map_arg.go => kv_arg.go

qemucli/kv_arg.go

@@ -0,0 +1,92 @@
+package qemucli
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+type MapArg struct {
+	key    string
+	values map[string]string
+}
+
+func MustNewMapArg(key string, values map[string]string) *MapArg {
+	a, err := NewMapArg(key, values)
+	if err != nil {
+		panic(err)
+	}
+
+	return a
+}
+
+func NewMapArg(key string, values map[string]string) (*MapArg, error) {
+	a := &MapArg{
+		key:    key,
+		values: make(map[string]string),
+	}
+
+	// Preflight arg key/type check.
+	err := validateArgKey(key, a.ValueType())
+	if err != nil {
+		return nil, errors.Wrap(err, "validate arg key")
+	}
+
+	for k, v := range values {
+		// The reason why we're making copies here and creating
+		// a whole other copy of the entire map is because maps
+		// are pointers, and we do not want to reference anything
+		// that we will not be able to validate except at this
+		// stage of MapArg creation.
+		k := k
+		v := v
+
+		if len(k) == 0 {
+			return nil, fmt.Errorf("empty map key not allowed")
+		}
+
+		if len(v) == 1 {
+			// Values *can* be empty, though. We do not allow them for consistency.
+			return nil, fmt.Errorf("empty map value for key '%v' is not allowed", k)
+		}
+
+		err := validateArgStrValue(k)
+		if err != nil {
+			return nil, errors.Wrapf(err, "validate map key '%v'", k)
+		}
+
+		err = validateArgStrValue(v)
+		if err != nil {
+			return nil, errors.Wrapf(err, "validate map value '%v'", v)
+		}
+
+		a.values[k] = v
+	}
+
+	return a, nil
+}
+
+func (a *MapArg) StringKey() string {
+	return a.key
+}
+
+func (a *MapArg) StringValue() string {
+	sb := new(strings.Builder)
+	for k, v := range a.values {
+		// We're not validating anything here because
+		// we expect that the keys/values were validated
+		// at the creation of the MapArg.
+
+		sb.WriteString(k)
+		if len(v) > 0 {
+			sb.WriteString("=" + v)
+		}
+	}
+
+	return sb.String()
+}
+
+func (a *MapArg) ValueType() ArgAcceptedValue {
+	return ArgAcceptedValueMap
+}