Adding upstream version 0.10.5.

Signed-off-by: Daniel Baumann <daniel@debian.org>

internal/encoder/query.go

@@ -0,0 +1,135 @@
+package encoder
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+)
+
+var (
+	Marshal   func(interface{}) ([]byte, error)
+	Unmarshal func([]byte, interface{}) error
+)
+
+type FieldQuery struct {
+	Name   string
+	Fields []*FieldQuery
+	hash   string
+}
+
+func (q *FieldQuery) Hash() string {
+	if q.hash != "" {
+		return q.hash
+	}
+	b, _ := Marshal(q)
+	q.hash = string(b)
+	return q.hash
+}
+
+func (q *FieldQuery) MarshalJSON() ([]byte, error) {
+	if q.Name != "" {
+		if len(q.Fields) > 0 {
+			return Marshal(map[string][]*FieldQuery{q.Name: q.Fields})
+		}
+		return Marshal(q.Name)
+	}
+	return Marshal(q.Fields)
+}
+
+func (q *FieldQuery) QueryString() (FieldQueryString, error) {
+	b, err := Marshal(q)
+	if err != nil {
+		return "", err
+	}
+	return FieldQueryString(b), nil
+}
+
+type FieldQueryString string
+
+func (s FieldQueryString) Build() (*FieldQuery, error) {
+	var query interface{}
+	if err := Unmarshal([]byte(s), &query); err != nil {
+		return nil, err
+	}
+	return s.build(reflect.ValueOf(query))
+}
+
+func (s FieldQueryString) build(v reflect.Value) (*FieldQuery, error) {
+	switch v.Type().Kind() {
+	case reflect.String:
+		return s.buildString(v)
+	case reflect.Map:
+		return s.buildMap(v)
+	case reflect.Slice:
+		return s.buildSlice(v)
+	case reflect.Interface:
+		return s.build(reflect.ValueOf(v.Interface()))
+	}
+	return nil, fmt.Errorf("failed to build field query")
+}
+
+func (s FieldQueryString) buildString(v reflect.Value) (*FieldQuery, error) {
+	b := []byte(v.String())
+	switch b[0] {
+	case '[', '{':
+		var query interface{}
+		if err := Unmarshal(b, &query); err != nil {
+			return nil, err
+		}
+		if str, ok := query.(string); ok {
+			return &FieldQuery{Name: str}, nil
+		}
+		return s.build(reflect.ValueOf(query))
+	}
+	return &FieldQuery{Name: string(b)}, nil
+}
+
+func (s FieldQueryString) buildSlice(v reflect.Value) (*FieldQuery, error) {
+	fields := make([]*FieldQuery, 0, v.Len())
+	for i := 0; i < v.Len(); i++ {
+		def, err := s.build(v.Index(i))
+		if err != nil {
+			return nil, err
+		}
+		fields = append(fields, def)
+	}
+	return &FieldQuery{Fields: fields}, nil
+}
+
+func (s FieldQueryString) buildMap(v reflect.Value) (*FieldQuery, error) {
+	keys := v.MapKeys()
+	if len(keys) != 1 {
+		return nil, fmt.Errorf("failed to build field query object")
+	}
+	key := keys[0]
+	if key.Type().Kind() != reflect.String {
+		return nil, fmt.Errorf("failed to build field query. invalid object key type")
+	}
+	name := key.String()
+	def, err := s.build(v.MapIndex(key))
+	if err != nil {
+		return nil, err
+	}
+	return &FieldQuery{
+		Name:   name,
+		Fields: def.Fields,
+	}, nil
+}
+
+type queryKey struct{}
+
+func FieldQueryFromContext(ctx context.Context) *FieldQuery {
+	query := ctx.Value(queryKey{})
+	if query == nil {
+		return nil
+	}
+	q, ok := query.(*FieldQuery)
+	if !ok {
+		return nil
+	}
+	return q
+}
+
+func SetFieldQueryToContext(ctx context.Context, query *FieldQuery) context.Context {
+	return context.WithValue(ctx, queryKey{}, query)
+}