Struct trie_db::NibbleSlice

pub struct NibbleSlice<'a> { /* fields omitted */ }

Nibble-orientated view onto byte-slice, allowing nibble-precision offsets.

This is an immutable struct. No operations actually change it.

Example

use patricia_trie::nibbleslice::NibbleSlice;
fn main() {
  let d1 = &[0x01u8, 0x23, 0x45];
  let d2 = &[0x34u8, 0x50, 0x12];
  let d3 = &[0x00u8, 0x12];
  let n1 = NibbleSlice::new(d1);			// 0,1,2,3,4,5
  let n2 = NibbleSlice::new(d2);			// 3,4,5,0,1,2
  let n3 = NibbleSlice::new_offset(d3, 1);	// 0,1,2
  assert!(n1 > n3);							// 0,1,2,... > 0,1,2
  assert!(n1 < n2);							// 0,... < 3,...
  assert!(n2.mid(3) == n3);					// 0,1,2 == 0,1,2
  assert!(n1.starts_with(&n3));
  assert_eq!(n1.common_prefix(&n3), 3);
  assert_eq!(n2.mid(3).common_prefix(&n1), 3);
}

Methods

impl<'a> NibbleSlice<'a>

pub fn new(data: &'a [u8]) -> Self

Create a new nibble slice with the given byte-slice.

pub fn new_offset(data: &'a [u8], offset: usize) -> Self

Create a new nibble slice with the given byte-slice with a nibble offset.

pub fn new_composed(a: &NibbleSlice<'a>, b: &NibbleSlice<'a>) -> Self

Create a composed nibble slice; one followed by the other.

pub fn iter(&'a self) -> NibbleSliceIterator<'a>

Get an iterator for the series of nibbles.

pub fn from_encoded(data: &'a [u8]) -> (NibbleSlice, bool)

Create a new nibble slice from the given HPE encoded data (e.g. output of encoded()).

pub fn is_empty(&self) -> bool

Is this an empty slice?

pub fn len(&self) -> usize

Get the length (in nibbles, naturally) of this slice.

pub fn at(&self, i: usize) -> u8

Get the nibble at position i.

pub fn mid(&self, i: usize) -> NibbleSlice<'a>

Return object which represents a view on to this slice (further) offset by i nibbles.

pub fn starts_with(&self, them: &Self) -> bool

Do we start with the same nibbles as the whole of them?

pub fn common_prefix(&self, them: &Self) -> usize

How many of the same nibbles at the beginning do we match with them?

pub fn encoded(&self, is_leaf: bool) -> ElasticArray36<u8>

Encode while nibble slice in prefixed hex notation, noting whether it is_leaf.

pub fn encoded_leftmost(&self, n: usize, is_leaf: bool) -> ElasticArray36<u8>

Encode only the leftmost n bytes of the nibble slice in prefixed hex notation, noting whether it is_leaf.

Trait Implementations

impl<'a> Eq for NibbleSlice<'a>

impl<'a> PartialOrd<NibbleSlice<'a>> for NibbleSlice<'a>

fn partial_cmp(&self, them: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use] fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use] fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use] fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use] fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> Copy for NibbleSlice<'a>

impl<'a> PartialEq<NibbleSlice<'a>> for NibbleSlice<'a>

fn eq(&self, them: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'a> Clone for NibbleSlice<'a>

fn clone(&self) -> NibbleSlice<'a>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Ord for NibbleSlice<'a>

fn cmp(&self, other: &NibbleSlice<'a>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl<'a> Debug for NibbleSlice<'a>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.