-
Notifications
You must be signed in to change notification settings - Fork 171
/
generics.go
195 lines (174 loc) · 4.01 KB
/
generics.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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
package std
import (
"fmt"
"google.golang.org/protobuf/proto"
"reflect"
"strings"
"sync"
)
type cloneable interface {
proto.Message
}
type Cloneable interface {
Clone() interface{}
}
func DeepClone[T any](t T) (dst T) {
ret := copyAny(t)
if v, ok := ret.(T); ok {
dst = v
return
}
return
}
func copySlice(x any) any {
v := reflect.ValueOf(x)
kind := v.Kind()
if kind != reflect.Slice {
panic(fmt.Sprintf("reflect: internal error: type %v is not a slice", kind))
}
size := v.Len()
t := reflect.TypeOf(x)
dc := reflect.MakeSlice(t, size, size)
for i := 0; i < size; i++ {
iv := reflect.ValueOf(copyAny(v.Index(i).Interface()))
if iv.IsValid() {
dc.Index(i).Set(iv)
}
}
return dc.Interface()
}
func copyArray(x any) any {
v := reflect.ValueOf(x)
if v.Kind() != reflect.Array {
panic(fmt.Errorf("reflect: internal error: must be an Array; got %v", v.Kind()))
}
t := reflect.TypeOf(x)
size := t.Len()
dc := reflect.New(reflect.ArrayOf(size, t.Elem())).Elem()
for i := 0; i < size; i++ {
item := copyAny(v.Index(i).Interface())
dc.Index(i).Set(reflect.ValueOf(item))
}
return dc.Interface()
}
func copyMap(x any) any {
v := reflect.ValueOf(x)
if v.Kind() != reflect.Map {
panic(fmt.Errorf("reflect: internal error: must be a Map; got %v", v.Kind()))
}
t := reflect.TypeOf(x)
dc := reflect.MakeMapWithSize(t, v.Len())
iter := v.MapRange()
for iter.Next() {
item := copyAny(iter.Value().Interface())
k := copyAny(iter.Key().Interface())
dc.SetMapIndex(reflect.ValueOf(k), reflect.ValueOf(item))
}
return dc.Interface()
}
func copyPointer(x any) any {
switch vv := x.(type) {
case proto.Message:
return proto.Clone(vv)
case Cloneable:
return vv.Clone()
case *sync.Map:
return copySyncMap(vv)
}
v := reflect.ValueOf(x)
if v.Kind() != reflect.Pointer {
panic(fmt.Errorf("reflect: internal error: must be a Pointer or Ptr; got %v", v.Kind()))
}
t := reflect.TypeOf(x)
dc := reflect.New(t.Elem())
if !v.IsNil() {
item := copyAny(v.Elem().Interface())
iv := reflect.ValueOf(item)
if iv.IsValid() {
dc.Elem().Set(reflect.ValueOf(item))
}
}
return dc.Interface()
}
func copySyncMap(x any) any {
sm, ok := x.(*sync.Map)
if !ok {
panic(fmt.Errorf("reflect: internal error: must be a sync map; got %v", reflect.TypeOf(x)))
}
cp := &sync.Map{}
sm.Range(func(k, v interface{}) bool {
vm, ok := v.(*sync.Map)
if ok {
cp.Store(k, copySyncMap(vm))
} else {
cp.Store(k, copyAny(v))
}
return true
})
return cp
}
func copyStruct(x any) any {
v := reflect.ValueOf(x)
if v.Kind() != reflect.Struct {
panic(fmt.Errorf("reflect: internal error: must be a Struct; got %v", v.Kind()))
}
t := reflect.TypeOf(x)
dc := reflect.New(t)
for i := 0; i < t.NumField(); i++ {
f := t.Field(i)
if f.PkgPath != "" {
continue
}
item := copyAny(v.Field(i).Interface())
dc.Elem().Field(i).Set(reflect.ValueOf(item))
}
return dc.Elem().Interface()
}
func copyAny(src any) (dst any) {
v := reflect.ValueOf(src)
if !v.IsValid() {
return src
}
// Look up the corresponding copy function.
switch v.Kind() {
case reflect.Map:
dst = copyMap(src)
case reflect.Slice:
dst = copySlice(src)
case reflect.Array:
dst = copyArray(src)
case reflect.String:
dst = strings.Clone(src.(string))
case reflect.Ptr, reflect.UnsafePointer:
dst = copyPointer(src)
case reflect.Interface:
dst = copyAny(src)
case reflect.Struct:
dst = copyStruct(src)
default:
fmt.Println("Shouldn't be there ?", v)
}
return
}
// Clone returns a copy of m. This is a shallow clone:
// the new keys and values are set using ordinary assignment.
func CloneMap[M ~map[K]V, K comparable, V any](m M) M {
// Preserve nil in case it matters.
if m == nil {
return nil
}
r := make(M, len(m))
for k, v := range m {
r[k] = v
}
return r
}
// Clone returns a copy of the slice.
// The elements are copied using assignment, so this is a shallow clone.
func CloneSlice[S ~[]E, E any](s S) S {
// Preserve nil in case it matters.
if s == nil {
return nil
}
return append(S([]E{}), s...)
}