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