_ Git - rust-lightning/blob - lightning/src/util/ser.rs

   1 //! A very simple serialization framework which is used to serialize/deserialize messages as well
   2 //! as ChannelsManagers and ChannelMonitors.
   3
   4 use std::result::Result;
   5 use std::io::{Read, Write};
   6 use std::collections::HashMap;
   7 use std::hash::Hash;
   8 use std::sync::Mutex;
   9 use std::cmp;
  10
  11 use secp256k1::Signature;
  12 use secp256k1::key::{PublicKey, SecretKey};
  13 use bitcoin::blockdata::script::Script;
  14 use bitcoin::blockdata::transaction::OutPoint;
  15 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
  16 use std::marker::Sized;
  17 use ln::msgs::DecodeError;
  18 use ln::channelmanager::{PaymentPreimage, PaymentHash};
  19 use util::byte_utils;
  20
  21 use util::byte_utils::{be64_to_array, be48_to_array, be32_to_array, be16_to_array, slice_to_be16, slice_to_be32, slice_to_be48, slice_to_be64};
  22
  23 const MAX_BUF_SIZE: usize = 64 * 1024;
  24
  25 /// A trait that is similar to std::io::Write but has one extra function which can be used to size
  26 /// buffers being written into.
  27 /// An impl is provided for any type that also impls std::io::Write which simply ignores size
  28 /// hints.
  29 pub trait Writer {
  30         /// Writes the given buf out. See std::io::Write::write_all for more
  31         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error>;
  32         /// Hints that data of the given size is about the be written. This may not always be called
  33         /// prior to data being written and may be safely ignored.
  34         fn size_hint(&mut self, size: usize);
  35 }
  36
  37 impl<W: Write> Writer for W {
  38         #[inline]
  39         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  40                 <Self as ::std::io::Write>::write_all(self, buf)
  41         }
  42         #[inline]
  43         fn size_hint(&mut self, _size: usize) { }
  44 }
  45
  46 pub(crate) struct WriterWriteAdaptor<'a, W: Writer + 'a>(pub &'a mut W);
  47 impl<'a, W: Writer + 'a> Write for WriterWriteAdaptor<'a, W> {
  48         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  49                 self.0.write_all(buf)
  50         }
  51         fn write(&mut self, buf: &[u8]) -> Result<usize, ::std::io::Error> {
  52                 self.0.write_all(buf)?;
  53                 Ok(buf.len())
  54         }
  55         fn flush(&mut self) -> Result<(), ::std::io::Error> {
  56                 Ok(())
  57         }
  58 }
  59
  60 struct VecWriter(Vec<u8>);
  61 impl Writer for VecWriter {
  62         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  63                 self.0.extend_from_slice(buf);
  64                 Ok(())
  65         }
  66         fn size_hint(&mut self, size: usize) {
  67                 self.0.reserve_exact(size);
  68         }
  69 }
  70
  71 pub(crate) struct LengthCalculatingWriter(pub usize);
  72 impl Writer for LengthCalculatingWriter {
  73         #[inline]
  74         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  75                 self.0 += buf.len();
  76                 Ok(())
  77         }
  78         #[inline]
  79         fn size_hint(&mut self, _size: usize) {}
  80 }
  81
  82 /// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream
  83 /// forward to ensure we always consume exactly the fixed length specified.
  84 pub(crate) struct FixedLengthReader<R: Read> {
  85         read: R,
  86         bytes_read: u64,
  87         total_fixed_len: u64,
  88 }
  89 impl<R: Read> FixedLengthReader<R> {
  90         pub fn new(read: R, total_fixed_len: u64) -> Self {
  91                 Self { read, bytes_read: 0, total_fixed_len }
  92         }
  93
  94         pub fn bytes_remain(&mut self) -> bool {
  95                 self.bytes_read != self.total_fixed_len
  96         }
  97
  98         pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
  99                 ::std::io::copy(self, &mut ::std::io::sink()).unwrap();
 100                 if self.bytes_read != self.total_fixed_len {
 101                         Err(DecodeError::ShortRead)
 102                 } else {
 103                         Ok(())
 104                 }
 105         }
 106 }
 107 impl<R: Read> Read for FixedLengthReader<R> {
 108         fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
 109                 if self.total_fixed_len == self.bytes_read {
 110                         Ok(0)
 111                 } else {
 112                         let read_len = cmp::min(dest.len() as u64, self.total_fixed_len - self.bytes_read);
 113                         match self.read.read(&mut dest[0..(read_len as usize)]) {
 114                                 Ok(v) => {
 115                                         self.bytes_read += v as u64;
 116                                         Ok(v)
 117                                 },
 118                                 Err(e) => Err(e),
 119                         }
 120                 }
 121         }
 122 }
 123
 124 /// A Read which tracks whether any bytes have been read at all. This allows us to distinguish
 125 /// between "EOF reached before we started" and "EOF reached mid-read".
 126 pub(crate) struct ReadTrackingReader<R: Read> {
 127         read: R,
 128         pub have_read: bool,
 129 }
 130 impl<R: Read> ReadTrackingReader<R> {
 131         pub fn new(read: R) -> Self {
 132                 Self { read, have_read: false }
 133         }
 134 }
 135 impl<R: Read> Read for ReadTrackingReader<R> {
 136         fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
 137                 match self.read.read(dest) {
 138                         Ok(0) => Ok(0),
 139                         Ok(len) => {
 140                                 self.have_read = true;
 141                                 Ok(len)
 142                         },
 143                         Err(e) => Err(e),
 144                 }
 145         }
 146 }
 147
 148 /// A trait that various rust-lightning types implement allowing them to be written out to a Writer
 149 pub trait Writeable {
 150         /// Writes self out to the given Writer
 151         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error>;
 152
 153         /// Writes self out to a Vec<u8>
 154         fn encode(&self) -> Vec<u8> {
 155                 let mut msg = VecWriter(Vec::new());
 156                 self.write(&mut msg).unwrap();
 157                 msg.0
 158         }
 159
 160         /// Writes self out to a Vec<u8>
 161         fn encode_with_len(&self) -> Vec<u8> {
 162                 let mut msg = VecWriter(Vec::new());
 163                 0u16.write(&mut msg).unwrap();
 164                 self.write(&mut msg).unwrap();
 165                 let len = msg.0.len();
 166                 msg.0[..2].copy_from_slice(&byte_utils::be16_to_array(len as u16 - 2));
 167                 msg.0
 168         }
 169 }
 170
 171 /// A trait that various rust-lightning types implement allowing them to be read in from a Read
 172 pub trait Readable<R>
 173         where Self: Sized,
 174               R: Read
 175 {
 176         /// Reads a Self in from the given Read
 177         fn read(reader: &mut R) -> Result<Self, DecodeError>;
 178 }
 179
 180 /// A trait that various higher-level rust-lightning types implement allowing them to be read in
 181 /// from a Read given some additional set of arguments which is required to deserialize.
 182 pub trait ReadableArgs<R, P>
 183         where Self: Sized,
 184               R: Read
 185 {
 186         /// Reads a Self in from the given Read
 187         fn read(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 188 }
 189
 190 pub(crate) struct U48(pub u64);
 191 impl Writeable for U48 {
 192         #[inline]
 193         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 194                 writer.write_all(&be48_to_array(self.0))
 195         }
 196 }
 197 impl<R: Read> Readable<R> for U48 {
 198         #[inline]
 199         fn read(reader: &mut R) -> Result<U48, DecodeError> {
 200                 let mut buf = [0; 6];
 201                 reader.read_exact(&mut buf)?;
 202                 Ok(U48(slice_to_be48(&buf)))
 203         }
 204 }
 205
 206 /// Lightning TLV uses a custom variable-length integer called BigSize. It is similar to Bitcoin's
 207 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
 208 ///
 209 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
 210 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
 211 /// you're looking for an example of a variable-length integer to use for your own project, move
 212 /// along, this is a rather poor design.
 213 pub(crate) struct BigSize(pub u64);
 214 impl Writeable for BigSize {
 215         #[inline]
 216         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 217                 match self.0 {
 218                         0...0xFC => {
 219                                 (self.0 as u8).write(writer)
 220                         },
 221                         0xFD...0xFFFF => {
 222                                 0xFDu8.write(writer)?;
 223                                 (self.0 as u16).write(writer)
 224                         },
 225                         0x10000...0xFFFFFFFF => {
 226                                 0xFEu8.write(writer)?;
 227                                 (self.0 as u32).write(writer)
 228                         },
 229                         _ => {
 230                                 0xFFu8.write(writer)?;
 231                                 (self.0 as u64).write(writer)
 232                         },
 233                 }
 234         }
 235 }
 236 impl<R: Read> Readable<R> for BigSize {
 237         #[inline]
 238         fn read(reader: &mut R) -> Result<BigSize, DecodeError> {
 239                 let n: u8 = Readable::read(reader)?;
 240                 match n {
 241                         0xFF => {
 242                                 let x: u64 = Readable::read(reader)?;
 243                                 if x < 0x100000000 {
 244                                         Err(DecodeError::InvalidValue)
 245                                 } else {
 246                                         Ok(BigSize(x))
 247                                 }
 248                         }
 249                         0xFE => {
 250                                 let x: u32 = Readable::read(reader)?;
 251                                 if x < 0x10000 {
 252                                         Err(DecodeError::InvalidValue)
 253                                 } else {
 254                                         Ok(BigSize(x as u64))
 255                                 }
 256                         }
 257                         0xFD => {
 258                                 let x: u16 = Readable::read(reader)?;
 259                                 if x < 0xFD {
 260                                         Err(DecodeError::InvalidValue)
 261                                 } else {
 262                                         Ok(BigSize(x as u64))
 263                                 }
 264                         }
 265                         n => Ok(BigSize(n as u64))
 266                 }
 267         }
 268 }
 269
 270 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
 271 /// variabe-length integer which is simply truncated by skipping high zero bytes. This type
 272 /// encapsulates such integers implementing Readable/Writeable for them.
 273 #[cfg_attr(test, derive(PartialEq, Debug))]
 274 pub(crate) struct HighZeroBytesDroppedVarInt<T>(pub T);
 275
 276 macro_rules! impl_writeable_primitive {
 277         ($val_type:ty, $meth_write:ident, $len: expr, $meth_read:ident) => {
 278                 impl Writeable for $val_type {
 279                         #[inline]
 280                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 281                                 writer.write_all(&$meth_write(*self))
 282                         }
 283                 }
 284                 impl Writeable for HighZeroBytesDroppedVarInt<$val_type> {
 285                         #[inline]
 286                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 287                                 // Skip any full leading 0 bytes when writing (in BE):
 288                                 writer.write_all(&$meth_write(self.0)[(self.0.leading_zeros()/8) as usize..$len])
 289                         }
 290                 }
 291                 impl<R: Read> Readable<R> for $val_type {
 292                         #[inline]
 293                         fn read(reader: &mut R) -> Result<$val_type, DecodeError> {
 294                                 let mut buf = [0; $len];
 295                                 reader.read_exact(&mut buf)?;
 296                                 Ok($meth_read(&buf))
 297                         }
 298                 }
 299                 impl<R: Read> Readable<R> for HighZeroBytesDroppedVarInt<$val_type> {
 300                         #[inline]
 301                         fn read(reader: &mut R) -> Result<HighZeroBytesDroppedVarInt<$val_type>, DecodeError> {
 302                                 // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
 303                                 // the high bytes being dropped. To do so, we start reading in the middle of buf
 304                                 // and then convert the appropriate number of bytes with extra high bytes out of
 305                                 // buf.
 306                                 let mut buf = [0; $len*2];
 307                                 let mut read_len = reader.read(&mut buf[$len..])?;
 308                                 let mut total_read_len = read_len;
 309                                 while read_len != 0 && total_read_len != $len {
 310                                         read_len = reader.read(&mut buf[($len + read_len)..])?;
 311                                         total_read_len += read_len;
 312                                 }
 313                                 if total_read_len == 0 || buf[$len] != 0 {
 314                                         let first_byte = $len - ($len - total_read_len);
 315                                         Ok(HighZeroBytesDroppedVarInt($meth_read(&buf[first_byte..first_byte + $len])))
 316                                 } else {
 317                                         // If the encoding had extra zero bytes, return a failure even though we know
 318                                         // what they meant (as the TLV test vectors require this)
 319                                         Err(DecodeError::InvalidValue)
 320                                 }
 321                         }
 322                 }
 323         }
 324 }
 325
 326 impl_writeable_primitive!(u64, be64_to_array, 8, slice_to_be64);
 327 impl_writeable_primitive!(u32, be32_to_array, 4, slice_to_be32);
 328 impl_writeable_primitive!(u16, be16_to_array, 2, slice_to_be16);
 329
 330 impl Writeable for u8 {
 331         #[inline]
 332         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 333                 writer.write_all(&[*self])
 334         }
 335 }
 336 impl<R: Read> Readable<R> for u8 {
 337         #[inline]
 338         fn read(reader: &mut R) -> Result<u8, DecodeError> {
 339                 let mut buf = [0; 1];
 340                 reader.read_exact(&mut buf)?;
 341                 Ok(buf[0])
 342         }
 343 }
 344
 345 impl Writeable for bool {
 346         #[inline]
 347         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 348                 writer.write_all(&[if *self {1} else {0}])
 349         }
 350 }
 351 impl<R: Read> Readable<R> for bool {
 352         #[inline]
 353         fn read(reader: &mut R) -> Result<bool, DecodeError> {
 354                 let mut buf = [0; 1];
 355                 reader.read_exact(&mut buf)?;
 356                 if buf[0] != 0 && buf[0] != 1 {
 357                         return Err(DecodeError::InvalidValue);
 358                 }
 359                 Ok(buf[0] == 1)
 360         }
 361 }
 362
 363 // u8 arrays
 364 macro_rules! impl_array {
 365         ( $size:expr ) => (
 366                 impl Writeable for [u8; $size]
 367                 {
 368                         #[inline]
 369                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 370                                 w.write_all(self)
 371                         }
 372                 }
 373
 374                 impl<R: Read> Readable<R> for [u8; $size]
 375                 {
 376                         #[inline]
 377                         fn read(r: &mut R) -> Result<Self, DecodeError> {
 378                                 let mut buf = [0u8; $size];
 379                                 r.read_exact(&mut buf)?;
 380                                 Ok(buf)
 381                         }
 382                 }
 383         );
 384 }
 385
 386 //TODO: performance issue with [u8; size] with impl_array!()
 387 impl_array!(3); // for rgb
 388 impl_array!(4); // for IPv4
 389 impl_array!(10); // for OnionV2
 390 impl_array!(16); // for IPv6
 391 impl_array!(32); // for channel id & hmac
 392 impl_array!(33); // for PublicKey
 393 impl_array!(64); // for Signature
 394 impl_array!(1300); // for OnionPacket.hop_data
 395
 396 // HashMap
 397 impl<K, V> Writeable for HashMap<K, V>
 398         where K: Writeable + Eq + Hash,
 399               V: Writeable
 400 {
 401         #[inline]
 402         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 403         (self.len() as u16).write(w)?;
 404                 for (key, value) in self.iter() {
 405                         key.write(w)?;
 406                         value.write(w)?;
 407                 }
 408                 Ok(())
 409         }
 410 }
 411
 412 impl<R, K, V> Readable<R> for HashMap<K, V>
 413         where R: Read,
 414               K: Readable<R> + Eq + Hash,
 415               V: Readable<R>
 416 {
 417         #[inline]
 418         fn read(r: &mut R) -> Result<Self, DecodeError> {
 419                 let len: u16 = Readable::read(r)?;
 420                 let mut ret = HashMap::with_capacity(len as usize);
 421                 for _ in 0..len {
 422                         ret.insert(K::read(r)?, V::read(r)?);
 423                 }
 424                 Ok(ret)
 425         }
 426 }
 427
 428 // Vectors
 429 impl Writeable for Vec<u8> {
 430         #[inline]
 431         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 432                 (self.len() as u16).write(w)?;
 433                 w.write_all(&self)
 434         }
 435 }
 436
 437 impl<R: Read> Readable<R> for Vec<u8> {
 438         #[inline]
 439         fn read(r: &mut R) -> Result<Self, DecodeError> {
 440                 let len: u16 = Readable::read(r)?;
 441                 let mut ret = Vec::with_capacity(len as usize);
 442                 ret.resize(len as usize, 0);
 443                 r.read_exact(&mut ret)?;
 444                 Ok(ret)
 445         }
 446 }
 447 impl Writeable for Vec<Signature> {
 448         #[inline]
 449         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 450                 (self.len() as u16).write(w)?;
 451                 for e in self.iter() {
 452                         e.write(w)?;
 453                 }
 454                 Ok(())
 455         }
 456 }
 457
 458 impl<R: Read> Readable<R> for Vec<Signature> {
 459         #[inline]
 460         fn read(r: &mut R) -> Result<Self, DecodeError> {
 461                 let len: u16 = Readable::read(r)?;
 462                 let byte_size = (len as usize)
 463                                 .checked_mul(33)
 464                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 465                 if byte_size > MAX_BUF_SIZE {
 466                         return Err(DecodeError::BadLengthDescriptor);
 467                 }
 468                 let mut ret = Vec::with_capacity(len as usize);
 469                 for _ in 0..len { ret.push(Signature::read(r)?); }
 470                 Ok(ret)
 471         }
 472 }
 473
 474 impl Writeable for Script {
 475         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 476                 (self.len() as u16).write(w)?;
 477                 w.write_all(self.as_bytes())
 478         }
 479 }
 480
 481 impl<R: Read> Readable<R> for Script {
 482         fn read(r: &mut R) -> Result<Self, DecodeError> {
 483                 let len = <u16 as Readable<R>>::read(r)? as usize;
 484                 let mut buf = vec![0; len];
 485                 r.read_exact(&mut buf)?;
 486                 Ok(Script::from(buf))
 487         }
 488 }
 489
 490 impl Writeable for PublicKey {
 491         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 492                 self.serialize().write(w)
 493         }
 494 }
 495
 496 impl<R: Read> Readable<R> for PublicKey {
 497         fn read(r: &mut R) -> Result<Self, DecodeError> {
 498                 let buf: [u8; 33] = Readable::read(r)?;
 499                 match PublicKey::from_slice(&buf) {
 500                         Ok(key) => Ok(key),
 501                         Err(_) => return Err(DecodeError::InvalidValue),
 502                 }
 503         }
 504 }
 505
 506 impl Writeable for SecretKey {
 507         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 508                 let mut ser = [0; 32];
 509                 ser.copy_from_slice(&self[..]);
 510                 ser.write(w)
 511         }
 512 }
 513
 514 impl<R: Read> Readable<R> for SecretKey {
 515         fn read(r: &mut R) -> Result<Self, DecodeError> {
 516                 let buf: [u8; 32] = Readable::read(r)?;
 517                 match SecretKey::from_slice(&buf) {
 518                         Ok(key) => Ok(key),
 519                         Err(_) => return Err(DecodeError::InvalidValue),
 520                 }
 521         }
 522 }
 523
 524 impl Writeable for Sha256dHash {
 525         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 526                 w.write_all(&self[..])
 527         }
 528 }
 529
 530 impl<R: Read> Readable<R> for Sha256dHash {
 531         fn read(r: &mut R) -> Result<Self, DecodeError> {
 532                 use bitcoin_hashes::Hash;
 533
 534                 let buf: [u8; 32] = Readable::read(r)?;
 535                 Ok(Sha256dHash::from_slice(&buf[..]).unwrap())
 536         }
 537 }
 538
 539 impl Writeable for Signature {
 540         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 541                 self.serialize_compact().write(w)
 542         }
 543 }
 544
 545 impl<R: Read> Readable<R> for Signature {
 546         fn read(r: &mut R) -> Result<Self, DecodeError> {
 547                 let buf: [u8; 64] = Readable::read(r)?;
 548                 match Signature::from_compact(&buf) {
 549                         Ok(sig) => Ok(sig),
 550                         Err(_) => return Err(DecodeError::InvalidValue),
 551                 }
 552         }
 553 }
 554
 555 impl Writeable for PaymentPreimage {
 556         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 557                 self.0.write(w)
 558         }
 559 }
 560
 561 impl<R: Read> Readable<R> for PaymentPreimage {
 562         fn read(r: &mut R) -> Result<Self, DecodeError> {
 563                 let buf: [u8; 32] = Readable::read(r)?;
 564                 Ok(PaymentPreimage(buf))
 565         }
 566 }
 567
 568 impl Writeable for PaymentHash {
 569         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 570                 self.0.write(w)
 571         }
 572 }
 573
 574 impl<R: Read> Readable<R> for PaymentHash {
 575         fn read(r: &mut R) -> Result<Self, DecodeError> {
 576                 let buf: [u8; 32] = Readable::read(r)?;
 577                 Ok(PaymentHash(buf))
 578         }
 579 }
 580
 581 impl<T: Writeable> Writeable for Option<T> {
 582         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 583                 match *self {
 584                         None => 0u8.write(w)?,
 585                         Some(ref data) => {
 586                                 1u8.write(w)?;
 587                                 data.write(w)?;
 588                         }
 589                 }
 590                 Ok(())
 591         }
 592 }
 593
 594 impl<R, T> Readable<R> for Option<T>
 595         where R: Read,
 596               T: Readable<R>
 597 {
 598         fn read(r: &mut R) -> Result<Self, DecodeError> {
 599                 match <u8 as Readable<R>>::read(r)? {
 600                         0 => Ok(None),
 601                         1 => Ok(Some(Readable::read(r)?)),
 602                         _ => return Err(DecodeError::InvalidValue),
 603                 }
 604         }
 605 }
 606
 607 impl Writeable for OutPoint {
 608         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 609                 self.txid.write(w)?;
 610                 self.vout.write(w)?;
 611                 Ok(())
 612         }
 613 }
 614
 615 impl<R: Read> Readable<R> for OutPoint {
 616         fn read(r: &mut R) -> Result<Self, DecodeError> {
 617                 let txid = Readable::read(r)?;
 618                 let vout = Readable::read(r)?;
 619                 Ok(OutPoint {
 620                         txid,
 621                         vout,
 622                 })
 623         }
 624 }
 625
 626 impl<R: Read, T: Readable<R>> Readable<R> for Mutex<T> {
 627         fn read(r: &mut R) -> Result<Self, DecodeError> {
 628                 let t: T = Readable::read(r)?;
 629                 Ok(Mutex::new(t))
 630         }
 631 }
 632 impl<T: Writeable> Writeable for Mutex<T> {
 633         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 634                 self.lock().unwrap().write(w)
 635         }
 636 }
 637
 638 impl<R: Read, A: Readable<R>, B: Readable<R>> Readable<R> for (A, B) {
 639         fn read(r: &mut R) -> Result<Self, DecodeError> {
 640                 let a: A = Readable::read(r)?;
 641                 let b: B = Readable::read(r)?;
 642                 Ok((a, b))
 643         }
 644 }
 645 impl<A: Writeable, B: Writeable> Writeable for (A, B) {
 646         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 647                 self.0.write(w)?;
 648                 self.1.write(w)
 649         }
 650 }