github.com/cs3org/reva/v2@v2.27.7/pkg/storage/utils/indexer/reflect.go (about)

     1  // Copyright 2018-2022 CERN
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  //
    15  // In applying this license, CERN does not waive the privileges and immunities
    16  // granted to it by virtue of its status as an Intergovernmental Organization
    17  // or submit itself to any jurisdiction.
    18  
    19  package indexer
    20  
    21  import (
    22  	"errors"
    23  	"fmt"
    24  	"path"
    25  	"reflect"
    26  	"strconv"
    27  	"strings"
    28  
    29  	"github.com/cs3org/reva/v2/pkg/storage/utils/indexer/option"
    30  )
    31  
    32  func getType(v interface{}) (reflect.Value, error) {
    33  	rv := reflect.ValueOf(v)
    34  	for rv.Kind() == reflect.Ptr || rv.Kind() == reflect.Interface {
    35  		rv = rv.Elem()
    36  	}
    37  	if !rv.IsValid() {
    38  		return reflect.Value{}, errors.New("failed to read value via reflection")
    39  	}
    40  
    41  	return rv, nil
    42  }
    43  
    44  func getTypeFQN(t interface{}) string {
    45  	typ, _ := getType(t)
    46  	typeName := path.Join(typ.Type().PkgPath(), typ.Type().Name())
    47  	typeName = strings.ReplaceAll(typeName, "/", ".")
    48  	return typeName
    49  }
    50  
    51  func valueOf(v interface{}, indexBy option.IndexBy) (string, error) {
    52  	switch idxBy := indexBy.(type) {
    53  	case option.IndexByField:
    54  		return valueOfField(v, string(idxBy))
    55  	case option.IndexByFunc:
    56  		return idxBy.Func(v)
    57  	default:
    58  		return "", fmt.Errorf("unknown indexBy type")
    59  	}
    60  }
    61  
    62  func valueOfField(v interface{}, field string) (string, error) {
    63  	parts := strings.Split(field, ".")
    64  	for i, part := range parts {
    65  		r := reflect.ValueOf(v)
    66  		if r.Kind() == reflect.Ptr {
    67  			r = r.Elem()
    68  		}
    69  		f := reflect.Indirect(r).FieldByName(part)
    70  		if f.Kind() == reflect.Ptr {
    71  			f = f.Elem()
    72  		}
    73  
    74  		switch {
    75  		case f.Kind() == reflect.Struct && i != len(parts)-1:
    76  			v = f.Interface()
    77  		case f.Kind() == reflect.String:
    78  			return f.String(), nil
    79  		case f.IsZero():
    80  			return "", nil
    81  		default:
    82  			return strconv.Itoa(int(f.Int())), nil
    83  		}
    84  	}
    85  	return "", nil
    86  }