Merge pull request #11 from openset/master

Update: UnsafeToBytes
thinkeridea · Jan 6, 2020 · 5b54d82 · 5b54d82
2 parents 64bce00 + acc8668
commit 5b54d82
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Showing 2 changed files with 14 additions and 10 deletions.
diff --git a/exstrings/convert.go b/exstrings/convert.go
@@ -15,10 +15,7 @@
 
 package exstrings
 
-import (
-	"reflect"
-	"unsafe"
-)
+import "unsafe"
 
 /*
 UnsafeToBytes 把 string 转换为 []byte 没有多余的内存开销。
@@ -63,12 +60,12 @@ UnsafeToBytes 把 string 转换为 []byte 没有多余的内存开销。
 当然还有更多的使用方法，可以极大的提升我们程序的性能。
 */
 func UnsafeToBytes(s string) []byte {
-	strHeader := (*reflect.StringHeader)(unsafe.Pointer(&s))
-	return *(*[]byte)(unsafe.Pointer(&reflect.SliceHeader{
-		Data: strHeader.Data,
-		Len:  strHeader.Len,
-		Cap:  strHeader.Len,
-	}))
+	return *(*[]byte)(unsafe.Pointer(
+		&struct {
+			string
+			Cap int
+		}{s, len(s)},
+	))
 }
 
 /*

diff --git a/exstrings/convert_test.go b/exstrings/convert_test.go
@@ -64,3 +64,10 @@ func TestBytes(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkUnsafeToBytes(b *testing.B) {
+	str := strings.Repeat("abc", 128)
+	for i := 0; i < b.N; i++ {
+		UnsafeToBytes(str)
+	}
+}