Add WriteAllTo method and container serialization

container/container.go

@@ -2,6 +2,7 @@ package container
 
 import (
 	"errors"
+	"io"
 
 	"github.com/safing/portbase/formats/varint"
 )
@@ -146,6 +147,21 @@ func (c *Container) WriteToSlice(slice []byte) (n int, containerEmptied bool) {
 	return n, true
 }
 
+// WriteAllTo writes all the data to the given io.Writer. Data IS NOT copied (but may be by writer) and IS NOT consumed.
+func (c *Container) WriteAllTo(writer io.Writer) error {
+	for i := c.offset; i < len(c.compartments); i++ {
+		written := 0
+		for written < len(c.compartments[i]) {
+			n, err := writer.Write(c.compartments[i][written:])
+			if err != nil {
+				return err
+			}
+			written += n
+		}
+	}
+	return nil
+}
+
 func (c *Container) clean() {
 	if c.offset > 100 {
 		c.renewCompartments()

container/serialization.go

@@ -0,0 +1,21 @@
+package container
+
+import (
+	"encoding/json"
+)
+
+// MarshalJSON serializes the container as a JSON byte array.
+func (c *Container) MarshalJSON() ([]byte, error) {
+	return json.Marshal(c.CompileData())
+}
+
+// UnmarshalJSON unserializes a container from a JSON byte array.
+func (c *Container) UnmarshalJSON(data []byte) error {
+	var raw []byte
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return err
+	}
+
+	c.compartments = [][]byte{raw}
+	return nil
+}