func NewIterator(qs *TripleStore, collection string, d quad.Direction, val graph.Value) *Iterator {
name := qs.NameOf(val)
constraint := bson.M{d.String(): name}
size, err := qs.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
}
return &Iterator{
uid: iterator.NextUID(),
name: name,
constraint: constraint,
collection: collection,
qs: qs,
dir: d,
iter: qs.db.C(collection).Find(constraint).Iter(),
size: int64(size),
hash: val.(string),
isAll: false,
}
}
func (qs *QuadStore) sizeForIterator(isAll bool, dir quad.Direction, val string) int64 {
var err error
if isAll {
return qs.Size()
}
if qs.noSizes {
if dir == quad.Predicate {
return (qs.Size() / 100) + 1
}
return (qs.Size() / 1000) + 1
}
if val, ok := qs.lru.Get(val + string(dir.Prefix())); ok {
return val
}
var size int64
glog.V(4).Infoln("sql: getting size for select %s, %s", dir.String(), val)
err = qs.db.QueryRow(
fmt.Sprintf("SELECT count(*) FROM quads WHERE %s_hash = $1;", dir.String()), hashOf(val)).Scan(&size)
if err != nil {
glog.Errorln("Error getting size from SQL database: %v", err)
return 0
}
qs.lru.Put(val+string(dir.Prefix()), size)
return size
}
func (qs *TripleStore) TripleIterator(d quad.Direction, val graph.Value) graph.Iterator {
var prefix string
switch d {
case quad.Subject:
prefix = "sp"
case quad.Predicate:
prefix = "po"
case quad.Object:
prefix = "os"
case quad.Label:
prefix = "cp"
default:
panic("unreachable " + d.String())
}
return NewIterator(prefix, d, val, qs)
}
func (qs *QuadStore) QuadIterator(d quad.Direction, val graph.Value) graph.Iterator {
var bucket []byte
switch d {
case quad.Subject:
bucket = spoBucket
case quad.Predicate:
bucket = posBucket
case quad.Object:
bucket = ospBucket
case quad.Label:
bucket = cpsBucket
default:
panic("unreachable " + d.String())
}
return NewIterator(bucket, d, val, qs)
}
// QuadIterator ??
func (qs *QuadStore) QuadIterator(d quad.Direction, val graph.Value) graph.Iterator {
var db string
switch d {
case quad.Subject:
db = spoDB
case quad.Predicate:
db = posDB
case quad.Object:
db = ospDB
case quad.Label:
db = cpsDB
default:
panic("unreachable " + d.String())
}
return NewIterator(db, d, val, qs)
}
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 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 (it *LinksTo) buildIteratorFor(d quad.Direction, val graph.Value) *mgo.Iter {
name := it.qs.NameOf(val)
constraint := it.buildConstraint()
constraint[d.String()] = name
return it.qs.db.C(it.collection).Find(constraint).Iter()
}
func (it *LinksTo) buildIteratorFor(d quad.Direction, val graph.Value) *mgo.Iter {
constraint := it.buildConstraint()
constraint[d.String()] = string(val.(NodeHash))
return it.qs.db.C(it.collection).Find(constraint).Iter()
}