Struct Patch 

pub struct Patch { /* private fields */ }

The recorded effect of one committed transaction. Re-apply it with Patch::apply (redo) or undo it with Patch::revert.

A patch only applies to the mesh that produced it, at the matching revision: revert needs the mesh exactly as the commit left it, apply needs it exactly as it was before the commit.

Implementations

impl Patch

pub fn changes(&self) -> &ChangeSet

The changes this patch makes when applied.

pub fn is_empty(&self) -> bool

True when the transaction changed nothing.

pub fn base_revision(&self) -> u64

Mesh revision before the commit.

pub fn revision(&self) -> u64

Mesh revision after the commit.

pub fn byte_size(&self) -> usize

Approximate heap memory held by this patch.

pub fn apply(&self, mesh: &mut Mesh) -> Result<ChangeSet>

Re-applies the patch (redo). The mesh must be at Patch::base_revision. If memory runs out, the mesh is left unchanged.

pub fn revert(&self, mesh: &mut Mesh) -> Result<ChangeSet>

Undoes the patch. The mesh must be at Patch::revision.

pub fn release(&self, mesh: &mut Mesh, side: PatchSide)

Returns the slots this patch reserves to the mesh’s free lists, for a patch that is dropped without being undone or redone again: the removed slots for PatchSide::Undoable, the created slots for PatchSide::Redoable. Does nothing when the patch is stale (another mesh, or the mesh was compacted), because its slots no longer exist.

Call it at most once per patch, and only when the patch is discarded from a history. Calling it twice, or while a history still holds the patch, corrupts slot reuse.

Trait Implementations

impl Clone for Patch

fn clone(&self) -> Patch

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Patch

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

Formats the value using the given formatter.