Struct trie_db::NibbleSlice

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

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);
}

Implementations

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

Get an iterator for the series of nibbles.

pub fn from_stored(i: &NodeKey) -> NibbleSlice<'_>

Get nibble slice from a NodeKey.

pub fn to_stored(&self) -> NodeKey

Helper function to create a owned NodeKey from this NibbleSlice.

pub fn to_stored_range(&self, nb: usize) -> NodeKey

Helper function to create a owned NodeKey from this NibbleSlice, and for a given number of nibble. Warning this method can be slow (number of nibble does not align the original padding).

pub fn is_empty(&self) -> bool

Return true if the slice contains no nibbles.

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 advance(&mut self, i: usize)

Advance the view on the slice by i nibbles.

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

Move back to a previously valid fix offset position.

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 right(&'a self) -> Partial<'_>

Return Partial representation of this slice: first encoded byte and following slice.

pub fn right_iter(&'a self) -> impl Iterator<Item = u8> + 'a

Return an iterator over Partial bytes representation.

pub fn right_range_iter(&'a self, to: usize) -> impl Iterator<Item = u8> + 'a

Return Partial bytes iterator over a range of byte.. Warning can be slow when unaligned (similar to to_stored_range).

pub fn left(&'a self) -> Prefix<'_>

Return left portion of NibbleSlice, if the slice originates from a full key it will be the Prefix of the node.

pub fn original_data_as_prefix(&self) -> Prefix<'_>

Get Prefix representation of the inner data.

This means the entire inner data will be returned as Prefix, ignoring any offset.

pub fn left_owned(&'a self) -> (SmallVec<[u8; 40]>, Option<u8>)

Owned version of a Prefix from a left method call.

pub fn starts_with_vec(&self, other: &NibbleVec) -> bool

Same as Self::starts_with but using NibbleVec.

Trait Implementations

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> Debug for NibbleSlice<'a>

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

Formats the value using the given formatter.

impl<'a> From<NibbleSlice<'a>> for NodeKey

fn from(slice: NibbleSlice<'a>) -> NodeKey

Converts to this type from the input type.

impl<'a> From<NibbleSlice<'a>> for NibbleVec

fn from(s: NibbleSlice<'a>) -> Self

Converts to this type from the input type.

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

fn cmp(&self, them: &Self) -> Ordering

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

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

fn eq(&self, other: &NibbleVec) -> bool

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

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

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

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

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

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

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

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

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

fn lt(&self, other: &Rhs) -> bool

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

fn le(&self, other: &Rhs) -> bool

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

fn gt(&self, other: &Rhs) -> bool

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

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> Eq for NibbleSlice<'a>