Struct ChangeTracker 

pub struct ChangeTracker { /* private fields */ }

Tracks changes to objects in the session.

Uses snapshot comparison to detect when objects have been modified.

Implementations

impl ChangeTracker

pub fn new() -> Self

Create a new empty change tracker.

pub fn snapshot<T: Model + Serialize>(&mut self, key: ObjectKey, obj: &T)

Take a snapshot of an object.

This stores the serialized state of the object for later comparison.

pub fn snapshot_raw(&mut self, key: ObjectKey, data: Vec<u8>)

Take a snapshot from raw bytes.

pub fn is_dirty<T: Model + Serialize>(&self, key: &ObjectKey, obj: &T) -> bool

Check if an object has changed since its snapshot.

Returns true if:

• The object has no snapshot (treated as dirty)
• The current state differs from the snapshot

pub fn is_dirty_raw(&self, key: &ObjectKey, current: &[u8]) -> bool

Check if raw bytes match the snapshot.

pub fn changed_fields<T: Model + Serialize>( &self, key: &ObjectKey, obj: &T, ) -> Vec<&'static str>

Get changed fields between snapshot and current state.

Returns a list of field names that have different values.

pub fn changed_fields_raw( &self, key: &ObjectKey, current_bytes: &[u8], field_names: &[&'static str], ) -> Vec<&'static str>

Get changed fields from raw JSON bytes.

pub fn attribute_changes<T: Model + Serialize>( &self, key: &ObjectKey, obj: &T, ) -> Vec<AttributeChange>

Get detailed attribute changes between snapshot and current state.

Returns AttributeChange structs with field name, old value, and new value.

pub fn has_snapshot(&self, key: &ObjectKey) -> bool

Check if a snapshot exists for the given key.

pub fn get_snapshot(&self, key: &ObjectKey) -> Option<&ObjectSnapshot>

Get the snapshot for a key.

pub fn clear(&mut self, key: &ObjectKey)

Clear snapshot for a specific object.

Call this after commit or when discarding changes.

pub fn clear_all(&mut self)

Clear all snapshots.

Call this after commit or rollback to reset tracking state.

pub fn refresh<T: Model + Serialize>(&mut self, key: ObjectKey, obj: &T)

Update snapshot after flush (new baseline).

Call this after a successful flush to set the current state as the new baseline.

pub fn len(&self) -> usize

Number of tracked snapshots.

pub fn is_empty(&self) -> bool

Check if there are no snapshots.

Trait Implementations

impl Default for ChangeTracker

fn default() -> Self

Returns the “default value” for a type.