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|
package reflect2
import (
"reflect"
"runtime"
"sync"
"unsafe"
)
type Type interface {
Kind() reflect.Kind
// New return pointer to data of this type
New() interface{}
// UnsafeNew return the allocated space pointed by unsafe.Pointer
UnsafeNew() unsafe.Pointer
// PackEFace cast a unsafe pointer to object represented pointer
PackEFace(ptr unsafe.Pointer) interface{}
// Indirect dereference object represented pointer to this type
Indirect(obj interface{}) interface{}
// UnsafeIndirect dereference pointer to this type
UnsafeIndirect(ptr unsafe.Pointer) interface{}
// Type1 returns reflect.Type
Type1() reflect.Type
Implements(thatType Type) bool
String() string
RType() uintptr
// interface{} of this type has pointer like behavior
LikePtr() bool
IsNullable() bool
IsNil(obj interface{}) bool
UnsafeIsNil(ptr unsafe.Pointer) bool
Set(obj interface{}, val interface{})
UnsafeSet(ptr unsafe.Pointer, val unsafe.Pointer)
AssignableTo(anotherType Type) bool
}
type ListType interface {
Type
Elem() Type
SetIndex(obj interface{}, index int, elem interface{})
UnsafeSetIndex(obj unsafe.Pointer, index int, elem unsafe.Pointer)
GetIndex(obj interface{}, index int) interface{}
UnsafeGetIndex(obj unsafe.Pointer, index int) unsafe.Pointer
}
type ArrayType interface {
ListType
Len() int
}
type SliceType interface {
ListType
MakeSlice(length int, cap int) interface{}
UnsafeMakeSlice(length int, cap int) unsafe.Pointer
Grow(obj interface{}, newLength int)
UnsafeGrow(ptr unsafe.Pointer, newLength int)
Append(obj interface{}, elem interface{})
UnsafeAppend(obj unsafe.Pointer, elem unsafe.Pointer)
LengthOf(obj interface{}) int
UnsafeLengthOf(ptr unsafe.Pointer) int
SetNil(obj interface{})
UnsafeSetNil(ptr unsafe.Pointer)
Cap(obj interface{}) int
UnsafeCap(ptr unsafe.Pointer) int
}
type StructType interface {
Type
NumField() int
Field(i int) StructField
FieldByName(name string) StructField
FieldByIndex(index []int) StructField
FieldByNameFunc(match func(string) bool) StructField
}
type StructField interface {
Offset() uintptr
Name() string
PkgPath() string
Type() Type
Tag() reflect.StructTag
Index() []int
Anonymous() bool
Set(obj interface{}, value interface{})
UnsafeSet(obj unsafe.Pointer, value unsafe.Pointer)
Get(obj interface{}) interface{}
UnsafeGet(obj unsafe.Pointer) unsafe.Pointer
}
type MapType interface {
Type
Key() Type
Elem() Type
MakeMap(cap int) interface{}
UnsafeMakeMap(cap int) unsafe.Pointer
SetIndex(obj interface{}, key interface{}, elem interface{})
UnsafeSetIndex(obj unsafe.Pointer, key unsafe.Pointer, elem unsafe.Pointer)
TryGetIndex(obj interface{}, key interface{}) (interface{}, bool)
GetIndex(obj interface{}, key interface{}) interface{}
UnsafeGetIndex(obj unsafe.Pointer, key unsafe.Pointer) unsafe.Pointer
Iterate(obj interface{}) MapIterator
UnsafeIterate(obj unsafe.Pointer) MapIterator
}
type MapIterator interface {
HasNext() bool
Next() (key interface{}, elem interface{})
UnsafeNext() (key unsafe.Pointer, elem unsafe.Pointer)
}
type PtrType interface {
Type
Elem() Type
}
type InterfaceType interface {
NumMethod() int
}
type Config struct {
UseSafeImplementation bool
}
type API interface {
TypeOf(obj interface{}) Type
Type2(type1 reflect.Type) Type
}
var ConfigUnsafe = Config{UseSafeImplementation: false}.Froze()
var ConfigSafe = Config{UseSafeImplementation: true}.Froze()
type frozenConfig struct {
useSafeImplementation bool
cache *sync.Map
}
func (cfg Config) Froze() *frozenConfig {
return &frozenConfig{
useSafeImplementation: cfg.UseSafeImplementation,
cache: new(sync.Map),
}
}
func (cfg *frozenConfig) TypeOf(obj interface{}) Type {
cacheKey := uintptr(unpackEFace(obj).rtype)
typeObj, found := cfg.cache.Load(cacheKey)
if found {
return typeObj.(Type)
}
return cfg.Type2(reflect.TypeOf(obj))
}
func (cfg *frozenConfig) Type2(type1 reflect.Type) Type {
if type1 == nil {
return nil
}
cacheKey := uintptr(unpackEFace(type1).data)
typeObj, found := cfg.cache.Load(cacheKey)
if found {
return typeObj.(Type)
}
type2 := cfg.wrapType(type1)
cfg.cache.Store(cacheKey, type2)
return type2
}
func (cfg *frozenConfig) wrapType(type1 reflect.Type) Type {
safeType := safeType{Type: type1, cfg: cfg}
switch type1.Kind() {
case reflect.Struct:
if cfg.useSafeImplementation {
return &safeStructType{safeType}
}
return newUnsafeStructType(cfg, type1)
case reflect.Array:
if cfg.useSafeImplementation {
return &safeSliceType{safeType}
}
return newUnsafeArrayType(cfg, type1)
case reflect.Slice:
if cfg.useSafeImplementation {
return &safeSliceType{safeType}
}
return newUnsafeSliceType(cfg, type1)
case reflect.Map:
if cfg.useSafeImplementation {
return &safeMapType{safeType}
}
return newUnsafeMapType(cfg, type1)
case reflect.Ptr, reflect.Chan, reflect.Func:
if cfg.useSafeImplementation {
return &safeMapType{safeType}
}
return newUnsafePtrType(cfg, type1)
case reflect.Interface:
if cfg.useSafeImplementation {
return &safeMapType{safeType}
}
if type1.NumMethod() == 0 {
return newUnsafeEFaceType(cfg, type1)
}
return newUnsafeIFaceType(cfg, type1)
default:
if cfg.useSafeImplementation {
return &safeType
}
return newUnsafeType(cfg, type1)
}
}
func TypeOf(obj interface{}) Type {
return ConfigUnsafe.TypeOf(obj)
}
func TypeOfPtr(obj interface{}) PtrType {
return TypeOf(obj).(PtrType)
}
func Type2(type1 reflect.Type) Type {
if type1 == nil {
return nil
}
return ConfigUnsafe.Type2(type1)
}
func PtrTo(typ Type) Type {
return Type2(reflect.PtrTo(typ.Type1()))
}
func PtrOf(obj interface{}) unsafe.Pointer {
return unpackEFace(obj).data
}
func RTypeOf(obj interface{}) uintptr {
return uintptr(unpackEFace(obj).rtype)
}
func IsNil(obj interface{}) bool {
if obj == nil {
return true
}
return unpackEFace(obj).data == nil
}
func IsNullable(kind reflect.Kind) bool {
switch kind {
case reflect.Ptr, reflect.Map, reflect.Chan, reflect.Func, reflect.Slice, reflect.Interface:
return true
}
return false
}
func likePtrKind(kind reflect.Kind) bool {
switch kind {
case reflect.Ptr, reflect.Map, reflect.Chan, reflect.Func:
return true
}
return false
}
func likePtrType(typ reflect.Type) bool {
if likePtrKind(typ.Kind()) {
return true
}
if typ.Kind() == reflect.Struct {
if typ.NumField() != 1 {
return false
}
return likePtrType(typ.Field(0).Type)
}
if typ.Kind() == reflect.Array {
if typ.Len() != 1 {
return false
}
return likePtrType(typ.Elem())
}
return false
}
// NoEscape hides a pointer from escape analysis. noescape is
// the identity function but escape analysis doesn't think the
// output depends on the input. noescape is inlined and currently
// compiles down to zero instructions.
// USE CAREFULLY!
//go:nosplit
func NoEscape(p unsafe.Pointer) unsafe.Pointer {
x := uintptr(p)
return unsafe.Pointer(x ^ 0)
}
func UnsafeCastString(str string) []byte {
bytes := make([]byte, 0)
stringHeader := (*reflect.StringHeader)(unsafe.Pointer(&str))
sliceHeader := (*reflect.SliceHeader)(unsafe.Pointer(&bytes))
sliceHeader.Data = stringHeader.Data
sliceHeader.Cap = stringHeader.Len
sliceHeader.Len = stringHeader.Len
runtime.KeepAlive(str)
return bytes
}
|
