Added placeholder types for datastore indexes and pages

Author: dimitribouniol

Sources/CodableDatastore/Persistence/Disk Persistence/Datastore/DatastoreIndex.swift

@@ -0,0 +1,34 @@
+//
+//  DatastoreIndex.swift
+//  CodableDatastore
+//
+//  Created by Dimitri Bouniol on 2023-06-23.
+//  Copyright © 2023 Mochi Development, Inc. All rights reserved.
+//
+
+import Foundation
+
+typealias DatastoreIndexIdentifier = TypedIdentifier<DiskPersistence<ReadOnly>.Datastore.Index>
+typealias DatastoreIndexManifestIdentifier = DatedIdentifier<DiskPersistence<ReadOnly>.Datastore.Index>
+
+enum DatastoreIndexRootIdentifier: Hashable {
+    case primary(manifest: DatastoreIndexManifestIdentifier)
+    case direct(index: DatastoreIndexIdentifier, manifest: DatastoreIndexManifestIdentifier)
+    case secondary(index: DatastoreIndexIdentifier, manifest: DatastoreIndexManifestIdentifier)
+}
+
+extension DiskPersistence.Datastore {
+    actor Index: Identifiable {
+        unowned let datastore: DiskPersistence<AccessMode>.Datastore
+        
+        let id: DatastoreIndexRootIdentifier
+        
+        init(
+            datastore: DiskPersistence<AccessMode>.Datastore,
+            id: DatastoreIndexRootIdentifier
+        ) {
+            self.datastore = datastore
+            self.id = id
+        }
+    }
+}

Sources/CodableDatastore/Persistence/Disk Persistence/Datastore/DatastorePage.swift

@@ -0,0 +1,28 @@
+//
+//  DatastorePage.swift
+//  CodableDatastore
+//
+//  Created by Dimitri Bouniol on 2023-06-23.
+//  Copyright © 2023 Mochi Development, Inc. All rights reserved.
+//
+
+import Foundation
+
+typealias DatastorePageIdentifier = DatedIdentifier<DiskPersistence<ReadOnly>.Datastore.Page>
+
+extension DiskPersistence.Datastore {
+    actor Page: Identifiable {
+        unowned let datastore: DiskPersistence<AccessMode>.Datastore
+        
+        let id: (index: Index.ID, page: DatastorePageIdentifier)
+        
+        init(
+            datastore: DiskPersistence<AccessMode>.Datastore,
+            indexID: Index.ID,
+            pageID: DatastorePageIdentifier
+        ) {
+            self.datastore = datastore
+            self.id = (index: indexID, page: pageID)
+        }
+    }
+}

Sources/CodableDatastore/Persistence/Disk Persistence/Datastore/DatastoreRootManifest.swift

@@ -32,10 +32,10 @@ struct DatastoreRootManifest: Codable, Equatable, Identifiable {
     var primaryIndexManifest: IndexInfo
 
     /// A pointer to the direct indexes' root objects.
-    var directIndexManifests: [String: IndexInfo] = [:]
+    var directIndexManifests: [DatastoreIndexIdentifier: IndexInfo] = [:]
 
     /// A pointer to the secondary indexes' root objects.
-    var secondaryIndexManifests: [String: IndexInfo] = [:]
+    var secondaryIndexManifests: [DatastoreIndexIdentifier: IndexInfo] = [:]
 }
 
 extension DatastoreRootManifest {
@@ -44,9 +44,9 @@ extension DatastoreRootManifest {
         var key: String
 
         /// The identifier for the index on disk.
-        var id: DatastoreIdentifier
+        var id: DatastoreIndexIdentifier
 
         /// The root object of the index.
-        var root: DatastoreRootIdentifier
+        var root: DatastoreIndexManifestIdentifier
     }
 }

Sources/CodableDatastore/Persistence/Disk Persistence/Datastore/PersistenceDatastore.swift

@@ -20,6 +20,16 @@ extension DiskPersistence {
 
         var lastUpdateDescriptorTask: Task<Any, Error>?
 
+        /// The root objects that are being tracked in memory.
+        var trackedRootObjects: [RootObject.ID : RootObject] = [:]
+        var trackedIndex: [Index.ID : Index] = [:]
+        var trackedPages: [Page.ID : Page] = [:]
+        
+        /// The root objects on the file system that are actively loaded in memory.
+        var loadedRootObjects: [RootObject.ID : RootObject] = [:]
+        var loadedIndex: [Index.ID : Index] = [:]
+        var loadedPages: [Page.ID : Page] = [:]
+        
         init(
             id: DatastoreIdentifier,
             snapshot: Snapshot<AccessMode>