Initial commit

protocol/map.go

@@ -0,0 +1,58 @@
+package protocol
+
+import "io"
+import "fmt"
+
+// Map is a string-to-string map with non-unique keys. Each key can be
+// associated with multiple values. This is typically used for things like HTTP
+// headers.
+type Map map[string] []string
+
+// ReadMap reads a map with a 16-bit length containing strings which have a
+// 16-bit size. The length of the map corresponds to how many key/value pairs
+// it has, and not how long the map is.
+func ReadMap (reader io.Reader) (m Map, err error) {
+	length, err := ReadU16(reader)
+	if err != nil { return nil, err }
+
+	m = make(Map)
+	for length > 0 {
+		key, err := ReadString16(reader)
+		if err != nil { return m, err }
+		value, err := ReadString16(reader)
+		if err != nil { return m, err }
+		m.Add(key, value)
+		length --
+	}
+
+	return m, err
+}
+
+func (m Map) Serialize (writer io.Writer) (err error) {
+	if uint(len(m)) > MaxIntOfSize(2) {
+		panic(fmt.Sprintf("len(%d) cannot fit in U16", len(m)))
+	}
+
+	length := 0
+	for _, item := range m {
+		length += len(item)
+	}
+	
+	err = WriteU16(writer, uint16(length))
+	if err != nil { return }
+	
+	for key, values := range m {
+	for _, value := range values {
+		err = WriteString16(writer, key)
+		if err != nil { return }
+		err = WriteString16(writer, value)
+		if err != nil { return }
+	}}
+
+	return
+}
+
+// Add adds a value to the map under the specified key.
+func (m Map) Add (key, value string) {
+	m[key] = append(m[key], value)
+}