Matteo Scandolo | a428586 | 2020-12-01 18:10:10 -0800 | [diff] [blame^] | 1 | package reflect2 |
| 2 | |
| 3 | import ( |
| 4 | "reflect" |
| 5 | "unsafe" |
| 6 | ) |
| 7 | |
| 8 | // sliceHeader is a safe version of SliceHeader used within this package. |
| 9 | type sliceHeader struct { |
| 10 | Data unsafe.Pointer |
| 11 | Len int |
| 12 | Cap int |
| 13 | } |
| 14 | |
| 15 | type UnsafeSliceType struct { |
| 16 | unsafeType |
| 17 | elemRType unsafe.Pointer |
| 18 | pElemRType unsafe.Pointer |
| 19 | elemSize uintptr |
| 20 | } |
| 21 | |
| 22 | func newUnsafeSliceType(cfg *frozenConfig, type1 reflect.Type) SliceType { |
| 23 | elemType := type1.Elem() |
| 24 | return &UnsafeSliceType{ |
| 25 | unsafeType: *newUnsafeType(cfg, type1), |
| 26 | pElemRType: unpackEFace(reflect.PtrTo(elemType)).data, |
| 27 | elemRType: unpackEFace(elemType).data, |
| 28 | elemSize: elemType.Size(), |
| 29 | } |
| 30 | } |
| 31 | |
| 32 | func (type2 *UnsafeSliceType) Set(obj interface{}, val interface{}) { |
| 33 | objEFace := unpackEFace(obj) |
| 34 | assertType("Type.Set argument 1", type2.ptrRType, objEFace.rtype) |
| 35 | valEFace := unpackEFace(val) |
| 36 | assertType("Type.Set argument 2", type2.ptrRType, valEFace.rtype) |
| 37 | type2.UnsafeSet(objEFace.data, valEFace.data) |
| 38 | } |
| 39 | |
| 40 | func (type2 *UnsafeSliceType) UnsafeSet(ptr unsafe.Pointer, val unsafe.Pointer) { |
| 41 | *(*sliceHeader)(ptr) = *(*sliceHeader)(val) |
| 42 | } |
| 43 | |
| 44 | func (type2 *UnsafeSliceType) IsNil(obj interface{}) bool { |
| 45 | if obj == nil { |
| 46 | return true |
| 47 | } |
| 48 | objEFace := unpackEFace(obj) |
| 49 | assertType("Type.IsNil argument 1", type2.ptrRType, objEFace.rtype) |
| 50 | return type2.UnsafeIsNil(objEFace.data) |
| 51 | } |
| 52 | |
| 53 | func (type2 *UnsafeSliceType) UnsafeIsNil(ptr unsafe.Pointer) bool { |
| 54 | if ptr == nil { |
| 55 | return true |
| 56 | } |
| 57 | return (*sliceHeader)(ptr).Data == nil |
| 58 | } |
| 59 | |
| 60 | func (type2 *UnsafeSliceType) SetNil(obj interface{}) { |
| 61 | objEFace := unpackEFace(obj) |
| 62 | assertType("SliceType.SetNil argument 1", type2.ptrRType, objEFace.rtype) |
| 63 | type2.UnsafeSetNil(objEFace.data) |
| 64 | } |
| 65 | |
| 66 | func (type2 *UnsafeSliceType) UnsafeSetNil(ptr unsafe.Pointer) { |
| 67 | header := (*sliceHeader)(ptr) |
| 68 | header.Len = 0 |
| 69 | header.Cap = 0 |
| 70 | header.Data = nil |
| 71 | } |
| 72 | |
| 73 | func (type2 *UnsafeSliceType) MakeSlice(length int, cap int) interface{} { |
| 74 | return packEFace(type2.ptrRType, type2.UnsafeMakeSlice(length, cap)) |
| 75 | } |
| 76 | |
| 77 | func (type2 *UnsafeSliceType) UnsafeMakeSlice(length int, cap int) unsafe.Pointer { |
| 78 | header := &sliceHeader{unsafe_NewArray(type2.elemRType, cap), length, cap} |
| 79 | return unsafe.Pointer(header) |
| 80 | } |
| 81 | |
| 82 | func (type2 *UnsafeSliceType) LengthOf(obj interface{}) int { |
| 83 | objEFace := unpackEFace(obj) |
| 84 | assertType("SliceType.Len argument 1", type2.ptrRType, objEFace.rtype) |
| 85 | return type2.UnsafeLengthOf(objEFace.data) |
| 86 | } |
| 87 | |
| 88 | func (type2 *UnsafeSliceType) UnsafeLengthOf(obj unsafe.Pointer) int { |
| 89 | header := (*sliceHeader)(obj) |
| 90 | return header.Len |
| 91 | } |
| 92 | |
| 93 | func (type2 *UnsafeSliceType) SetIndex(obj interface{}, index int, elem interface{}) { |
| 94 | objEFace := unpackEFace(obj) |
| 95 | assertType("SliceType.SetIndex argument 1", type2.ptrRType, objEFace.rtype) |
| 96 | elemEFace := unpackEFace(elem) |
| 97 | assertType("SliceType.SetIndex argument 3", type2.pElemRType, elemEFace.rtype) |
| 98 | type2.UnsafeSetIndex(objEFace.data, index, elemEFace.data) |
| 99 | } |
| 100 | |
| 101 | func (type2 *UnsafeSliceType) UnsafeSetIndex(obj unsafe.Pointer, index int, elem unsafe.Pointer) { |
| 102 | header := (*sliceHeader)(obj) |
| 103 | elemPtr := arrayAt(header.Data, index, type2.elemSize, "i < s.Len") |
| 104 | typedmemmove(type2.elemRType, elemPtr, elem) |
| 105 | } |
| 106 | |
| 107 | func (type2 *UnsafeSliceType) GetIndex(obj interface{}, index int) interface{} { |
| 108 | objEFace := unpackEFace(obj) |
| 109 | assertType("SliceType.GetIndex argument 1", type2.ptrRType, objEFace.rtype) |
| 110 | elemPtr := type2.UnsafeGetIndex(objEFace.data, index) |
| 111 | return packEFace(type2.pElemRType, elemPtr) |
| 112 | } |
| 113 | |
| 114 | func (type2 *UnsafeSliceType) UnsafeGetIndex(obj unsafe.Pointer, index int) unsafe.Pointer { |
| 115 | header := (*sliceHeader)(obj) |
| 116 | return arrayAt(header.Data, index, type2.elemSize, "i < s.Len") |
| 117 | } |
| 118 | |
| 119 | func (type2 *UnsafeSliceType) Append(obj interface{}, elem interface{}) { |
| 120 | objEFace := unpackEFace(obj) |
| 121 | assertType("SliceType.Append argument 1", type2.ptrRType, objEFace.rtype) |
| 122 | elemEFace := unpackEFace(elem) |
| 123 | assertType("SliceType.Append argument 2", type2.pElemRType, elemEFace.rtype) |
| 124 | type2.UnsafeAppend(objEFace.data, elemEFace.data) |
| 125 | } |
| 126 | |
| 127 | func (type2 *UnsafeSliceType) UnsafeAppend(obj unsafe.Pointer, elem unsafe.Pointer) { |
| 128 | header := (*sliceHeader)(obj) |
| 129 | oldLen := header.Len |
| 130 | type2.UnsafeGrow(obj, oldLen+1) |
| 131 | type2.UnsafeSetIndex(obj, oldLen, elem) |
| 132 | } |
| 133 | |
| 134 | func (type2 *UnsafeSliceType) Cap(obj interface{}) int { |
| 135 | objEFace := unpackEFace(obj) |
| 136 | assertType("SliceType.Cap argument 1", type2.ptrRType, objEFace.rtype) |
| 137 | return type2.UnsafeCap(objEFace.data) |
| 138 | } |
| 139 | |
| 140 | func (type2 *UnsafeSliceType) UnsafeCap(ptr unsafe.Pointer) int { |
| 141 | return (*sliceHeader)(ptr).Cap |
| 142 | } |
| 143 | |
| 144 | func (type2 *UnsafeSliceType) Grow(obj interface{}, newLength int) { |
| 145 | objEFace := unpackEFace(obj) |
| 146 | assertType("SliceType.Grow argument 1", type2.ptrRType, objEFace.rtype) |
| 147 | type2.UnsafeGrow(objEFace.data, newLength) |
| 148 | } |
| 149 | |
| 150 | func (type2 *UnsafeSliceType) UnsafeGrow(obj unsafe.Pointer, newLength int) { |
| 151 | header := (*sliceHeader)(obj) |
| 152 | if newLength <= header.Cap { |
| 153 | header.Len = newLength |
| 154 | return |
| 155 | } |
| 156 | newCap := calcNewCap(header.Cap, newLength) |
| 157 | newHeader := (*sliceHeader)(type2.UnsafeMakeSlice(header.Len, newCap)) |
| 158 | typedslicecopy(type2.elemRType, *newHeader, *header) |
| 159 | header.Data = newHeader.Data |
| 160 | header.Cap = newHeader.Cap |
| 161 | header.Len = newLength |
| 162 | } |
| 163 | |
| 164 | func calcNewCap(cap int, expectedCap int) int { |
| 165 | if cap == 0 { |
| 166 | cap = expectedCap |
| 167 | } else { |
| 168 | for cap < expectedCap { |
| 169 | if cap < 1024 { |
| 170 | cap += cap |
| 171 | } else { |
| 172 | cap += cap / 4 |
| 173 | } |
| 174 | } |
| 175 | } |
| 176 | return cap |
| 177 | } |