/
wal_segment_no.go
46 lines (35 loc) · 1.08 KB
/
wal_segment_no.go
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package postgres
import (
"fmt"
)
type WalSegmentNo uint64
func newWalSegmentNo(lsn LSN) WalSegmentNo {
return WalSegmentNo(getSegmentNoFromLsn(lsn))
}
func getSegmentNoFromLsn(lsn LSN) uint64 {
return uint64(lsn) / WalSegmentSize
}
func newWalSegmentNoFromFilename(filename string) (WalSegmentNo, error) {
_, no, err := ParseWALFilename(filename)
return WalSegmentNo(no), err
}
func (walSegmentNo WalSegmentNo) next() WalSegmentNo {
return walSegmentNo.add(1)
}
func (walSegmentNo WalSegmentNo) previous() WalSegmentNo {
return walSegmentNo.sub(1)
}
func (walSegmentNo WalSegmentNo) add(n uint64) WalSegmentNo {
return WalSegmentNo(uint64(walSegmentNo) + n)
}
func (walSegmentNo WalSegmentNo) sub(n uint64) WalSegmentNo {
return WalSegmentNo(uint64(walSegmentNo) - n)
}
func (walSegmentNo WalSegmentNo) firstLsn() LSN {
return LSN(uint64(walSegmentNo) * WalSegmentSize)
}
func (walSegmentNo WalSegmentNo) getFilename(timeline uint32) string {
return fmt.Sprintf(walFileFormat,
timeline, uint64(walSegmentNo)/xLogSegmentsPerXLogID,
uint64(walSegmentNo)%xLogSegmentsPerXLogID)
}