init

pbuf/pooler.go

@@ -0,0 +1,68 @@
+package pbuf
+
+import (
+	"bytes"
+	"io"
+	"reflect"
+)
+
+type bufpooler struct{}
+
+func (bufpooler) New(config any, pooled bytes.Buffer) bytes.Buffer {
+	switch c := config.(type) {
+	case int:
+		pooled.Grow(c)
+		return pooled
+	case []byte:
+		if len(c) > 0 || pooled.Cap() < cap(c) {
+			return *bytes.NewBuffer(c)
+		}
+		return pooled
+	case string:
+		pooled.Grow(len(c))
+		pooled.WriteString(c)
+		return pooled
+	default:
+		panic("config type " + reflect.ValueOf(config).Type().String() + " isn't supported")
+	}
+}
+
+func (bufpooler) Parse(obj any, pooled bytes.Buffer) bytes.Buffer {
+	switch o := obj.(type) {
+	case *bytes.Buffer:
+		return *o
+	case bytes.Buffer:
+		return o
+	case []byte:
+		pooled.Write(o)
+		return pooled
+	case string:
+		pooled.WriteString(o)
+		return pooled
+	case io.Reader:
+		_, err := io.Copy(&pooled, o)
+		if err != nil {
+			panic(err)
+		}
+		return pooled
+	default:
+		panic("object type " + reflect.ValueOf(obj).Type().String() + " isn't supported")
+	}
+}
+
+func (bufpooler) Reset(item *bytes.Buffer) {
+	// See https://golang.org/issue/23199
+	const maxSize = 1 << 16
+	if item.Cap() > maxSize { // drop large buffer
+		*item = bytes.Buffer{}
+		return
+	}
+	item.Reset()
+}
+
+func (bufpooler) Copy(dst, src *bytes.Buffer) {
+	_, err := io.Copy(dst, src)
+	if err != nil {
+		panic(err)
+	}
+}