Enum rustreexo::accumulator::node_hash::NodeHash

source ·

pub enum NodeHash {
    Empty,
    Placeholder,
    Some([u8; 32]),
}

Expand description

NodeHash is a wrapper around a 32 byte array that represents a hash of a node in the tree.

Example

use rustreexo::accumulator::node_hash::NodeHash;
let hash = NodeHash::new([0; 32]);
assert_eq!(
    hash.to_string().as_str(),
    "0000000000000000000000000000000000000000000000000000000000000000"
);

Variants§

§

Empty

§

Placeholder

§

Some([u8; 32])

Implementations§

source §

impl NodeHash

source

pub fn is_empty(&self) -> bool

Tells whether this hash is empty. We use empty hashes throughout the code to represent leaves we want to delete.

source

pub fn new(inner: [u8; 32]) -> Self

Creates a new NodeHash from a 32 byte array.

Example

use rustreexo::accumulator::node_hash::NodeHash;
let hash = NodeHash::new([0; 32]);
assert_eq!(
    hash.to_string().as_str(),
    "0000000000000000000000000000000000000000000000000000000000000000"
);

source

pub fn empty() -> Self

Creates an empty hash. This is used to represent leaves we want to delete.

Example

use rustreexo::accumulator::node_hash::NodeHash;
let hash = NodeHash::empty();
assert!(hash.is_empty());

source

pub fn parent_hash(left: &NodeHash, right: &NodeHash) -> NodeHash

parent_hash return the merkle parent of the two passed in nodes.

Example

use std::str::FromStr;

use rustreexo::accumulator::node_hash::NodeHash;
let left = NodeHash::new([0; 32]);
let right = NodeHash::new([1; 32]);
let parent = NodeHash::parent_hash(&left, &right);
let expected_parent =
    NodeHash::from_str("34e33ca0c40b7bd33d28932ca9e35170def7309a3bf91ecda5e1ceb067548a12")
        .unwrap();
assert_eq!(parent, expected_parent);

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pub const fn placeholder() -> Self

Returns a arbitrary placeholder hash that is unlikely to collide with any other hash. We use this while computing roots to destroy. Don’t confuse this with an empty hash.

Methods from Deref<Target = [u8; 32]>§

1.57.0 · source

pub fn as_slice(&self) -> &[T]

Returns a slice containing the entire array. Equivalent to &s[..].

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pub fn each_ref(&self) -> [&T; N]

🔬This is a nightly-only experimental API. (array_methods)

Borrows each element and returns an array of references with the same size as self.

Example

#![feature(array_methods)]

let floats = [3.1, 2.7, -1.0];
let float_refs: [&f64; 3] = floats.each_ref();
assert_eq!(float_refs, [&3.1, &2.7, &-1.0]);

This method is particularly useful if combined with other methods, like map. This way, you can avoid moving the original array if its elements are not Copy.

#![feature(array_methods)]

let strings = ["Ferris".to_string(), "♥".to_string(), "Rust".to_string()];
let is_ascii = strings.each_ref().map(|s| s.is_ascii());
assert_eq!(is_ascii, [true, false, true]);

// We can still access the original array: it has not been moved.
assert_eq!(strings.len(), 3);

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pub fn split_array_ref<const M: usize>(&self) -> (&[T; M], &[T])

🔬This is a nightly-only experimental API. (split_array)

Divides one array reference into two at an index.

The first will contain all indices from [0, M) (excluding the index M itself) and the second will contain all indices from [M, N) (excluding the index N itself).

Panics

Panics if M > N.

Examples

#![feature(split_array)]

let v = [1, 2, 3, 4, 5, 6];

{
   let (left, right) = v.split_array_ref::<0>();
   assert_eq!(left, &[]);
   assert_eq!(right, &[1, 2, 3, 4, 5, 6]);
}

{
    let (left, right) = v.split_array_ref::<2>();
    assert_eq!(left, &[1, 2]);
    assert_eq!(right, &[3, 4, 5, 6]);
}

{
    let (left, right) = v.split_array_ref::<6>();
    assert_eq!(left, &[1, 2, 3, 4, 5, 6]);
    assert_eq!(right, &[]);
}

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pub fn rsplit_array_ref<const M: usize>(&self) -> (&[T], &[T; M])

🔬This is a nightly-only experimental API. (split_array)

Divides one array reference into two at an index from the end.

The first will contain all indices from [0, N - M) (excluding the index N - M itself) and the second will contain all indices from [N - M, N) (excluding the index N itself).

Panics

Panics if M > N.

Examples

#![feature(split_array)]

let v = [1, 2, 3, 4, 5, 6];

{
   let (left, right) = v.rsplit_array_ref::<0>();
   assert_eq!(left, &[1, 2, 3, 4, 5, 6]);
   assert_eq!(right, &[]);
}

{
    let (left, right) = v.rsplit_array_ref::<2>();
    assert_eq!(left, &[1, 2, 3, 4]);
    assert_eq!(right, &[5, 6]);
}

{
    let (left, right) = v.rsplit_array_ref::<6>();
    assert_eq!(left, &[]);
    assert_eq!(right, &[1, 2, 3, 4, 5, 6]);
}

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pub fn as_ascii(&self) -> Option<&[AsciiChar; N]>

🔬This is a nightly-only experimental API. (ascii_char)

Converts this array of bytes into a array of ASCII characters, or returns None if any of the characters is non-ASCII.

Examples

#![feature(ascii_char)]
#![feature(const_option)]

const HEX_DIGITS: [std::ascii::Char; 16] =
    *b"0123456789abcdef".as_ascii().unwrap();

assert_eq!(HEX_DIGITS[1].as_str(), "1");
assert_eq!(HEX_DIGITS[10].as_str(), "a");