1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
// Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package queue
import (
"reflect"
"code.gitea.io/gitea/modules/json"
)
// Mappable represents an interface that can MapTo another interface
type Mappable interface {
MapTo(v interface{}) error
}
// toConfig will attempt to convert a given configuration cfg into the provided exemplar type.
//
// It will tolerate the cfg being passed as a []byte or string of a json representation of the
// exemplar or the correct type of the exemplar itself
func toConfig(exemplar, cfg interface{}) (interface{}, error) {
// First of all check if we've got the same type as the exemplar - if so it's all fine.
if reflect.TypeOf(cfg).AssignableTo(reflect.TypeOf(exemplar)) {
return cfg, nil
}
// Now if not - does it provide a MapTo function we can try?
if mappable, ok := cfg.(Mappable); ok {
newVal := reflect.New(reflect.TypeOf(exemplar))
if err := mappable.MapTo(newVal.Interface()); err == nil {
return newVal.Elem().Interface(), nil
}
// MapTo has failed us ... let's try the json route ...
}
// OK we've been passed a byte array right?
configBytes, ok := cfg.([]byte)
if !ok {
// oh ... it's a string then?
var configStr string
configStr, ok = cfg.(string)
configBytes = []byte(configStr)
}
if !ok {
// hmm ... can we marshal it to json?
var err error
configBytes, err = json.Marshal(cfg)
ok = err == nil
}
if !ok {
// no ... we've tried hard enough at this point - throw an error!
return nil, ErrInvalidConfiguration{cfg: cfg}
}
// OK unmarshal the byte array into a new copy of the exemplar
newVal := reflect.New(reflect.TypeOf(exemplar))
if err := json.Unmarshal(configBytes, newVal.Interface()); err != nil {
// If we can't unmarshal it then return an error!
return nil, ErrInvalidConfiguration{cfg: cfg, err: err}
}
return newVal.Elem().Interface(), nil
}
// unmarshalAs will attempt to unmarshal provided bytes as the provided exemplar
func unmarshalAs(bs []byte, exemplar interface{}) (data Data, err error) {
if exemplar != nil {
t := reflect.TypeOf(exemplar)
n := reflect.New(t)
ne := n.Elem()
err = json.Unmarshal(bs, ne.Addr().Interface())
data = ne.Interface().(Data)
} else {
err = json.Unmarshal(bs, &data)
}
return data, err
}
// assignableTo will check if provided data is assignable to the same type as the exemplar
// if the provided exemplar is nil then it will always return true
func assignableTo(data Data, exemplar interface{}) bool {
if exemplar == nil {
return true
}
// Assert data is of same type as exemplar
t := reflect.TypeOf(data)
exemplarType := reflect.TypeOf(exemplar)
return t.AssignableTo(exemplarType) && data != nil
}
|
