136 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			136 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| package encoder
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| type FieldQueryString string
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| type queryKey struct{}
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| 
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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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| 
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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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