Make progress on related objects.

Frameworks/RSDatabase/RSDatabase.xcodeproj/project.pbxproj

@@ -33,8 +33,10 @@
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-		844D97411F2D32F300CEDDEA /* DatabaseObjectCache.swift in Sources */ = {isa = PBXBuildFile; fileRef = 844D97401F2D32F300CEDDEA /* DatabaseObjectCache.swift */; };
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+		848E22541F6652990031D7C5 /* DatabaseRelatedObjectsTable.swift in Sources */ = {isa = PBXBuildFile; fileRef = 844ECFB81F5B17F9005E405A /* DatabaseRelatedObjectsTable.swift */; };
+		848E22561F6652C70031D7C5 /* RelatedObjectsLookupTable.swift in Sources */ = {isa = PBXBuildFile; fileRef = 848E22551F6652C70031D7C5 /* RelatedObjectsLookupTable.swift */; };
+		848E22581F6653960031D7C5 /* RelatedObjectIDsLookupTable.swift in Sources */ = {isa = PBXBuildFile; fileRef = 848E22571F6653960031D7C5 /* RelatedObjectIDsLookupTable.swift */; };
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 		84ABC1D11F364B07000DCC55 /* DatabaseLookupTable.swift in Sources */ = {isa = PBXBuildFile; fileRef = 84ABC1D01F364B07000DCC55 /* DatabaseLookupTable.swift */; };
 		84ABC1D21F364B07000DCC55 /* DatabaseLookupTable.swift in Sources */ = {isa = PBXBuildFile; fileRef = 84ABC1D01F364B07000DCC55 /* DatabaseLookupTable.swift */; };
@@ -73,10 +75,11 @@
 		84419ADD1B5ABD7F00C26BB2 /* RSDatabaseQueue.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = RSDatabaseQueue.m; path = RSDatabase/RSDatabaseQueue.m; sourceTree = "<group>"; };
 		84419B031B5ABFF700C26BB2 /* FMResultSet+RSExtras.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = "FMResultSet+RSExtras.h"; path = "RSDatabase/FMResultSet+RSExtras.h"; sourceTree = "<group>"; };
 		84419B041B5ABFF700C26BB2 /* FMResultSet+RSExtras.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = "FMResultSet+RSExtras.m"; path = "RSDatabase/FMResultSet+RSExtras.m"; sourceTree = "<group>"; };
-		844D97401F2D32F300CEDDEA /* DatabaseObjectCache.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = DatabaseObjectCache.swift; path = RSDatabase/DatabaseObjectCache.swift; sourceTree = "<group>"; };
-		844ECFB81F5B17F9005E405A /* DatabaseRelatedObjectsTable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = DatabaseRelatedObjectsTable.swift; path = RSDatabase/DatabaseRelatedObjectsTable.swift; sourceTree = "<group>"; };
+		844ECFB81F5B17F9005E405A /* DatabaseRelatedObjectsTable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DatabaseRelatedObjectsTable.swift; sourceTree = "<group>"; };
+		848E22551F6652C70031D7C5 /* RelatedObjectsLookupTable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RelatedObjectsLookupTable.swift; sourceTree = "<group>"; };
+		848E22571F6653960031D7C5 /* RelatedObjectIDsLookupTable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RelatedObjectIDsLookupTable.swift; sourceTree = "<group>"; };
 		849BF8C51C94FB8E0071D1DA /* libsqlite3.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libsqlite3.tbd; path = usr/lib/libsqlite3.tbd; sourceTree = SDKROOT; };
-		84ABC1D01F364B07000DCC55 /* DatabaseLookupTable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = DatabaseLookupTable.swift; path = RSDatabase/DatabaseLookupTable.swift; sourceTree = "<group>"; };
+		84ABC1D01F364B07000DCC55 /* DatabaseLookupTable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DatabaseLookupTable.swift; sourceTree = "<group>"; };
 		84C6DD001F395C13009AFB47 /* DatabaseObject.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = DatabaseObject.swift; path = RSDatabase/DatabaseObject.swift; sourceTree = "<group>"; };
 		84DDF18B1C94FC45005E6CF5 /* FMDatabase.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = FMDatabase.h; sourceTree = "<group>"; };
 		84DDF18C1C94FC45005E6CF5 /* FMDatabase.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = FMDatabase.m; sourceTree = "<group>"; };
@@ -136,6 +139,17 @@
 			name = Frameworks;
 			sourceTree = "<group>";
 		};
+		848E22531F66528C0031D7C5 /* Related Objects */ = {
+			isa = PBXGroup;
+			children = (
+				84ABC1D01F364B07000DCC55 /* DatabaseLookupTable.swift */,
+				848E22551F6652C70031D7C5 /* RelatedObjectsLookupTable.swift */,
+				848E22571F6653960031D7C5 /* RelatedObjectIDsLookupTable.swift */,
+				844ECFB81F5B17F9005E405A /* DatabaseRelatedObjectsTable.swift */,
+			);
+			path = "Related Objects";
+			sourceTree = "<group>";
+		};
 		84DDF18A1C94FC45005E6CF5 /* FMDB */ = {
 			isa = PBXGroup;
 			children = (
@@ -164,9 +178,7 @@
 				84419AD91B5ABD7400C26BB2 /* NSString+RSDatabase.m */,
 				84C6DD001F395C13009AFB47 /* DatabaseObject.swift */,
 				840405DA1F1C158C00DF0296 /* DatabaseTable.swift */,
-				844ECFB81F5B17F9005E405A /* DatabaseRelatedObjectsTable.swift */,
-				84ABC1D01F364B07000DCC55 /* DatabaseLookupTable.swift */,
-				844D97401F2D32F300CEDDEA /* DatabaseObjectCache.swift */,
+				848E22531F66528C0031D7C5 /* Related Objects */,
 				84DDF18A1C94FC45005E6CF5 /* FMDB */,
 				84F22C5A1B52E0D9000060CE /* Info.plist */,
 				849BF8C51C94FB8E0071D1DA /* libsqlite3.tbd */,
@@ -358,6 +370,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				848E22541F6652990031D7C5 /* DatabaseRelatedObjectsTable.swift in Sources */,
 				8400AC001E0CFC0700AA7C57 /* RSDatabaseQueue.m in Sources */,
 				8400AC061E0CFC0700AA7C57 /* NSString+RSDatabase.m in Sources */,
 				84ABC1D21F364B07000DCC55 /* DatabaseLookupTable.swift in Sources */,
@@ -385,7 +398,8 @@
 				844ECFB91F5B17F9005E405A /* DatabaseRelatedObjectsTable.swift in Sources */,
 				84419B061B5ABFF700C26BB2 /* FMResultSet+RSExtras.m in Sources */,
 				84DDF1991C94FC45005E6CF5 /* FMDatabaseAdditions.m in Sources */,
-				844D97411F2D32F300CEDDEA /* DatabaseObjectCache.swift in Sources */,
+				848E22581F6653960031D7C5 /* RelatedObjectIDsLookupTable.swift in Sources */,
+				848E22561F6652C70031D7C5 /* RelatedObjectsLookupTable.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Frameworks/RSDatabase/RSDatabase/DatabaseObjectCache.swift

@@ -1,85 +0,0 @@
-//
-//  DatabaseObjectCache.swift
-//  RSDatabase
-//
-//  Created by Brent Simmons on 7/29/17.
-//  Copyright © 2017 Ranchero Software, LLC. All rights reserved.
-//
-
-import Foundation
-
-// Not thread-safe.
-
-public final class DatabaseObjectCache {
-
-	private var dictionary = [String: DatabaseObject]()
-
-	public init() {
-		// Compiler seems to want a public init method.
-	}
-	
-	public func addObjects(_ objects: [DatabaseObject]) {
-
-		objects.forEach { add($0) }
-	}
-
-	public func addObjectsNotCached(_ objects: [DatabaseObject]) {
-
-		objects.forEach { addIfNotCached($0) }
-	}
-
-	public func add(_ object: DatabaseObject) {
-
-		self[object.databaseID] = object
-	}
-
-	public func addIfNotCached(_ object: DatabaseObject) {
-
-		let identifier = object.databaseID
-		if let _ = self[identifier] {
-			return
-		}
-		self[identifier] = object
-	}
-
-	public func removeObjects(_ objects: [DatabaseObject]) {
-
-		objects.forEach { removeObject($0) }
-	}
-
-	public func removeObject(_ object: DatabaseObject) {
-
-		self[object.databaseID] = nil
-	}
-
-	public func uniquedObjects(_ objects: [DatabaseObject]) -> [DatabaseObject] {
-
-		// Return cached version of each object.
-		// When an object is not already cached, cache it,
-		// then consider that version the unique version.
-
-		return objects.map { (object) -> DatabaseObject in
-
-			if let cachedObject = self[object.databaseID] {
-				return cachedObject
-			}
-			add(object)
-			return object
-		}
-	}
-
-	public func objectWithIDIsCached(_ identifier: String) -> Bool {
-
-		return self[identifier] != nil
-	}
-
-	public subscript(_ identifier: String) -> DatabaseObject? {
-		get {
-			return dictionary[identifier]
-		}
-		set {
-			dictionary[identifier] = newValue
-		}
-	}
-}
-

Frameworks/RSDatabase/Related Objects/DatabaseLookupTable.swift

@@ -20,7 +20,8 @@ public final class DatabaseLookupTable {
 	private let relationshipName: String
 	private let relatedTable: DatabaseRelatedObjectsTable
 	private let cache: DatabaseLookupTableCache
-
+	private var objectIDsWithNoRelatedObjects = Set<String>()
+	
 	public init(name: String, objectIDKey: String, relatedObjectIDKey: String, relatedTable: DatabaseRelatedObjectsTable, relationshipName: String) {
 
 		self.name = name
@@ -31,6 +32,31 @@ public final class DatabaseLookupTable {
 		self.cache = DatabaseLookupTableCache(relationshipName)
 	}
 
+	public func fetchRelatedObjects(for objectIDs: Set<String>, in database: FMDatabase) -> RelatedObjectsLookupTable? {
+	
+		let objectIDsThatMayHaveRelatedObjects = objectIDs.subtracting(objectIDsWithNoRelatedObjects)
+		if objectIDsThatMayHaveRelatedObjects.isEmpty {
+			return nil
+		}
+	
+		guard let lookupTable = fetchLookupTable(objectIDsThatMayHaveRelatedObjects, database) else {
+			objectIDsWithNoRelatedObjects.formUnion(objectIDsThatMayHaveRelatedObjects)
+			return nil
+		}
+		
+		if let relatedObjects = fetchRelatedObjectsReferencedByLookupTable(LookupTable, database) {
+			
+			let relatedObjectsDictionary = relatedObjectsDictionary(lookupTable, relatedObjects)
+			
+			let objectIDsWithNoFetchedRelatedObjects = objectIDsThatMayHaveRelatedObjects.subtracting(Set(relatedObjectsDictionary.keys))
+			objectIDsWithNoRelatedObjects.formUnion(objectIDsWithNoFetchedRelatedObjects)
+			
+			return relatedObjectsDictionary
+		}
+		
+		return nil
+	}
+	
 	public func attachRelatedObjects(to objects: [DatabaseObject], in database: FMDatabase) {
 		
 		let objectsThatMayHaveRelatedObjects = cache.objectsThatMayHaveRelatedObjects(objects)
@@ -198,6 +224,16 @@ private extension DatabaseLookupTable {
 		attachRelatedObjectsUsingLookupTable(objects, lookupTable, database)
 	}
 	
+	func fetchRelatedObjectsReferencedByLookupTable(_ lookupTable: LookupTable, _ database: FMDatabase) -> [DatabaseObject]? {
+		
+		let relatedObjectIDs = lookupTable.relatedObjectIDs()
+		if (relatedObjectIDs.isEmpty) {
+			return nil
+		}
+		
+		return fetchRelatedObjectsWithIDs(relatedObjectIDs)
+	}
+	
 	func attachRelatedObjectsUsingLookupTable(_ objects: [DatabaseObject], _ lookupTable: LookupTable, _ database: FMDatabase) {
 		
 		let relatedObjectIDs = lookupTable.relatedObjectIDs()
@@ -269,6 +305,17 @@ private extension DatabaseLookupTable {
 		}
 		return LookupValue(objectID: objectID, relatedObjectID: relatedObjectID)
 	}
+	
+	func relatedObjectsDictionary(_ lookupTable: LookupTable, relatedObjects: [DatabaseObject]) -> RelatedObjectsDictionary? {
+		
+		var relatedObjectsDictionary = RelatedObjectsDictionary()
+		let d = relatedObjects.dictionary()
+		
+		
+		
+		
+		return relatedObjectsDictionary.isEmpty ? nil : relatedObjectsDictionary
+	}
 }
 
 // MARK: -
@@ -300,6 +347,11 @@ private struct LookupTable {
 		self.init(dictionary: d)
 	}
 
+	func objectIDs() -> Set<String> {
+		
+		return Set(dictionary.keys)
+	}
+	
 	func relatedObjectIDs() -> Set<String> {
 		
 		var ids = Set<String>()
@@ -376,12 +428,18 @@ private final class DatabaseLookupTableCache {
 		}
 	}
 	
-	func objectsThatMayHaveRelatedObjects(_ objects: [DatabaseObject]) -> [DatabaseObject] {
+	func objectIDsThatMayHaveRelatedObjects(_ objectIDs: Set<String>) -> Set<String> {
 		
 		// Filter out objects that are known to have no related objects
-		return objects.filter{ !objectIDsWithNoRelationship.contains($0.databaseID) }
+		return Set(objectIDs.filter{ !objectIDsWithNoRelationship.contains($0) })
 	}
 	
+//	func objectsThatMayHaveRelatedObjects(_ objects: [DatabaseObject]) -> [DatabaseObject] {
+//
+//		// Filter out objects that are known to have no related objects
+//		return objects.filter{ !objectIDsWithNoRelationship.contains($0.databaseID) }
+//	}
+	
 	func lookupTableForObjectIDs(_ objectIDs: Set<String>) -> LookupTable {
 		
 		var d = [String: Set<String>]()

Frameworks/RSDatabase/Related Objects/RelatedObjectIDsLookupTable.swift

@@ -0,0 +1,59 @@
+//
+//  RelatedObjectIDsLookupTable.swift
+//  RSDatabase
+//
+//  Created by Brent Simmons on 9/10/17.
+//  Copyright © 2017 Ranchero Software, LLC. All rights reserved.
+//
+
+import Foundation
+
+// Maps objectIDs to Set<String> where the Strings are relatedObjectIDs.
+
+struct RelatedObjectIDsLookupTable {
+	
+	private let dictionary: [String: Set<String>] // objectID: Set<relatedObjectID>
+	
+	init(dictionary: [String: Set<String>]) {
+		
+		self.dictionary = dictionary
+	}
+	
+	init(lookupValues: Set<LookupValue>) {
+		
+		var d = [String: Set<String>]()
+		
+		for lookupValue in lookupValues {
+			let objectID = lookupValue.objectID
+			let relatedObjectID: String = lookupValue.relatedObjectID
+			if d[objectID] == nil {
+				d[objectID] = Set([relatedObjectID])
+			}
+			else {
+				d[objectID]!.insert(relatedObjectID)
+			}
+		}
+		
+		self.init(dictionary: d)
+	}
+	
+	func objectIDs() -> Set<String> {
+		
+		return Set(dictionary.keys)
+	}
+	
+	func relatedObjectIDs() -> Set<String> {
+		
+		var ids = Set<String>()
+		for (_, relatedObjectIDs) in dictionary {
+			ids.formUnion(relatedObjectIDs)
+		}
+		return ids
+	}
+	
+	subscript(_ objectID: String) -> Set<String>? {
+		get {
+			return dictionary[objectID]
+		}
+	}
+}

Frameworks/RSDatabase/Related Objects/RelatedObjectsLookupTable.swift

@@ -0,0 +1,45 @@
+//
+//  RelatedObjectsLookupTable.swift
+//  RSDatabase
+//
+//  Created by Brent Simmons on 9/10/17.
+//  Copyright © 2017 Ranchero Software, LLC. All rights reserved.
+//
+
+import Foundation
+
+public struct RelatedObjectsLookupTable {
+	
+	private let dictionary: [String: [DatabaseObject]] // objectID: relatedObjects
+	
+	init(relatedObjects: relatedObjects, lookupTable: LookupTable) {
+		
+		var d = [String: [DatabaseObject]]()
+		
+		let relatedObjectsDictionary = relatedObjects.dictionary()
+		let objectIDs = lookupTable.objectIDs()
+		
+		for objectID in lookupTable.objectIDs() {
+			
+			if let relatedObjectIDs = lookupTable[objectID] {
+				let relatedObjects = relatedObjectIDs.flatMap{ relatedObjectsDictionary[$0] }
+				if !relatedObjects.isEmpty {
+					d[objectID] = relatedObjects
+				}
+			}
+		}
+		
+		self.dictionary = d
+	}
+	
+	public func objectIDs() -> Set<String> {
+		
+		return Set(dictionary.keys)
+	}
+	
+	public subscript(_ objectID: String) -> [DatabaseObject]? {
+		get {
+			return dictionary[objectID]
+		}
+	}
+}