channeldb+utxonursery+lnwire: use lnwire's OutPoint,TxOut serialization

lnwire/outpoint.go

@@ -0,0 +1,59 @@
+package lnwire
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"math"
+
+	"github.com/roasbeef/btcd/chaincfg/chainhash"
+	"github.com/roasbeef/btcd/wire"
+)
+
+// WriteOutPoint serializes a wire.OutPoint struct into the passed io.Writer
+// stream.
+func WriteOutPoint(w io.Writer, o *wire.OutPoint) error {
+	if _, err := w.Write(o.Hash[:chainhash.HashSize]); err != nil {
+		return err
+	}
+
+	if o.Index > math.MaxUint16 {
+		return fmt.Errorf("index for outpoint (%v) is "+
+			"greater than max index of %v", o.Index, math.MaxUint16)
+	}
+
+	var idx [2]byte
+	binary.BigEndian.PutUint16(idx[:], uint16(o.Index))
+	if _, err := w.Write(idx[:]); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// ReadOutPoint deserializes a wire.OutPoint struct from the passed io.Reader
+// stream.
+func ReadOutPoint(r io.Reader, o *wire.OutPoint) error {
+	var h [chainhash.HashSize]byte
+	if _, err := io.ReadFull(r, h[:]); err != nil {
+		return err
+	}
+	hash, err := chainhash.NewHash(h[:])
+	if err != nil {
+		return err
+	}
+
+	var idxBytes [2]byte
+	_, err = io.ReadFull(r, idxBytes[:])
+	if err != nil {
+		return err
+	}
+	index := binary.BigEndian.Uint16(idxBytes[:])
+
+	*o = wire.OutPoint{
+		Hash:  *hash,
+		Index: uint32(index),
+	}
+
+	return nil
+}