encoding/binary: add Size, to replace the functionality of the old TotalSize

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5644063

1 files changed, 6 insertions, 0 deletions

diff --git a/src/pkg/encoding/binary/binary.go b/src/pkg/encoding/binary/binary.go
index 4be83f53bd..7f10d40a11 100644
--- a/src/pkg/encoding/binary/binary.go
+++ b/src/pkg/encoding/binary/binary.go
@@ -253,6 +253,12 @@ func Write(w io.Writer, order ByteOrder, data interface{}) error {
 	return err
 }
 
+// Size returns how many bytes Write would generate to encode the value v, assuming
+// the Write would succeed.
+func Size(v interface{}) int {
+	return dataSize(reflect.ValueOf(v))
+}
+
 // dataSize returns the number of bytes the actual data represented by v occupies in memory.
 // For compound structures, it sums the sizes of the elements. Thus, for instance, for a slice
 // it returns the length of the slice times the element size and does not count the memory