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fq/format/postgres/pg_wal.go
2022-10-28 13:13:33 +03:00

96 lines
2.0 KiB
Go

package postgres
import (
"fmt"
"github.com/wader/fq/format/postgres/common/pg_wal/pgproee"
"github.com/wader/fq/format/postgres/common/pg_wal/postgres"
"github.com/wader/fq/format"
"github.com/wader/fq/pkg/decode"
"github.com/wader/fq/pkg/interp"
"strconv"
"strings"
)
// partial parsing of WAL
func init() {
interp.RegisterFormat(decode.Format{
Name: format.PG_WAL,
Description: "PostgreSQL write-ahead log file",
DecodeFn: decodePGWAL,
DecodeInArg: format.PostgresWalIn{
Flavour: PG_FLAVOUR_POSTGRES14,
Lsn: "",
},
})
}
func ParseLsn(lsn string) (uint32, error) {
// check for 0/4E394440
str1 := lsn
if strings.Contains(lsn, "/") {
parts := strings.Split(lsn, "/")
if len(parts) != 2 {
return 0, fmt.Errorf("invalid lsn = %s", lsn)
}
str1 = parts[1]
}
// parse hex to coded file name + file offset
r1, err := strconv.ParseInt(str1, 16, 64)
if err != nil {
return 0, err
}
return uint32(r1), err
}
func XLogSegmentOffset(xLogPtr uint32) uint32 {
const walSegSizeBytes = 16 * 1024 * 1024
return xLogPtr & (walSegSizeBytes - 1)
}
func decodePGWAL(d *decode.D, in any) any {
d.Endian = decode.LittleEndian
pgIn, ok := in.(format.PostgresWalIn)
if !ok {
d.Fatalf("DecodeInArg must be PostgresIn!\n")
}
maxOffset := uint32(0xFFFFFFFF)
if pgIn.Lsn != "" {
lsn, err := ParseLsn(pgIn.Lsn)
if err != nil {
d.Fatalf("Failed to ParseLsn, err = %v\n", err)
}
maxOffset = XLogSegmentOffset(lsn)
}
switch pgIn.Flavour {
case PG_FLAVOUR_POSTGRES10,
PG_FLAVOUR_POSTGRES11,
PG_FLAVOUR_POSTGRES12,
PG_FLAVOUR_POSTGRES13,
PG_FLAVOUR_POSTGRES14,
PG_FLAVOUR_PGPRO10,
PG_FLAVOUR_PGPRO11,
PG_FLAVOUR_PGPRO12,
PG_FLAVOUR_PGPRO13,
PG_FLAVOUR_PGPRO14:
return postgres.DecodePGWAL(d, maxOffset)
case PG_FLAVOUR_PGPROEE10,
PG_FLAVOUR_PGPROEE11,
PG_FLAVOUR_PGPROEE12,
PG_FLAVOUR_PGPROEE13,
PG_FLAVOUR_PGPROEE14:
return pgproee.DecodePGWAL(d, maxOffset)
default:
break
}
return postgres.DecodePGWAL(d, maxOffset)
}