(U)VarInt binary methods; Txs have sequence numbers

binary/int.go

@@ -2,6 +2,7 @@ package binary
 
 import (
 	"encoding/binary"
+	"errors"
 	"io"
 )
 
@@ -42,6 +43,7 @@ func ReadUInt8(r io.Reader, n *int64, err *error) uint8 {
 func WriteInt16(w io.Writer, i int16, n *int64, err *error) {
 	buf := make([]byte, 2)
 	binary.LittleEndian.PutUint16(buf, uint16(i))
+	*n += 2
 	WriteTo(w, buf, n, err)
 }
 
@@ -56,6 +58,7 @@ func ReadInt16(r io.Reader, n *int64, err *error) int16 {
 func WriteUInt16(w io.Writer, i uint16, n *int64, err *error) {
 	buf := make([]byte, 2)
 	binary.LittleEndian.PutUint16(buf, uint16(i))
+	*n += 2
 	WriteTo(w, buf, n, err)
 }
 
@@ -70,6 +73,7 @@ func ReadUInt16(r io.Reader, n *int64, err *error) uint16 {
 func WriteInt32(w io.Writer, i int32, n *int64, err *error) {
 	buf := make([]byte, 4)
 	binary.LittleEndian.PutUint32(buf, uint32(i))
+	*n += 4
 	WriteTo(w, buf, n, err)
 }
 
@@ -84,6 +88,7 @@ func ReadInt32(r io.Reader, n *int64, err *error) int32 {
 func WriteUInt32(w io.Writer, i uint32, n *int64, err *error) {
 	buf := make([]byte, 4)
 	binary.LittleEndian.PutUint32(buf, uint32(i))
+	*n += 4
 	WriteTo(w, buf, n, err)
 }
 
@@ -98,6 +103,7 @@ func ReadUInt32(r io.Reader, n *int64, err *error) uint32 {
 func WriteInt64(w io.Writer, i int64, n *int64, err *error) {
 	buf := make([]byte, 8)
 	binary.LittleEndian.PutUint64(buf, uint64(i))
+	*n += 8
 	WriteTo(w, buf, n, err)
 }
 
@@ -112,6 +118,7 @@ func ReadInt64(r io.Reader, n *int64, err *error) int64 {
 func WriteUInt64(w io.Writer, i uint64, n *int64, err *error) {
 	buf := make([]byte, 8)
 	binary.LittleEndian.PutUint64(buf, uint64(i))
+	*n += 8
 	WriteTo(w, buf, n, err)
 }
 
@@ -120,3 +127,76 @@ func ReadUInt64(r io.Reader, n *int64, err *error) uint64 {
 	ReadFull(r, buf, n, err)
 	return uint64(binary.LittleEndian.Uint64(buf))
 }
+
+// VarInt
+
+func WriteVarInt(w io.Writer, i int64, n *int64, err *error) {
+	buf := make([]byte, 9)
+	*n += int64(binary.PutVarint(buf, int64(i)))
+	WriteTo(w, buf, n, err)
+}
+
+func ReadVarInt(r io.Reader, n *int64, err *error) int64 {
+	res, n_, err_ := readVarint(r)
+	*n += n_
+	*err = err_
+	return res
+}
+
+// UVarInt
+
+func WriteUVarInt(w io.Writer, i uint64, n *int64, err *error) {
+	buf := make([]byte, 9)
+	*n += int64(binary.PutUvarint(buf, uint64(i)))
+	WriteTo(w, buf, n, err)
+}
+
+func ReadUVarInt(r io.Reader, n *int64, err *error) uint64 {
+	res, n_, err_ := readUvarint(r)
+	*n += n_
+	*err = err_
+	return res
+}
+
+//-----------------------------------------------------------------------------
+
+var overflow = errors.New("binary: varint overflows a 64-bit integer")
+
+// Modified to return number of bytes read, from
+// http://golang.org/src/pkg/encoding/binary/varint.go?s=3652:3699#L116
+func readUvarint(r io.Reader) (uint64, int64, error) {
+	var x uint64
+	var s uint
+	var buf = make([]byte, 1)
+	for i := 0; ; i++ {
+		for {
+			n, err := r.Read(buf)
+			if err != nil {
+				return x, int64(i), err
+			}
+			if n > 0 {
+				break
+			}
+		}
+		b := buf[0]
+		if b < 0x80 {
+			if i > 9 || i == 9 && b > 1 {
+				return x, int64(i), overflow
+			}
+			return x | uint64(b)<<s, int64(i), nil
+		}
+		x |= uint64(b&0x7f) << s
+		s += 7
+	}
+}
+
+// Modified to return number of bytes read, from
+// http://golang.org/src/pkg/encoding/binary/varint.go?s=3652:3699#L116
+func readVarint(r io.Reader) (int64, int64, error) {
+	ux, n, err := readUvarint(r) // ok to continue in presence of error
+	x := int64(ux >> 1)
+	if ux&1 != 0 {
+		x = ^x
+	}
+	return x, n, err
+}