Enum ArtNode 

pub enum ArtNode {
    Node4 {
        prefix: Vec<u8>,
        keys: [u8; 4],
        children: [Option<Box<ArtNode>>; 4],
        offsets: Vec<u64>,
        overflow_offsets: Vec<u64>,
        count: u16,
    },
    Node16 {
        prefix: Vec<u8>,
        keys: [u8; 16],
        children: [Option<Box<ArtNode>>; 16],
        offsets: Vec<u64>,
        overflow_offsets: Vec<u64>,
        count: u16,
    },
    Node48 {
        prefix: Vec<u8>,
        child_index: [u8; 256],
        children: Box<[Option<Box<ArtNode>>; 48]>,
        offsets: Vec<u64>,
        overflow_offsets: Vec<u64>,
        count: u16,
    },
    Node256 {
        prefix: Vec<u8>,
        children: Box<[Option<Box<ArtNode>>; 256]>,
        offsets: Vec<u64>,
        overflow_offsets: Vec<u64>,
        count: u16,
    },
}

An ART node — stores a prefix, child pointers, and value offsets.

Uses a flat enum to model the four growth stages. Each variant stores a fixed-size array of children (or indirect index + compact array).

Variants

Node4

Fields

prefix: Vec<u8>

keys: [u8; 4]

children: [Option<Box<ArtNode>>; 4]

offsets: Vec<u64>

overflow_offsets: Vec<u64>

count: u16

Node16

Fields

prefix: Vec<u8>

keys: [u8; 16]

children: [Option<Box<ArtNode>>; 16]

offsets: Vec<u64>

overflow_offsets: Vec<u64>

count: u16

Node48

Fields

prefix: Vec<u8>

child_index: [u8; 256]

children: Box<[Option<Box<ArtNode>>; 48]>

offsets: Vec<u64>

overflow_offsets: Vec<u64>

count: u16

Node256

Fields

prefix: Vec<u8>

children: Box<[Option<Box<ArtNode>>; 256]>

offsets: Vec<u64>

overflow_offsets: Vec<u64>

count: u16

Implementations

impl ArtNode

pub fn new_node4() -> Self

Create a new empty Node4.

pub fn kind(&self) -> NodeKind

Get the node kind.

pub fn count(&self) -> u16

Get the number of children.

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

Get the prefix bytes.

pub fn prefix_mut(&mut self) -> &mut Vec<u8>

Get the prefix bytes (mutable).

pub fn has_offsets(&self) -> bool

Returns true if this node has any offsets (i.e., it’s a leaf or contains leaves).

pub fn all_offsets(&self) -> Vec<u64>

Get all offsets (primary + overflow) as a slice.

pub fn insert_child(&mut self, byte: u8, child: Box<ArtNode>)

Insert a child at the given byte. Grows the node if necessary.

pub fn get_child(&self, byte: u8) -> Option<&ArtNode>

Get a child by byte, if it exists.

pub fn get_child_mut(&mut self, byte: u8) -> Option<&mut Box<ArtNode>>

Get a mutable child by byte, if it exists.

pub fn get_or_insert_child(&mut self, byte: u8) -> &mut Box<ArtNode>

Get or insert a child node at the given byte. Returns a mutable reference to the child, creating a new empty Node4 if needed.

pub fn remove_child(&mut self, byte: u8)

Remove a child by byte. Does not shrink the node.

pub fn add_offset(&mut self, offset: u64)

Add a value offset to this node.

pub fn remove_offset(&mut self, offset: u64) -> bool

Remove a specific offset from this node’s offsets or overflow. Returns true if the offset was found and removed.

pub fn clear_offsets(&mut self)

Clear all offsets from this node.

pub fn is_empty(&self) -> bool

Returns true if this node is empty (no children, no offsets, no prefix).

Trait Implementations

impl Clone for ArtNode

fn clone(&self) -> ArtNode

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ArtNode

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

Formats the value using the given formatter.