diff options
Diffstat (limited to 'vendor/github.com/modern-go/reflect2/reflect2.go')
-rw-r--r-- | vendor/github.com/modern-go/reflect2/reflect2.go | 298 |
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)) +} |