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path: root/vendor/github.com/modern-go/reflect2/reflect2.go
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-rw-r--r--vendor/github.com/modern-go/reflect2/reflect2.go298
1 files changed, 298 insertions, 0 deletions
diff --git a/vendor/github.com/modern-go/reflect2/reflect2.go b/vendor/github.com/modern-go/reflect2/reflect2.go
new file mode 100644
index 000000000..63b49c799
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/reflect2.go
@@ -0,0 +1,298 @@
+package reflect2
+
+import (
+ "github.com/modern-go/concurrent"
+ "reflect"
+ "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 *concurrent.Map
+}
+
+func (cfg Config) Froze() *frozenConfig {
+ return &frozenConfig{
+ useSafeImplementation: cfg.UseSafeImplementation,
+ cache: concurrent.NewMap(),
+ }
+}
+
+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 {
+ stringHeader := (*reflect.StringHeader)(unsafe.Pointer(&str))
+ sliceHeader := &reflect.SliceHeader{
+ Data: stringHeader.Data,
+ Cap: stringHeader.Len,
+ Len: stringHeader.Len,
+ }
+ return *(*[]byte)(unsafe.Pointer(sliceHeader))
+}