src/libserialize/opaque.rs

   1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use leb128::{self, read_signed_leb128, write_signed_leb128};
  12 use std::borrow::Cow;
  13 use std::io::{self, Write};
  14 use serialize;
  15
  16 // -----------------------------------------------------------------------------
  17 // Encoder
  18 // -----------------------------------------------------------------------------
  19
  20 pub type EncodeResult = io::Result<()>;
  21
  22 pub struct Encoder<'a> {
  23     pub cursor: &'a mut io::Cursor<Vec<u8>>,
  24 }
  25
  26 impl<'a> Encoder<'a> {
  27     pub fn new(cursor: &'a mut io::Cursor<Vec<u8>>) -> Encoder<'a> {
  28         Encoder { cursor: cursor }
  29     }
  30
  31     pub fn emit_raw_bytes(&mut self, s: &[u8]) -> EncodeResult {
  32         self.cursor.write_all(s)
  33     }
  34 }
  35
  36
  37 macro_rules! write_uleb128 {
  38     ($enc:expr, $value:expr, $fun:ident) => {{
  39         let pos = $enc.cursor.position() as usize;
  40         let bytes_written = leb128::$fun($enc.cursor.get_mut(), pos, $value);
  41         $enc.cursor.set_position((pos + bytes_written) as u64);
  42         Ok(())
  43     }}
  44 }
  45
  46 macro_rules! write_sleb128 {
  47     ($enc:expr, $value:expr) => {{
  48         let pos = $enc.cursor.position() as usize;
  49         let bytes_written = write_signed_leb128($enc.cursor.get_mut(), pos, $value as i128);
  50         $enc.cursor.set_position((pos + bytes_written) as u64);
  51         Ok(())
  52     }}
  53 }
  54
  55 impl<'a> serialize::Encoder for Encoder<'a> {
  56     type Error = io::Error;
  57
  58     #[inline]
  59     fn emit_nil(&mut self) -> EncodeResult {
  60         Ok(())
  61     }
  62
  63     #[inline]
  64     fn emit_usize(&mut self, v: usize) -> EncodeResult {
  65         write_uleb128!(self, v, write_usize_leb128)
  66     }
  67
  68     #[inline]
  69     fn emit_u128(&mut self, v: u128) -> EncodeResult {
  70         write_uleb128!(self, v, write_u128_leb128)
  71     }
  72
  73     #[inline]
  74     fn emit_u64(&mut self, v: u64) -> EncodeResult {
  75         write_uleb128!(self, v, write_u64_leb128)
  76     }
  77
  78     #[inline]
  79     fn emit_u32(&mut self, v: u32) -> EncodeResult {
  80         write_uleb128!(self, v, write_u32_leb128)
  81     }
  82
  83     #[inline]
  84     fn emit_u16(&mut self, v: u16) -> EncodeResult {
  85         write_uleb128!(self, v, write_u16_leb128)
  86     }
  87
  88     #[inline]
  89     fn emit_u8(&mut self, v: u8) -> EncodeResult {
  90         let pos = self.cursor.position() as usize;
  91         leb128::write_to_vec(self.cursor.get_mut(), pos, v);
  92         self.cursor.set_position((pos + 1) as u64);
  93         Ok(())
  94     }
  95
  96     #[inline]
  97     fn emit_isize(&mut self, v: isize) -> EncodeResult {
  98         write_sleb128!(self, v)
  99     }
 100
 101     #[inline]
 102     fn emit_i128(&mut self, v: i128) -> EncodeResult {
 103         write_sleb128!(self, v)
 104     }
 105
 106     #[inline]
 107     fn emit_i64(&mut self, v: i64) -> EncodeResult {
 108         write_sleb128!(self, v)
 109     }
 110
 111     #[inline]
 112     fn emit_i32(&mut self, v: i32) -> EncodeResult {
 113         write_sleb128!(self, v)
 114     }
 115
 116     #[inline]
 117     fn emit_i16(&mut self, v: i16) -> EncodeResult {
 118         write_sleb128!(self, v)
 119     }
 120
 121     #[inline]
 122     fn emit_i8(&mut self, v: i8) -> EncodeResult {
 123         let as_u8: u8 = unsafe { ::std::mem::transmute(v) };
 124         self.emit_u8(as_u8)
 125     }
 126
 127     #[inline]
 128     fn emit_bool(&mut self, v: bool) -> EncodeResult {
 129         self.emit_u8(if v {
 130             1
 131         } else {
 132             0
 133         })
 134     }
 135
 136     #[inline]
 137     fn emit_f64(&mut self, v: f64) -> EncodeResult {
 138         let as_u64: u64 = unsafe { ::std::mem::transmute(v) };
 139         self.emit_u64(as_u64)
 140     }
 141
 142     #[inline]
 143     fn emit_f32(&mut self, v: f32) -> EncodeResult {
 144         let as_u32: u32 = unsafe { ::std::mem::transmute(v) };
 145         self.emit_u32(as_u32)
 146     }
 147
 148     #[inline]
 149     fn emit_char(&mut self, v: char) -> EncodeResult {
 150         self.emit_u32(v as u32)
 151     }
 152
 153     #[inline]
 154     fn emit_str(&mut self, v: &str) -> EncodeResult {
 155         self.emit_usize(v.len())?;
 156         let _ = self.cursor.write_all(v.as_bytes());
 157         Ok(())
 158     }
 159 }
 160
 161 impl<'a> Encoder<'a> {
 162     #[inline]
 163     pub fn position(&self) -> usize {
 164         self.cursor.position() as usize
 165     }
 166 }
 167
 168 // -----------------------------------------------------------------------------
 169 // Decoder
 170 // -----------------------------------------------------------------------------
 171
 172 pub struct Decoder<'a> {
 173     pub data: &'a [u8],
 174     position: usize,
 175 }
 176
 177 impl<'a> Decoder<'a> {
 178     pub fn new(data: &'a [u8], position: usize) -> Decoder<'a> {
 179         Decoder {
 180             data,
 181             position,
 182         }
 183     }
 184
 185     #[inline]
 186     pub fn position(&self) -> usize {
 187         self.position
 188     }
 189
 190     #[inline]
 191     pub fn set_position(&mut self, pos: usize) {
 192         self.position = pos
 193     }
 194
 195     #[inline]
 196     pub fn advance(&mut self, bytes: usize) {
 197         self.position += bytes;
 198     }
 199
 200     pub fn read_raw_bytes(&mut self, s: &mut [u8]) -> Result<(), String> {
 201         let start = self.position;
 202         let end = start + s.len();
 203
 204         s.copy_from_slice(&self.data[start..end]);
 205
 206         self.position = end;
 207
 208         Ok(())
 209     }
 210 }
 211
 212 macro_rules! read_uleb128 {
 213     ($dec:expr, $t:ty, $fun:ident) => ({
 214         let (value, bytes_read) = leb128::$fun(&$dec.data[$dec.position ..]);
 215         $dec.position += bytes_read;
 216         Ok(value)
 217     })
 218 }
 219
 220 macro_rules! read_sleb128 {
 221     ($dec:expr, $t:ty) => ({
 222         let (value, bytes_read) = read_signed_leb128($dec.data, $dec.position);
 223         $dec.position += bytes_read;
 224         Ok(value as $t)
 225     })
 226 }
 227
 228
 229 impl<'a> serialize::Decoder for Decoder<'a> {
 230     type Error = String;
 231
 232     #[inline]
 233     fn read_nil(&mut self) -> Result<(), Self::Error> {
 234         Ok(())
 235     }
 236
 237     #[inline]
 238     fn read_u128(&mut self) -> Result<u128, Self::Error> {
 239         read_uleb128!(self, u128, read_u128_leb128)
 240     }
 241
 242     #[inline]
 243     fn read_u64(&mut self) -> Result<u64, Self::Error> {
 244         read_uleb128!(self, u64, read_u64_leb128)
 245     }
 246
 247     #[inline]
 248     fn read_u32(&mut self) -> Result<u32, Self::Error> {
 249         read_uleb128!(self, u32, read_u32_leb128)
 250     }
 251
 252     #[inline]
 253     fn read_u16(&mut self) -> Result<u16, Self::Error> {
 254         read_uleb128!(self, u16, read_u16_leb128)
 255     }
 256
 257     #[inline]
 258     fn read_u8(&mut self) -> Result<u8, Self::Error> {
 259         let value = self.data[self.position];
 260         self.position += 1;
 261         Ok(value)
 262     }
 263
 264     #[inline]
 265     fn read_usize(&mut self) -> Result<usize, Self::Error> {
 266         read_uleb128!(self, usize, read_usize_leb128)
 267     }
 268
 269     #[inline]
 270     fn read_i128(&mut self) -> Result<i128, Self::Error> {
 271         read_sleb128!(self, i128)
 272     }
 273
 274     #[inline]
 275     fn read_i64(&mut self) -> Result<i64, Self::Error> {
 276         read_sleb128!(self, i64)
 277     }
 278
 279     #[inline]
 280     fn read_i32(&mut self) -> Result<i32, Self::Error> {
 281         read_sleb128!(self, i32)
 282     }
 283
 284     #[inline]
 285     fn read_i16(&mut self) -> Result<i16, Self::Error> {
 286         read_sleb128!(self, i16)
 287     }
 288
 289     #[inline]
 290     fn read_i8(&mut self) -> Result<i8, Self::Error> {
 291         let as_u8 = self.data[self.position];
 292         self.position += 1;
 293         unsafe { Ok(::std::mem::transmute(as_u8)) }
 294     }
 295
 296     #[inline]
 297     fn read_isize(&mut self) -> Result<isize, Self::Error> {
 298         read_sleb128!(self, isize)
 299     }
 300
 301     #[inline]
 302     fn read_bool(&mut self) -> Result<bool, Self::Error> {
 303         let value = self.read_u8()?;
 304         Ok(value != 0)
 305     }
 306
 307     #[inline]
 308     fn read_f64(&mut self) -> Result<f64, Self::Error> {
 309         let bits = self.read_u64()?;
 310         Ok(unsafe { ::std::mem::transmute(bits) })
 311     }
 312
 313     #[inline]
 314     fn read_f32(&mut self) -> Result<f32, Self::Error> {
 315         let bits = self.read_u32()?;
 316         Ok(unsafe { ::std::mem::transmute(bits) })
 317     }
 318
 319     #[inline]
 320     fn read_char(&mut self) -> Result<char, Self::Error> {
 321         let bits = self.read_u32()?;
 322         Ok(::std::char::from_u32(bits).unwrap())
 323     }
 324
 325     #[inline]
 326     fn read_str(&mut self) -> Result<Cow<str>, Self::Error> {
 327         let len = self.read_usize()?;
 328         let s = ::std::str::from_utf8(&self.data[self.position..self.position + len]).unwrap();
 329         self.position += len;
 330         Ok(Cow::Borrowed(s))
 331     }
 332
 333     fn error(&mut self, err: &str) -> Self::Error {
 334         err.to_string()
 335     }
 336 }
 337
 338
 339 #[cfg(test)]
 340 mod tests {
 341     use serialize::{Encodable, Decodable};
 342     use std::io::Cursor;
 343     use std::fmt::Debug;
 344     use super::{Encoder, Decoder};
 345
 346     #[derive(PartialEq, Clone, Debug, RustcEncodable, RustcDecodable)]
 347     struct Struct {
 348         a: (),
 349         b: u8,
 350         c: u16,
 351         d: u32,
 352         e: u64,
 353         f: usize,
 354
 355         g: i8,
 356         h: i16,
 357         i: i32,
 358         j: i64,
 359         k: isize,
 360
 361         l: char,
 362         m: String,
 363         n: f32,
 364         o: f64,
 365         p: bool,
 366         q: Option<u32>,
 367     }
 368
 369
 370     fn check_round_trip<T: Encodable + Decodable + PartialEq + Debug>(values: Vec<T>) {
 371         let mut cursor = Cursor::new(Vec::new());
 372
 373         for value in &values {
 374             let mut encoder = Encoder::new(&mut cursor);
 375             Encodable::encode(&value, &mut encoder).unwrap();
 376         }
 377
 378         let data = cursor.into_inner();
 379         let mut decoder = Decoder::new(&data[..], 0);
 380
 381         for value in values {
 382             let decoded = Decodable::decode(&mut decoder).unwrap();
 383             assert_eq!(value, decoded);
 384         }
 385     }
 386
 387     #[test]
 388     fn test_unit() {
 389         check_round_trip(vec![(), (), (), ()]);
 390     }
 391
 392     #[test]
 393     fn test_u8() {
 394         let mut vec = vec![];
 395         for i in ::std::u8::MIN..::std::u8::MAX {
 396             vec.push(i);
 397         }
 398         check_round_trip(vec);
 399     }
 400
 401     #[test]
 402     fn test_u16() {
 403         for i in ::std::u16::MIN..::std::u16::MAX {
 404             check_round_trip(vec![1, 2, 3, i, i, i]);
 405         }
 406     }
 407
 408     #[test]
 409     fn test_u32() {
 410         check_round_trip(vec![1, 2, 3, ::std::u32::MIN, 0, 1, ::std::u32::MAX, 2, 1]);
 411     }
 412
 413     #[test]
 414     fn test_u64() {
 415         check_round_trip(vec![1, 2, 3, ::std::u64::MIN, 0, 1, ::std::u64::MAX, 2, 1]);
 416     }
 417
 418     #[test]
 419     fn test_usize() {
 420         check_round_trip(vec![1, 2, 3, ::std::usize::MIN, 0, 1, ::std::usize::MAX, 2, 1]);
 421     }
 422
 423     #[test]
 424     fn test_i8() {
 425         let mut vec = vec![];
 426         for i in ::std::i8::MIN..::std::i8::MAX {
 427             vec.push(i);
 428         }
 429         check_round_trip(vec);
 430     }
 431
 432     #[test]
 433     fn test_i16() {
 434         for i in ::std::i16::MIN..::std::i16::MAX {
 435             check_round_trip(vec![-1, 2, -3, i, i, i, 2]);
 436         }
 437     }
 438
 439     #[test]
 440     fn test_i32() {
 441         check_round_trip(vec![-1, 2, -3, ::std::i32::MIN, 0, 1, ::std::i32::MAX, 2, 1]);
 442     }
 443
 444     #[test]
 445     fn test_i64() {
 446         check_round_trip(vec![-1, 2, -3, ::std::i64::MIN, 0, 1, ::std::i64::MAX, 2, 1]);
 447     }
 448
 449     #[test]
 450     fn test_isize() {
 451         check_round_trip(vec![-1, 2, -3, ::std::isize::MIN, 0, 1, ::std::isize::MAX, 2, 1]);
 452     }
 453
 454     #[test]
 455     fn test_bool() {
 456         check_round_trip(vec![false, true, true, false, false]);
 457     }
 458
 459     #[test]
 460     fn test_f32() {
 461         let mut vec = vec![];
 462         for i in -100..100 {
 463             vec.push((i as f32) / 3.0);
 464         }
 465         check_round_trip(vec);
 466     }
 467
 468     #[test]
 469     fn test_f64() {
 470         let mut vec = vec![];
 471         for i in -100..100 {
 472             vec.push((i as f64) / 3.0);
 473         }
 474         check_round_trip(vec);
 475     }
 476
 477     #[test]
 478     fn test_char() {
 479         let vec = vec!['a', 'b', 'c', 'd', 'A', 'X', ' ', '#', 'Ö', 'Ä', 'µ', '€'];
 480         check_round_trip(vec);
 481     }
 482
 483     #[test]
 484     fn test_string() {
 485         let vec = vec!["abcbuÖeiovÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
 486                        "abcbuÖganeiovÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
 487                        "abcbuÖganeiovÄnameÜavmpßvmea€µsbpapmaebn".to_string(),
 488                        "abcbuÖganeiovÄnameÜavmpßvmeabpnvapeapmaebn".to_string(),
 489                        "abcbuÖganeiÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
 490                        "abcbuÖganeiovÄnameÜavmpßvmea€µsbpmaebn".to_string(),
 491                        "abcbuÖganeiovÄnameÜavmpßvmea€µnvapeapmaebn".to_string()];
 492
 493         check_round_trip(vec);
 494     }
 495
 496     #[test]
 497     fn test_option() {
 498         check_round_trip(vec![Some(-1i8)]);
 499         check_round_trip(vec![Some(-2i16)]);
 500         check_round_trip(vec![Some(-3i32)]);
 501         check_round_trip(vec![Some(-4i64)]);
 502         check_round_trip(vec![Some(-5isize)]);
 503
 504         let none_i8: Option<i8> = None;
 505         check_round_trip(vec![none_i8]);
 506
 507         let none_i16: Option<i16> = None;
 508         check_round_trip(vec![none_i16]);
 509
 510         let none_i32: Option<i32> = None;
 511         check_round_trip(vec![none_i32]);
 512
 513         let none_i64: Option<i64> = None;
 514         check_round_trip(vec![none_i64]);
 515
 516         let none_isize: Option<isize> = None;
 517         check_round_trip(vec![none_isize]);
 518     }
 519
 520     #[test]
 521     fn test_struct() {
 522         check_round_trip(vec![Struct {
 523                                   a: (),
 524                                   b: 10,
 525                                   c: 11,
 526                                   d: 12,
 527                                   e: 13,
 528                                   f: 14,
 529
 530                                   g: 15,
 531                                   h: 16,
 532                                   i: 17,
 533                                   j: 18,
 534                                   k: 19,
 535
 536                                   l: 'x',
 537                                   m: "abc".to_string(),
 538                                   n: 20.5,
 539                                   o: 21.5,
 540                                   p: false,
 541                                   q: None,
 542                               }]);
 543
 544         check_round_trip(vec![Struct {
 545                                   a: (),
 546                                   b: 101,
 547                                   c: 111,
 548                                   d: 121,
 549                                   e: 131,
 550                                   f: 141,
 551
 552                                   g: -15,
 553                                   h: -16,
 554                                   i: -17,
 555                                   j: -18,
 556                                   k: -19,
 557
 558                                   l: 'y',
 559                                   m: "def".to_string(),
 560                                   n: -20.5,
 561                                   o: -21.5,
 562                                   p: true,
 563                                   q: Some(1234567),
 564                               }]);
 565     }
 566
 567     #[derive(PartialEq, Clone, Debug, RustcEncodable, RustcDecodable)]
 568     enum Enum {
 569         Variant1,
 570         Variant2(usize, f32),
 571         Variant3 {
 572             a: i32,
 573             b: char,
 574             c: bool,
 575         },
 576     }
 577
 578     #[test]
 579     fn test_enum() {
 580         check_round_trip(vec![Enum::Variant1,
 581                               Enum::Variant2(1, 2.5),
 582                               Enum::Variant3 {
 583                                   a: 3,
 584                                   b: 'b',
 585                                   c: false,
 586                               },
 587                               Enum::Variant3 {
 588                                   a: -4,
 589                                   b: 'f',
 590                                   c: true,
 591                               }]);
 592     }
 593
 594     #[test]
 595     fn test_sequence() {
 596         let mut vec = vec![];
 597         for i in -100i64..100i64 {
 598             vec.push(i * 100000);
 599         }
 600
 601         check_round_trip(vec![vec]);
 602     }
 603
 604     #[test]
 605     fn test_hash_map() {
 606         use std::collections::HashMap;
 607         let mut map = HashMap::new();
 608         for i in -100i64..100i64 {
 609             map.insert(i * 100000, i * 10000);
 610         }
 611
 612         check_round_trip(vec![map]);
 613     }
 614
 615     #[test]
 616     fn test_tuples() {
 617         check_round_trip(vec![('x', (), false, 0.5f32)]);
 618         check_round_trip(vec![(9i8, 10u16, 1.5f64)]);
 619         check_round_trip(vec![(-12i16, 11u8, 12usize)]);
 620         check_round_trip(vec![(1234567isize, 100000000000000u64, 99999999999999i64)]);
 621         check_round_trip(vec![(String::new(), "some string".to_string())]);
 622     }
 623 }