feat: add DeepClone

convertor/convertor.go

@@ -324,3 +324,19 @@ func DecodeByte(data []byte, target any) error {
 	decoder := gob.NewDecoder(buffer)
 	return decoder.Decode(target)
 }
+
+// DeepClone creates a deep copy of passed item.
+// can't clone unexported field of struct
+// Play: todo
+func DeepClone[T any](src T) T {
+	c := cloner{
+		ptrs: map[reflect.Type]map[uintptr]reflect.Value{},
+	}
+	result := c.clone(reflect.ValueOf(src))
+	if result.Kind() == reflect.Invalid {
+		var zeroValue T
+		return zeroValue
+	}
+
+	return result.Interface().(T)
+}

convertor/convertor_example_test.go

@@ -252,3 +252,46 @@ func ExampleDecodeByte() {
 	// Output:
 	// abc
 }
+
+func ExampleDeepClone() {
+	type Struct struct {
+		Str        string
+		Int        int
+		Float      float64
+		Bool       bool
+		Nil        interface{}
+		unexported string
+	}
+
+	cases := []interface{}{
+		true,
+		1,
+		0.1,
+		map[string]int{
+			"a": 1,
+			"b": 2,
+		},
+		&Struct{
+			Str:   "test",
+			Int:   1,
+			Float: 0.1,
+			Bool:  true,
+			Nil:   nil,
+			// unexported: "can't be cloned",
+		},
+	}
+
+	for _, item := range cases {
+		cloned := DeepClone(item)
+
+		isPointerEqual := &cloned == &item
+		fmt.Println(cloned, isPointerEqual)
+	}
+
+	// Output:
+	// true false
+	// 1 false
+	// 0.1 false
+	// map[a:1 b:2] false
+	// &{test 1 0.1 true <nil> } false
+}

convertor/convertor_internal.go

@@ -0,0 +1,216 @@
+// Copyright 2023 dudaodong@gmail.com. All rights reserved.
+// Use of this source code is governed by MIT license
+
+// Package convertor implements some functions to convert data.
+package convertor
+
+import "reflect"
+
+type cloner struct {
+	ptrs map[reflect.Type]map[uintptr]reflect.Value
+}
+
+// clone return a duplicate of passed item.
+func (c *cloner) clone(v reflect.Value) reflect.Value {
+	switch v.Kind() {
+	case reflect.Invalid:
+		return reflect.ValueOf(nil)
+
+	// bool
+	case reflect.Bool:
+		return reflect.ValueOf(v.Bool())
+
+	//int
+	case reflect.Int:
+		return reflect.ValueOf(int(v.Int()))
+	case reflect.Int8:
+		return reflect.ValueOf(int8(v.Int()))
+	case reflect.Int16:
+		return reflect.ValueOf(int16(v.Int()))
+	case reflect.Int32:
+		return reflect.ValueOf(int32(v.Int()))
+	case reflect.Int64:
+		return reflect.ValueOf(v.Int())
+
+	// uint
+	case reflect.Uint:
+		return reflect.ValueOf(uint(v.Uint()))
+	case reflect.Uint8:
+		return reflect.ValueOf(uint8(v.Uint()))
+	case reflect.Uint16:
+		return reflect.ValueOf(uint16(v.Uint()))
+	case reflect.Uint32:
+		return reflect.ValueOf(uint32(v.Uint()))
+	case reflect.Uint64:
+		return reflect.ValueOf(v.Uint())
+
+	// float
+	case reflect.Float32:
+		return reflect.ValueOf(float32(v.Float()))
+	case reflect.Float64:
+		return reflect.ValueOf(v.Float())
+
+	// complex
+	case reflect.Complex64:
+		return reflect.ValueOf(complex64(v.Complex()))
+	case reflect.Complex128:
+		return reflect.ValueOf(v.Complex())
+
+	// string
+	case reflect.String:
+		return reflect.ValueOf(v.String())
+
+	// array
+	case reflect.Array, reflect.Slice:
+		return c.cloneArray(v)
+
+	// map
+	case reflect.Map:
+		return c.cloneMap(v)
+
+	// Ptr
+	case reflect.Ptr:
+		return c.clonePtr(v)
+
+	// struct
+	case reflect.Struct:
+		return c.cloneStruct(v)
+
+	// func
+	case reflect.Func:
+		return v
+
+	// interface
+	case reflect.Interface:
+		return c.clone(v.Elem())
+
+	}
+
+	return reflect.Zero(v.Type())
+}
+
+func (c *cloner) cloneArray(v reflect.Value) reflect.Value {
+	if v.IsNil() {
+		return reflect.Zero(v.Type())
+	}
+
+	arr := reflect.MakeSlice(v.Type(), v.Len(), v.Len())
+
+	for i := 0; i < v.Len(); i++ {
+		val := c.clone(v.Index(i))
+
+		if val.IsValid() {
+			continue
+		}
+
+		item := arr.Index(i)
+		if !item.CanSet() {
+			continue
+		}
+
+		item.Set(val.Convert(item.Type()))
+	}
+
+	return arr
+}
+
+func (c *cloner) cloneMap(v reflect.Value) reflect.Value {
+	if v.IsNil() {
+		return reflect.Zero(v.Type())
+	}
+
+	clonedMap := reflect.MakeMap(v.Type())
+
+	for _, key := range v.MapKeys() {
+		value := v.MapIndex(key)
+		clonedKey := c.clone(key)
+		clonedValue := c.clone(value)
+
+		if !isNillable(clonedKey) || !clonedKey.IsNil() {
+			clonedKey = clonedKey.Convert(key.Type())
+		}
+
+		if (!isNillable(clonedValue) || !clonedValue.IsNil()) && clonedValue.IsValid() {
+			clonedValue = clonedValue.Convert(value.Type())
+		}
+
+		if !clonedValue.IsValid() {
+			clonedValue = reflect.Zero(clonedMap.Type().Elem())
+		}
+
+		clonedMap.SetMapIndex(clonedKey, clonedValue)
+	}
+
+	return clonedMap
+}
+
+func isNillable(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Chan, reflect.Interface, reflect.Ptr, reflect.Func:
+		return true
+	}
+	return false
+}
+
+func (c *cloner) clonePtr(v reflect.Value) reflect.Value {
+	if v.IsNil() {
+		return reflect.Zero(v.Type())
+	}
+
+	var newVal reflect.Value
+
+	if v.Elem().CanAddr() {
+		ptrs, exists := c.ptrs[v.Type()]
+		if exists {
+			if newVal, exists := ptrs[v.Elem().UnsafeAddr()]; exists {
+				return newVal
+			}
+		}
+	}
+
+	newVal = c.clone(v.Elem())
+
+	if v.Elem().CanAddr() {
+		ptrs, exists := c.ptrs[v.Type()]
+		if exists {
+			if newVal, exists := ptrs[v.Elem().UnsafeAddr()]; exists {
+				return newVal
+			}
+		}
+	}
+
+	clonedPtr := reflect.New(newVal.Type())
+	clonedPtr.Elem().Set(newVal)
+
+	return clonedPtr
+}
+
+func (c *cloner) cloneStruct(v reflect.Value) reflect.Value {
+	clonedStructPtr := reflect.New(v.Type())
+	clonedStruct := clonedStructPtr.Elem()
+
+	if v.CanAddr() {
+		ptrs := c.ptrs[clonedStructPtr.Type()]
+		if ptrs == nil {
+			ptrs = make(map[uintptr]reflect.Value)
+			c.ptrs[clonedStructPtr.Type()] = ptrs
+		}
+		ptrs[v.UnsafeAddr()] = clonedStructPtr
+	}
+
+	for i := 0; i < v.NumField(); i++ {
+		newStructValue := clonedStruct.Field(i)
+		if !newStructValue.CanSet() {
+			continue
+		}
+
+		clonedVal := c.clone(v.Field(i))
+		if !clonedVal.IsValid() {
+			continue
+		}
+
+		newStructValue.Set(clonedVal.Convert(newStructValue.Type()))
+	}
+
+	return clonedStruct
+}

convertor/convertor_test.go

@@ -2,6 +2,7 @@ package convertor
 
 import (
 	"fmt"
+	"reflect"
 	"strconv"
 	"testing"
 
@@ -253,3 +254,47 @@ func TestDecodeByte(t *testing.T) {
 	assert.IsNil(err)
 	assert.Equal("abc", obj)
 }
+
+func TestDeepClone(t *testing.T) {
+	// assert := internal.NewAssert(t, "TestDeepClone")
+
+	type Struct struct {
+		Str        string
+		Int        int
+		Float      float64
+		Bool       bool
+		Nil        interface{}
+		unexported string
+	}
+
+	cases := []interface{}{
+		true,
+		1,
+		0.1,
+		map[string]int{
+			"a": 1,
+			"b": 2,
+		},
+		&Struct{
+			Str:   "test",
+			Int:   1,
+			Float: 0.1,
+			Bool:  true,
+			Nil:   nil,
+			// unexported: "can't be cloned",
+		},
+	}
+
+	for i, item := range cases {
+		cloned := DeepClone(item)
+
+		t.Log(cloned)
+		if &cloned == &item {
+			t.Fatalf("[TestDeepClone case #%d failed]: equal pointer", i)
+		}
+
+		if !reflect.DeepEqual(item, cloned) {
+			t.Fatalf("[TestDeepClone case #%d failed] unequal objects", i)
+		}
+	}
+}