Enum grovedb_merk::tree::Link

pub enum Link {
    Reference {
        hash: CryptoHash,
        child_heights: (u8, u8),
        key: Vec<u8>,
        sum: Option<i64>,
    },
    Modified {
        pending_writes: usize,
        child_heights: (u8, u8),
        tree: TreeNode,
    },
    Uncommitted {
        hash: CryptoHash,
        child_heights: (u8, u8),
        tree: TreeNode,
        sum: Option<i64>,
    },
    Loaded {
        hash: CryptoHash,
        child_heights: (u8, u8),
        tree: TreeNode,
        sum: Option<i64>,
    },
}

Represents a reference to a child tree node. Links may or may not contain the child’s Tree instance (storing its key if not).

Variants

Reference

Represents a child tree node which has been pruned from memory, only retaining a reference to it (its key). The child node can always be fetched from the backing store by this key when necessary.

Fields

hash: CryptoHash

Hash

child_heights: (u8, u8)

Child heights

key: Vec<u8>

Key

sum: Option<i64>

Sum

Modified

Represents a tree node which has been modified since the Tree’s last hash computation. The child’s hash is not stored since it has not yet been recomputed. The child’s Tree instance is stored in the link.

Fields

pending_writes: usize

Pending writes

child_heights: (u8, u8)

Child heights

tree: TreeNode

Tree

Uncommitted

Represents a tree node which has been modified since the Tree’s last commit, but which has an up-to-date hash. The child’s Tree instance is stored in the link.

Fields

hash: CryptoHash

Hash

child_heights: (u8, u8)

Child heights

tree: TreeNode

Tree

sum: Option<i64>

Sum

Loaded

Represents a tree node which has not been modified, has an up-to-date hash, and which is being retained in memory.

Fields

hash: CryptoHash

Hash

child_heights: (u8, u8)

Child heights

tree: TreeNode

Tree

sum: Option<i64>

Sum

Implementations

impl Link

pub const fn from_modified_tree(tree: TreeNode) -> Self

Creates a Link::Modified from the given Tree.

pub fn maybe_from_modified_tree(maybe_tree: Option<TreeNode>) -> Option<Self>

Creates a Link::Modified from the given tree, if any. If None, returns None.

pub const fn is_reference(&self) -> bool

Returns true if the link is of the Link::Reference variant.

pub const fn is_modified(&self) -> bool

Returns true if the link is of the Link::Modified variant.

pub const fn is_uncommitted(&self) -> bool

Returns true if the link is of the Link::Uncommitted variant.

pub const fn is_stored(&self) -> bool

Returns true if the link is of the Link::Loaded variant.

pub fn key(&self) -> &[u8]

Returns the key of the tree referenced by this link, as a slice.

pub const fn tree(&self) -> Option<&TreeNode>

Returns the Tree instance of the tree referenced by the link. If the link is of variant Link::Reference, the returned value will be None.

pub const fn hash(&self) -> &CryptoHash

Returns the hash of the tree referenced by the link. Panics if link is of variant Link::Modified since we have not yet recomputed the tree’s hash.

pub const fn sum(&self) -> Option<i64>

Returns the sum of the tree referenced by the link. Panics if link is of variant Link::Modified since we have not yet recomputed the tree’s hash.

pub const fn height(&self) -> u8

Returns the height of the children of the tree referenced by the link, if any (note: not the height of the referenced tree itself). Return value is (left_child_height, right_child_height).

pub const fn balance_factor(&self) -> i8

Returns the balance factor of the tree referenced by the link.

pub fn into_reference(self) -> Self

Consumes the link and converts to variant Link::Reference. Panics if the link is of variant Link::Modified or Link::Uncommitted.

pub const fn encoded_link_size( not_prefixed_key_len: u32, is_sum_tree: bool, ) -> u32

Encoded link size

pub fn encoding_cost(&self) -> Result<usize>

The encoding cost is always 8 bytes for the sum instead of a varint

Trait Implementations

impl Clone for Link

fn clone(&self) -> Link

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Link

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

Formats the value using the given formatter.

impl Decode for Link

fn decode<R: Read>(input: R) -> Result<Self>

Reads bytes from the reader and returns the decoded value.

fn decode_into<R: Read>(&mut self, input: R) -> Result<()>

Reads bytes from the reader and mutates self to the decoded value.

impl Encode for Link

fn encode_into<W: Write>(&self, out: &mut W) -> Result<()>

Writes the encoded representation of the value to the destination writer. Can error due to either a write error from dest, or an encoding error for types where invalid values are possible.

fn encoding_length(&self) -> Result<usize>

Calculates the length of the encoding for this value. Can error for types where invalid values are possible.

fn encode(&self) -> Result<Vec<u8>, Error>

Returns the encoded representation of the value as a Vec<u8>.

impl PartialEq for Link

fn eq(&self, other: &Link) -> 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 StructuralPartialEq for Link

impl Terminated for Link