ToMany fixes: clarify and fix the relation direction, replaceSubrange() rework to filter out ops canceling each other, added ManyToManyTests.swift based on model from integration test (imported entity sources and related generated code)

Author: greenrobot

Source/Gemfile.lock

@@ -7,15 +7,15 @@ GEM
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    algoliasearch (1.27.1)
+    algoliasearch (1.27.2)
       httpclient (~> 2.8, >= 2.8.3)
       json (>= 1.5.1)
     atomos (0.1.3)
     claide (1.0.3)
-    cocoapods (1.8.4)
+    cocoapods (1.9.1)
       activesupport (>= 4.0.2, < 5)
       claide (>= 1.0.2, < 2.0)
-      cocoapods-core (= 1.8.4)
+      cocoapods-core (= 1.9.1)
       cocoapods-deintegrate (>= 1.0.3, < 2.0)
       cocoapods-downloader (>= 1.2.2, < 2.0)
       cocoapods-plugins (>= 1.0.0, < 2.0)
@@ -30,34 +30,38 @@ GEM
       molinillo (~> 0.6.6)
       nap (~> 1.0)
       ruby-macho (~> 1.4)
-      xcodeproj (>= 1.11.1, < 2.0)
-    cocoapods-core (1.8.4)
+      xcodeproj (>= 1.14.0, < 2.0)
+    cocoapods-core (1.9.1)
       activesupport (>= 4.0.2, < 6)
       algoliasearch (~> 1.0)
       concurrent-ruby (~> 1.1)
       fuzzy_match (~> 2.0.4)
       nap (~> 1.0)
+      netrc (~> 0.11)
+      typhoeus (~> 1.0)
     cocoapods-deintegrate (1.0.4)
     cocoapods-downloader (1.3.0)
     cocoapods-plugins (1.0.0)
       nap
     cocoapods-search (1.0.0)
     cocoapods-stats (1.1.0)
-    cocoapods-trunk (1.4.1)
+    cocoapods-trunk (1.5.0)
       nap (>= 0.8, < 2.0)
       netrc (~> 0.11)
-    cocoapods-try (1.1.0)
+    cocoapods-try (1.2.0)
     colored2 (3.1.2)
-    concurrent-ruby (1.1.5)
+    concurrent-ruby (1.1.6)
     escape (0.0.4)
-    ffi (1.11.3)
+    ethon (0.12.0)
+      ffi (>= 1.3.0)
+    ffi (1.12.2)
     fourflusher (2.3.1)
     fuzzy_match (2.0.4)
     gh_inspector (1.1.3)
     httpclient (2.8.3)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    jazzy (0.13.0)
+    jazzy (0.13.3)
       cocoapods (~> 1.5)
       mustache (~> 1.1)
       open4
@@ -68,25 +72,27 @@ GEM
       xcinvoke (~> 0.3.0)
     json (2.3.0)
     liferaft (0.0.6)
-    minitest (5.13.0)
+    minitest (5.14.0)
     molinillo (0.6.6)
     mustache (1.1.1)
     nanaimo (0.2.6)
     nap (1.1.0)
     netrc (0.11.0)
     open4 (1.3.4)
     redcarpet (3.5.0)
-    rouge (3.14.0)
+    rouge (3.18.0)
     ruby-macho (1.4.0)
-    sassc (2.2.1)
+    sassc (2.3.0)
       ffi (~> 1.9)
-    sqlite3 (1.4.1)
+    sqlite3 (1.4.2)
     thread_safe (0.3.6)
-    tzinfo (1.2.5)
+    typhoeus (1.4.0)
+      ethon (>= 0.9.0)
+    tzinfo (1.2.7)
       thread_safe (~> 0.1)
     xcinvoke (0.3.0)
       liferaft (~> 0.0.6)
-    xcodeproj (1.14.0)
+    xcodeproj (1.16.0)
       CFPropertyList (>= 2.3.3, < 4.0)
       atomos (~> 0.1.3)
       claide (>= 1.0.2, < 2.0)
@@ -104,4 +110,4 @@ RUBY VERSION
    ruby 2.3.7p456
 
 BUNDLED WITH
-   2.0.2
+   2.1.4

Source/ios-framework/CommonSource/Relation/Box+BacklinkIds.swift

@@ -61,23 +61,25 @@ extension Box {
             return idArray(sourceIds, type: SourceType.self)
     }
 
-    internal func removeRelation(relationId: obx_schema_id, owningId: Id, referencedId: Id) throws {
-        if owningId == 0 {
+    internal func removeRelation(relationId: obx_schema_id, sourceId: Id, targetId: Id) throws {
+        if sourceId == 0 {
             throw ObjectBoxError.cannotRelateToUnsavedEntities(message: "Owning object hasn't been put yet.")
         }
-        if referencedId == 0 {
+        if targetId == 0 {
             throw ObjectBoxError.cannotRelateToUnsavedEntities(message: "Referenced object hasn't been put yet.")
         }
-        try check(error: obx_box_rel_remove(cBox, relationId, owningId, referencedId))
+        let obxErr = obx_box_rel_remove(cBox, relationId, sourceId, targetId)
+        try check(error: obxErr, message: "Could not remove relation data")
     }
 
-    internal func putRelation(relationId: obx_schema_id, owningId: Id, referencedId: Id) throws {
-        if owningId == 0 {
+    internal func putRelation(relationId: obx_schema_id, sourceId: Id, targetId: Id) throws {
+        if sourceId == 0 {
             throw ObjectBoxError.cannotRelateToUnsavedEntities(message: "Owning object hasn't been put yet.")
         }
-        if referencedId == 0 {
+        if targetId == 0 {
             throw ObjectBoxError.cannotRelateToUnsavedEntities(message: "Referenced object hasn't been put yet.")
         }
-        try check(error: obx_box_rel_put(cBox, relationId, referencedId, owningId))
+        let obxErr = obx_box_rel_put(cBox, relationId, sourceId, targetId)
+        try check(error: obxErr, message: "Could not add relation data")
     }
 }

Source/ios-framework/CommonSource/Relation/ToMany.swift

@@ -130,6 +130,9 @@ where S == S.EntityBindingType.EntityType {
         precondition(!targetId.needsIdGeneration, "Can form Backlinks for persisted entities only.")
         self.resolverAndCollection = ResolverAndCollection({
             do {
+                #if DEBUG
+                print("RESOLVE", "propertyId:", sourceProperty.propertyId, "entityId:", targetId.value)
+                #endif
                 return try sourceBox
                     .backlinkIds(propertyId: sourceProperty.propertyId, entityId: targetId.value)
                     .compactMap { try sourceBox.get(id: $0.value) }
@@ -148,6 +151,9 @@ where S == S.EntityBindingType.EntityType {
             // Entity hasn't been written yet and has no array? It's empty.
             guard sourceId.value != 0 else { return [] }
             do {
+                #if DEBUG
+                print ("RESOLVE STANDALONE", "relationId:", relationId, "sourceId:", sourceId.value)
+                #endif
                 let ids: [ReferencedType.EntityBindingType.IdType] = try targetBox.relationTargetIds(
                     relationId: relationId,
                     sourceId: sourceId.value,
@@ -173,6 +179,9 @@ where S == S.EntityBindingType.EntityType {
             // Entity hasn't been written yet and has no array? It's empty.
             guard targetId.value != 0 else { return [] }
             do {
+                #if DEBUG
+                print ("RESOLVE STANDALONE_BACK", "relationId:", relationId, "targetId:", targetId.value)
+                #endif
                 return try sourceBox
                     .relationSourceIds(relationId: relationId, targetId: targetId.value, targetType: OwningType.self)
                     .compactMap { try sourceBox.get($0.value) }
@@ -203,35 +212,42 @@ where S == S.EntityBindingType.EntityType {
     }
 
     /// - Important: Must lock relationCacheLock to call this.
-    internal func applyToManyToDb(relationId: obx_schema_id, referencedId: Id) throws {
+    internal func applyToManyStandaloneToDb(relationId: obx_schema_id, ownerObjectId: Id) throws {
         guard let owningBox = owningBox else { return }
-        if referencedId == 0 {
+        if ownerObjectId == 0 {
             throw ObjectBoxError.cannotRelateToUnsavedEntities(message: "Referenced object hasn't been put yet.")
         }
-        for currEntity in removed {
-            if currEntity.entityId == 0 {
+        // Note: decided against sorted IDs; relations are written two way ({SOURCE}{TARGET} and {TARGET}{SOURCE}).
+        //       Thus the internal relation cursor has to seek back and forth anyway, probably voiding any perf gain.
+
+        for target in removed {
+            if target.entityId == 0 {
                 throw ObjectBoxError.cannotRelateToUnsavedEntities(message: "Owning object hasn't been put yet.")
             }
-            try check(error: obx_box_rel_remove(owningBox, relationId, currEntity.entityId, referencedId))
+            let obxErr = obx_box_rel_remove(owningBox, relationId, ownerObjectId, target.entityId)
+            try check(error: obxErr, message: "Could not remove relation data")
         }
-        for currEntity in added {
-            if currEntity.entityId == 0 {
+        for target in added {
+            if target.entityId == 0 {
                 throw ObjectBoxError.cannotRelateToUnsavedEntities(message: "Owning object hasn't been put yet.")
             }
-            try check(error: obx_box_rel_put(owningBox, relationId, referencedId, currEntity.entityId))
+            let obxErr = obx_box_rel_put(owningBox, relationId, ownerObjectId, target.entityId)
+            try check(error: obxErr, message: "Could not add relation data")
         }
     }
 
     /// - Important: Must lock relationCacheLock to call this.
-    internal func applyToManyBacklinkToDb(relationId: obx_schema_id, owningId: Id) throws {
+    internal func applyToManyStandaloneBacklinkToDb(relationId: obx_schema_id, ownerObjectId: Id) throws {
+        // Need to use the target box as it owns the relation.
+        // Thus we need to "reverse" the direction, e.g. the owning object of the ToMany becomes the relation target.
         guard let referencedBox = referencedBox else { return }
-        for currEntity in removed {
+        for target in removed {
             try referencedBox.removeRelation(relationId: relationId,
-                                             owningId: owningId, referencedId: currEntity.entityId)
+                                             sourceId: target.entityId, targetId: ownerObjectId)
         }
-        for currEntity in added {
+        for target in added {
             try referencedBox.putRelation(relationId: relationId,
-                                          owningId: owningId, referencedId: currEntity.entityId)
+                                          sourceId: target.entityId, targetId: ownerObjectId)
         }
     }
 
@@ -261,13 +277,13 @@ where S == S.EntityBindingType.EntityType {
                         throw ObjectBoxError.cannotRelateToUnsavedEntities(message: "Owning entity of backlink hasn't "
                             + "been put yet.")
                     }
-                    try applyToManyBacklinkToDb(relationId: relationId, owningId: owningId)
+                    try applyToManyStandaloneBacklinkToDb(relationId: relationId, ownerObjectId: owningId)
                 } else if case .toMany(let relationId, let referencedId) = info {
                     if referencedId == 0 {
                         throw ObjectBoxError.cannotRelateToUnsavedEntities(message: "Related entity hasn't "
                             + "been put yet")
                     }
-                    try applyToManyToDb(relationId: relationId, referencedId: referencedId)
+                    try applyToManyStandaloneToDb(relationId: relationId, ownerObjectId: referencedId)
                 }
             }
         } else {
@@ -338,24 +354,52 @@ extension ToMany: RangeReplaceableCollection {
     public convenience init() {
         self.init(nilLiteral: ())
     }
-    
+
     public func replaceSubrange<C, R>(_ subrange: R, with newElements: __owned C)
-        where C: Collection, R: RangeExpression, ReferencedType == C.Element, Index == R.Bound {
-            relationCacheLock.wait()
-            defer { relationCacheLock.signal() }
-            if resolverAndCollection.collection.isEmpty && newElements.isEmpty { return }
-            
-            let replacedComparableElements = resolverAndCollection.collection[subrange].map {
-                return IdComparableReferencedType(entity: $0)
+        where C: Collection, R: RangeExpression, ReferencedType == C.Element, Index == R.Bound
+    {
+        relationCacheLock.wait()
+        defer { relationCacheLock.signal() }
+        if resolverAndCollection.collection.isEmpty && newElements.isEmpty { return }
+
+        let slice: ArraySlice<S> = resolverAndCollection.collection[subrange]
+        var removeSet = Set<IdComparableReferencedType>(minimumCapacity: slice.count)
+        for obj in slice {
+            removeSet.insert(IdComparableReferencedType(entity: obj))
+        }
+
+        var addSet = Set<IdComparableReferencedType>(minimumCapacity: newElements.count)
+        for obj in newElements {
+            let wrapped = IdComparableReferencedType(entity: obj)
+            if wrapped.entityId != 0 {
+                if removeSet.contains(wrapped) {
+                    removeSet.remove(wrapped)  // unchanged relation; neither add nor remove
+                } else {
+                    addSet.insert(wrapped)  // actually new
+                }
+            } else {
+                // We cannot throw here, better this than nothing for now:
+                print("Warning: ignoring new object (its ID is 0) in ToMany (unsupported as of now)")
+            }
+        }
+
+        for objRemove in removeSet {
+            if added.contains(objRemove) {
+                added.remove(objRemove)  // remove after add: cancel add
+            } else {
+                removed.insert(objRemove)  // actually remove
             }
-            let newComparableElements = newElements.map { return IdComparableReferencedType(entity: $0) }
-            
-            newComparableElements.forEach { removed.remove($0) }
-            replacedComparableElements.forEach { removed.insert($0) }
-            replacedComparableElements.forEach { added.remove($0) }
-            newComparableElements.forEach { added.insert($0) }
-            
-            resolverAndCollection.collection.replaceSubrange(subrange, with: newElements)
+        }
+
+        for objAdd in addSet {
+            if removed.contains(objAdd) {
+                removed.remove(objAdd)  // add after remove: cancel remove
+            } else {
+                added.insert(objAdd)  // actually add
+            }
+        }
+
+        resolverAndCollection.collection.replaceSubrange(subrange, with: newElements)
     }
 }
 
@@ -383,7 +427,11 @@ extension ToMany: CustomDebugStringConvertible {
 extension ToMany {
     /// Helper object to provide custom comparison to entities based on ID,
     /// so we can keep a Set of entities.
-    struct IdComparableReferencedType: Hashable {
+    struct IdComparableReferencedType: Hashable, Comparable {
+        static func <(lhs: ToMany<S>.IdComparableReferencedType, rhs: ToMany<S>.IdComparableReferencedType) -> Bool {
+            return lhs.entityId < rhs.entityId
+        }
+
         let entity: ReferencedType
 
         var entityId: Id {

Source/ios-framework/CommonSource/Store+SwiftRefinedAPI.swift

@@ -51,7 +51,6 @@ extension Store {
         } else {
             return try block(transaction)
         }
-
     }
 
     /// Internal version that gives the block a Transaction

Source/ios-framework/CommonSource/Store.swift

@@ -40,7 +40,7 @@ public class Store: CustomDebugStringConvertible {
     internal var supportsLargeArrays = false
 
     /// Returns the version of ObjectBox Swift.
-    public static var version = "1.3.0"
+    public static var version = "1.3.1"
 
     /// Returns the versions of ObjectBox Swift, the ObjectBox lib, and ObjectBox core.
     public static var versionAll: String {