From: Matt Joiner <anacrolix@gmail.com>
Date: Wed, 18 Mar 2015 07:09:54 +0000 (+1100)
Subject: util: Support CopyExact with pointer source
X-Git-Tag: v1.0.0~1278
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=0f7c4c5bda4616d55f62fa0c64da28e9272ef0ce;p=btrtrc.git

util: Support CopyExact with pointer source

Nice to avoid copying large value types.
---

diff --git a/util/copy.go b/util/copy.go
index fda4cffc..94d98255 100644
--- a/util/copy.go
+++ b/util/copy.go
@@ -14,6 +14,9 @@ func CopyExact(dest interface{}, src interface{}) {
 	if dV.Kind() == reflect.Array && !dV.CanAddr() {
 		panic(fmt.Sprintf("dest not addressable: %T", dest))
 	}
+	if sV.Kind() == reflect.Ptr {
+		sV = sV.Elem()
+	}
 	if sV.Kind() == reflect.String {
 		sV = sV.Convert(reflect.SliceOf(dV.Type().Elem()))
 	}
diff --git a/util/copy_test.go b/util/copy_test.go
index 18c9e2d6..45298710 100644
--- a/util/copy_test.go
+++ b/util/copy_test.go
@@ -78,3 +78,12 @@ func TestCopySrcNilInterface(t *testing.T) {
 	}()
 	CopyExact(&arr, nil)
 }
+
+func TestCopySrcPtr(t *testing.T) {
+	var bigDst [1024]byte
+	var bigSrc [1024]byte = [1024]byte{'h', 'i'}
+	CopyExact(&bigDst, &bigSrc)
+	if !bytes.Equal(bigDst[:], bigSrc[:]) {
+		t.FailNow()
+	}
+}