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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952
//! Common types and utilities used in incremental Merkle tree implementations.
//!
//! # Navigating Tree Structure
//!
//! Several different abstractions are used for navigating tree structure. Consider this example
//! binary tree:
//!
//! ```text
//! a
//! / \
//! / \
//! / \
//! b c
//! / \ / \
//! d e f g
//! ````
//!
//! **Location Abstractions:**
//!
//! - [Level] represents the height from the leaves. Examples: `e` is level 0, `c` is level 1, `a`
//! is level 2.
//! - `index` is the 0-based distance from the left-most node _on a given [Level]_. Examples: `f`
//! has index 2, `c` has index 1, and `a` has index 0.
//! - [Position] is a type abstraction of the index of a leaf at [Level] 0.
//! - [Address] locates any node within a tree by representing the [Level] and `index`. Examples:
//! the [Address] of `c` is at [Level] 1 and index 1, the [Address] of `f` is at [Level] 0,
//! index 2.
//!
//! **Relationship Abstractions:**
//!
//! A given node has these navigational relationships:
//!
//! - `parent` - the node directly above at one higher [Level].
//! - `child` - the complementary relationship to parent; a parent may have up to two children
//! because only binary trees are supported.
//! - `sibling` - the other node with the same parent.
//! - `cousin` - a node at the same [Level] excluding the sibling.
//! - `ommer` - the parent's sibling.
//! - `root` - the single node with the largest [Level].
//! - `ancestor` - the parent or an ancestor of the parent; the root is an ancestor of every
//! other node.
//!
//! Note: we often refer to `ommers` (plural) when describing leaf-to-root paths, so in that
//! context `ommers` refers to the node's ommer, plus each ancestor's ommer.
#![cfg_attr(docsrs, feature(doc_cfg))]
use either::Either;
use std::cmp::Ordering;
use std::convert::{TryFrom, TryInto};
use std::fmt;
use std::num::TryFromIntError;
use std::ops::{Add, AddAssign, Range, Sub};
pub mod frontier;
#[cfg(feature = "legacy-api")]
#[cfg_attr(docsrs, doc(cfg(feature = "legacy-api")))]
pub mod witness;
#[cfg(any(test, feature = "test-dependencies"))]
#[cfg_attr(docsrs, doc(cfg(feature = "test-dependencies")))]
pub mod testing;
/// A type for metadata that is used to determine when and how a leaf can be pruned from a tree.
#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
pub enum Retention<C> {
Ephemeral,
Checkpoint { id: C, is_marked: bool },
Marked,
}
impl<C> Retention<C> {
pub fn is_checkpoint(&self) -> bool {
matches!(self, Retention::Checkpoint { .. })
}
pub fn is_marked(&self) -> bool {
match self {
Retention::Ephemeral => false,
Retention::Checkpoint { is_marked, .. } => *is_marked,
Retention::Marked => true,
}
}
pub fn map<'a, D, F: Fn(&'a C) -> D>(&'a self, f: F) -> Retention<D> {
match self {
Retention::Ephemeral => Retention::Ephemeral,
Retention::Checkpoint { id, is_marked } => Retention::Checkpoint {
id: f(id),
is_marked: *is_marked,
},
Retention::Marked => Retention::Marked,
}
}
}
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum Source {
/// The sibling to the address can be derived from the incremental frontier
/// at the contained ommer index
Past(u8),
/// The sibling to the address must be obtained from values discovered by
/// the addition of more nodes to the tree
Future,
}
#[must_use = "iterators are lazy and do nothing unless consumed"]
struct WitnessAddrsIter {
root_level: Level,
current: Address,
ommer_count: u8,
}
impl Iterator for WitnessAddrsIter {
type Item = (Address, Source);
fn next(&mut self) -> Option<(Address, Source)> {
if self.current.level() < self.root_level {
let current = self.current;
let source = if current.is_right_child() {
Source::Past(self.ommer_count)
} else {
Source::Future
};
self.current = current.parent();
if matches!(source, Source::Past(_)) {
self.ommer_count += 1;
}
Some((current.sibling(), source))
} else {
None
}
}
}
/// A type representing the position of a leaf in a Merkle tree.
#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[repr(transparent)]
pub struct Position(u64);
impl Position {
/// Return whether the position refers to the right-hand child of a subtree with
/// its root at level 1.
pub fn is_right_child(&self) -> bool {
self.0 & 0x1 == 1
}
/// Returns the minimum possible level of the root of a binary tree containing at least
/// `self + 1` leaves.
pub fn root_level(&self) -> Level {
Level((u64::BITS - self.0.leading_zeros()) as u8)
}
/// Returns the number of cousins and/or ommers required to construct an authentication
/// path to the root of a merkle tree that has `self + 1` leaves.
pub fn past_ommer_count(&self) -> u8 {
(0..self.root_level().0)
.filter(|i| (self.0 >> i) & 0x1 == 1)
.count()
.try_into()
.unwrap() // this is safe because we're counting within a `u8` range
}
/// Returns whether the binary tree having `self` as the position of the rightmost leaf
/// contains a perfect balanced tree with a root at level `root_level` that contains the
/// aforesaid leaf.
pub fn is_complete_subtree(&self, root_level: Level) -> bool {
!(0..(root_level.0)).any(|l| self.0 & (1 << l) == 0)
}
/// Returns an iterator over the addresses of nodes required to create a witness for this
/// position, beginning with the sibling of the leaf at this position and ending with the
/// sibling of the ancestor of the leaf at this position that is required to compute a root at
/// the specified level.
pub fn witness_addrs(&self, root_level: Level) -> impl Iterator<Item = (Address, Source)> {
WitnessAddrsIter {
root_level,
current: Address::from(*self),
ommer_count: 0,
}
}
}
impl From<Position> for u64 {
fn from(p: Position) -> Self {
p.0
}
}
impl From<u64> for Position {
fn from(sz: u64) -> Self {
Self(sz)
}
}
impl Add<u64> for Position {
type Output = Position;
fn add(self, other: u64) -> Self {
Position(self.0 + other)
}
}
impl AddAssign<u64> for Position {
fn add_assign(&mut self, other: u64) {
self.0 += other
}
}
impl Sub<u64> for Position {
type Output = Position;
fn sub(self, other: u64) -> Self {
if self.0 < other {
panic!("position underflow");
}
Position(self.0 - other)
}
}
impl TryFrom<usize> for Position {
type Error = TryFromIntError;
fn try_from(sz: usize) -> Result<Self, Self::Error> {
<u64>::try_from(sz).map(Self)
}
}
impl TryFrom<Position> for usize {
type Error = TryFromIntError;
fn try_from(p: Position) -> Result<Self, Self::Error> {
<usize>::try_from(p.0)
}
}
/// A type-safe wrapper for indexing into "levels" of a binary tree, such that
/// nodes at level `0` are leaves, nodes at level `1` are parents of nodes at
/// level `0`, and so forth. This type is capable of representing levels in
/// trees containing up to 2^255 leaves.
#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[repr(transparent)]
pub struct Level(u8);
impl Level {
pub const fn new(value: u8) -> Self {
Self(value)
}
// TODO: replace with an instance for `Step<Level>` once `step_trait`
// is stabilized
pub fn iter_to(self, other: Level) -> impl Iterator<Item = Self> {
(self.0..other.0).map(Level)
}
}
impl Add<u8> for Level {
type Output = Self;
fn add(self, value: u8) -> Self {
Self(self.0 + value)
}
}
impl From<u8> for Level {
fn from(value: u8) -> Self {
Self(value)
}
}
impl From<Level> for u8 {
fn from(level: Level) -> u8 {
level.0
}
}
impl From<Level> for u32 {
fn from(level: Level) -> u32 {
level.0.into()
}
}
impl From<Level> for u64 {
fn from(level: Level) -> u64 {
level.0.into()
}
}
impl From<Level> for usize {
fn from(level: Level) -> usize {
// Supporting sub-8-bit platforms isn't on our roadmap.
level.0 as usize
}
}
impl TryFrom<usize> for Level {
type Error = TryFromIntError;
fn try_from(sz: usize) -> Result<Self, Self::Error> {
<u8>::try_from(sz).map(Self)
}
}
impl Sub<u8> for Level {
type Output = Self;
fn sub(self, value: u8) -> Self {
if self.0 < value {
panic!("underflow")
}
Self(self.0 - value)
}
}
/// The address of a node of the Merkle tree.
/// When `level == 0`, the index has the same value as the
/// position.
#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Address {
level: Level,
index: u64,
}
impl Address {
/// Construct a new address from its constituent parts.
pub fn from_parts(level: Level, index: u64) -> Self {
Address { level, index }
}
/// Returns the address at the given level that contains the specified leaf position.
pub fn above_position(level: Level, position: Position) -> Self {
Address {
level,
index: position.0 >> level.0,
}
}
/// Returns the level of the root of the tree having its root at this address.
pub fn level(&self) -> Level {
self.level
}
/// Returns the index of the address.
///
/// The index of an address is defined as the number of subtrees with their roots
/// at the address's level that appear to the left of this address in a binary
/// tree of arbitrary height > level * 2 + 1.
pub fn index(&self) -> u64 {
self.index
}
/// The address of the node one level higher than this in a binary tree that contains
/// this address as either its left or right child.
pub fn parent(&self) -> Address {
Address {
level: self.level + 1,
index: self.index >> 1,
}
}
/// Returns the address that shares the same parent as this address.
pub fn sibling(&self) -> Address {
Address {
level: self.level,
index: self.index ^ 1,
}
}
/// Returns the immediate children of this address.
pub fn children(&self) -> Option<(Address, Address)> {
if self.level == Level::from(0) {
None
} else {
let left = Address {
level: self.level - 1,
index: self.index << 1,
};
let right = Address {
level: self.level - 1,
index: (self.index << 1) + 1,
};
Some((left, right))
}
}
/// Returns whether this address is an ancestor of the specified address.
pub fn is_ancestor_of(&self, addr: &Self) -> bool {
self.level > addr.level && { addr.index >> (self.level.0 - addr.level.0) == self.index }
}
/// Returns the common ancestor of `self` and `other` having the smallest level value.
pub fn common_ancestor(&self, other: &Self) -> Self {
// We can leverage the symmetry of a binary tree to share the calculation logic,
// by ordering the nodes.
let (higher, lower) = if self.level >= other.level {
(self, other)
} else {
(other, self)
};
// We follow the lower node's subtree up to the same level as the higher node, and
// then use their XOR distance to determine how many levels of the tree their
// Merkle paths differ on.
let lower_ancestor_idx = lower.index >> (higher.level.0 - lower.level.0);
let index_delta = higher.index ^ lower_ancestor_idx;
let level_delta = (u64::BITS - index_delta.leading_zeros()) as u8;
Address {
level: higher.level + level_delta,
index: std::cmp::max(higher.index, lower_ancestor_idx) >> level_delta,
}
}
/// Returns whether this address is an ancestor of, or is equal to,
/// the specified address.
pub fn contains(&self, addr: &Self) -> bool {
self == addr || self.is_ancestor_of(addr)
}
/// Returns the minimum value among the range of leaf positions that are contained within the
/// tree with its root at this address.
pub fn position_range_start(&self) -> Position {
(self.index << self.level.0).try_into().unwrap()
}
/// Returns the (exclusive) end of the range of leaf positions that are contained within the
/// tree with its root at this address.
pub fn position_range_end(&self) -> Position {
((self.index + 1) << self.level.0).try_into().unwrap()
}
/// Returns the maximum value among the range of leaf positions that are contained within the
/// tree with its root at this address.
pub fn max_position(&self) -> Position {
self.position_range_end() - 1
}
/// Returns the end-exclusive range of leaf positions that are contained within the tree with
/// its root at this address.
pub fn position_range(&self) -> Range<Position> {
Range {
start: self.position_range_start(),
end: self.position_range_end(),
}
}
/// Returns either the ancestor of this address at the given level (if the level is greater
/// than or equal to that of this address) or the range of indices of root addresses of
/// subtrees with roots at the given level contained within the tree with its root at this
/// address otherwise.
pub fn context(&self, level: Level) -> Either<Address, Range<u64>> {
if level >= self.level {
Either::Left(Address {
level,
index: self.index >> (level.0 - self.level.0),
})
} else {
let shift = self.level.0 - level.0;
Either::Right(Range {
start: self.index << shift,
end: (self.index + 1) << shift,
})
}
}
/// Returns whether the tree with this root address contains the given leaf position, or if not
/// whether an address at the same level with a greater or lesser index will contain the
/// specified leaf position.
pub fn position_cmp(&self, pos: Position) -> Ordering {
let range = self.position_range();
if range.start > pos {
Ordering::Greater
} else if range.end <= pos {
Ordering::Less
} else {
Ordering::Equal
}
}
/// Returns whether this address is the left-hand child of its parent
pub fn is_left_child(&self) -> bool {
self.index & 0x1 == 0
}
/// Returns whether this address is the right-hand child of its parent
pub fn is_right_child(&self) -> bool {
self.index & 0x1 == 1
}
pub fn current_incomplete(&self) -> Address {
// find the first zero bit in the index, searching from the least significant bit
let mut index = self.index;
for level in self.level.0.. {
if index & 0x1 == 1 {
index >>= 1;
} else {
return Address {
level: Level(level),
index,
};
}
}
unreachable!("The loop will always terminate via return in at most 64 iterations.")
}
pub fn next_incomplete_parent(&self) -> Address {
if self.is_right_child() {
self.current_incomplete()
} else {
let complete = Address {
level: self.level,
index: self.index + 1,
};
complete.current_incomplete()
}
}
/// Increments this address's index by 1 and returns the resulting address.
pub fn next_at_level(&self) -> Address {
Address {
level: self.level,
index: self.index + 1,
}
}
}
impl From<Position> for Address {
fn from(p: Position) -> Self {
Address {
level: 0.into(),
index: p.into(),
}
}
}
impl<'a> From<&'a Position> for Address {
fn from(p: &'a Position) -> Self {
Address {
level: 0.into(),
index: (*p).into(),
}
}
}
impl From<Address> for Option<Position> {
fn from(addr: Address) -> Self {
if addr.level == 0.into() {
Some(addr.index.into())
} else {
None
}
}
}
impl<'a> From<&'a Address> for Option<Position> {
fn from(addr: &'a Address) -> Self {
if addr.level == 0.into() {
Some(addr.index.into())
} else {
None
}
}
}
/// A path from a position in a particular commitment tree to the root of that tree.
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct MerklePath<H, const DEPTH: u8> {
path_elems: Vec<H>,
position: Position,
}
impl<H, const DEPTH: u8> MerklePath<H, DEPTH> {
/// Constructs a Merkle path directly from a path and position.
#[allow(clippy::result_unit_err)]
pub fn from_parts(path_elems: Vec<H>, position: Position) -> Result<Self, ()> {
if path_elems.len() == usize::from(DEPTH) {
Ok(MerklePath {
path_elems,
position,
})
} else {
Err(())
}
}
pub fn path_elems(&self) -> &[H] {
&self.path_elems
}
pub fn position(&self) -> Position {
self.position
}
}
impl<H: Hashable, const DEPTH: u8> MerklePath<H, DEPTH> {
/// Returns the root of the tree corresponding to this path applied to `leaf`.
pub fn root(&self, leaf: H) -> H {
self.path_elems
.iter()
.zip(0u8..)
.fold(leaf, |root, (h, i)| {
if (self.position.0 >> i) & 0x1 == 0 {
H::combine(i.into(), &root, h)
} else {
H::combine(i.into(), h, &root)
}
})
}
}
/// A trait describing the operations that make a type suitable for use as
/// a leaf or node value in a merkle tree.
pub trait Hashable: fmt::Debug {
fn empty_leaf() -> Self;
/// Combines two provided nodes that both exist at the specified level of the tree,
/// producing a new node at level `level + 1`.
fn combine(level: Level, a: &Self, b: &Self) -> Self;
/// Produces an empty root at the specified level of the tree by combining empty leaf values.
///
/// At each successive level, the value is produced by combining the value at the level below
/// with a copy of itself.
fn empty_root(level: Level) -> Self
where
Self: Sized,
{
Level::from(0)
.iter_to(level)
.fold(Self::empty_leaf(), |v, lvl| Self::combine(lvl, &v, &v))
}
}
#[cfg(test)]
pub(crate) mod tests {
use crate::MerklePath;
use super::{Address, Level, Position, Source};
use core::ops::Range;
use either::Either;
#[test]
fn position_is_complete_subtree() {
assert!(Position(0).is_complete_subtree(Level(0)));
assert!(Position(1).is_complete_subtree(Level(1)));
assert!(!Position(2).is_complete_subtree(Level(1)));
assert!(!Position(2).is_complete_subtree(Level(2)));
assert!(Position(3).is_complete_subtree(Level(2)));
assert!(!Position(4).is_complete_subtree(Level(2)));
assert!(Position(7).is_complete_subtree(Level(3)));
assert!(Position(u32::MAX as u64).is_complete_subtree(Level(32)));
}
#[test]
fn position_past_ommer_count() {
assert_eq!(0, Position(0).past_ommer_count());
assert_eq!(1, Position(1).past_ommer_count());
assert_eq!(1, Position(2).past_ommer_count());
assert_eq!(2, Position(3).past_ommer_count());
assert_eq!(1, Position(4).past_ommer_count());
assert_eq!(3, Position(7).past_ommer_count());
assert_eq!(1, Position(8).past_ommer_count());
}
#[test]
fn position_root_level() {
assert_eq!(Level(0), Position(0).root_level());
assert_eq!(Level(1), Position(1).root_level());
assert_eq!(Level(2), Position(2).root_level());
assert_eq!(Level(2), Position(3).root_level());
assert_eq!(Level(3), Position(4).root_level());
assert_eq!(Level(3), Position(7).root_level());
assert_eq!(Level(4), Position(8).root_level());
}
#[test]
fn position_witness_addrs() {
use Source::*;
let path_elem = |l, i, s| (Address::from_parts(Level::from(l), i), s);
assert_eq!(
vec![path_elem(0, 1, Future), path_elem(1, 1, Future)],
Position::from(0)
.witness_addrs(Level::from(2))
.collect::<Vec<_>>()
);
assert_eq!(
vec![path_elem(0, 3, Future), path_elem(1, 0, Past(0))],
Position::from(2)
.witness_addrs(Level::from(2))
.collect::<Vec<_>>()
);
assert_eq!(
vec![
path_elem(0, 2, Past(0)),
path_elem(1, 0, Past(1)),
path_elem(2, 1, Future)
],
Position::from(3)
.witness_addrs(Level::from(3))
.collect::<Vec<_>>()
);
assert_eq!(
vec![
path_elem(0, 5, Future),
path_elem(1, 3, Future),
path_elem(2, 0, Past(0)),
path_elem(3, 1, Future)
],
Position::from(4)
.witness_addrs(Level::from(4))
.collect::<Vec<_>>()
);
assert_eq!(
vec![
path_elem(0, 7, Future),
path_elem(1, 2, Past(0)),
path_elem(2, 0, Past(1)),
path_elem(3, 1, Future)
],
Position::from(6)
.witness_addrs(Level::from(4))
.collect::<Vec<_>>()
);
}
#[test]
fn address_current_incomplete() {
let addr = |l, i| Address::from_parts(Level(l), i);
assert_eq!(addr(0, 0), addr(0, 0).current_incomplete());
assert_eq!(addr(1, 0), addr(0, 1).current_incomplete());
assert_eq!(addr(0, 2), addr(0, 2).current_incomplete());
assert_eq!(addr(2, 0), addr(0, 3).current_incomplete());
}
#[test]
fn address_next_incomplete_parent() {
let addr = |l, i| Address::from_parts(Level(l), i);
assert_eq!(addr(1, 0), addr(0, 0).next_incomplete_parent());
assert_eq!(addr(1, 0), addr(0, 1).next_incomplete_parent());
assert_eq!(addr(2, 0), addr(0, 2).next_incomplete_parent());
assert_eq!(addr(2, 0), addr(0, 3).next_incomplete_parent());
assert_eq!(addr(3, 0), addr(2, 0).next_incomplete_parent());
assert_eq!(addr(1, 2), addr(0, 4).next_incomplete_parent());
assert_eq!(addr(3, 0), addr(1, 2).next_incomplete_parent());
}
#[test]
fn addr_is_ancestor() {
let l0 = Level(0);
let l1 = Level(1);
assert!(Address::from_parts(l1, 0).is_ancestor_of(&Address::from_parts(l0, 0)));
assert!(Address::from_parts(l1, 0).is_ancestor_of(&Address::from_parts(l0, 1)));
assert!(!Address::from_parts(l1, 0).is_ancestor_of(&Address::from_parts(l0, 2)));
}
#[test]
fn addr_position_range() {
assert_eq!(
Address::from_parts(Level(0), 0).position_range(),
Range {
start: Position(0),
end: Position(1)
}
);
assert_eq!(
Address::from_parts(Level(1), 0).position_range(),
Range {
start: Position(0),
end: Position(2)
}
);
assert_eq!(
Address::from_parts(Level(2), 1).position_range(),
Range {
start: Position(4),
end: Position(8)
}
);
}
#[test]
fn addr_above_position() {
assert_eq!(
Address::above_position(Level(3), Position(9)),
Address::from_parts(Level(3), 1)
);
}
#[test]
fn addr_children() {
assert_eq!(Address::from_parts(Level(0), 1).children(), None);
assert_eq!(
Address::from_parts(Level(3), 1).children(),
Some((
Address::from_parts(Level(2), 2),
Address::from_parts(Level(2), 3),
))
);
}
#[test]
fn addr_is_ancestor_of() {
assert!(Address::from_parts(Level(3), 1).is_ancestor_of(&Address::from_parts(Level(2), 2)));
assert!(Address::from_parts(Level(3), 1).is_ancestor_of(&Address::from_parts(Level(1), 7)));
assert!(!Address::from_parts(Level(3), 1).is_ancestor_of(&Address::from_parts(Level(1), 8)));
}
#[test]
fn addr_context() {
assert_eq!(
Address::from_parts(Level(3), 1).context(Level(0)),
Either::Right(Range { start: 8, end: 16 })
);
assert_eq!(
Address::from_parts(Level(3), 4).context(Level(5)),
Either::Left(Address::from_parts(Level(5), 1))
);
}
#[test]
fn merkle_path_root() {
let path: MerklePath<String, 3> = MerklePath::from_parts(
vec!["a".to_string(), "cd".to_string(), "efgh".to_string()],
Position(1),
)
.unwrap();
assert_eq!(path.root("b".to_string()), "abcdefgh".to_string());
let path: MerklePath<String, 3> = MerklePath::from_parts(
vec!["d".to_string(), "ab".to_string(), "efgh".to_string()],
Position(2),
)
.unwrap();
assert_eq!(path.root("c".to_string()), "abcdefgh".to_string());
}
#[test]
fn addr_common_ancestor() {
// rt
// --------------- ----------------
// ------- ------- right -------
// ----- left ----- ----- ----- ----- ----- -----
// -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(2), 1).common_ancestor(&Address::from_parts(Level(3), 2)),
Address::from_parts(Level(5), 0)
);
// --------------------------
// --------------- ----------------
// ------- rt ------- -------
// ----- ----- left ----- ----- ----- ----- -----
// -- -- -- -- -- -- -- rg -- -- -- -- -- -- -- --
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(2), 2).common_ancestor(&Address::from_parts(Level(1), 7)),
Address::from_parts(Level(3), 1)
);
// --------------------------
// --------------- ----------------
// ------- rt ------- -------
// ----- ----- left ----- ----- ----- ----- -----
// -- -- -- -- -- -- rg -- -- -- -- -- -- -- -- --
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(2), 2).common_ancestor(&Address::from_parts(Level(1), 6)),
Address::from_parts(Level(3), 1)
);
// --------------------------
// --------------- ----------------
// ------- ------- ------- -------
// ----- ----- all ----- ----- ----- ----- -----
// -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(2), 2).common_ancestor(&Address::from_parts(Level(2), 2)),
Address::from_parts(Level(2), 2)
);
// --------------------------
// --------------- ----------------
// ------- ------- ------- -------
// ----- ----- lf,rt ----- ----- ----- ----- -----
// -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
// - - - - - - - - - rg - - - - - - - - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(2), 2).common_ancestor(&Address::from_parts(Level(0), 9)),
Address::from_parts(Level(2), 2)
);
// --------------------------
// --------------- ----------------
// ------- ------- ------- -------
// ----- ----- rg,rt ----- ----- ----- ----- -----
// -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
// - - - - - - - - - lf - - - - - - - - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(0), 9).common_ancestor(&Address::from_parts(Level(2), 2)),
Address::from_parts(Level(2), 2)
);
// --------------------------
// --------------- ----------------
// ------- ------- ------- -------
// ----- ----- ----- rt ----- ----- ----- -----
// -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
// - - - - - - - - - - - - lf - - rg - - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(0), 12).common_ancestor(&Address::from_parts(Level(0), 15)),
Address::from_parts(Level(2), 3)
);
// --------------------------
// --------------- ----------------
// ------- ------- ------- -------
// ----- ----- ----- rt ----- ----- ----- -----
// -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
// - - - - - - - - - - - - - lf - rg - - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(0), 13).common_ancestor(&Address::from_parts(Level(0), 15)),
Address::from_parts(Level(2), 3)
);
// --------------------------
// --------------- ----------------
// ------- ------- ------- -------
// ----- ----- ----- rt ----- ----- ----- -----
// -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
// - - - - - - - - - - - - - lf rg - - - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(0), 13).common_ancestor(&Address::from_parts(Level(0), 14)),
Address::from_parts(Level(2), 3)
);
// --------------------------
// --------------- ----------------
// ------- ------- ------- -------
// ----- ----- ----- ----- ----- ----- ----- -----
// -- -- -- -- -- -- -- rt -- -- -- -- -- -- -- --
// - - - - - - - - - - - - - - lf rg - - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(0), 14).common_ancestor(&Address::from_parts(Level(0), 15)),
Address::from_parts(Level(1), 7)
);
// rt
// --------------- ----------------
// ------- ------- ------- -------
// ----- ----- ----- ----- ----- ----- ----- -----
// -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
// - - - - - - - - - - - - - - - lf rg - - - - - - - - - - - - - - -
assert_eq!(
Address::from_parts(Level(0), 15).common_ancestor(&Address::from_parts(Level(0), 16)),
Address::from_parts(Level(5), 0)
);
}
}