pcopy.Copy主要用于两个类型间的深度拷贝, 前身是deepcopy
新加预热函数。Copy时打开加速开关，达到性能提升4-10倍的效果。
警告:
高性能的同时可能会有些bug, 如果发现bug可以去掉pcopy.WithUsePreheat()试下， 结果不一致，可以提issue。
- 高性能, 相对第一个版本提升4-10倍的性能
- 支持异构结构体拷贝, dst和src可以是不同的类型，会拷贝dst和src交集的部分
- 多类型支持struct/map/slice/array/int...int64/uint...uint64/ 等等
go get github.com/antlabs/pcopy package main import ( "fmt" "github.com/antlabs/pcopy" ) type dst struct { ID int Result string } type src struct{ ID int Text string } func main() { d, s := dst{}, src{ID:3} pcopy.Preheat(&dst{}, &src{}) // 一对类型只要预热一次 pcopy.Copy(&d, &s, pcopy.WithUsePreheat()) fmt.Printf("%#v\n", d) }package main import ( "fmt" "github.com/antlabs/pcopy" ) func main() { i := []int{1, 2, 3, 4, 5, 6} var o []int pcopy.Preheat(&o, &i) pcopy.Copy(&o, &i, pcopy.WithUsePreheat()) fmt.Printf("%#v\n", o) }package main import ( "fmt" "github.com/antlabs/pcopy" ) func main() { i := map[string]int{ "cat": 100, "head": 10, "tr": 3, "tail": 44, } var o map[string]int pcopy.Preheat(&o, &i) pcopy.Copy(&o, &i, pcopy.WithUsePreheat()) fmt.Printf("%#v\n", o) }经常看到，对同一个结构体的，有值更新操作，都是一堆手工if 然后赋值的代码。不仅容易出错，还累。快使用pcopy解放双手。
type option struct { Int int Float64 float64 S string } func main() { var a, b option if b.Int != 0 { a.Int = b.Int } if b.Float64 != 0.0 { a.Float64 = b.Float64 } if b.S != "" { a.S = b.S } pcopy.Preheat(&a, &b) //只要预热一次 //可以约化成 pcopy.Copy(&a, &b, pcopy.WithUsePreheat()) }从零实现的pcopy相比json序列化与反序列化方式拥有更好的性能
goos: darwin goarch: arm64 pkg: benchmark Benchmark_Use_reflectValue_MiniCopy-8 334728 3575 ns/op Benchmark_Use_reflectValue_DeepCopy-8 595302 1956 ns/op Benchmark_Use_reflectValue_Copier-8 203574 5860 ns/op Benchmark_Use_Ptr_jsoniter-8 821113 1477 ns/op Benchmark_Use_Ptr_pcopy-8 3390382 354.0 ns/op Benchmark_Use_Ptr_coven-8 1414197 848.7 ns/op PASS ok benchmark 9.771s 从下面的压测数据可以看到，基本提供了4-10倍的性能提升
goos: darwin goarch: arm64 pkg: github.com/antlabs/pcopy Benchmark_BaseMap_Unsafe_Pcopy-8 529747 2343 ns/op Benchmark_BaseMap_miniCopy-8 62181 19212 ns/op Benchmark_BaseMap_Reflect-8 93810 12756 ns/op Benchmark_BaseSlice_Unsafe_Pcopy-8 2013764 595.1 ns/op Benchmark_BaseSlice_miniCopy-8 154918 7728 ns/op Benchmark_BaseSlice_Reflect-8 188720 6393 ns/op Benchmark_BaseType_Unsafe_Pcopy-8 4872112 243.8 ns/op Benchmark_BaseType_MiniCopy-8 517814 2278 ns/op Benchmark_BaseType_Pcopy-8 635156 1886 ns/op Benchmark_CompositeMap_Unsafe_Pcopy-8 486253 2409 ns/op Benchmark_CompositeMap_miniCopy-8 229674 5173 ns/op Benchmark_CompositeMap_Reflect-8 475243 2490 ns/op Benchmark_GetLikeFavorited_Unsafe_Pcopy2-8 446907 2662 ns/op Benchmark_GetLikeFavorited_Unsafe_Pcopy-8 470217 2572 ns/op Benchmark_GetLikeFavorited_MiniCopy-8 85674 13989 ns/op Benchmark_GetLikeFavorited_Reflect_Pcopy-8 121603 9856 ns/op Benchmark_GetRedPoint_Unsafe_Pcopy-8 1626688 736.1 ns/op Benchmark_GetRedPoint_MiniCopy-8 650004 1871 ns/op Benchmark_GetRedPoint_Reflect_Pcopy-8 1669778 722.0 ns/op Benchmark_Interface_Unsafe_Pcopy-8 2869022 421.3 ns/op Benchmark_Interface_MiniCopy-8 413936 2704 ns/op Benchmark_Interface_Pcopy-8 440250 2688 ns/op Benchmark_Interface_BaseSlice_Unsafe_Pcopy-8 1266501 947.4 ns/op Benchmark_Interface_BaseSlice_MiniCopy-8 141610 8422 ns/op Benchmark_Interface_BaseSlice_Pcopy-8 203906 5917 ns/op Benchmark_Ptr_BaseType1_Unsafe_Pcopy-8 910153 1310 ns/op Benchmark_Ptr_BaseType1_Reflect_Pcopy-8 391117 3026 ns/op Benchmark_Ptr_BaseSlice_Unsafe_Pcopy-8 698156 1704 ns/op Benchmark_Ptr_BaseSlice_Reflect_Pcopy-8 219999 5415 ns/op Benchmark_SliceWithStruct_Unsafe_Pcopy-8 1395982 860.3 ns/op Benchmark_SliceWithStruct_miniCopy-8 163154 7298 ns/op Benchmark_SliceWithStruct_Reflect_Pcopy-8 190728 6213 ns/op