Scott Baker | 1fe7273 | 2019-10-21 10:58:51 -0700 | [diff] [blame] | 1 | // Go support for Protocol Buffers - Google's data interchange format |
| 2 | // |
| 3 | // Copyright 2012 The Go Authors. All rights reserved. |
| 4 | // https://github.com/golang/protobuf |
| 5 | // |
| 6 | // Redistribution and use in source and binary forms, with or without |
| 7 | // modification, are permitted provided that the following conditions are |
| 8 | // met: |
| 9 | // |
| 10 | // * Redistributions of source code must retain the above copyright |
| 11 | // notice, this list of conditions and the following disclaimer. |
| 12 | // * Redistributions in binary form must reproduce the above |
| 13 | // copyright notice, this list of conditions and the following disclaimer |
| 14 | // in the documentation and/or other materials provided with the |
| 15 | // distribution. |
| 16 | // * Neither the name of Google Inc. nor the names of its |
| 17 | // contributors may be used to endorse or promote products derived from |
| 18 | // this software without specific prior written permission. |
| 19 | // |
| 20 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 21 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 22 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 23 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 24 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 25 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 26 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 27 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 28 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 29 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 30 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 31 | |
| 32 | // +build purego appengine js |
| 33 | |
| 34 | // This file contains an implementation of proto field accesses using package reflect. |
| 35 | // It is slower than the code in pointer_unsafe.go but it avoids package unsafe and can |
| 36 | // be used on App Engine. |
| 37 | |
| 38 | package proto |
| 39 | |
| 40 | import ( |
| 41 | "reflect" |
| 42 | "sync" |
| 43 | ) |
| 44 | |
| 45 | const unsafeAllowed = false |
| 46 | |
| 47 | // A field identifies a field in a struct, accessible from a pointer. |
| 48 | // In this implementation, a field is identified by the sequence of field indices |
| 49 | // passed to reflect's FieldByIndex. |
| 50 | type field []int |
| 51 | |
| 52 | // toField returns a field equivalent to the given reflect field. |
| 53 | func toField(f *reflect.StructField) field { |
| 54 | return f.Index |
| 55 | } |
| 56 | |
| 57 | // invalidField is an invalid field identifier. |
| 58 | var invalidField = field(nil) |
| 59 | |
| 60 | // zeroField is a noop when calling pointer.offset. |
| 61 | var zeroField = field([]int{}) |
| 62 | |
| 63 | // IsValid reports whether the field identifier is valid. |
| 64 | func (f field) IsValid() bool { return f != nil } |
| 65 | |
| 66 | // The pointer type is for the table-driven decoder. |
| 67 | // The implementation here uses a reflect.Value of pointer type to |
| 68 | // create a generic pointer. In pointer_unsafe.go we use unsafe |
| 69 | // instead of reflect to implement the same (but faster) interface. |
| 70 | type pointer struct { |
| 71 | v reflect.Value |
| 72 | } |
| 73 | |
| 74 | // toPointer converts an interface of pointer type to a pointer |
| 75 | // that points to the same target. |
| 76 | func toPointer(i *Message) pointer { |
| 77 | return pointer{v: reflect.ValueOf(*i)} |
| 78 | } |
| 79 | |
| 80 | // toAddrPointer converts an interface to a pointer that points to |
| 81 | // the interface data. |
| 82 | func toAddrPointer(i *interface{}, isptr, deref bool) pointer { |
| 83 | v := reflect.ValueOf(*i) |
| 84 | u := reflect.New(v.Type()) |
| 85 | u.Elem().Set(v) |
| 86 | if deref { |
| 87 | u = u.Elem() |
| 88 | } |
| 89 | return pointer{v: u} |
| 90 | } |
| 91 | |
| 92 | // valToPointer converts v to a pointer. v must be of pointer type. |
| 93 | func valToPointer(v reflect.Value) pointer { |
| 94 | return pointer{v: v} |
| 95 | } |
| 96 | |
| 97 | // offset converts from a pointer to a structure to a pointer to |
| 98 | // one of its fields. |
| 99 | func (p pointer) offset(f field) pointer { |
| 100 | return pointer{v: p.v.Elem().FieldByIndex(f).Addr()} |
| 101 | } |
| 102 | |
| 103 | func (p pointer) isNil() bool { |
| 104 | return p.v.IsNil() |
| 105 | } |
| 106 | |
| 107 | // grow updates the slice s in place to make it one element longer. |
| 108 | // s must be addressable. |
| 109 | // Returns the (addressable) new element. |
| 110 | func grow(s reflect.Value) reflect.Value { |
| 111 | n, m := s.Len(), s.Cap() |
| 112 | if n < m { |
| 113 | s.SetLen(n + 1) |
| 114 | } else { |
| 115 | s.Set(reflect.Append(s, reflect.Zero(s.Type().Elem()))) |
| 116 | } |
| 117 | return s.Index(n) |
| 118 | } |
| 119 | |
| 120 | func (p pointer) toInt64() *int64 { |
| 121 | return p.v.Interface().(*int64) |
| 122 | } |
| 123 | func (p pointer) toInt64Ptr() **int64 { |
| 124 | return p.v.Interface().(**int64) |
| 125 | } |
| 126 | func (p pointer) toInt64Slice() *[]int64 { |
| 127 | return p.v.Interface().(*[]int64) |
| 128 | } |
| 129 | |
| 130 | var int32ptr = reflect.TypeOf((*int32)(nil)) |
| 131 | |
| 132 | func (p pointer) toInt32() *int32 { |
| 133 | return p.v.Convert(int32ptr).Interface().(*int32) |
| 134 | } |
| 135 | |
| 136 | // The toInt32Ptr/Slice methods don't work because of enums. |
| 137 | // Instead, we must use set/get methods for the int32ptr/slice case. |
| 138 | /* |
| 139 | func (p pointer) toInt32Ptr() **int32 { |
| 140 | return p.v.Interface().(**int32) |
| 141 | } |
| 142 | func (p pointer) toInt32Slice() *[]int32 { |
| 143 | return p.v.Interface().(*[]int32) |
| 144 | } |
| 145 | */ |
| 146 | func (p pointer) getInt32Ptr() *int32 { |
| 147 | if p.v.Type().Elem().Elem() == reflect.TypeOf(int32(0)) { |
| 148 | // raw int32 type |
| 149 | return p.v.Elem().Interface().(*int32) |
| 150 | } |
| 151 | // an enum |
| 152 | return p.v.Elem().Convert(int32PtrType).Interface().(*int32) |
| 153 | } |
| 154 | func (p pointer) setInt32Ptr(v int32) { |
| 155 | // Allocate value in a *int32. Possibly convert that to a *enum. |
| 156 | // Then assign it to a **int32 or **enum. |
| 157 | // Note: we can convert *int32 to *enum, but we can't convert |
| 158 | // **int32 to **enum! |
| 159 | p.v.Elem().Set(reflect.ValueOf(&v).Convert(p.v.Type().Elem())) |
| 160 | } |
| 161 | |
| 162 | // getInt32Slice copies []int32 from p as a new slice. |
| 163 | // This behavior differs from the implementation in pointer_unsafe.go. |
| 164 | func (p pointer) getInt32Slice() []int32 { |
| 165 | if p.v.Type().Elem().Elem() == reflect.TypeOf(int32(0)) { |
| 166 | // raw int32 type |
| 167 | return p.v.Elem().Interface().([]int32) |
| 168 | } |
| 169 | // an enum |
| 170 | // Allocate a []int32, then assign []enum's values into it. |
| 171 | // Note: we can't convert []enum to []int32. |
| 172 | slice := p.v.Elem() |
| 173 | s := make([]int32, slice.Len()) |
| 174 | for i := 0; i < slice.Len(); i++ { |
| 175 | s[i] = int32(slice.Index(i).Int()) |
| 176 | } |
| 177 | return s |
| 178 | } |
| 179 | |
| 180 | // setInt32Slice copies []int32 into p as a new slice. |
| 181 | // This behavior differs from the implementation in pointer_unsafe.go. |
| 182 | func (p pointer) setInt32Slice(v []int32) { |
| 183 | if p.v.Type().Elem().Elem() == reflect.TypeOf(int32(0)) { |
| 184 | // raw int32 type |
| 185 | p.v.Elem().Set(reflect.ValueOf(v)) |
| 186 | return |
| 187 | } |
| 188 | // an enum |
| 189 | // Allocate a []enum, then assign []int32's values into it. |
| 190 | // Note: we can't convert []enum to []int32. |
| 191 | slice := reflect.MakeSlice(p.v.Type().Elem(), len(v), cap(v)) |
| 192 | for i, x := range v { |
| 193 | slice.Index(i).SetInt(int64(x)) |
| 194 | } |
| 195 | p.v.Elem().Set(slice) |
| 196 | } |
| 197 | func (p pointer) appendInt32Slice(v int32) { |
| 198 | grow(p.v.Elem()).SetInt(int64(v)) |
| 199 | } |
| 200 | |
| 201 | func (p pointer) toUint64() *uint64 { |
| 202 | return p.v.Interface().(*uint64) |
| 203 | } |
| 204 | func (p pointer) toUint64Ptr() **uint64 { |
| 205 | return p.v.Interface().(**uint64) |
| 206 | } |
| 207 | func (p pointer) toUint64Slice() *[]uint64 { |
| 208 | return p.v.Interface().(*[]uint64) |
| 209 | } |
| 210 | func (p pointer) toUint32() *uint32 { |
| 211 | return p.v.Interface().(*uint32) |
| 212 | } |
| 213 | func (p pointer) toUint32Ptr() **uint32 { |
| 214 | return p.v.Interface().(**uint32) |
| 215 | } |
| 216 | func (p pointer) toUint32Slice() *[]uint32 { |
| 217 | return p.v.Interface().(*[]uint32) |
| 218 | } |
| 219 | func (p pointer) toBool() *bool { |
| 220 | return p.v.Interface().(*bool) |
| 221 | } |
| 222 | func (p pointer) toBoolPtr() **bool { |
| 223 | return p.v.Interface().(**bool) |
| 224 | } |
| 225 | func (p pointer) toBoolSlice() *[]bool { |
| 226 | return p.v.Interface().(*[]bool) |
| 227 | } |
| 228 | func (p pointer) toFloat64() *float64 { |
| 229 | return p.v.Interface().(*float64) |
| 230 | } |
| 231 | func (p pointer) toFloat64Ptr() **float64 { |
| 232 | return p.v.Interface().(**float64) |
| 233 | } |
| 234 | func (p pointer) toFloat64Slice() *[]float64 { |
| 235 | return p.v.Interface().(*[]float64) |
| 236 | } |
| 237 | func (p pointer) toFloat32() *float32 { |
| 238 | return p.v.Interface().(*float32) |
| 239 | } |
| 240 | func (p pointer) toFloat32Ptr() **float32 { |
| 241 | return p.v.Interface().(**float32) |
| 242 | } |
| 243 | func (p pointer) toFloat32Slice() *[]float32 { |
| 244 | return p.v.Interface().(*[]float32) |
| 245 | } |
| 246 | func (p pointer) toString() *string { |
| 247 | return p.v.Interface().(*string) |
| 248 | } |
| 249 | func (p pointer) toStringPtr() **string { |
| 250 | return p.v.Interface().(**string) |
| 251 | } |
| 252 | func (p pointer) toStringSlice() *[]string { |
| 253 | return p.v.Interface().(*[]string) |
| 254 | } |
| 255 | func (p pointer) toBytes() *[]byte { |
| 256 | return p.v.Interface().(*[]byte) |
| 257 | } |
| 258 | func (p pointer) toBytesSlice() *[][]byte { |
| 259 | return p.v.Interface().(*[][]byte) |
| 260 | } |
| 261 | func (p pointer) toExtensions() *XXX_InternalExtensions { |
| 262 | return p.v.Interface().(*XXX_InternalExtensions) |
| 263 | } |
| 264 | func (p pointer) toOldExtensions() *map[int32]Extension { |
| 265 | return p.v.Interface().(*map[int32]Extension) |
| 266 | } |
| 267 | func (p pointer) getPointer() pointer { |
| 268 | return pointer{v: p.v.Elem()} |
| 269 | } |
| 270 | func (p pointer) setPointer(q pointer) { |
| 271 | p.v.Elem().Set(q.v) |
| 272 | } |
| 273 | func (p pointer) appendPointer(q pointer) { |
| 274 | grow(p.v.Elem()).Set(q.v) |
| 275 | } |
| 276 | |
| 277 | // getPointerSlice copies []*T from p as a new []pointer. |
| 278 | // This behavior differs from the implementation in pointer_unsafe.go. |
| 279 | func (p pointer) getPointerSlice() []pointer { |
| 280 | if p.v.IsNil() { |
| 281 | return nil |
| 282 | } |
| 283 | n := p.v.Elem().Len() |
| 284 | s := make([]pointer, n) |
| 285 | for i := 0; i < n; i++ { |
| 286 | s[i] = pointer{v: p.v.Elem().Index(i)} |
| 287 | } |
| 288 | return s |
| 289 | } |
| 290 | |
| 291 | // setPointerSlice copies []pointer into p as a new []*T. |
| 292 | // This behavior differs from the implementation in pointer_unsafe.go. |
| 293 | func (p pointer) setPointerSlice(v []pointer) { |
| 294 | if v == nil { |
| 295 | p.v.Elem().Set(reflect.New(p.v.Elem().Type()).Elem()) |
| 296 | return |
| 297 | } |
| 298 | s := reflect.MakeSlice(p.v.Elem().Type(), 0, len(v)) |
| 299 | for _, p := range v { |
| 300 | s = reflect.Append(s, p.v) |
| 301 | } |
| 302 | p.v.Elem().Set(s) |
| 303 | } |
| 304 | |
| 305 | // getInterfacePointer returns a pointer that points to the |
| 306 | // interface data of the interface pointed by p. |
| 307 | func (p pointer) getInterfacePointer() pointer { |
| 308 | if p.v.Elem().IsNil() { |
| 309 | return pointer{v: p.v.Elem()} |
| 310 | } |
| 311 | return pointer{v: p.v.Elem().Elem().Elem().Field(0).Addr()} // *interface -> interface -> *struct -> struct |
| 312 | } |
| 313 | |
| 314 | func (p pointer) asPointerTo(t reflect.Type) reflect.Value { |
| 315 | // TODO: check that p.v.Type().Elem() == t? |
| 316 | return p.v |
| 317 | } |
| 318 | |
| 319 | func atomicLoadUnmarshalInfo(p **unmarshalInfo) *unmarshalInfo { |
| 320 | atomicLock.Lock() |
| 321 | defer atomicLock.Unlock() |
| 322 | return *p |
| 323 | } |
| 324 | func atomicStoreUnmarshalInfo(p **unmarshalInfo, v *unmarshalInfo) { |
| 325 | atomicLock.Lock() |
| 326 | defer atomicLock.Unlock() |
| 327 | *p = v |
| 328 | } |
| 329 | func atomicLoadMarshalInfo(p **marshalInfo) *marshalInfo { |
| 330 | atomicLock.Lock() |
| 331 | defer atomicLock.Unlock() |
| 332 | return *p |
| 333 | } |
| 334 | func atomicStoreMarshalInfo(p **marshalInfo, v *marshalInfo) { |
| 335 | atomicLock.Lock() |
| 336 | defer atomicLock.Unlock() |
| 337 | *p = v |
| 338 | } |
| 339 | func atomicLoadMergeInfo(p **mergeInfo) *mergeInfo { |
| 340 | atomicLock.Lock() |
| 341 | defer atomicLock.Unlock() |
| 342 | return *p |
| 343 | } |
| 344 | func atomicStoreMergeInfo(p **mergeInfo, v *mergeInfo) { |
| 345 | atomicLock.Lock() |
| 346 | defer atomicLock.Unlock() |
| 347 | *p = v |
| 348 | } |
| 349 | func atomicLoadDiscardInfo(p **discardInfo) *discardInfo { |
| 350 | atomicLock.Lock() |
| 351 | defer atomicLock.Unlock() |
| 352 | return *p |
| 353 | } |
| 354 | func atomicStoreDiscardInfo(p **discardInfo, v *discardInfo) { |
| 355 | atomicLock.Lock() |
| 356 | defer atomicLock.Unlock() |
| 357 | *p = v |
| 358 | } |
| 359 | |
| 360 | var atomicLock sync.Mutex |