gitroast/vendor/github.com/pingcap/go-themis/themis_scan.go

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package themis
import (
"bytes"
"encoding/binary"
"github.com/ngaut/log"
"github.com/pingcap/go-hbase"
)
type ThemisScanner struct {
scan *hbase.Scan
txn *themisTxn
tbl []byte
}
func newThemisScanner(tbl []byte, txn *themisTxn, batchSize int, c hbase.HBaseClient) *ThemisScanner {
s := hbase.NewScan(tbl, batchSize, c)
// add start ts
b := bytes.NewBuffer(nil)
binary.Write(b, binary.BigEndian, txn.startTs)
s.AddAttr("_themisTransationStartTs_", b.Bytes())
return &ThemisScanner{
scan: s,
txn: txn,
tbl: tbl,
}
}
func (s *ThemisScanner) setStartRow(start []byte) {
s.scan.StartRow = start
}
func (s *ThemisScanner) setStopRow(stop []byte) {
s.scan.StopRow = stop
}
func (s *ThemisScanner) SetTimeRange(tsRangeFrom uint64, tsRangeTo uint64) {
s.scan.TsRangeFrom = tsRangeFrom
s.scan.TsRangeTo = tsRangeTo
}
func (s *ThemisScanner) SetMaxVersions(maxVersions uint32) {
s.scan.MaxVersions = maxVersions
}
func (s *ThemisScanner) createGetFromScan(row []byte) *hbase.Get {
return s.scan.CreateGetFromScan(row)
}
func (s *ThemisScanner) Next() *hbase.ResultRow {
r := s.scan.Next()
if r == nil {
return nil
}
// if we encounter conflict locks, we need to clean lock for this row and read again
if isLockResult(r) {
g := s.createGetFromScan(r.Row)
r, err := s.txn.tryToCleanLockAndGetAgain(s.tbl, g, r.SortedColumns)
if err != nil {
log.Error(err)
return nil
}
// empty result indicates the current row has been erased, we should get next row
if r == nil {
return s.Next()
} else {
return r
}
}
return r
}
func (s *ThemisScanner) Closed() bool {
return s.scan.Closed()
}
func (s *ThemisScanner) Close() {
if !s.scan.Closed() {
// TODO: handle error, now just log
if err := s.scan.Close(); err != nil {
log.Warnf("scanner close error, scan: %s, error: %v", s.scan, err)
}
}
}