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path: root/vendor/github.com/modern-go/reflect2/unsafe_slice.go
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-rw-r--r--vendor/github.com/modern-go/reflect2/unsafe_slice.go177
1 files changed, 177 insertions, 0 deletions
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_slice.go b/vendor/github.com/modern-go/reflect2/unsafe_slice.go
new file mode 100644
index 000000000..1c6d876c7
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_slice.go
@@ -0,0 +1,177 @@
+package reflect2
+
+import (
+ "reflect"
+ "unsafe"
+)
+
+// sliceHeader is a safe version of SliceHeader used within this package.
+type sliceHeader struct {
+ Data unsafe.Pointer
+ Len int
+ Cap int
+}
+
+type UnsafeSliceType struct {
+ unsafeType
+ elemRType unsafe.Pointer
+ pElemRType unsafe.Pointer
+ elemSize uintptr
+}
+
+func newUnsafeSliceType(cfg *frozenConfig, type1 reflect.Type) SliceType {
+ elemType := type1.Elem()
+ return &UnsafeSliceType{
+ unsafeType: *newUnsafeType(cfg, type1),
+ pElemRType: unpackEFace(reflect.PtrTo(elemType)).data,
+ elemRType: unpackEFace(elemType).data,
+ elemSize: elemType.Size(),
+ }
+}
+
+func (type2 *UnsafeSliceType) Set(obj interface{}, val interface{}) {
+ objEFace := unpackEFace(obj)
+ assertType("Type.Set argument 1", type2.ptrRType, objEFace.rtype)
+ valEFace := unpackEFace(val)
+ assertType("Type.Set argument 2", type2.ptrRType, valEFace.rtype)
+ type2.UnsafeSet(objEFace.data, valEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeSet(ptr unsafe.Pointer, val unsafe.Pointer) {
+ *(*sliceHeader)(ptr) = *(*sliceHeader)(val)
+}
+
+func (type2 *UnsafeSliceType) IsNil(obj interface{}) bool {
+ if obj == nil {
+ return true
+ }
+ objEFace := unpackEFace(obj)
+ assertType("Type.IsNil argument 1", type2.ptrRType, objEFace.rtype)
+ return type2.UnsafeIsNil(objEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeIsNil(ptr unsafe.Pointer) bool {
+ if ptr == nil {
+ return true
+ }
+ return (*sliceHeader)(ptr).Data == nil
+}
+
+func (type2 *UnsafeSliceType) SetNil(obj interface{}) {
+ objEFace := unpackEFace(obj)
+ assertType("SliceType.SetNil argument 1", type2.ptrRType, objEFace.rtype)
+ type2.UnsafeSetNil(objEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeSetNil(ptr unsafe.Pointer) {
+ header := (*sliceHeader)(ptr)
+ header.Len = 0
+ header.Cap = 0
+ header.Data = nil
+}
+
+func (type2 *UnsafeSliceType) MakeSlice(length int, cap int) interface{} {
+ return packEFace(type2.ptrRType, type2.UnsafeMakeSlice(length, cap))
+}
+
+func (type2 *UnsafeSliceType) UnsafeMakeSlice(length int, cap int) unsafe.Pointer {
+ header := &sliceHeader{unsafe_NewArray(type2.elemRType, cap), length, cap}
+ return unsafe.Pointer(header)
+}
+
+func (type2 *UnsafeSliceType) LengthOf(obj interface{}) int {
+ objEFace := unpackEFace(obj)
+ assertType("SliceType.Len argument 1", type2.ptrRType, objEFace.rtype)
+ return type2.UnsafeLengthOf(objEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeLengthOf(obj unsafe.Pointer) int {
+ header := (*sliceHeader)(obj)
+ return header.Len
+}
+
+func (type2 *UnsafeSliceType) SetIndex(obj interface{}, index int, elem interface{}) {
+ objEFace := unpackEFace(obj)
+ assertType("SliceType.SetIndex argument 1", type2.ptrRType, objEFace.rtype)
+ elemEFace := unpackEFace(elem)
+ assertType("SliceType.SetIndex argument 3", type2.pElemRType, elemEFace.rtype)
+ type2.UnsafeSetIndex(objEFace.data, index, elemEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeSetIndex(obj unsafe.Pointer, index int, elem unsafe.Pointer) {
+ header := (*sliceHeader)(obj)
+ elemPtr := arrayAt(header.Data, index, type2.elemSize, "i < s.Len")
+ typedmemmove(type2.elemRType, elemPtr, elem)
+}
+
+func (type2 *UnsafeSliceType) GetIndex(obj interface{}, index int) interface{} {
+ objEFace := unpackEFace(obj)
+ assertType("SliceType.GetIndex argument 1", type2.ptrRType, objEFace.rtype)
+ elemPtr := type2.UnsafeGetIndex(objEFace.data, index)
+ return packEFace(type2.pElemRType, elemPtr)
+}
+
+func (type2 *UnsafeSliceType) UnsafeGetIndex(obj unsafe.Pointer, index int) unsafe.Pointer {
+ header := (*sliceHeader)(obj)
+ return arrayAt(header.Data, index, type2.elemSize, "i < s.Len")
+}
+
+func (type2 *UnsafeSliceType) Append(obj interface{}, elem interface{}) {
+ objEFace := unpackEFace(obj)
+ assertType("SliceType.Append argument 1", type2.ptrRType, objEFace.rtype)
+ elemEFace := unpackEFace(elem)
+ assertType("SliceType.Append argument 2", type2.pElemRType, elemEFace.rtype)
+ type2.UnsafeAppend(objEFace.data, elemEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeAppend(obj unsafe.Pointer, elem unsafe.Pointer) {
+ header := (*sliceHeader)(obj)
+ oldLen := header.Len
+ type2.UnsafeGrow(obj, oldLen+1)
+ type2.UnsafeSetIndex(obj, oldLen, elem)
+}
+
+func (type2 *UnsafeSliceType) Cap(obj interface{}) int {
+ objEFace := unpackEFace(obj)
+ assertType("SliceType.Cap argument 1", type2.ptrRType, objEFace.rtype)
+ return type2.UnsafeCap(objEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeCap(ptr unsafe.Pointer) int {
+ return (*sliceHeader)(ptr).Cap
+}
+
+func (type2 *UnsafeSliceType) Grow(obj interface{}, newLength int) {
+ objEFace := unpackEFace(obj)
+ assertType("SliceType.Grow argument 1", type2.ptrRType, objEFace.rtype)
+ type2.UnsafeGrow(objEFace.data, newLength)
+}
+
+func (type2 *UnsafeSliceType) UnsafeGrow(obj unsafe.Pointer, newLength int) {
+ header := (*sliceHeader)(obj)
+ if newLength <= header.Cap {
+ header.Len = newLength
+ return
+ }
+ newCap := calcNewCap(header.Cap, newLength)
+ newHeader := (*sliceHeader)(type2.UnsafeMakeSlice(header.Len, newCap))
+ typedslicecopy(type2.elemRType, *newHeader, *header)
+ header.Data = newHeader.Data
+ header.Cap = newHeader.Cap
+ header.Len = newLength
+}
+
+func calcNewCap(cap int, expectedCap int) int {
+ if cap == 0 {
+ cap = expectedCap
+ } else {
+ for cap < expectedCap {
+ if cap < 1024 {
+ cap += cap
+ } else {
+ cap += cap / 4
+ }
+ }
+ }
+ return cap
+}