Serge Bazanski | cc25bdf | 2018-10-25 14:02:58 +0200 | [diff] [blame] | 1 | package common |
| 2 | |
| 3 | // Copyright 2009 The Go Authors. All rights reserved. |
| 4 | // Use of this source code is governed by a BSD-style |
| 5 | // license that can be found in the LICENSE file. |
| 6 | |
| 7 | // Package binary implements simple translation between numbers and byte |
| 8 | // sequences and encoding and decoding of varints. |
| 9 | // |
| 10 | // Numbers are translated by reading and writing fixed-size values. |
| 11 | // A fixed-size value is either a fixed-size arithmetic |
| 12 | // type (int8, uint8, int16, float32, complex64, ...) |
| 13 | // or an array or struct containing only fixed-size values. |
| 14 | // |
| 15 | // The varint functions encode and decode single integer values using |
| 16 | // a variable-length encoding; smaller values require fewer bytes. |
| 17 | // For a specification, see |
| 18 | // http://code.google.com/apis/protocolbuffers/docs/encoding.html. |
| 19 | // |
| 20 | // This package favors simplicity over efficiency. Clients that require |
| 21 | // high-performance serialization, especially for large data structures, |
| 22 | // should look at more advanced solutions such as the encoding/gob |
| 23 | // package or protocol buffers. |
| 24 | import ( |
| 25 | "errors" |
| 26 | "io" |
| 27 | "math" |
| 28 | "reflect" |
| 29 | ) |
| 30 | |
| 31 | // A ByteOrder specifies how to convert byte sequences into |
| 32 | // 16-, 32-, or 64-bit unsigned integers. |
| 33 | type ByteOrder interface { |
| 34 | Uint16([]byte) uint16 |
| 35 | Uint32([]byte) uint32 |
| 36 | Uint64([]byte) uint64 |
| 37 | PutUint16([]byte, uint16) |
| 38 | PutUint32([]byte, uint32) |
| 39 | PutUint64([]byte, uint64) |
| 40 | String() string |
| 41 | } |
| 42 | |
| 43 | // LittleEndian is the little-endian implementation of ByteOrder. |
| 44 | var LittleEndian littleEndian |
| 45 | |
| 46 | // BigEndian is the big-endian implementation of ByteOrder. |
| 47 | var BigEndian bigEndian |
| 48 | |
| 49 | type littleEndian struct{} |
| 50 | |
| 51 | func (littleEndian) Uint16(b []byte) uint16 { return uint16(b[0]) | uint16(b[1])<<8 } |
| 52 | |
| 53 | func (littleEndian) PutUint16(b []byte, v uint16) { |
| 54 | b[0] = byte(v) |
| 55 | b[1] = byte(v >> 8) |
| 56 | } |
| 57 | |
| 58 | func (littleEndian) Uint32(b []byte) uint32 { |
| 59 | return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24 |
| 60 | } |
| 61 | |
| 62 | func (littleEndian) PutUint32(b []byte, v uint32) { |
| 63 | b[0] = byte(v) |
| 64 | b[1] = byte(v >> 8) |
| 65 | b[2] = byte(v >> 16) |
| 66 | b[3] = byte(v >> 24) |
| 67 | } |
| 68 | |
| 69 | func (littleEndian) Uint64(b []byte) uint64 { |
| 70 | return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | |
| 71 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 |
| 72 | } |
| 73 | |
| 74 | func (littleEndian) PutUint64(b []byte, v uint64) { |
| 75 | b[0] = byte(v) |
| 76 | b[1] = byte(v >> 8) |
| 77 | b[2] = byte(v >> 16) |
| 78 | b[3] = byte(v >> 24) |
| 79 | b[4] = byte(v >> 32) |
| 80 | b[5] = byte(v >> 40) |
| 81 | b[6] = byte(v >> 48) |
| 82 | b[7] = byte(v >> 56) |
| 83 | } |
| 84 | |
| 85 | func (littleEndian) String() string { return "LittleEndian" } |
| 86 | |
| 87 | func (littleEndian) GoString() string { return "binary.LittleEndian" } |
| 88 | |
| 89 | type bigEndian struct{} |
| 90 | |
| 91 | func (bigEndian) Uint16(b []byte) uint16 { return uint16(b[1]) | uint16(b[0])<<8 } |
| 92 | |
| 93 | func (bigEndian) PutUint16(b []byte, v uint16) { |
| 94 | b[0] = byte(v >> 8) |
| 95 | b[1] = byte(v) |
| 96 | } |
| 97 | |
| 98 | func (bigEndian) Uint32(b []byte) uint32 { |
| 99 | return uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24 |
| 100 | } |
| 101 | |
| 102 | func (bigEndian) PutUint32(b []byte, v uint32) { |
| 103 | b[0] = byte(v >> 24) |
| 104 | b[1] = byte(v >> 16) |
| 105 | b[2] = byte(v >> 8) |
| 106 | b[3] = byte(v) |
| 107 | } |
| 108 | |
| 109 | func (bigEndian) Uint64(b []byte) uint64 { |
| 110 | return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 | |
| 111 | uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56 |
| 112 | } |
| 113 | |
| 114 | func (bigEndian) PutUint64(b []byte, v uint64) { |
| 115 | b[0] = byte(v >> 56) |
| 116 | b[1] = byte(v >> 48) |
| 117 | b[2] = byte(v >> 40) |
| 118 | b[3] = byte(v >> 32) |
| 119 | b[4] = byte(v >> 24) |
| 120 | b[5] = byte(v >> 16) |
| 121 | b[6] = byte(v >> 8) |
| 122 | b[7] = byte(v) |
| 123 | } |
| 124 | |
| 125 | func (bigEndian) String() string { return "BigEndian" } |
| 126 | |
| 127 | func (bigEndian) GoString() string { return "binary.BigEndian" } |
| 128 | |
| 129 | // Read reads structured binary data from r into data. |
| 130 | // Data must be a pointer to a fixed-size value or a slice |
| 131 | // of fixed-size values. |
| 132 | // Bytes read from r are decoded using the specified byte order |
| 133 | // and written to successive fields of the data. |
| 134 | // When reading into structs, the field data for fields with |
| 135 | // blank (_) field names is skipped; i.e., blank field names |
| 136 | // may be used for padding. |
| 137 | // When reading into a struct, all non-blank fields must be exported. |
| 138 | func Read(r io.Reader, order ByteOrder, data interface{}) error { |
| 139 | // Fast path for basic types and slices. |
| 140 | if n := intDataSize(data); n != 0 { |
| 141 | var b [8]byte |
| 142 | var bs []byte |
| 143 | if n > len(b) { |
| 144 | bs = make([]byte, n) |
| 145 | } else { |
| 146 | bs = b[:n] |
| 147 | } |
| 148 | if _, err := io.ReadFull(r, bs); err != nil { |
| 149 | return err |
| 150 | } |
| 151 | switch data := data.(type) { |
| 152 | case *int8: |
| 153 | *data = int8(b[0]) |
| 154 | case *uint8: |
| 155 | *data = b[0] |
| 156 | case *int16: |
| 157 | *data = int16(order.Uint16(bs)) |
| 158 | case *uint16: |
| 159 | *data = order.Uint16(bs) |
| 160 | case *int32: |
| 161 | *data = int32(order.Uint32(bs)) |
| 162 | case *uint32: |
| 163 | *data = order.Uint32(bs) |
| 164 | case *int64: |
| 165 | *data = int64(order.Uint64(bs)) |
| 166 | case *uint64: |
| 167 | *data = order.Uint64(bs) |
| 168 | case []int8: |
| 169 | for i, x := range bs { // Easier to loop over the input for 8-bit values. |
| 170 | data[i] = int8(x) |
| 171 | } |
| 172 | case []uint8: |
| 173 | copy(data, bs) |
| 174 | case []int16: |
| 175 | for i := range data { |
| 176 | data[i] = int16(order.Uint16(bs[2*i:])) |
| 177 | } |
| 178 | case []uint16: |
| 179 | for i := range data { |
| 180 | data[i] = order.Uint16(bs[2*i:]) |
| 181 | } |
| 182 | case []int32: |
| 183 | for i := range data { |
| 184 | data[i] = int32(order.Uint32(bs[4*i:])) |
| 185 | } |
| 186 | case []uint32: |
| 187 | for i := range data { |
| 188 | data[i] = order.Uint32(bs[4*i:]) |
| 189 | } |
| 190 | case []int64: |
| 191 | for i := range data { |
| 192 | data[i] = int64(order.Uint64(bs[8*i:])) |
| 193 | } |
| 194 | case []uint64: |
| 195 | for i := range data { |
| 196 | data[i] = order.Uint64(bs[8*i:]) |
| 197 | } |
| 198 | } |
| 199 | return nil |
| 200 | } |
| 201 | |
| 202 | // Fallback to reflect-based decoding. |
| 203 | v := reflect.ValueOf(data) |
| 204 | size := -1 |
| 205 | switch v.Kind() { |
| 206 | case reflect.Ptr: |
| 207 | v = v.Elem() |
| 208 | size = dataSize(v) |
| 209 | case reflect.Slice: |
| 210 | size = dataSize(v) |
| 211 | } |
| 212 | if size < 0 { |
| 213 | return errors.New("binary.Read: invalid type " + reflect.TypeOf(data).String()) |
| 214 | } |
| 215 | d := &decoder{order: order, buf: make([]byte, size)} |
| 216 | if _, err := io.ReadFull(r, d.buf); err != nil { |
| 217 | return err |
| 218 | } |
| 219 | d.value(v) |
| 220 | return nil |
| 221 | } |
| 222 | |
| 223 | // Write writes the binary representation of data into w. |
| 224 | // Data must be a fixed-size value or a slice of fixed-size |
| 225 | // values, or a pointer to such data. |
| 226 | // Bytes written to w are encoded using the specified byte order |
| 227 | // and read from successive fields of the data. |
| 228 | // When writing structs, zero values are written for fields |
| 229 | // with blank (_) field names. |
| 230 | func Write(w io.Writer, order ByteOrder, data interface{}) error { |
| 231 | // Fast path for basic types and slices. |
| 232 | if n := intDataSize(data); n != 0 { |
| 233 | var b [8]byte |
| 234 | var bs []byte |
| 235 | if n > len(b) { |
| 236 | bs = make([]byte, n) |
| 237 | } else { |
| 238 | bs = b[:n] |
| 239 | } |
| 240 | switch v := data.(type) { |
| 241 | case *int8: |
| 242 | bs = b[:1] |
| 243 | b[0] = byte(*v) |
| 244 | case int8: |
| 245 | bs = b[:1] |
| 246 | b[0] = byte(v) |
| 247 | case []int8: |
| 248 | for i, x := range v { |
| 249 | bs[i] = byte(x) |
| 250 | } |
| 251 | case *uint8: |
| 252 | bs = b[:1] |
| 253 | b[0] = *v |
| 254 | case uint8: |
| 255 | bs = b[:1] |
| 256 | b[0] = byte(v) |
| 257 | case []uint8: |
| 258 | bs = v |
| 259 | case *int16: |
| 260 | bs = b[:2] |
| 261 | order.PutUint16(bs, uint16(*v)) |
| 262 | case int16: |
| 263 | bs = b[:2] |
| 264 | order.PutUint16(bs, uint16(v)) |
| 265 | case []int16: |
| 266 | for i, x := range v { |
| 267 | order.PutUint16(bs[2*i:], uint16(x)) |
| 268 | } |
| 269 | case *uint16: |
| 270 | bs = b[:2] |
| 271 | order.PutUint16(bs, *v) |
| 272 | case uint16: |
| 273 | bs = b[:2] |
| 274 | order.PutUint16(bs, v) |
| 275 | case []uint16: |
| 276 | for i, x := range v { |
| 277 | order.PutUint16(bs[2*i:], x) |
| 278 | } |
| 279 | case *int32: |
| 280 | bs = b[:4] |
| 281 | order.PutUint32(bs, uint32(*v)) |
| 282 | case int32: |
| 283 | bs = b[:4] |
| 284 | order.PutUint32(bs, uint32(v)) |
| 285 | case []int32: |
| 286 | for i, x := range v { |
| 287 | order.PutUint32(bs[4*i:], uint32(x)) |
| 288 | } |
| 289 | case *uint32: |
| 290 | bs = b[:4] |
| 291 | order.PutUint32(bs, *v) |
| 292 | case uint32: |
| 293 | bs = b[:4] |
| 294 | order.PutUint32(bs, v) |
| 295 | case []uint32: |
| 296 | for i, x := range v { |
| 297 | order.PutUint32(bs[4*i:], x) |
| 298 | } |
| 299 | case *int64: |
| 300 | bs = b[:8] |
| 301 | order.PutUint64(bs, uint64(*v)) |
| 302 | case int64: |
| 303 | bs = b[:8] |
| 304 | order.PutUint64(bs, uint64(v)) |
| 305 | case []int64: |
| 306 | for i, x := range v { |
| 307 | order.PutUint64(bs[8*i:], uint64(x)) |
| 308 | } |
| 309 | case *uint64: |
| 310 | bs = b[:8] |
| 311 | order.PutUint64(bs, *v) |
| 312 | case uint64: |
| 313 | bs = b[:8] |
| 314 | order.PutUint64(bs, v) |
| 315 | case []uint64: |
| 316 | for i, x := range v { |
| 317 | order.PutUint64(bs[8*i:], x) |
| 318 | } |
| 319 | } |
| 320 | _, err := w.Write(bs) |
| 321 | return err |
| 322 | } |
| 323 | |
| 324 | // Fallback to reflect-based encoding. |
| 325 | v := reflect.Indirect(reflect.ValueOf(data)) |
| 326 | size := dataSize(v) |
| 327 | if size < 0 { |
| 328 | return errors.New("binary.Write: invalid type " + reflect.TypeOf(data).String()) |
| 329 | } |
| 330 | buf := make([]byte, size) |
| 331 | e := &encoder{order: order, buf: buf} |
| 332 | e.value(v) |
| 333 | _, err := w.Write(buf) |
| 334 | return err |
| 335 | } |
| 336 | |
| 337 | // Size returns how many bytes Write would generate to encode the value v, which |
| 338 | // must be a fixed-size value or a slice of fixed-size values, or a pointer to such data. |
| 339 | // If v is neither of these, Size returns -1. |
| 340 | func Size(v interface{}) int { |
| 341 | return dataSize(reflect.Indirect(reflect.ValueOf(v))) |
| 342 | } |
| 343 | |
| 344 | // dataSize returns the number of bytes the actual data represented by v occupies in memory. |
| 345 | // For compound structures, it sums the sizes of the elements. Thus, for instance, for a slice |
| 346 | // it returns the length of the slice times the element size and does not count the memory |
| 347 | // occupied by the header. If the type of v is not acceptable, dataSize returns -1. |
| 348 | func dataSize(v reflect.Value) int { |
| 349 | if v.Kind() == reflect.Slice { |
| 350 | if s := sizeof(v.Type().Elem()); s >= 0 { |
| 351 | return s * v.Len() |
| 352 | } |
| 353 | return -1 |
| 354 | } |
| 355 | return sizeof(v.Type()) |
| 356 | } |
| 357 | |
| 358 | // sizeof returns the size >= 0 of variables for the given type or -1 if the type is not acceptable. |
| 359 | func sizeof(t reflect.Type) int { |
| 360 | switch t.Kind() { |
| 361 | case reflect.Array: |
| 362 | if s := sizeof(t.Elem()); s >= 0 { |
| 363 | return s * t.Len() |
| 364 | } |
| 365 | |
| 366 | case reflect.Struct: |
| 367 | sum := 0 |
| 368 | for i, n := 0, t.NumField(); i < n; i++ { |
| 369 | s := sizeof(t.Field(i).Type) |
| 370 | if s < 0 { |
| 371 | return -1 |
| 372 | } |
| 373 | sum += s |
| 374 | } |
| 375 | return sum |
| 376 | |
| 377 | case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, |
| 378 | reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, |
| 379 | reflect.Float32, reflect.Float64, reflect.Complex64, reflect.Complex128, reflect.Ptr: |
| 380 | return int(t.Size()) |
| 381 | } |
| 382 | |
| 383 | return -1 |
| 384 | } |
| 385 | |
| 386 | type coder struct { |
| 387 | order ByteOrder |
| 388 | buf []byte |
| 389 | } |
| 390 | |
| 391 | type decoder coder |
| 392 | type encoder coder |
| 393 | |
| 394 | func (d *decoder) uint8() uint8 { |
| 395 | x := d.buf[0] |
| 396 | d.buf = d.buf[1:] |
| 397 | return x |
| 398 | } |
| 399 | |
| 400 | func (e *encoder) uint8(x uint8) { |
| 401 | e.buf[0] = x |
| 402 | e.buf = e.buf[1:] |
| 403 | } |
| 404 | |
| 405 | func (d *decoder) uint16() uint16 { |
| 406 | x := d.order.Uint16(d.buf[0:2]) |
| 407 | d.buf = d.buf[2:] |
| 408 | return x |
| 409 | } |
| 410 | |
| 411 | func (e *encoder) uint16(x uint16) { |
| 412 | e.order.PutUint16(e.buf[0:2], x) |
| 413 | e.buf = e.buf[2:] |
| 414 | } |
| 415 | |
| 416 | func (d *decoder) uint32() uint32 { |
| 417 | x := d.order.Uint32(d.buf[0:4]) |
| 418 | d.buf = d.buf[4:] |
| 419 | return x |
| 420 | } |
| 421 | |
| 422 | func (e *encoder) uint32(x uint32) { |
| 423 | e.order.PutUint32(e.buf[0:4], x) |
| 424 | e.buf = e.buf[4:] |
| 425 | } |
| 426 | |
| 427 | func (d *decoder) uint64() uint64 { |
| 428 | x := d.order.Uint64(d.buf[0:8]) |
| 429 | d.buf = d.buf[8:] |
| 430 | return x |
| 431 | } |
| 432 | |
| 433 | func (e *encoder) uint64(x uint64) { |
| 434 | e.order.PutUint64(e.buf[0:8], x) |
| 435 | e.buf = e.buf[8:] |
| 436 | } |
| 437 | |
| 438 | func (d *decoder) int8() int8 { return int8(d.uint8()) } |
| 439 | |
| 440 | func (e *encoder) int8(x int8) { e.uint8(uint8(x)) } |
| 441 | |
| 442 | func (d *decoder) int16() int16 { return int16(d.uint16()) } |
| 443 | |
| 444 | func (e *encoder) int16(x int16) { e.uint16(uint16(x)) } |
| 445 | |
| 446 | func (d *decoder) int32() int32 { return int32(d.uint32()) } |
| 447 | |
| 448 | func (e *encoder) int32(x int32) { e.uint32(uint32(x)) } |
| 449 | |
| 450 | func (d *decoder) int64() int64 { return int64(d.uint64()) } |
| 451 | |
| 452 | func (e *encoder) int64(x int64) { e.uint64(uint64(x)) } |
| 453 | |
| 454 | func (d *decoder) value(v reflect.Value) { |
| 455 | switch v.Kind() { |
| 456 | case reflect.Array: |
| 457 | l := v.Len() |
| 458 | for i := 0; i < l; i++ { |
| 459 | d.value(v.Index(i)) |
| 460 | } |
| 461 | |
| 462 | case reflect.Struct: |
| 463 | t := v.Type() |
| 464 | l := v.NumField() |
| 465 | for i := 0; i < l; i++ { |
| 466 | // Note: Calling v.CanSet() below is an optimization. |
| 467 | // It would be sufficient to check the field name, |
| 468 | // but creating the StructField info for each field is |
| 469 | // costly (run "go test -bench=ReadStruct" and compare |
| 470 | // results when making changes to this code). |
| 471 | if v := v.Field(i); v.CanSet() || t.Field(i).Name != "_" { |
| 472 | d.value(v) |
| 473 | } else { |
| 474 | d.skip(v) |
| 475 | } |
| 476 | } |
| 477 | |
| 478 | case reflect.Slice: |
| 479 | l := v.Len() |
| 480 | for i := 0; i < l; i++ { |
| 481 | d.value(v.Index(i)) |
| 482 | } |
| 483 | |
| 484 | case reflect.Int8: |
| 485 | v.SetInt(int64(d.int8())) |
| 486 | case reflect.Int16: |
| 487 | v.SetInt(int64(d.int16())) |
| 488 | case reflect.Int32: |
| 489 | v.SetInt(int64(d.int32())) |
| 490 | case reflect.Int64: |
| 491 | v.SetInt(d.int64()) |
| 492 | |
| 493 | case reflect.Uint8: |
| 494 | v.SetUint(uint64(d.uint8())) |
| 495 | case reflect.Uint16: |
| 496 | v.SetUint(uint64(d.uint16())) |
| 497 | case reflect.Uint32: |
| 498 | v.SetUint(uint64(d.uint32())) |
| 499 | case reflect.Uint64: |
| 500 | v.SetUint(d.uint64()) |
| 501 | |
| 502 | case reflect.Float32: |
| 503 | v.SetFloat(float64(math.Float32frombits(d.uint32()))) |
| 504 | case reflect.Float64: |
| 505 | v.SetFloat(math.Float64frombits(d.uint64())) |
| 506 | |
| 507 | case reflect.Complex64: |
| 508 | v.SetComplex(complex( |
| 509 | float64(math.Float32frombits(d.uint32())), |
| 510 | float64(math.Float32frombits(d.uint32())), |
| 511 | )) |
| 512 | case reflect.Complex128: |
| 513 | v.SetComplex(complex( |
| 514 | math.Float64frombits(d.uint64()), |
| 515 | math.Float64frombits(d.uint64()), |
| 516 | )) |
| 517 | } |
| 518 | } |
| 519 | |
| 520 | func (e *encoder) value(v reflect.Value) { |
| 521 | switch v.Kind() { |
| 522 | case reflect.Array: |
| 523 | l := v.Len() |
| 524 | for i := 0; i < l; i++ { |
| 525 | e.value(v.Index(i)) |
| 526 | } |
| 527 | |
| 528 | case reflect.Struct: |
| 529 | t := v.Type() |
| 530 | l := v.NumField() |
| 531 | for i := 0; i < l; i++ { |
| 532 | // see comment for corresponding code in decoder.value() |
| 533 | if v := v.Field(i); v.CanSet() || t.Field(i).Name != "_" { |
| 534 | e.value(v) |
| 535 | } else { |
| 536 | e.skip(v) |
| 537 | } |
| 538 | } |
| 539 | |
| 540 | case reflect.Slice: |
| 541 | l := v.Len() |
| 542 | for i := 0; i < l; i++ { |
| 543 | e.value(v.Index(i)) |
| 544 | } |
| 545 | |
| 546 | case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: |
| 547 | switch v.Type().Kind() { |
| 548 | case reflect.Int8: |
| 549 | e.int8(int8(v.Int())) |
| 550 | case reflect.Int16: |
| 551 | e.int16(int16(v.Int())) |
| 552 | case reflect.Int32: |
| 553 | e.int32(int32(v.Int())) |
| 554 | case reflect.Int64: |
| 555 | e.int64(v.Int()) |
| 556 | } |
| 557 | |
| 558 | case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: |
| 559 | switch v.Type().Kind() { |
| 560 | case reflect.Uint8: |
| 561 | e.uint8(uint8(v.Uint())) |
| 562 | case reflect.Uint16: |
| 563 | e.uint16(uint16(v.Uint())) |
| 564 | case reflect.Uint32: |
| 565 | e.uint32(uint32(v.Uint())) |
| 566 | case reflect.Uint64: |
| 567 | e.uint64(v.Uint()) |
| 568 | } |
| 569 | |
| 570 | case reflect.Float32, reflect.Float64: |
| 571 | switch v.Type().Kind() { |
| 572 | case reflect.Float32: |
| 573 | e.uint32(math.Float32bits(float32(v.Float()))) |
| 574 | case reflect.Float64: |
| 575 | e.uint64(math.Float64bits(v.Float())) |
| 576 | } |
| 577 | |
| 578 | case reflect.Complex64, reflect.Complex128: |
| 579 | switch v.Type().Kind() { |
| 580 | case reflect.Complex64: |
| 581 | x := v.Complex() |
| 582 | e.uint32(math.Float32bits(float32(real(x)))) |
| 583 | e.uint32(math.Float32bits(float32(imag(x)))) |
| 584 | case reflect.Complex128: |
| 585 | x := v.Complex() |
| 586 | e.uint64(math.Float64bits(real(x))) |
| 587 | e.uint64(math.Float64bits(imag(x))) |
| 588 | } |
| 589 | } |
| 590 | } |
| 591 | |
| 592 | func (d *decoder) skip(v reflect.Value) { |
| 593 | d.buf = d.buf[dataSize(v):] |
| 594 | } |
| 595 | |
| 596 | func (e *encoder) skip(v reflect.Value) { |
| 597 | n := dataSize(v) |
| 598 | for i := range e.buf[0:n] { |
| 599 | e.buf[i] = 0 |
| 600 | } |
| 601 | e.buf = e.buf[n:] |
| 602 | } |
| 603 | |
| 604 | // intDataSize returns the size of the data required to represent the data when encoded. |
| 605 | // It returns zero if the type cannot be implemented by the fast path in Read or Write. |
| 606 | func intDataSize(data interface{}) int { |
| 607 | switch data := data.(type) { |
| 608 | case int8, *int8, *uint8: |
| 609 | return 1 |
| 610 | case []int8: |
| 611 | return len(data) |
| 612 | case []uint8: |
| 613 | return len(data) |
| 614 | case int16, *int16, *uint16: |
| 615 | return 2 |
| 616 | case []int16: |
| 617 | return 2 * len(data) |
| 618 | case []uint16: |
| 619 | return 2 * len(data) |
| 620 | case int32, *int32, *uint32: |
| 621 | return 4 |
| 622 | case []int32: |
| 623 | return 4 * len(data) |
| 624 | case []uint32: |
| 625 | return 4 * len(data) |
| 626 | case int64, *int64, *uint64: |
| 627 | return 8 |
| 628 | case []int64: |
| 629 | return 8 * len(data) |
| 630 | case []uint64: |
| 631 | return 8 * len(data) |
| 632 | } |
| 633 | return 0 |
| 634 | } |