fq/format/postgres/pg_wal.go

package postgres

import (
	"github.com/wader/fq/format"
	"github.com/wader/fq/format/postgres/flavours/postgres14"
	"github.com/wader/fq/pkg/decode"
	"github.com/wader/fq/pkg/interp"
)

// TO DO
// not ready yet

func init() {
	interp.RegisterFormat(decode.Format{
		Name:        format.PG_WAL,
		Description: "PostgreSQL write-ahead log file",
		DecodeFn:    decodePgwal,
		DecodeInArg: format.PostgresIn{
			Flavour: "default",
		},
	})
}

// https://pgpedia.info/x/XLOG_PAGE_MAGIC.html
const (
	XLOG_PAGE_MAGIC_15 = uint16(0xD10F)
	XLOG_PAGE_MAGIC_14 = uint16(0xD10D)
	XLOG_PAGE_MAGIC_13 = uint16(0xD106)
	XLOG_PAGE_MAGIC_12 = uint16(0xD101)
	XLOG_PAGE_MAGIC_11 = uint16(0xD098)
	XLOG_PAGE_MAGIC_10 = uint16(0xD097)
	XLOG_PAGE_MAGIC_96 = uint16(0xD093)
)

func decodePgwal(d *decode.D, in any) any {
	d.Endian = decode.LittleEndian

	flavour := in.(format.PostgresIn).Flavour
	switch flavour {
	//case PG_FLAVOUR_POSTGRES11:
	//	return postgres11.DecodePgControl(d, in)
	case PG_FLAVOUR_POSTGRES14, PG_FLAVOUR_POSTGRES:
		return postgres14.DecodePgwal(d, in)
	//case PG_FLAVOUR_PGPROEE14:
	//	return pgproee14.DecodePgControl(d, in)
	default:
		break
	}

	return probePgwal(d, in)
}

func probePgwal(d *decode.D, in any) any {
	// read version
	xlp_magic := uint16(d.U16())

	// restore position
	d.SeekAbs(0)

	switch xlp_magic {
	case XLOG_PAGE_MAGIC_14:
		return postgres14.DecodePgwal(d, in)
	default:
		d.Fatalf("unsupported xlp_magic = %X\n", xlp_magic)
	}
	return nil
}