/
aggregate.go
63 lines (54 loc) · 1.17 KB
/
aggregate.go
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package executor
import (
"github.com/gotodb/gotodb/stage"
"io"
"github.com/gotodb/gotodb/metadata"
"github.com/gotodb/gotodb/pb"
"github.com/gotodb/gotodb/row"
"github.com/gotodb/gotodb/util"
"github.com/vmihailenco/msgpack"
)
func (e *Executor) SetInstructionAggregate(instruction *pb.Instruction) error {
var job stage.AggregateJob
if err := msgpack.Unmarshal(instruction.EncodedStageJobBytes, &job); err != nil {
return err
}
e.StageJob = &job
return nil
}
func (e *Executor) RunAggregate() error {
md := &metadata.Metadata{}
//read md
for _, reader := range e.Readers {
if err := util.ReadObject(reader, md); err != nil {
return err
}
}
//write md
writer := e.Writers[0]
if err := util.WriteObject(writer, md); err != nil {
return err
}
rbWriter := row.NewRowsBuffer(md, nil, writer)
//write rows
for _, reader := range e.Readers {
rbReader := row.NewRowsBuffer(md, reader, nil)
for {
rg, err := rbReader.Read()
if err == io.EOF {
err = nil
break
}
if err != nil {
return err
}
if err = rbWriter.Write(rg); err != nil {
return err
}
}
}
if err := rbWriter.Flush(); err != nil {
return err
}
return nil
}