func NewMongoIterator(ts *MongoTripleStore, collection string, dir string, val graph.TSVal) *MongoIterator {
var m MongoIterator
graph.BaseIteratorInit(&m.BaseIterator)
m.name = ts.GetNameFor(val)
m.collection = collection
switch dir {
case "s":
m.constraint = bson.M{"Sub": m.name}
case "p":
m.constraint = bson.M{"Pred": m.name}
case "o":
m.constraint = bson.M{"Obj": m.name}
case "c":
m.constraint = bson.M{"Provenance": m.name}
}
m.ts = ts
m.dir = dir
m.iter = ts.db.C(collection).Find(m.constraint).Iter()
size, err := ts.db.C(collection).Find(m.constraint).Count()
if err != nil {
glog.Errorln("Trouble getting size for iterator! ", err)
return nil
}
m.size = int64(size)
m.hash = val.(string)
m.isAll = false
return &m
}
func NewLlrbIterator(tree *llrb.LLRB, data string) *LlrbIterator {
var it LlrbIterator
graph.BaseIteratorInit(&it.BaseIterator)
it.tree = tree
it.iterLast = Int64(-1)
it.data = data
return &it
}
func NewLevelDBAllIterator(prefix, dir string, ts *LevelDBTripleStore) *LevelDBAllIterator {
var it LevelDBAllIterator
graph.BaseIteratorInit(&it.BaseIterator)
it.ro = &leveldb_opt.ReadOptions{}
it.ro.DontFillCache = true
it.it = ts.db.NewIterator(nil, it.ro)
it.prefix = []byte(prefix)
it.dir = dir
it.open = true
it.ts = ts
it.it.Seek(it.prefix)
if !it.it.Valid() {
it.open = false
it.it.Release()
}
return &it
}
func NewLevelDBIterator(prefix, dir string, value graph.TSVal, ts *LevelDBTripleStore) *LevelDBIterator {
var it LevelDBIterator
graph.BaseIteratorInit(&it.BaseIterator)
it.checkId = value.([]byte)
it.dir = dir
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 = &leveldb_opt.ReadOptions{}
it.ro.DontFillCache = true
it.it = ts.db.NewIterator(nil, it.ro)
it.open = true
it.ts = ts
ok := it.it.Seek(it.nextPrefix)
if !ok {
it.open = false
it.it.Release()
}
return &it
}