diff options
Diffstat (limited to 'vendor/github.com/modern-go/reflect2/unsafe_slice.go')
-rw-r--r-- | vendor/github.com/modern-go/reflect2/unsafe_slice.go | 177 |
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 00000000..1c6d876c --- /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 +} |