Create ObjectCache and start using it.

Frameworks/Database/StatusesTable.swift

@@ -13,10 +13,10 @@ import RSParser
 import Data
 
 final class StatusesTable: DatabaseTable {
-	
+
-	var cachedStatuses = [String: ArticleStatus]()
 	let name: String
 	let queue: RSDatabaseQueue
+	let cache = ObjectCache<ArticleStatus>(keyPathForID: \ArticleStatus.articleID)
 
 	init(name: String, queue: RSDatabaseQueue) {
 
@@ -35,11 +35,11 @@ final class StatusesTable: DatabaseTable {
 		
 		articles.forEach { (oneArticle) in
 			
-			if let cachedStatus = cachedStatusForArticleID(oneArticle.articleID) {
+			if let cachedStatus = cache[oneArticle.articleID] {
 				oneArticle.status = cachedStatus
 			}
 			else if let oneArticleStatus = oneArticle.status {
-				cacheStatus(oneArticleStatus)
+				cache.add(oneArticleStatus)
 			}
 		}
 	}
@@ -170,11 +170,6 @@ private extension StatusesManager {
 
 	// MARK: Cache
 	
-	func cachedStatusForArticleID(_ articleID: String) -> ArticleStatus? {
-		
-		return cachedStatuses[articleID]
-	}
-	
 	func cacheStatus(_ status: ArticleStatus) {
 		
 		cacheStatuses(Set([status]))

Frameworks/RSDatabase/RSDatabase.xcodeproj/project.pbxproj

@@ -33,6 +33,7 @@
 		84419AE71B5ABD7F00C26BB2 /* RSDatabaseQueue.m in Sources */ = {isa = PBXBuildFile; fileRef = 84419ADD1B5ABD7F00C26BB2 /* RSDatabaseQueue.m */; };
 		84419B051B5ABFF700C26BB2 /* FMResultSet+RSExtras.h in Headers */ = {isa = PBXBuildFile; fileRef = 84419B031B5ABFF700C26BB2 /* FMResultSet+RSExtras.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		84419B061B5ABFF700C26BB2 /* FMResultSet+RSExtras.m in Sources */ = {isa = PBXBuildFile; fileRef = 84419B041B5ABFF700C26BB2 /* FMResultSet+RSExtras.m */; };
+		844D97411F2D32F300CEDDEA /* ObjectCache.swift in Sources */ = {isa = PBXBuildFile; fileRef = 844D97401F2D32F300CEDDEA /* ObjectCache.swift */; };
 		849BF8C61C94FB8E0071D1DA /* libsqlite3.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 849BF8C51C94FB8E0071D1DA /* libsqlite3.tbd */; };
 		84DDF1961C94FC45005E6CF5 /* FMDatabase.h in Headers */ = {isa = PBXBuildFile; fileRef = 84DDF18B1C94FC45005E6CF5 /* FMDatabase.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		84DDF1971C94FC45005E6CF5 /* FMDatabase.m in Sources */ = {isa = PBXBuildFile; fileRef = 84DDF18C1C94FC45005E6CF5 /* FMDatabase.m */; };
@@ -68,6 +69,7 @@
 		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 /* ObjectCache.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = ObjectCache.swift; path = RSDatabase/ObjectCache.swift; sourceTree = "<group>"; };
 		849BF8C51C94FB8E0071D1DA /* libsqlite3.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libsqlite3.tbd; path = usr/lib/libsqlite3.tbd; sourceTree = SDKROOT; };
 		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>"; };
@@ -154,6 +156,7 @@
 				84419AD81B5ABD7400C26BB2 /* NSString+RSDatabase.h */,
 				84419AD91B5ABD7400C26BB2 /* NSString+RSDatabase.m */,
 				840405DA1F1C158C00DF0296 /* DatabaseTable.swift */,
+				844D97401F2D32F300CEDDEA /* ObjectCache.swift */,
 				84DDF18A1C94FC45005E6CF5 /* FMDB */,
 				84F22C5A1B52E0D9000060CE /* Info.plist */,
 				849BF8C51C94FB8E0071D1DA /* libsqlite3.tbd */,
@@ -368,6 +371,7 @@
 				84DDF1A01C94FC45005E6CF5 /* FMResultSet.m in Sources */,
 				84419B061B5ABFF700C26BB2 /* FMResultSet+RSExtras.m in Sources */,
 				84DDF1991C94FC45005E6CF5 /* FMDatabaseAdditions.m in Sources */,
+				844D97411F2D32F300CEDDEA /* ObjectCache.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Frameworks/RSDatabase/RSDatabase/ObjectCache.swift

@@ -0,0 +1,59 @@
+//
+//  ObjectCache.swift
+//  RSDatabase
+//
+//  Created by Brent Simmons on 7/29/17.
+//  Copyright © 2017 Ranchero Software, LLC. All rights reserved.
+//
+
+import Foundation
+
+public final class ObjectCache<T> {
+
+	private let keyPathForID: KeyPath<T,String>
+	private var dictionary = [String: T]()
+
+	public init(keyPathForID: KeyPath<T,String>) {
+
+		self.keyPathForID = keyPathForID
+	}
+
+	public func addObjects(_ objects: [T]) {
+
+		objects.forEach { addObject($0) }
+	}
+
+	public func add(_ object: T) {
+
+		let identifier = identifierForObject(object)
+		self[identifier] = object
+	}
+
+	public func removeObjects(_ objects: [T]) {
+
+		objects.forEach { removeObject($0) }
+	}
+
+	public func removeObject(_ object: T) {
+
+		let identifier = identifierForObject(object)
+		self[identifier] = nil
+	}
+
+	public subscript(_ identifier: String) -> T? {
+		get {
+			return dictionary[identifier]
+		}
+		set {
+			dictionary[identifier] = T
+		}
+	}
+}
+
+private extension ObjectCache {
+
+	func identifierForObject(_ object: T) -> String {
+
+		return object[keyPath: keyPathForID]
+	}
+}