-
Notifications
You must be signed in to change notification settings - Fork 0
/
factory.go
147 lines (116 loc) · 3.56 KB
/
factory.go
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
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
package factory
import (
"context"
"fmt"
"github.com/expgo/structure"
"github.com/expgo/sync"
"reflect"
)
const NewMethodName = "New"
var factories = make(map[reflect.Type]*_factory)
var factoriesLock = sync.NewRWMutex()
type _factory struct {
factory any
factoryType reflect.Type
returnType reflect.Type
methodName string
params []string
}
func (f *_factory) MethodName(methodName string) *_factory {
if f.factoryType.Kind() == reflect.Func {
panic("factory is func, couldn't call MethodName")
}
if len(methodName) > 0 {
f.methodName = methodName
}
return f
}
func (f *_factory) Params(params ...string) *_factory {
f.params = params
return f
}
func (f *_factory) CheckValid() {
ft := f.factoryType
vt := f.returnType
if ft.Kind() == reflect.Func {
if ft.NumOut() != 1 {
panic(fmt.Errorf("func factory must return one value: %s", vt.String()))
}
if !ft.Out(0).AssignableTo(vt) {
panic("func factory's return can't assign to the register type")
}
if ft.NumIn() != len(f.params) {
panic("func factory params is not equals with params in")
}
} else if ft.Kind() == reflect.Ptr && ft.Elem().Kind() == reflect.Struct {
newMethod, ok := ft.MethodByName(f.methodName)
if !ok {
panic(fmt.Errorf("can't find new method from factory of type %s", vt.String()))
}
if newMethod.Type.NumOut() != 1 {
panic(fmt.Errorf("*struct factory must return one value: %s", vt.String()))
}
if !newMethod.Type.Out(0).AssignableTo(vt) {
panic("*struct factory's return can't assign to the register type")
}
if newMethod.Type.NumIn() != len(f.params)+1 {
panic("*struct factory params is not equals with params in")
}
} else {
panic(fmt.Errorf("factory %s input must be a *struct or a func", vt.String()))
}
}
func Factory[T any](f any) *_factory {
return FactoryWithType(reflect.TypeOf((*T)(nil)), f)
}
func FactoryWithType(vt reflect.Type, f any) *_factory {
if vt.Elem().Kind() == reflect.Interface {
vt = vt.Elem()
}
fac := &_factory{
factory: f,
factoryType: reflect.TypeOf(f),
returnType: vt,
methodName: NewMethodName,
}
factoriesLock.RLock()
_, loaded := factories[vt]
factoriesLock.RUnlock()
if loaded {
panic(fmt.Errorf("factory already exist: %s", vt.String()))
}
factoriesLock.Lock()
factories[vt] = fac
factoriesLock.Unlock()
return fac
}
func callFactory(ctx context.Context, f *_factory, self any, fieldValue reflect.Value, structField reflect.StructField, newParams []string) error {
vt := f.factoryType
if newParams == nil || len(newParams) != len(f.params) {
newParams = f.params
}
if vt.Kind() == reflect.Func {
funcValue := reflect.ValueOf(f.factory)
funcType := funcValue.Type()
params, err := _getMethodParams(ctx, self, funcType, newParams, funcType.Name())
if err != nil {
panic(fmt.Errorf("factory func %s error: %v", structField.Type.String(), err))
}
values := funcValue.Call(params)
return structure.SetField(fieldValue, values[0].Interface())
} else {
newMethod, ok := vt.MethodByName(f.methodName)
if ok {
if newMethod.Type.NumOut() != 1 {
panic("new method must only return one value")
}
params, err := _getMethodParams(ctx, self, newMethod.Type, newParams, newMethod.Name)
if err != nil {
panic(fmt.Errorf("factory new %s error: %v", structField.Type.String(), err))
}
values := newMethod.Func.Call(append([]reflect.Value{reflect.ValueOf(f.factory)}, params...))
return structure.SetField(fieldValue, values[0].Interface())
}
return fmt.Errorf("can't find new method from factory of type %s", structField.Type.String())
}
}