Tidy up patch structs, add AppliedPatchSet

src/snapshot/patch.rs

@@ -7,15 +7,19 @@ use rbx_dom_weak::{RbxId, RbxValue};
 use super::{InstanceMetadata, InstanceSnapshot};
 
 /// A set of different kinds of patches that can be applied to an RbxTree.
+///
+/// These patches shouldn't be persisted: there's no mechanism in place to make
+/// sure that another patch wasn't applied before this one that could cause a
+/// conflict!
 #[derive(Debug, Default, Clone, PartialEq)]
 pub struct PatchSet<'a> {
     pub removed_instances: Vec<RbxId>,
-    pub added_instances: Vec<PatchAddInstance<'a>>,
+    pub added_instances: Vec<PatchAdd<'a>>,
-    pub updated_instances: Vec<PatchUpdateInstance>,
+    pub updated_instances: Vec<PatchUpdate>,
 }
 
 impl<'a> PatchSet<'a> {
-    pub fn new() -> PatchSet<'a> {
+    pub fn new() -> Self {
         PatchSet {
             removed_instances: Vec::new(),
             added_instances: Vec::new(),
@@ -26,14 +30,14 @@ impl<'a> PatchSet<'a> {
 
 /// A patch containing an instance that was added to the tree.
 #[derive(Debug, Clone, PartialEq)]
-pub struct PatchAddInstance<'a> {
+pub struct PatchAdd<'a> {
     pub parent_id: RbxId,
     pub instance: InstanceSnapshot<'a>,
 }
 
-/// A patch indicating that properties (or the name) of an instance changed.
+/// A patch indicating that properties of an instance changed.
 #[derive(Debug, Clone, PartialEq)]
-pub struct PatchUpdateInstance {
+pub struct PatchUpdate {
     pub id: RbxId,
     pub changed_name: Option<String>,
     pub changed_class_name: Option<String>,
@@ -45,3 +49,43 @@ pub struct PatchUpdateInstance {
     /// Changed Rojo-specific metadata, if any of it changed.
     pub changed_metadata: Option<InstanceMetadata>,
 }
+
+/// Applied patch sets have the same rough shape as PatchSet, but are
+/// descriptive of the operation that happened instead of prescribing what
+/// mutations to apply to the tree.
+///
+/// Applied patch sets are generated by applying a patch to a tree, and are
+/// suitable for sending over the network to a synchronized tree like the Rojo
+/// Studio plugin.
+///
+// TODO: Introduce machinery to detect conflicts, like keeping previous +
+// current values in all fields.
+pub struct AppliedPatchSet {
+    pub removed: Vec<RbxId>,
+    pub added: Vec<AppliedPatchAdd>,
+    pub updated: Vec<AppliedPatchUpdate>,
+}
+
+impl AppliedPatchSet {
+    pub fn new() -> Self {
+        AppliedPatchSet {
+            removed: Vec::new(),
+            added: Vec::new(),
+            updated: Vec::new(),
+        }
+    }
+}
+
+pub struct AppliedPatchAdd {
+    pub instance_id: RbxId,
+}
+
+pub struct AppliedPatchUpdate {
+    pub id: RbxId,
+
+    // TODO: Store previous values in order to detect application conflicts
+    pub changed_name: Option<String>,
+    pub changed_class_name: Option<String>,
+    pub changed_properties: HashMap<String, Option<RbxValue>>,
+    pub changed_metadata: Option<InstanceMetadata>,
+}

src/snapshot/patch_apply.rs

@@ -5,7 +5,7 @@ use std::collections::HashMap;
 use rbx_dom_weak::{RbxId, RbxInstanceProperties, RbxValue};
 
 use super::{
-    patch::{PatchSet, PatchUpdateInstance},
+    patch::{PatchSet, PatchUpdate},
     InstancePropertiesWithMeta, InstanceSnapshot, RojoTree,
 };
 
@@ -95,11 +95,7 @@ fn apply_add_child(
     }
 }
 
-fn apply_update_child(
+fn apply_update_child(context: &PatchApplyContext, tree: &mut RojoTree, patch: &PatchUpdate) {
-    context: &PatchApplyContext,
-    tree: &mut RojoTree,
-    patch: &PatchUpdateInstance,
-) {
     if let Some(metadata) = &patch.changed_metadata {
         tree.update_metadata(patch.id, metadata.clone());
     }
@@ -150,7 +146,7 @@ mod test {
     use maplit::hashmap;
     use rbx_dom_weak::RbxValue;
 
-    use super::super::PatchAddInstance;
+    use super::super::PatchAdd;
 
     #[test]
     fn add_from_empty() {
@@ -179,7 +175,7 @@ mod test {
         };
 
         let patch_set = PatchSet {
-            added_instances: vec![PatchAddInstance {
+            added_instances: vec![PatchAdd {
                 parent_id: root_id,
                 instance: snapshot.clone(),
             }],
@@ -217,7 +213,7 @@ mod test {
 
         let root_id = tree.get_root_id();
 
-        let patch = PatchUpdateInstance {
+        let patch = PatchUpdate {
             id: root_id,
             changed_name: Some("Foo".to_owned()),
             changed_class_name: Some("NewClassName".to_owned()),

src/snapshot/patch_compute.rs

@@ -6,7 +6,7 @@ use std::collections::{HashMap, HashSet};
 use rbx_dom_weak::{RbxId, RbxValue};
 
 use super::{
-    patch::{PatchAddInstance, PatchSet, PatchUpdateInstance},
+    patch::{PatchAdd, PatchSet, PatchUpdate},
     InstanceSnapshot, InstanceWithMeta, RojoTree,
 };
 
@@ -33,7 +33,7 @@ struct ComputePatchContext {
     snapshot_id_to_instance_id: HashMap<RbxId, RbxId>,
 }
 
-fn rewrite_refs_in_updates(context: &ComputePatchContext, updates: &mut [PatchUpdateInstance]) {
+fn rewrite_refs_in_updates(context: &ComputePatchContext, updates: &mut [PatchUpdate]) {
     for update in updates {
         for property_value in update.changed_properties.values_mut() {
             if let Some(RbxValue::Ref { value: Some(id) }) = property_value {
@@ -47,7 +47,7 @@ fn rewrite_refs_in_updates(context: &ComputePatchContext, updates: &mut [PatchUp
     }
 }
 
-fn rewrite_refs_in_additions(context: &ComputePatchContext, additions: &mut [PatchAddInstance]) {
+fn rewrite_refs_in_additions(context: &ComputePatchContext, additions: &mut [PatchAdd]) {
     for addition in additions {
         rewrite_refs_in_snapshot(context, &mut addition.instance);
     }
@@ -145,7 +145,7 @@ fn compute_property_patches(
         return;
     }
 
-    patch_set.updated_instances.push(PatchUpdateInstance {
+    patch_set.updated_instances.push(PatchUpdate {
         id: instance.id(),
         changed_name,
         changed_class_name,
@@ -204,7 +204,7 @@ fn compute_children_patches<'a>(
                 );
             }
             None => {
-                patch_set.added_instances.push(PatchAddInstance {
+                patch_set.added_instances.push(PatchAdd {
                     parent_id: id,
                     instance: snapshot_child.clone(),
                 });
@@ -269,7 +269,7 @@ mod test {
         let patch_set = compute_patch_set(&snapshot, &tree, root_id);
 
         let expected_patch_set = PatchSet {
-            updated_instances: vec![PatchUpdateInstance {
+            updated_instances: vec![PatchUpdate {
                 id: root_id,
                 changed_name: None,
                 changed_class_name: None,
@@ -330,7 +330,7 @@ mod test {
         let patch_set = compute_patch_set(&snapshot, &tree, root_id);
 
         let expected_patch_set = PatchSet {
-            added_instances: vec![PatchAddInstance {
+            added_instances: vec![PatchAdd {
                 parent_id: root_id,
                 instance: InstanceSnapshot {
                     snapshot_id: None,