lnd.xprv/watchtower/wtdb/codec.go
2019-06-13 17:40:04 -07:00

144 lines
2.9 KiB
Go

package wtdb
import (
"io"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/lnwallet"
"github.com/lightningnetwork/lnd/watchtower/blob"
"github.com/lightningnetwork/lnd/watchtower/wtpolicy"
)
// UnknownElementType is an alias for channeldb.UnknownElementType.
type UnknownElementType = channeldb.UnknownElementType
// ReadElement deserializes a single element from the provided io.Reader.
func ReadElement(r io.Reader, element interface{}) error {
err := channeldb.ReadElement(r, element)
switch {
// Known to channeldb codec.
case err == nil:
return nil
// Fail if error is not UnknownElementType.
case err != nil:
if _, ok := err.(UnknownElementType); !ok {
return err
}
}
// Process any wtdb-specific extensions to the codec.
switch e := element.(type) {
case *SessionID:
if _, err := io.ReadFull(r, e[:]); err != nil {
return err
}
case *blob.BreachHint:
if _, err := io.ReadFull(r, e[:]); err != nil {
return err
}
case *wtpolicy.Policy:
var (
blobType uint16
sweepFeeRate uint64
)
err := channeldb.ReadElements(r,
&blobType,
&e.MaxUpdates,
&e.RewardBase,
&e.RewardRate,
&sweepFeeRate,
)
if err != nil {
return err
}
e.BlobType = blob.Type(blobType)
e.SweepFeeRate = lnwallet.SatPerKWeight(sweepFeeRate)
// Type is still unknown to wtdb extensions, fail.
default:
return channeldb.NewUnknownElementType(
"ReadElement", element,
)
}
return nil
}
// WriteElement serializes a single element into the provided io.Writer.
func WriteElement(w io.Writer, element interface{}) error {
err := channeldb.WriteElement(w, element)
switch {
// Known to channeldb codec.
case err == nil:
return nil
// Fail if error is not UnknownElementType.
case err != nil:
if _, ok := err.(UnknownElementType); !ok {
return err
}
}
// Process any wtdb-specific extensions to the codec.
switch e := element.(type) {
case SessionID:
if _, err := w.Write(e[:]); err != nil {
return err
}
case blob.BreachHint:
if _, err := w.Write(e[:]); err != nil {
return err
}
case wtpolicy.Policy:
return channeldb.WriteElements(w,
uint16(e.BlobType),
e.MaxUpdates,
e.RewardBase,
e.RewardRate,
uint64(e.SweepFeeRate),
)
// Type is still unknown to wtdb extensions, fail.
default:
return channeldb.NewUnknownElementType(
"WriteElement", element,
)
}
return nil
}
// WriteElements serializes a variadic list of elements into the given
// io.Writer.
func WriteElements(w io.Writer, elements ...interface{}) error {
for _, element := range elements {
if err := WriteElement(w, element); err != nil {
return err
}
}
return nil
}
// ReadElements deserializes the provided io.Reader into a variadic list of
// target elements.
func ReadElements(r io.Reader, elements ...interface{}) error {
for _, element := range elements {
if err := ReadElement(r, element); err != nil {
return err
}
}
return nil
}