Method encodeValue

encoder.go:155–202

Encode Attribute value

(tag Tag, v Value)

// Encode Attribute value
func (me *messageEncoder) encodeValue(tag Tag, v Value) error {
	// Check Value type vs the Tag
	tagType := tag.Type()
	if tagType == TypeVoid {
		v = Void{} // Ignore supplied value
	} else if tagType != v.Type() {
		return fmt.Errorf("Tag %s: %s value required, %s present",
			tag, tagType, v.Type())
	}

	// Convert Value to bytes in wire representation.
	data, err := v.encode()
	if err != nil {
		return err
	}

	if len(data) > math.MaxInt16 {
		return fmt.Errorf("Attribute value exceeds %d bytes",
			math.MaxInt16)
	}

	// TagExtension encoding rules enforcement.
	if tag == TagExtension {
		if len(data) < 4 {
			return fmt.Errorf(
				"Extension tag truncated (%d bytes)", len(data))
		}

		t := binary.BigEndian.Uint32(data)
		if t > 0x7fffffff {
			return fmt.Errorf(
				"Extension tag 0x%8.8x out of range", t)
		}
	}

	// Encode the value
	err = me.encodeU16(uint16(len(data)))
	if err == nil {
		err = me.write(data)
	}

	// Handle collection
	if collection, ok := v.(Collection); ok {
		return me.encodeCollection(tag, collection)
	}

	return err
}

// Encode collection
func (me *messageEncoder) encodeCollection(tag Tag, collection Collection) error {