Merge pull request #189 from Mido-sys/optimize_memory_allocation_comp…

…ile_write

Avoid the memory allocation of WriteString

compiler.go

@@ -2,6 +2,7 @@ package plush
 
 import (
 	"fmt"
+	"unsafe"
 
 	"github.com/gobuffalo/plush/v4/token"
 
@@ -73,24 +74,24 @@ func (c *compiler) write(bb *strings.Builder, i interface{}) {
 	switch t := i.(type) {
 	case time.Time:
 		if dtf, ok := c.ctx.Value("TIME_FORMAT").(string); ok {
-			bb.WriteString(t.Format(dtf))
+			bb.Write(unsafeGetBytes(t.Format(dtf)))
 			return
 		}
-		bb.WriteString(t.Format(DefaultTimeFormat))
+		bb.Write(unsafeGetBytes(t.Format(DefaultTimeFormat)))
 	case *time.Time:
 		c.write(bb, *t)
 	case interfaceable:
 		c.write(bb, t.Interface())
 	case string, ast.Printable, bool:
-		bb.WriteString(template.HTMLEscaper(t))
+		bb.Write(unsafeGetBytes(template.HTMLEscaper(t)))
 	case template.HTML:
-		bb.WriteString(string(t))
+		bb.Write(unsafeGetBytes(string(t)))
 	case HTMLer:
-		bb.WriteString(string(t.HTML()))
+		bb.Write(unsafeGetBytes(string(t.HTML())))
 	case uint, uint8, uint16, uint32, uint64, int, int8, int16, int32, int64, float32, float64:
-		bb.WriteString(fmt.Sprint(t))
+		bb.Write(unsafeGetBytes(fmt.Sprint(t)))
 	case fmt.Stringer:
-		bb.WriteString(t.String())
+		bb.Write(unsafeGetBytes(t.String()))
 	case []string:
 		for _, ii := range t {
 			c.write(bb, ii)
@@ -1091,3 +1092,12 @@ func (c *compiler) evalIndexCallee(rv reflect.Value, node *ast.IndexExpression)
 
 	return vvs, nil
 }
+
+func unsafeGetBytes(s string) []byte {
+	if s == "" {
+		return []byte{}
+	}
+	return (*[0x7fff0000]byte)(unsafe.Pointer(
+		(*reflect.StringHeader)(unsafe.Pointer(&s)).Data),
+	)[:len(s):len(s)]
+}