Struct NodeDataFingerprint 

pub struct NodeDataFingerprint {
    pub content_hash: u64,
    pub state_hash: u64,
    pub inline_css_hash: u64,
    pub ids_classes_hash: u64,
    pub callbacks_hash: u64,
    pub attrs_hash: u64,
    pub dataset_hash: u64,
}

Per-node hash broken into independent fields for fast change detection.

Instead of a single u64 hash (which loses all granularity), this stores separate hashes per field category. Comparing two fingerprints is O(1) (6 integer comparisons) and immediately tells us WHICH category changed, avoiding the more expensive compute_node_changes() for unchanged nodes.

Two-tier strategy:

• Tier 1 (this struct): O(1) per node, identifies which categories changed.
• Tier 2 (compute_node_changes): O(n) per changed field, does field-by-field comparison only for nodes that Tier 1 identified as changed.

Fields

content_hash: u64

Hash of node_type (Text content, Image ref, Div, etc.)

state_hash: u64

Hash of styled_node_state (hover, focus, active bits)

inline_css_hash: u64

Hash of inline CSS properties

ids_classes_hash: u64

Hash of ids_and_classes

callbacks_hash: u64

Hash of callbacks (event types + function pointers)

attrs_hash: u64

Hash of the layout-relevant attributes (contenteditable, flags)

dataset_hash: u64

Hash of the dataset’s PRESENCE and TYPE — never its allocation.

A widget’s dataset is state, not layout. Most widgets allocate a fresh RefAny on every build, and RefAny hashes by pointer, so hashing the dataset into attrs_hash (which maps to CONTENTEDITABLE, a layout change) made every with_dataset node LAYOUT-DIRTY on every RefreshDom: the TextArea became a standalone layout root on each callback, was re-laid-out with its min-height while its flex container kept the old slot, and painted 64 px into a 36 px slot — over the slider beneath it. A dataset change is NodeChangeSet::DATASET, which affects neither layout nor paint.

Implementations

impl NodeDataFingerprint

pub fn compute(node: &NodeData, styled_state: Option<&StyledNodeState>) -> Self

Compute a fingerprint from a node’s data and styled state.

pub const fn diff(&self, other: &Self) -> NodeChangeSet

Returns a quick NodeChangeSet by comparing two fingerprints. This is O(1) — just comparing 7 u64s.

The result is conservative: if a field hash differs, we set the broadest applicable flag. For precise classification (e.g., which CSS properties changed and their relayout_scope()), the caller should fall back to compute_node_changes() for changed nodes.

pub fn is_identical(&self, other: &Self) -> bool

Returns true if the fingerprint is identical (no changes at all).

pub const fn might_affect_layout(&self, other: &Self) -> bool

Quick check: could this change affect layout?

pub const fn might_affect_visuals(&self, other: &Self) -> bool

Quick check: could this change affect visuals at all?

Trait Implementations

impl Clone for NodeDataFingerprint

fn clone(&self) -> NodeDataFingerprint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for NodeDataFingerprint

impl Debug for NodeDataFingerprint

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

Formats the value using the given formatter.

impl Default for NodeDataFingerprint

fn default() -> NodeDataFingerprint

Returns the “default value” for a type.

impl Eq for NodeDataFingerprint

impl Hash for NodeDataFingerprint

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

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 PartialEq for NodeDataFingerprint

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for NodeDataFingerprint