func (d *decoder) decodeSlice(name string, o *hcl.Object, result reflect.Value) error {
// If we have an interface, then we can address the interface,
// but not the slice itself, so get the element but set the interface
set := result
if result.Kind() == reflect.Interface {
result = result.Elem()
}
// Create the slice if it isn't nil
resultType := result.Type()
resultElemType := resultType.Elem()
if result.IsNil() {
resultSliceType := reflect.SliceOf(resultElemType)
result = reflect.MakeSlice(
resultSliceType, 0, 0)
}
// Determine how we're doing this
expand := true
switch o.Type {
case hcl.ValueTypeObject:
expand = false
default:
// Array or anything else: we expand values and take it all
}
i := 0
for _, o := range o.Elem(expand) {
fieldName := fmt.Sprintf("%s[%d]", name, i)
// Decode
val := reflect.Indirect(reflect.New(resultElemType))
if err := d.decode(fieldName, o, val); err != nil {
return err
}
// Append it onto the slice
result = reflect.Append(result, val)
i += 1
}
set.Set(result)
return nil
}
func (d *decoder) decodeStruct(name string, o *hcl.Object, result reflect.Value) error {
if o.Type != hcl.ValueTypeObject {
return fmt.Errorf("%s: not an object type for struct (%v)", name, o.Type)
}
// This slice will keep track of all the structs we'll be decoding.
// There can be more than one struct if there are embedded structs
// that are squashed.
structs := make([]reflect.Value, 1, 5)
structs[0] = result
// Compile the list of all the fields that we're going to be decoding
// from all the structs.
fields := make(map[*reflect.StructField]reflect.Value)
for len(structs) > 0 {
structVal := structs[0]
structs = structs[1:]
structType := structVal.Type()
for i := 0; i < structType.NumField(); i++ {
fieldType := structType.Field(i)
if fieldType.Anonymous {
fieldKind := fieldType.Type.Kind()
if fieldKind != reflect.Struct {
return fmt.Errorf(
"%s: unsupported type to struct: %s",
fieldType.Name, fieldKind)
}
// We have an embedded field. We "squash" the fields down
// if specified in the tag.
squash := false
tagParts := strings.Split(fieldType.Tag.Get(tagName), ",")
for _, tag := range tagParts[1:] {
if tag == "squash" {
squash = true
break
}
}
if squash {
structs = append(
structs, result.FieldByName(fieldType.Name))
continue
}
}
// Normal struct field, store it away
fields[&fieldType] = structVal.Field(i)
}
}
usedKeys := make(map[string]struct{})
decodedFields := make([]string, 0, len(fields))
decodedFieldsVal := make([]reflect.Value, 0)
unusedKeysVal := make([]reflect.Value, 0)
for fieldType, field := range fields {
if !field.IsValid() {
// This should never happen
panic("field is not valid")
}
// If we can't set the field, then it is unexported or something,
// and we just continue onwards.
if !field.CanSet() {
continue
}
fieldName := fieldType.Name
// This is whether or not we expand the object into its children
// later.
expand := false
tagValue := fieldType.Tag.Get(tagName)
tagParts := strings.SplitN(tagValue, ",", 2)
if len(tagParts) >= 2 {
switch tagParts[1] {
case "expand":
expand = true
case "decodedFields":
decodedFieldsVal = append(decodedFieldsVal, field)
continue
case "key":
field.SetString(o.Key)
continue
case "unusedKeys":
unusedKeysVal = append(unusedKeysVal, field)
continue
}
}
if tagParts[0] != "" {
fieldName = tagParts[0]
}
// Find the element matching this name
obj := o.Get(fieldName, true)
if obj == nil {
continue
}
// Track the used key
usedKeys[fieldName] = struct{}{}
// Create the field name and decode. We range over the elements
// because we actually want the value.
fieldName = fmt.Sprintf("%s.%s", name, fieldName)
for _, obj := range obj.Elem(expand) {
if err := d.decode(fieldName, obj, field); err != nil {
return err
}
}
decodedFields = append(decodedFields, fieldType.Name)
}
if len(decodedFieldsVal) > 0 {
// Sort it so that it is deterministic
sort.Strings(decodedFields)
for _, v := range decodedFieldsVal {
v.Set(reflect.ValueOf(decodedFields))
}
}
// If we want to know what keys are unused, compile that
if len(unusedKeysVal) > 0 {
/*
unusedKeys := make([]string, 0, int(obj.Len())-len(usedKeys))
for _, elem := range obj.Elem {
k := elem.Key()
if _, ok := usedKeys[k]; !ok {
unusedKeys = append(unusedKeys, k)
}
}
if len(unusedKeys) == 0 {
unusedKeys = nil
}
for _, v := range unusedKeysVal {
v.Set(reflect.ValueOf(unusedKeys))
}
*/
}
return nil
}
func (d *decoder) decodeMap(name string, o *hcl.Object, result reflect.Value) error {
if o.Type != hcl.ValueTypeObject {
return fmt.Errorf("%s: not an object type for map (%v)", name, o.Type)
}
// If we have an interface, then we can address the interface,
// but not the slice itself, so get the element but set the interface
set := result
if result.Kind() == reflect.Interface {
result = result.Elem()
}
resultType := result.Type()
resultElemType := resultType.Elem()
resultKeyType := resultType.Key()
if resultKeyType.Kind() != reflect.String {
return fmt.Errorf(
"%s: map must have string keys", name)
}
// Make a map if it is nil
resultMap := result
if result.IsNil() {
resultMap = reflect.MakeMap(
reflect.MapOf(resultKeyType, resultElemType))
}
// Go through each element and decode it.
for _, o := range o.Elem(false) {
if o.Value == nil {
continue
}
for _, o := range o.Elem(true) {
// Make the field name
fieldName := fmt.Sprintf("%s.%s", name, o.Key)
// Get the key/value as reflection values
key := reflect.ValueOf(o.Key)
val := reflect.Indirect(reflect.New(resultElemType))
// If we have a pre-existing value in the map, use that
oldVal := resultMap.MapIndex(key)
if oldVal.IsValid() {
val.Set(oldVal)
}
// Decode!
if err := d.decode(fieldName, o, val); err != nil {
return err
}
// Set the value on the map
resultMap.SetMapIndex(key, val)
}
}
// Set the final map if we can
set.Set(resultMap)
return nil
}
func (d *decoder) decodeInterface(name string, o *hcl.Object, result reflect.Value) error {
var set reflect.Value
redecode := true
switch o.Type {
case hcl.ValueTypeObject:
// If we're at the root or we're directly within a slice, then we
// decode objects into map[string]interface{}, otherwise we decode
// them into lists.
if len(d.stack) == 0 || d.stack[len(d.stack)-1] == reflect.Slice {
var temp map[string]interface{}
tempVal := reflect.ValueOf(temp)
result := reflect.MakeMap(
reflect.MapOf(
reflect.TypeOf(""),
tempVal.Type().Elem()))
set = result
} else {
var temp []map[string]interface{}
tempVal := reflect.ValueOf(temp)
result := reflect.MakeSlice(
reflect.SliceOf(tempVal.Type().Elem()), 0, int(o.Len()))
set = result
}
case hcl.ValueTypeList:
var temp []interface{}
tempVal := reflect.ValueOf(temp)
result := reflect.MakeSlice(
reflect.SliceOf(tempVal.Type().Elem()), 0, 0)
set = result
case hcl.ValueTypeBool:
var result bool
set = reflect.Indirect(reflect.New(reflect.TypeOf(result)))
case hcl.ValueTypeFloat:
var result float64
set = reflect.Indirect(reflect.New(reflect.TypeOf(result)))
case hcl.ValueTypeInt:
var result int
set = reflect.Indirect(reflect.New(reflect.TypeOf(result)))
case hcl.ValueTypeString:
set = reflect.Indirect(reflect.New(reflect.TypeOf("")))
default:
return fmt.Errorf(
"%s: cannot decode into interface: %T",
name, o)
}
// Set the result to what its supposed to be, then reset
// result so we don't reflect into this method anymore.
result.Set(set)
if redecode {
// Revisit the node so that we can use the newly instantiated
// thing and populate it.
if err := d.decode(name, o, result); err != nil {
return err
}
}
return nil
}