KCD/MOCGenerator.swift

   1 //
   2 //  ManagedObjectContextGenerator.swift
   3 //  KCD
   4 //
   5 //  Created by Hori,Masaki on 2017/03/21.
   6 //  Copyright © 2017年 Hori,Masaki. All rights reserved.
   7 //
   8
   9 import Cocoa
  10
  11 final class MOCGenerator {
  12
  13     let config: CoreDataConfiguration
  14
  15     init(_ config: CoreDataConfiguration) {
  16
  17         self.config = config
  18     }
  19
  20     func genarate() throws -> (model: NSManagedObjectModel, coordinator: NSPersistentStoreCoordinator, moc: NSManagedObjectContext) {
  21
  22         let model = try createModel()
  23         let coordinator = try createCoordinator(model)
  24         let moc = createContext(coordinator)
  25
  26         return (model: model, coordinator: coordinator, moc: moc)
  27     }
  28
  29     func removeDataFile() {
  30
  31         ["", "-wal", "-shm"]
  32             .map { config.fileName + $0 }
  33             .map(ApplicationDirecrories.support.appendingPathComponent)
  34             .forEach(removeFile)
  35     }
  36
  37     private func removeFile(at url: URL) {
  38
  39         do {
  40
  41             try FileManager.default.removeItem(at: url)
  42
  43         } catch {
  44
  45             print("Could not remove file for URL (\(url))")
  46         }
  47     }
  48
  49     // MARK: - NSManagedObjectContext and ...
  50     private func createModel() throws -> NSManagedObjectModel {
  51
  52         guard let modelURL = Bundle.main.url(forResource: config.modelName, withExtension: "momd"),
  53             let model = NSManagedObjectModel(contentsOf: modelURL) else {
  54
  55                 throw CoreDataError.couldNotCreateModel
  56         }
  57
  58         return model
  59     }
  60
  61     private func isMigrationError(_ code: Int) -> Bool {
  62         return [
  63             NSPersistentStoreIncompatibleVersionHashError,
  64             NSMigrationError,
  65             NSMigrationConstraintViolationError,
  66             NSMigrationCancelledError,
  67             NSMigrationMissingSourceModelError,
  68             NSMigrationMissingMappingModelError,
  69             NSMigrationManagerSourceStoreError,
  70             NSMigrationManagerDestinationStoreError,
  71             NSEntityMigrationPolicyError
  72         ].contains(code)
  73     }
  74
  75     private func createCoordinator(_ model: NSManagedObjectModel) throws -> NSPersistentStoreCoordinator {
  76
  77         if !checkDirectory(ApplicationDirecrories.support) {
  78
  79             throw CoreDataError.saveLocationIsUnuseable
  80         }
  81
  82         do {
  83
  84             return try makeCoordinator(model)
  85
  86         } catch (let error as NSError) {
  87
  88             // Data Modelが更新されていたらストアファイルを削除してもう一度
  89             if error.domain == NSCocoaErrorDomain,
  90                 isMigrationError(error.code),
  91                 config.tryRemake {
  92
  93                 removeDataFile()
  94
  95                 do {
  96
  97                     return try makeCoordinator(model)
  98
  99                 } catch {
 100
 101                     print("Fail to create NSPersistentStoreCoordinator twice.")
 102                 }
 103             }
 104
 105             throw CoreDataError.couldNotCreateCoordinator(error.localizedDescription)
 106         }
 107     }
 108
 109     private func makeCoordinator(_ model: NSManagedObjectModel) throws -> NSPersistentStoreCoordinator {
 110
 111         let coordinator: NSPersistentStoreCoordinator = NSPersistentStoreCoordinator(managedObjectModel: model)
 112         let url = ApplicationDirecrories.support.appendingPathComponent(config.fileName)
 113         try coordinator.addPersistentStore(ofType: config.type,
 114                                            configurationName: nil,
 115                                            at: url,
 116                                            options: config.options)
 117
 118         return coordinator
 119     }
 120
 121     private func createContext(_ coordinator: NSPersistentStoreCoordinator) -> NSManagedObjectContext {
 122
 123         let moc = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
 124         moc.persistentStoreCoordinator = coordinator
 125         moc.undoManager = nil
 126
 127         return moc
 128     }
 129 }