Struct StoredNibblesSubKey 

pub struct StoredNibblesSubKey(pub Nibbles);

Available on crate feature trie only.

The representation of nibbles of the merkle trie stored in the database.

Tuple Fields

0: Nibbles

Methods from Deref<Target = Nibbles>

pub fn pack(&self) -> SmallVec<[u8; 32]>

Packs the nibbles into the given slice.

This method combines each pair of consecutive nibbles into a single byte, effectively reducing the size of the data by a factor of two.

If the number of nibbles is odd, the last nibble is shifted left by 4 bits and added to the packed byte vector.

Examples

let nibbles = Nibbles::from_nibbles(&[0x0A, 0x0B, 0x0C]);
assert_eq!(nibbles.pack()[..], [0xAB, 0xC0]);

pub fn pack_to(&self, out: &mut [u8])

Packs the nibbles into the given slice.

See pack for more information.

Panics

Panics if the slice is not at least (self.len() + 1) / 2 bytes long.

Examples

let nibbles = Nibbles::from_nibbles(&[0x0A, 0x0B, 0x0C]);
let mut packed = [0; 2];
nibbles.pack_to(&mut packed);
assert_eq!(packed[..], [0xAB, 0xC0]);

pub unsafe fn pack_to_unchecked(&self, ptr: *mut u8)

Packs the nibbles into the given pointer.

See pack for more information.

Safety

ptr must be valid for at least (self.len() + 1) / 2 bytes.

Examples

let nibbles = Nibbles::from_nibbles(&[0x0A, 0x0B, 0x0C, 0x0D]);
let mut packed = [0; 2];
// SAFETY: enough capacity.
unsafe { nibbles.pack_to_unchecked(packed.as_mut_ptr()) };
assert_eq!(packed[..], [0xAB, 0xCD]);

pub unsafe fn pack_to_slice_unchecked(&self, out: &mut [MaybeUninit<u8>])

Packs the nibbles into the given slice without checking its length.

See pack for more information.

Safety

out must be valid for at least (self.len() + 1) / 2 bytes.

pub fn to_vec(&self) -> Vec<u8>

Converts the nibbles into a vector of nibbles.

Examples

let nibbles = Nibbles::from_nibbles(&[0x0A, 0x0B, 0x0C, 0x0D]);
assert_eq!(nibbles.to_vec(), vec![0x0A, 0x0B, 0x0C, 0x0D]);

pub fn iter(&self) -> NibblesIter<'_>

Returns an iterator over the nibbles.

Examples

let nibbles = Nibbles::from_nibbles(&[0x0A, 0x0B, 0x0C, 0x0D]);
let collected: Vec<u8> = nibbles.iter().collect();
assert_eq!(collected, vec![0x0A, 0x0B, 0x0C, 0x0D]);

pub fn get_byte(&self, i: usize) -> Option<u8>

Gets the byte at the given index by combining two consecutive nibbles.

Examples

let nibbles = Nibbles::from_nibbles(&[0x0A, 0x0B, 0x0C, 0x0D]);
assert_eq!(nibbles.get_byte(0), Some(0xAB));
assert_eq!(nibbles.get_byte(1), Some(0xBC));
assert_eq!(nibbles.get_byte(2), Some(0xCD));
assert_eq!(nibbles.get_byte(3), None);

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

Gets the byte at the given index by combining two consecutive nibbles.

Panics

Panics if i..i + 1 is out of bounds.

Examples

let nibbles = Nibbles::from_nibbles(&[0x0A, 0x0B, 0x0C, 0x0D]);
// SAFETY: in range.
unsafe {
    assert_eq!(nibbles.get_byte_unchecked(0), 0xAB);
    assert_eq!(nibbles.get_byte_unchecked(1), 0xBC);
    assert_eq!(nibbles.get_byte_unchecked(2), 0xCD);
}

pub fn increment(&self) -> Option<Nibbles>

Increments the nibble sequence by one.

pub fn is_leaf(&self) -> bool

The last element of the hex vector is used to determine whether the nibble sequence represents a leaf or an extension node. If the last element is 0x10 (16), then it’s a leaf.

pub fn starts_with(&self, other: &Nibbles) -> bool

Returns true if this nibble sequence starts with the given prefix.

pub fn ends_with(&self, other: &Nibbles) -> bool

Returns true if this nibble sequence ends with the given suffix.

pub fn get(&self, i: usize) -> Option<u8>

Returns the nibble at the given index.

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

Returns the nibble at the given index.

Panics

Panics if the index is out of bounds.

pub fn first(&self) -> Option<u8>

Returns the first nibble of this nibble sequence.

pub fn last(&self) -> Option<u8>

Returns the last nibble of this nibble sequence.

pub fn common_prefix_length(&self, other: &Nibbles) -> usize

Returns the length of the common prefix between this nibble sequence and the given.

Examples

let a = Nibbles::from_nibbles(&[0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F]);
let b = Nibbles::from_nibbles(&[0x0A, 0x0B, 0x0C, 0x0E]);
assert_eq!(a.common_prefix_length(&b), 3);

pub fn is_empty(&self) -> bool

Returns true if this Nibbles is empty.

pub fn len(&self) -> usize

Returns the total number of nibbles in this Nibbles.

pub fn slice_unchecked(&self, start: usize, end: usize) -> Nibbles

Creates new nibbles containing the nibbles in the specified range [start, end) without checking bounds.

Safety

This method does not verify that the provided range is valid for this nibble sequence. The caller must ensure that start <= end and end <= self.len().

pub fn slice(&self, range: impl RangeBounds<usize>) -> Nibbles

Creates new nibbles containing the nibbles in the specified range.

Panics

This method will panic if the range is out of bounds for this nibble sequence.

pub fn join(&self, other: &Nibbles) -> Nibbles

Join two nibble sequences together.

Trait Implementations

impl<'arbitrary> Arbitrary<'arbitrary> for StoredNibblesSubKey

fn arbitrary( u: &mut Unstructured<'arbitrary>, ) -> Result<StoredNibblesSubKey, Error>

Generate an arbitrary value of Self from the given unstructured data.

fn arbitrary_take_rest( u: Unstructured<'arbitrary>, ) -> Result<StoredNibblesSubKey, Error>

Generate an arbitrary value of Self from the entirety of the given unstructured data.

fn size_hint(depth: usize) -> (usize, Option<usize>)

Get a size hint for how many bytes out of an Unstructured this type needs to construct itself.

fn try_size_hint( depth: usize, ) -> Result<(usize, Option<usize>), MaxRecursionReached>

Get a size hint for how many bytes out of an Unstructured this type needs to construct itself.

impl Clone for StoredNibblesSubKey

fn clone(&self) -> StoredNibblesSubKey

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Compact for StoredNibblesSubKey

fn to_compact<B>(&self, buf: &mut B) -> usize

where B: BufMut + AsMut<[u8]>,

Takes a buffer which can be written to. Ideally, it returns the length written to.

fn from_compact(buf: &[u8], _len: usize) -> (StoredNibblesSubKey, &[u8])

Takes a buffer which can be read from. Returns the object and buf with its internal cursor advanced (eg..advance(len)).

fn specialized_to_compact<B>(&self, buf: &mut B) -> usize

where B: BufMut + AsMut<[u8]>,

“Optional”: If there’s no good reason to use it, don’t.

fn specialized_from_compact(buf: &[u8], len: usize) -> (Self, &[u8])

“Optional”: If there’s no good reason to use it, don’t.

impl Compress for StoredNibblesSubKey

type Compressed = Vec<u8>

Compressed type.

fn compress_to_buf<B>(&self, buf: &mut B)

where B: BufMut + AsMut<[u8]>,

Compresses data to a given buffer.

fn uncompressable_ref(&self) -> Option<&[u8]>

If the type cannot be compressed, return its inner reference as Some(self.as_ref())

fn compress(self) -> Self::Compressed

Compresses data going into the database.

impl Debug for StoredNibblesSubKey

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

Formats the value using the given formatter.

impl Decode for StoredNibblesSubKey

fn decode(value: &[u8]) -> Result<StoredNibblesSubKey, DatabaseError>

Decodes data coming from the database.

fn decode_owned(value: Vec<u8>) -> Result<Self, DatabaseError>

Decodes owned data coming from the database.

impl Decompress for StoredNibblesSubKey

fn decompress(value: &[u8]) -> Result<StoredNibblesSubKey, DatabaseError>

Decompresses data coming from the database.

fn decompress_owned(value: Vec<u8>) -> Result<Self, DatabaseError>

Decompresses owned data coming from the database.

impl Deref for StoredNibblesSubKey

type Target = Nibbles

The resulting type after dereferencing.

fn deref(&self) -> &<StoredNibblesSubKey as Deref>::Target

Dereferences the value.

impl<'de> Deserialize<'de> for StoredNibblesSubKey

fn deserialize<__D>( __deserializer: __D, ) -> Result<StoredNibblesSubKey, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Encode for StoredNibblesSubKey

type Encoded = Vec<u8>

Encoded type.

fn encode(self) -> <StoredNibblesSubKey as Encode>::Encoded

Encodes data going into the database.

impl From<Nibbles> for StoredNibblesSubKey

fn from(value: Nibbles) -> StoredNibblesSubKey

Converts to this type from the input type.

impl From<StoredNibblesSubKey> for Nibbles

fn from(value: StoredNibblesSubKey) -> Nibbles

Converts to this type from the input type.

impl From<Vec<u8>> for StoredNibblesSubKey

fn from(value: Vec<u8>) -> StoredNibblesSubKey

Converts to this type from the input type.

impl Hash for StoredNibblesSubKey

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for StoredNibblesSubKey

fn cmp(&self, other: &StoredNibblesSubKey) -> 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,

Restrict a value to a certain interval.

impl PartialEq for StoredNibblesSubKey

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl PartialOrd for StoredNibblesSubKey

fn partial_cmp(&self, other: &StoredNibblesSubKey) -> Option<Ordering>

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl Serialize for StoredNibblesSubKey

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for StoredNibblesSubKey

impl StructuralPartialEq for StoredNibblesSubKey

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 40 bytes