,
size: -1,
hash: "",
isAll: false,
}
}
func NewAllIterator(qs *QuadStore, collection string) *Iterator {
return &Iterator{
uid: iterator.NextUID(),
qs: qs,
dir: quad.Any,
constraint: nil,
collection: collection,
iter: nil,
size: -1,
hash: "",
isAll: true,
}
}
func NewIterator(tree *b.Tree, qs *QuadStore, d quad.Direction, value graph.Value) *Iterator {
iter, err := tree.SeekFirst()
if err != nil {
iter = nil
}
return &Iterator{
uid: iterator.NextUID(),
qs: qs,
tree: tree,
iter: iter,
d: d,
value: value,
}
}
func NewSQLLinkIterator(qs *QuadStore, d quad.Direction, val string) *SQLIterator {
l := &SQLIterator{
uid: iterator.NextUID(),
qs: qs,
sql: &SQLLinkIterator{
constraints: []constraint{
constraint{
dir: d,
vals: []string{val},
},
},
tableName: newTableName(),
size: 0,
},
}
return l
}
func NewIterator(qs *QuadStore, collection string, d quad.Direction, val graph.Value) *Iterator {
h := val.(NodeHash)
constraint := bson.M{d.String(): string(h)}
return &Iterator{
uid: iterator.NextUID(),
constraint: constraint,
collection: collection,
qs: qs,
dir: d,
iter: nil,
size: -1,
hash: h,
isAll: false,
}
}
func newSQLLinkIterator(qs *QuadStore, d quad.Direction, hash NodeHash) *SQLIterator {
l := &SQLIterator{
uid: iterator.NextUID(),
qs: qs,
sql: &SQLLinkIterator{
constraints: []constraint{
constraint{
dir: d,
hashes: []NodeHash{hash},
},
},
tableName: newTableName(),
size: 0,
},
}
return l
}
func NewIterator(qs *QuadStore, collection string, d quad.Direction, val graph.Value) *Iterator {
name := qs.NameOf(val)
constraint := bson.M{d.String(): name}
return &Iterator{
uid: iterator.NextUID(),
name: name,
constraint: constraint,
collection: collection,
qs: qs,
dir: d,
iter: nil,
size: -1,
hash: val.(string),
isAll: false,
}
}
func NewIterator(bucket []byte, d quad.Direction, value graph.Value, qs *QuadStore) *Iterator {
tok := value.(*Token)
if !bytes.Equal(tok.bucket, nodeBucket) {
clog.Errorf("creating an iterator from a non-node value")
return &Iterator{done: true}
}
it := Iterator{
uid: iterator.NextUID(),
bucket: bucket,
dir: d,
qs: qs,
size: qs.SizeOf(value),
}
it.checkID = make([]byte, len(tok.key))
copy(it.checkID, tok.key)
return &it
}
func NewIterator(qs *QuadStore, k string, d quad.Direction, val graph.Value) *Iterator {
t := val.(*Token)
if t == nil {
clog.Errorf("Token == nil")
}
if t.Kind != nodeKind {
clog.Errorf("Cannot create an iterator from a non-node value")
return &Iterator{done: true}
}
if k != nodeKind && k != quadKind {
clog.Errorf("Cannot create iterator for unknown kind")
return &Iterator{done: true}
}
if qs.context == nil {
clog.Errorf("Cannot create iterator without a valid context")
return &Iterator{done: true}
}
name := quad.StringOf(qs.NameOf(t))
// The number of references to this node is held in the nodes entity
key := qs.createKeyFromToken(t)
foundNode := new(NodeEntry)
err := datastore.Get(qs.context, key, foundNode)
if err != nil && err != datastore.ErrNoSuchEntity {
clog.Errorf("Error: %v", err)
return &Iterator{done: true}
}
size := foundNode.Size
return &Iterator{
uid: iterator.NextUID(),
name: name,
dir: d,
qs: qs,
size: size,
isAll: false,
kind: k,
hash: t.Hash,
done: false,
}
}
func (qs *QuadStore) optimizeLinksTo(it *iterator.LinksTo) (graph.Iterator, bool) {
subs := it.SubIterators()
if len(subs) != 1 {
return it, false
}
primary := subs[0]
switch primary.Type() {
case graph.Fixed:
size, _ := primary.Size()
if size == 0 {
return iterator.NewNull(), true
}
if size == 1 {
if !primary.Next() {
panic("sql: unexpected size during optimize")
}
val := primary.Result()
newIt := qs.QuadIterator(it.Direction(), val)
nt := newIt.Tagger()
nt.CopyFrom(it)
for _, tag := range primary.Tagger().Tags() {
nt.AddFixed(tag, val)
}
it.Close()
return newIt, true
} else if size > 1 {
var vals []NodeHash
for primary.Next() {
vals = append(vals, primary.Result().(NodeHash))
}
lsql := &SQLLinkIterator{
constraints: []constraint{
constraint{
dir: it.Direction(),
hashes: vals,
},
},
tableName: newTableName(),
size: 0,
}
l := &SQLIterator{
uid: iterator.NextUID(),
qs: qs,
sql: lsql,
}
nt := l.Tagger()
nt.CopyFrom(it)
for _, t := range primary.Tagger().Tags() {
lsql.tagdirs = append(lsql.tagdirs, tagDir{
dir: it.Direction(),
tag: t,
})
}
it.Close()
return l, true
}
case sqlType:
p := primary.(*SQLIterator)
newit, err := linksto(p.sql, it.Direction(), qs)
if err != nil {
clog.Errorf("%v", err)
return it, false
}
newit.Tagger().CopyFrom(it)
return newit, true
case graph.All:
linkit := &SQLLinkIterator{
tableName: newTableName(),
size: qs.Size(),
}
for _, t := range primary.Tagger().Tags() {
linkit.tagdirs = append(linkit.tagdirs, tagDir{
dir: it.Direction(),
tag: t,
})
}
for k, v := range primary.Tagger().Fixed() {
linkit.tagger.AddFixed(k, v)
}
linkit.tagger.CopyFrom(it)
newit := NewSQLIterator(qs, linkit)
return newit, true
}
return it, false
}