1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853
// SPDX-License-Identifier: CC0-1.0
//! Provides type [`LockTime`] that implements the logic around nLockTime/OP_CHECKLOCKTIMEVERIFY.
//!
//! There are two types of lock time: lock-by-blockheight and lock-by-blocktime, distinguished by
//! whether `LockTime < LOCKTIME_THRESHOLD`.
//!
use core::cmp::{Ordering, PartialOrd};
use core::{fmt, mem};
use internals::write_err;
#[cfg(all(test, mutate))]
use mutagen::mutate;
#[cfg(doc)]
use crate::absolute;
use crate::consensus::encode::{self, Decodable, Encodable};
use crate::error::ParseIntError;
use crate::io::{self, Read, Write};
use crate::parse::{impl_parse_str_from_int_fallible, impl_parse_str_from_int_infallible};
use crate::prelude::*;
use crate::string::FromHexStr;
/// The Threshold for deciding whether a lock time value is a height or a time (see [Bitcoin Core]).
///
/// `LockTime` values _below_ the threshold are interpreted as block heights, values _above_ (or
/// equal to) the threshold are interpreted as block times (UNIX timestamp, seconds since epoch).
///
/// Bitcoin is able to safely use this value because a block height greater than 500,000,000 would
/// never occur because it would represent a height in approximately 9500 years. Conversely, block
/// times under 500,000,000 will never happen because they would represent times before 1986 which
/// are, for obvious reasons, not useful within the Bitcoin network.
///
/// [Bitcoin Core]: https://github.com/bitcoin/bitcoin/blob/9ccaee1d5e2e4b79b0a7c29aadb41b97e4741332/src/script/script.h#L39
pub const LOCK_TIME_THRESHOLD: u32 = 500_000_000;
/// An absolute lock time value, representing either a block height or a UNIX timestamp (seconds
/// since epoch).
///
/// Used for transaction lock time (`nLockTime` in Bitcoin Core and [`crate::Transaction::lock_time`]
/// in this library) and also for the argument to opcode 'OP_CHECKLOCKTIMEVERIFY`.
///
/// ### Note on ordering
///
/// Because locktimes may be height- or time-based, and these metrics are incommensurate, there
/// is no total ordering on locktimes. We therefore have implemented [`PartialOrd`] but not [`Ord`].
/// For [`crate::Transaction`], which has a locktime field, we implement a total ordering to make
/// it easy to store transactions in sorted data structures, and use the locktime's 32-bit integer
/// consensus encoding to order it.
///
/// ### Relevant BIPs
///
/// * [BIP-65 OP_CHECKLOCKTIMEVERIFY](https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki)
/// * [BIP-113 Median time-past as endpoint for lock-time calculations](https://github.com/bitcoin/bips/blob/master/bip-0113.mediawiki)
///
/// # Examples
/// ```
/// # use bitcoin::absolute::{LockTime, LockTime::*};
/// # let n = LockTime::from_consensus(741521); // n OP_CHECKLOCKTIMEVERIFY
/// # let lock_time = LockTime::from_consensus(741521); // nLockTime
/// // To compare absolute lock times there are various `is_satisfied_*` methods, you may also use:
/// let is_satisfied = match (n, lock_time) {
/// (Blocks(n), Blocks(lock_time)) => n <= lock_time,
/// (Seconds(n), Seconds(lock_time)) => n <= lock_time,
/// _ => panic!("handle invalid comparison error"),
/// };
/// ```
#[derive(Clone, Copy, PartialEq, Eq, Hash)]
pub enum LockTime {
/// A block height lock time value.
///
/// # Examples
/// ```rust
/// use bitcoin::absolute::LockTime;
///
/// let block: u32 = 741521;
/// let n = LockTime::from_height(block).expect("valid height");
/// assert!(n.is_block_height());
/// assert_eq!(n.to_consensus_u32(), block);
/// ```
Blocks(Height),
/// A UNIX timestamp lock time value.
///
/// # Examples
/// ```rust
/// use bitcoin::absolute::LockTime;
///
/// let seconds: u32 = 1653195600; // May 22nd, 5am UTC.
/// let n = LockTime::from_time(seconds).expect("valid time");
/// assert!(n.is_block_time());
/// assert_eq!(n.to_consensus_u32(), seconds);
/// ```
Seconds(Time),
}
impl LockTime {
/// If [`crate::Transaction::lock_time`] is set to zero it is ignored, in other words a
/// transaction with nLocktime==0 is able to be included immediately in any block.
pub const ZERO: LockTime = LockTime::Blocks(Height::ZERO);
/// The number of bytes that the locktime contributes to the size of a transaction.
pub const SIZE: usize = 4; // Serialized length of a u32.
/// Constructs a `LockTime` from an nLockTime value or the argument to OP_CHEKCLOCKTIMEVERIFY.
///
/// # Examples
///
/// ```rust
/// # use bitcoin::absolute::LockTime;
/// # let n = LockTime::from_consensus(741521); // n OP_CHECKLOCKTIMEVERIFY
///
/// // `from_consensus` roundtrips as expected with `to_consensus_u32`.
/// let n_lock_time: u32 = 741521;
/// let lock_time = LockTime::from_consensus(n_lock_time);
/// assert_eq!(lock_time.to_consensus_u32(), n_lock_time);
#[inline]
pub fn from_consensus(n: u32) -> Self {
if is_block_height(n) {
Self::Blocks(Height::from_consensus(n).expect("n is valid"))
} else {
Self::Seconds(Time::from_consensus(n).expect("n is valid"))
}
}
/// Constructs a `LockTime` from `n`, expecting `n` to be a valid block height.
///
/// See [`LOCK_TIME_THRESHOLD`] for definition of a valid height value.
///
/// # Examples
/// ```rust
/// # use bitcoin::absolute::LockTime;
/// assert!(LockTime::from_height(741521).is_ok());
/// assert!(LockTime::from_height(1653195600).is_err());
/// ```
#[inline]
pub fn from_height(n: u32) -> Result<Self, Error> {
let height = Height::from_consensus(n)?;
Ok(LockTime::Blocks(height))
}
/// Constructs a `LockTime` from `n`, expecting `n` to be a valid block time.
///
/// See [`LOCK_TIME_THRESHOLD`] for definition of a valid time value.
///
/// # Examples
/// ```rust
/// # use bitcoin::absolute::LockTime;
/// assert!(LockTime::from_time(1653195600).is_ok());
/// assert!(LockTime::from_time(741521).is_err());
/// ```
#[inline]
pub fn from_time(n: u32) -> Result<Self, Error> {
let time = Time::from_consensus(n)?;
Ok(LockTime::Seconds(time))
}
/// Returns true if both lock times use the same unit i.e., both height based or both time based.
#[inline]
pub fn is_same_unit(&self, other: LockTime) -> bool {
mem::discriminant(self) == mem::discriminant(&other)
}
/// Returns true if this lock time value is a block height.
#[inline]
pub fn is_block_height(&self) -> bool {
match *self {
LockTime::Blocks(_) => true,
LockTime::Seconds(_) => false,
}
}
/// Returns true if this lock time value is a block time (UNIX timestamp).
#[inline]
pub fn is_block_time(&self) -> bool { !self.is_block_height() }
/// Returns true if this timelock constraint is satisfied by the respective `height`/`time`.
///
/// If `self` is a blockheight based lock then it is checked against `height` and if `self` is a
/// blocktime based lock it is checked against `time`.
///
/// A 'timelock constraint' refers to the `n` from `n OP_CHEKCLOCKTIMEVERIFY`, this constraint
/// is satisfied if a transaction with nLockTime ([`crate::Transaction::lock_time`]) set to
/// `height`/`time` is valid.
///
/// # Examples
/// ```no_run
/// # use bitcoin::absolute::{LockTime, Height, Time};
/// // Can be implemented if block chain data is available.
/// fn get_height() -> Height { todo!("return the current block height") }
/// fn get_time() -> Time { todo!("return the current block time") }
///
/// let n = LockTime::from_consensus(741521); // `n OP_CHEKCLOCKTIMEVERIFY`.
/// if n.is_satisfied_by(get_height(), get_time()) {
/// // Can create and mine a transaction that satisfies the OP_CLTV timelock constraint.
/// }
/// ````
#[inline]
#[cfg_attr(all(test, mutate), mutate)]
pub fn is_satisfied_by(&self, height: Height, time: Time) -> bool {
use LockTime::*;
match *self {
Blocks(n) => n <= height,
Seconds(n) => n <= time,
}
}
/// Returns true if satisfaction of `other` lock time implies satisfaction of this
/// [`absolute::LockTime`].
///
/// A lock time can only be satisfied by n blocks being mined or n seconds passing. If you have
/// two lock times (same unit) then the larger lock time being satisfied implies (in a
/// mathematical sense) the smaller one being satisfied.
///
/// This function is useful if you wish to check a lock time against various other locks e.g.,
/// filtering out locks which cannot be satisfied. Can also be used to remove the smaller value
/// of two `OP_CHECKLOCKTIMEVERIFY` operations within one branch of the script.
///
/// # Examples
///
/// ```rust
/// # use bitcoin::absolute::{LockTime, LockTime::*};
/// let lock_time = LockTime::from_consensus(741521);
/// let check = LockTime::from_consensus(741521 + 1);
/// assert!(lock_time.is_implied_by(check));
/// ```
#[inline]
#[cfg_attr(all(test, mutate), mutate)]
pub fn is_implied_by(&self, other: LockTime) -> bool {
use LockTime::*;
match (*self, other) {
(Blocks(this), Blocks(other)) => this <= other,
(Seconds(this), Seconds(other)) => this <= other,
_ => false, // Not the same units.
}
}
/// Returns the inner `u32` value. This is the value used when creating this `LockTime`
/// i.e., `n OP_CHECKLOCKTIMEVERIFY` or nLockTime.
///
/// # Warning
///
/// Do not compare values return by this method. The whole point of the `LockTime` type is to
/// assist in doing correct comparisons. Either use `is_satisfied_by`, `is_satisfied_by_lock`,
/// or use the pattern below:
///
/// # Examples
///
/// ```rust
/// # use bitcoin::absolute::{LockTime, LockTime::*};
/// # let n = LockTime::from_consensus(741521); // n OP_CHECKLOCKTIMEVERIFY
/// # let lock_time = LockTime::from_consensus(741521 + 1); // nLockTime
///
/// let is_satisfied = match (n, lock_time) {
/// (Blocks(n), Blocks(lock_time)) => n <= lock_time,
/// (Seconds(n), Seconds(lock_time)) => n <= lock_time,
/// _ => panic!("invalid comparison"),
/// };
///
/// // Or, if you have Rust 1.53 or greater
/// // let is_satisfied = n.partial_cmp(&lock_time).expect("invalid comparison").is_le();
/// ```
#[inline]
pub fn to_consensus_u32(self) -> u32 {
match self {
LockTime::Blocks(ref h) => h.to_consensus_u32(),
LockTime::Seconds(ref t) => t.to_consensus_u32(),
}
}
}
impl_parse_str_from_int_infallible!(LockTime, u32, from_consensus);
impl From<Height> for LockTime {
#[inline]
fn from(h: Height) -> Self { LockTime::Blocks(h) }
}
impl From<Time> for LockTime {
#[inline]
fn from(t: Time) -> Self { LockTime::Seconds(t) }
}
impl PartialOrd for LockTime {
#[inline]
fn partial_cmp(&self, other: &LockTime) -> Option<Ordering> {
use LockTime::*;
match (*self, *other) {
(Blocks(ref a), Blocks(ref b)) => a.partial_cmp(b),
(Seconds(ref a), Seconds(ref b)) => a.partial_cmp(b),
(_, _) => None,
}
}
}
impl fmt::Debug for LockTime {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use LockTime::*;
match *self {
Blocks(ref h) => write!(f, "{} blocks", h),
Seconds(ref t) => write!(f, "{} seconds", t),
}
}
}
impl fmt::Display for LockTime {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use LockTime::*;
if f.alternate() {
match *self {
Blocks(ref h) => write!(f, "block-height {}", h),
Seconds(ref t) => write!(f, "block-time {} (seconds since epoch)", t),
}
} else {
match *self {
Blocks(ref h) => fmt::Display::fmt(h, f),
Seconds(ref t) => fmt::Display::fmt(t, f),
}
}
}
}
impl FromHexStr for LockTime {
type Error = Error;
#[inline]
fn from_hex_str_no_prefix<S: AsRef<str> + Into<String>>(s: S) -> Result<Self, Self::Error> {
let packed_lock_time = crate::parse::hex_u32(s)?;
Ok(Self::from_consensus(packed_lock_time))
}
}
impl Encodable for LockTime {
#[inline]
fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
let v = self.to_consensus_u32();
v.consensus_encode(w)
}
}
impl Decodable for LockTime {
#[inline]
fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
u32::consensus_decode(r).map(LockTime::from_consensus)
}
}
#[cfg(feature = "serde")]
impl serde::Serialize for LockTime {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
serializer.serialize_u32(self.to_consensus_u32())
}
}
#[cfg(feature = "serde")]
impl<'de> serde::Deserialize<'de> for LockTime {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
struct Visitor;
impl<'de> serde::de::Visitor<'de> for Visitor {
type Value = u32;
fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result { f.write_str("a u32") }
// We cannot just implement visit_u32 because JSON (among other things) always
// calls visit_u64, even when called from Deserializer::deserialize_u32. The
// other visit_u*s have default implementations that forward to visit_u64.
fn visit_u64<E: serde::de::Error>(self, v: u64) -> Result<u32, E> {
use core::convert::TryInto;
v.try_into().map_err(|_| {
E::invalid_value(serde::de::Unexpected::Unsigned(v), &"a 32-bit number")
})
}
// Also do the signed version, just for good measure.
fn visit_i64<E: serde::de::Error>(self, v: i64) -> Result<u32, E> {
use core::convert::TryInto;
v.try_into().map_err(|_| {
E::invalid_value(serde::de::Unexpected::Signed(v), &"a 32-bit number")
})
}
}
deserializer.deserialize_u32(Visitor).map(LockTime::from_consensus)
}
}
/// An absolute block height, guaranteed to always contain a valid height value.
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(feature = "serde", serde(crate = "actual_serde"))]
pub struct Height(u32);
impl Height {
/// Absolute block height 0, the genesis block.
pub const ZERO: Self = Height(0);
/// The minimum absolute block height (0), the genesis block.
pub const MIN: Self = Self::ZERO;
/// The maximum absolute block height.
pub const MAX: Self = Height(LOCK_TIME_THRESHOLD - 1);
/// The minimum absolute block height (0), the genesis block.
///
/// This is provided for consistency with Rust 1.41.1, newer code should use [`Height::MIN`].
#[deprecated(since = "0.31.0", note = "Use Self::MIN instead")]
pub const fn min_value() -> Self { Self::MIN }
/// The maximum absolute block height.
///
/// This is provided for consistency with Rust 1.41.1, newer code should use [`Height::MAX`].
#[deprecated(since = "0.31.0", note = "Use Self::MAX instead")]
pub const fn max_value() -> Self { Self::MAX }
/// Constructs a new block height.
///
/// # Errors
///
/// If `n` does not represent a block height value (see documentation on [`LockTime`]).
///
/// # Examples
/// ```rust
/// use bitcoin::locktime::absolute::Height;
///
/// let h: u32 = 741521;
/// let height = Height::from_consensus(h).expect("invalid height value");
/// assert_eq!(height.to_consensus_u32(), h);
/// ```
#[inline]
pub fn from_consensus(n: u32) -> Result<Height, Error> {
if is_block_height(n) {
Ok(Self(n))
} else {
Err(ConversionError::invalid_height(n).into())
}
}
/// Converts this `Height` to its inner `u32` value.
///
/// # Examples
/// ```rust
/// use bitcoin::absolute::LockTime;
///
/// let n_lock_time: u32 = 741521;
/// let lock_time = LockTime::from_consensus(n_lock_time);
/// assert!(lock_time.is_block_height());
/// assert_eq!(lock_time.to_consensus_u32(), n_lock_time);
#[inline]
pub fn to_consensus_u32(self) -> u32 { self.0 }
}
impl_parse_str_from_int_fallible!(Height, u32, from_consensus, Error);
impl fmt::Display for Height {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { fmt::Display::fmt(&self.0, f) }
}
impl FromHexStr for Height {
type Error = Error;
#[inline]
fn from_hex_str_no_prefix<S: AsRef<str> + Into<String>>(s: S) -> Result<Self, Self::Error> {
let height = crate::parse::hex_u32(s)?;
Self::from_consensus(height)
}
}
/// A UNIX timestamp, seconds since epoch, guaranteed to always contain a valid time value.
///
/// Note that there is no manipulation of the inner value during construction or when using
/// `to_consensus_u32()`. Said another way, `Time(x)` means 'x seconds since epoch' _not_ '(x -
/// threshold) seconds since epoch'.
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(feature = "serde", serde(crate = "actual_serde"))]
pub struct Time(u32);
impl Time {
/// The minimum absolute block time (Tue Nov 05 1985 00:53:20 GMT+0000).
pub const MIN: Self = Time(LOCK_TIME_THRESHOLD);
/// The maximum absolute block time (Sun Feb 07 2106 06:28:15 GMT+0000).
pub const MAX: Self = Time(u32::max_value());
/// The minimum absolute block time.
///
/// This is provided for consistency with Rust 1.41.1, newer code should use [`Time::MIN`].
#[deprecated(since = "0.31.0", note = "Use Self::MIN instead")]
pub const fn min_value() -> Self { Self::MIN }
/// The maximum absolute block time.
///
/// This is provided for consistency with Rust 1.41.1, newer code should use [`Time::MAX`].
#[deprecated(since = "0.31.0", note = "Use Self::MAX instead")]
pub const fn max_value() -> Self { Self::MAX }
/// Constructs a new block time.
///
/// # Errors
///
/// If `n` does not encode a UNIX time stamp (see documentation on [`LockTime`]).
///
/// # Examples
/// ```rust
/// use bitcoin::locktime::absolute::Time;
///
/// let t: u32 = 1653195600; // May 22nd, 5am UTC.
/// let time = Time::from_consensus(t).expect("invalid time value");
/// assert_eq!(time.to_consensus_u32(), t);
/// ```
#[inline]
pub fn from_consensus(n: u32) -> Result<Time, Error> {
if is_block_time(n) {
Ok(Self(n))
} else {
Err(ConversionError::invalid_time(n).into())
}
}
/// Converts this `Time` to its inner `u32` value.
///
/// # Examples
/// ```rust
/// use bitcoin::absolute::LockTime;
///
/// let n_lock_time: u32 = 1653195600; // May 22nd, 5am UTC.
/// let lock_time = LockTime::from_consensus(n_lock_time);
/// assert_eq!(lock_time.to_consensus_u32(), n_lock_time);
/// ```
#[inline]
pub fn to_consensus_u32(self) -> u32 { self.0 }
}
impl_parse_str_from_int_fallible!(Time, u32, from_consensus, Error);
impl fmt::Display for Time {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { fmt::Display::fmt(&self.0, f) }
}
impl FromHexStr for Time {
type Error = Error;
#[inline]
fn from_hex_str_no_prefix<S: AsRef<str> + Into<String>>(s: S) -> Result<Self, Self::Error> {
let time = crate::parse::hex_u32(s)?;
Time::from_consensus(time)
}
}
/// Returns true if `n` is a block height i.e., less than 500,000,000.
fn is_block_height(n: u32) -> bool { n < LOCK_TIME_THRESHOLD }
/// Returns true if `n` is a UNIX timestamp i.e., greater than or equal to 500,000,000.
fn is_block_time(n: u32) -> bool { n >= LOCK_TIME_THRESHOLD }
/// Catchall type for errors that relate to time locks.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub enum Error {
/// An error occurred while converting a `u32` to a lock time variant.
Conversion(ConversionError),
/// An error occurred while operating on lock times.
Operation(OperationError),
/// An error occurred while parsing a string into an `u32`.
Parse(ParseIntError),
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use Error::*;
match *self {
Conversion(ref e) => write_err!(f, "error converting lock time value"; e),
Operation(ref e) => write_err!(f, "error during lock time operation"; e),
Parse(ref e) => write_err!(f, "failed to parse lock time from string"; e),
}
}
}
#[cfg(feature = "std")]
impl std::error::Error for Error {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
use Error::*;
match *self {
Conversion(ref e) => Some(e),
Operation(ref e) => Some(e),
Parse(ref e) => Some(e),
}
}
}
impl From<ConversionError> for Error {
#[inline]
fn from(e: ConversionError) -> Self { Error::Conversion(e) }
}
impl From<OperationError> for Error {
#[inline]
fn from(e: OperationError) -> Self { Error::Operation(e) }
}
impl From<ParseIntError> for Error {
#[inline]
fn from(e: ParseIntError) -> Self { Error::Parse(e) }
}
/// An error that occurs when converting a `u32` to a lock time variant.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub struct ConversionError {
/// The expected timelock unit, height (blocks) or time (seconds).
unit: LockTimeUnit,
/// The invalid input value.
input: u32,
}
impl ConversionError {
/// Constructs a `ConversionError` from an invalid `n` when expecting a height value.
fn invalid_height(n: u32) -> Self { Self { unit: LockTimeUnit::Blocks, input: n } }
/// Constructs a `ConversionError` from an invalid `n` when expecting a time value.
fn invalid_time(n: u32) -> Self { Self { unit: LockTimeUnit::Seconds, input: n } }
}
impl fmt::Display for ConversionError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "invalid lock time value {}, {}", self.input, self.unit)
}
}
#[cfg(feature = "std")]
impl std::error::Error for ConversionError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { None }
}
/// Describes the two types of locking, lock-by-blockheight and lock-by-blocktime.
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
enum LockTimeUnit {
/// Lock by blockheight.
Blocks,
/// Lock by blocktime.
Seconds,
}
impl fmt::Display for LockTimeUnit {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use LockTimeUnit::*;
match *self {
Blocks => write!(f, "expected lock-by-blockheight (must be < {})", LOCK_TIME_THRESHOLD),
Seconds => write!(f, "expected lock-by-blocktime (must be >= {})", LOCK_TIME_THRESHOLD),
}
}
}
/// Errors than occur when operating on lock times.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub enum OperationError {
/// Cannot compare different lock time units (height vs time).
InvalidComparison,
}
impl fmt::Display for OperationError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use OperationError::*;
match *self {
InvalidComparison =>
f.write_str("cannot compare different lock units (height vs time)"),
}
}
}
#[cfg(feature = "std")]
impl std::error::Error for OperationError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
use OperationError::*;
match *self {
InvalidComparison => None,
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn display_and_alternate() {
let n = LockTime::from_consensus(741521);
let s = format!("{}", n);
assert_eq!(&s, "741521");
let got = format!("{:#}", n);
assert_eq!(got, "block-height 741521");
}
#[test]
fn time_from_str_hex_happy_path() {
let actual = Time::from_hex_str("0x6289C350").unwrap();
let expected = Time::from_consensus(0x6289C350).unwrap();
assert_eq!(actual, expected);
}
#[test]
fn time_from_str_hex_no_prefix_happy_path() {
let time = Time::from_hex_str_no_prefix("6289C350").unwrap();
assert_eq!(time, Time(0x6289C350));
}
#[test]
fn time_from_str_hex_invalid_hex_should_err() {
let hex = "0xzb93";
let result = Time::from_hex_str(hex);
assert!(result.is_err());
}
#[test]
fn packed_lock_time_from_str_hex_happy_path() {
let actual = LockTime::from_hex_str("0xBA70D").unwrap();
let expected = LockTime::from_consensus(0xBA70D);
assert_eq!(actual, expected);
}
#[test]
fn packed_lock_time_from_str_hex_no_prefix_happy_path() {
let lock_time = LockTime::from_hex_str_no_prefix("BA70D").unwrap();
assert_eq!(lock_time, LockTime::from_consensus(0xBA70D));
}
#[test]
fn packed_lock_time_from_str_hex_invalid_hex_should_ergr() {
let hex = "0xzb93";
let result = LockTime::from_hex_str(hex);
assert!(result.is_err());
}
#[test]
fn height_from_str_hex_happy_path() {
let actual = Height::from_hex_str("0xBA70D").unwrap();
let expected = Height(0xBA70D);
assert_eq!(actual, expected);
}
#[test]
fn height_from_str_hex_no_prefix_happy_path() {
let height = Height::from_hex_str_no_prefix("BA70D").unwrap();
assert_eq!(height, Height(0xBA70D));
}
#[test]
fn height_from_str_hex_invalid_hex_should_err() {
let hex = "0xzb93";
let result = Height::from_hex_str(hex);
assert!(result.is_err());
}
#[test]
fn parses_correctly_to_height_or_time() {
let lock = LockTime::from_consensus(750_000);
assert!(lock.is_block_height());
assert!(!lock.is_block_time());
let t: u32 = 1653195600; // May 22nd, 5am UTC.
let lock = LockTime::from_consensus(t);
assert!(!lock.is_block_height());
assert!(lock.is_block_time());
}
#[test]
fn satisfied_by_height() {
let lock = LockTime::from_consensus(750_000);
let height = Height::from_consensus(800_000).expect("failed to parse height");
let t: u32 = 1653195600; // May 22nd, 5am UTC.
let time = Time::from_consensus(t).expect("invalid time value");
assert!(lock.is_satisfied_by(height, time))
}
#[test]
fn satisfied_by_time() {
let lock = LockTime::from_consensus(1053195600);
let t: u32 = 1653195600; // May 22nd, 5am UTC.
let time = Time::from_consensus(t).expect("invalid time value");
let height = Height::from_consensus(800_000).expect("failed to parse height");
assert!(lock.is_satisfied_by(height, time))
}
#[test]
fn satisfied_by_same_height() {
let h = 750_000;
let lock = LockTime::from_consensus(h);
let height = Height::from_consensus(h).expect("failed to parse height");
let t: u32 = 1653195600; // May 22nd, 5am UTC.
let time = Time::from_consensus(t).expect("invalid time value");
assert!(lock.is_satisfied_by(height, time))
}
#[test]
fn satisfied_by_same_time() {
let t: u32 = 1653195600; // May 22nd, 5am UTC.
let lock = LockTime::from_consensus(t);
let time = Time::from_consensus(t).expect("invalid time value");
let height = Height::from_consensus(800_000).expect("failed to parse height");
assert!(lock.is_satisfied_by(height, time))
}
#[test]
fn height_correctly_implies() {
let lock = LockTime::from_consensus(750_005);
assert!(!lock.is_implied_by(LockTime::from_consensus(750_004)));
assert!(lock.is_implied_by(LockTime::from_consensus(750_005)));
assert!(lock.is_implied_by(LockTime::from_consensus(750_006)));
}
#[test]
fn time_correctly_implies() {
let t: u32 = 1700000005;
let lock = LockTime::from_consensus(t);
assert!(!lock.is_implied_by(LockTime::from_consensus(1700000004)));
assert!(lock.is_implied_by(LockTime::from_consensus(1700000005)));
assert!(lock.is_implied_by(LockTime::from_consensus(1700000006)));
}
#[test]
fn incorrect_units_do_not_imply() {
let lock = LockTime::from_consensus(750_005);
assert!(!lock.is_implied_by(LockTime::from_consensus(1700000004)));
}
}