diskii/lib/disk/marshal.go

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// Copyright © 2016 Zellyn Hunter <zellyn@gmail.com>
// marshal.go contains helpers for marshaling sector structs to/from
// disk.
package disk
// SectorSource is the interface for types that can marshal to sectors.
type SectorSource interface {
// ToSector marshals the sector struct to exactly 256 bytes.
ToSector() ([]byte, error)
// GetTrack returns the track that a sector struct was loaded from.
GetTrack() byte
// GetSector returns the sector that a sector struct was loaded from.
GetSector() byte
}
// SectorSink is the interface for types that can unmarshal from sectors.
type SectorSink interface {
// FromSector unmarshals the sector struct from bytes. Input is
// expected to be exactly 256 bytes.
FromSector(data []byte) error
// SetTrack sets the track that a sector struct was loaded from.
SetTrack(track byte)
// SetSector sets the sector that a sector struct was loaded from.
SetSector(sector byte)
}
// UnmarshalLogicalSector reads a sector from a SectorDisk, and
// unmarshals it into a SectorSink, setting its track and sector.
func UnmarshalLogicalSector(d LogicalSectorDisk, ss SectorSink, track, sector byte) error {
bytes, err := d.ReadLogicalSector(track, sector)
if err != nil {
return err
}
if err := ss.FromSector(bytes); err != nil {
return err
}
ss.SetTrack(track)
ss.SetSector(sector)
return nil
}
// MarshalLogicalSector marshals a SectorSource to its sector on a
// SectorDisk.
func MarshalLogicalSector(d LogicalSectorDisk, ss SectorSource) error {
track := ss.GetTrack()
sector := ss.GetSector()
bytes, err := ss.ToSector()
if err != nil {
return err
}
return d.WriteLogicalSector(track, sector, bytes)
}