func (s *Service) processCreateIteratorRequest(conn net.Conn) {
defer conn.Close()
var itr influxql.Iterator
if err := func() error {
// Parse request.
var req CreateIteratorRequest
if err := DecodeLV(conn, &req); err != nil {
return err
}
// Collect iterator creators for each shard.
ics := make([]influxql.IteratorCreator, 0, len(req.ShardIDs))
for _, shardID := range req.ShardIDs {
ic := s.TSDBStore.ShardIteratorCreator(shardID)
if ic == nil {
return nil
}
ics = append(ics, ic)
}
// Generate a single iterator from all shards.
i, err := influxql.IteratorCreators(ics).CreateIterator(req.Opt)
if err != nil {
return err
}
itr = i
return nil
}(); err != nil {
itr.Close()
s.Logger.Printf("error reading CreateIterator request: %s", err)
EncodeTLV(conn, createIteratorResponseMessage, &CreateIteratorResponse{Err: err})
return
}
// Encode success response.
if err := EncodeTLV(conn, createIteratorResponseMessage, &CreateIteratorResponse{}); err != nil {
s.Logger.Printf("error writing CreateIterator response: %s", err)
return
}
// Exit if no iterator was produced.
if itr == nil {
return
}
// Stream iterator to connection.
if err := influxql.NewIteratorEncoder(conn).EncodeIterator(itr); err != nil {
s.Logger.Printf("error encoding CreateIterator iterator: %s", err)
return
}
}
// Ensure iterator can be encoded and decoded over a byte stream.
func TestIterator_EncodeDecode(t *testing.T) {
var buf bytes.Buffer
// Create an iterator with several points & stats.
itr := &FloatIterator{
Points: []influxql.FloatPoint{
{Name: "cpu", Tags: ParseTags("host=A"), Time: 0, Value: 0},
{Name: "mem", Tags: ParseTags("host=B"), Time: 1, Value: 10},
},
stats: influxql.IteratorStats{
SeriesN: 2,
PointN: 0,
},
}
// Encode to the buffer.
enc := influxql.NewIteratorEncoder(&buf)
enc.StatsInterval = 100 * time.Millisecond
if err := enc.EncodeIterator(itr); err != nil {
t.Fatal(err)
}
// Decode from the buffer.
dec, err := influxql.NewReaderIterator(&buf)
if err != nil {
t.Fatal(err)
}
// Initial stats should exist immediately.
fdec := dec.(influxql.FloatIterator)
if stats := fdec.Stats(); !reflect.DeepEqual(stats, influxql.IteratorStats{SeriesN: 2, PointN: 0}) {
t.Fatalf("unexpected stats(initial): %#v", stats)
}
// Read both points.
if p := fdec.Next(); !reflect.DeepEqual(p, &influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 0, Value: 0}) {
t.Fatalf("unexpected point(0); %#v", p)
} else if p := fdec.Next(); !reflect.DeepEqual(p, &influxql.FloatPoint{Name: "mem", Tags: ParseTags("host=B"), Time: 1, Value: 10}) {
t.Fatalf("unexpected point(1); %#v", p)
} else if p := fdec.Next(); p != nil {
t.Fatalf("unexpected point(eof); %#v", p)
}
}