NetNewsWire/Frameworks/Data/BatchUpdates.swift

77 lines
1.5 KiB
Swift

//
// BatchUpdates.swift
// DataModel
//
// Created by Brent Simmons on 9/12/16.
// Copyright © 2016 Ranchero Software, LLC. All rights reserved.
//
import Foundation
private final class BatchUpdatesTracker {
private var batchUpdatesCount = 0
var isPerformingBatchUpdates: Bool {
get {
return batchUpdatesCount > 0
}
}
func incrementBatchUpdatesCount() {
batchUpdatesCount = batchUpdatesCount + 1
}
func decrementBatchUpdatesCount() {
batchUpdatesCount = batchUpdatesCount - 1
if batchUpdatesCount < 1 {
if batchUpdatesCount < 0 {
assertionFailure("Batch updates count should never be below 0.")
batchUpdatesCount = 0
}
batchUpdatesCount = 0
postDataModelDidPerformBatchUpdates()
}
}
func postDataModelDidPerformBatchUpdates() {
NotificationCenter.default.post(name: .DataModelDidPerformBatchUpdates, object: nil)
}
}
fileprivate let batchUpdatesTracker = BatchUpdatesTracker()
public func dataModelIsPerformingBatchUpdates() -> Bool {
return batchUpdatesTracker.isPerformingBatchUpdates
}
public typealias BatchUpdatesBlock = () -> Void
public func performDataModelBatchUpdates(_ batchUpdatesBlock: BatchUpdatesBlock) {
startDataModelBatchUpdates()
batchUpdatesBlock()
endDataModelBatchUpdates()
}
private func startDataModelBatchUpdates() {
batchUpdatesTracker.incrementBatchUpdatesCount()
}
private func endDataModelBatchUpdates() {
batchUpdatesTracker.decrementBatchUpdatesCount()
}