160 lines
3.2 KiB
Swift
160 lines
3.2 KiB
Swift
//
|
||
// SingleFaviconDownloader.swift
|
||
// NetNewsWire
|
||
//
|
||
// Created by Brent Simmons on 11/23/17.
|
||
// Copyright © 2017 Ranchero Software. All rights reserved.
|
||
//
|
||
|
||
import Foundation
|
||
import RSCore
|
||
import RSWeb
|
||
|
||
// The image may be on disk already. If not, download it.
|
||
// Post .DidLoadFavicon notification once it’s in memory.
|
||
|
||
extension Notification.Name {
|
||
|
||
static let DidLoadFavicon = Notification.Name("DidLoadFaviconNotification")
|
||
}
|
||
|
||
final class SingleFaviconDownloader {
|
||
|
||
enum DiskStatus {
|
||
case unknown, notOnDisk, onDisk
|
||
}
|
||
|
||
let faviconURL: String
|
||
var iconImage: IconImage?
|
||
let homePageURL: String?
|
||
|
||
private var lastDownloadAttemptDate: Date
|
||
private var diskStatus = DiskStatus.unknown
|
||
private var diskCache: BinaryDiskCache
|
||
private let queue: DispatchQueue
|
||
|
||
private var diskKey: String {
|
||
return (faviconURL as NSString).rs_md5Hash()
|
||
}
|
||
|
||
init(faviconURL: String, homePageURL: String?, diskCache: BinaryDiskCache, queue: DispatchQueue) {
|
||
|
||
self.faviconURL = faviconURL
|
||
self.homePageURL = homePageURL
|
||
self.diskCache = diskCache
|
||
self.queue = queue
|
||
self.lastDownloadAttemptDate = Date()
|
||
|
||
findFavicon()
|
||
}
|
||
|
||
func downloadFaviconIfNeeded() {
|
||
|
||
// If we don’t have an image, and lastDownloadAttemptDate is a while ago, try again.
|
||
|
||
if let _ = iconImage {
|
||
return
|
||
}
|
||
|
||
let retryInterval: TimeInterval = 30 * 60 // 30 minutes
|
||
if Date().timeIntervalSince(lastDownloadAttemptDate) < retryInterval {
|
||
return
|
||
}
|
||
|
||
lastDownloadAttemptDate = Date()
|
||
findFavicon()
|
||
}
|
||
}
|
||
|
||
private extension SingleFaviconDownloader {
|
||
|
||
func findFavicon() {
|
||
|
||
readFromDisk { (image) in
|
||
|
||
if let image = image {
|
||
self.diskStatus = .onDisk
|
||
self.iconImage = IconImage(image)
|
||
self.postDidLoadFaviconNotification()
|
||
return
|
||
}
|
||
|
||
self.diskStatus = .notOnDisk
|
||
|
||
self.downloadFavicon { (image) in
|
||
|
||
if let image = image {
|
||
self.iconImage = IconImage(image)
|
||
}
|
||
|
||
self.postDidLoadFaviconNotification()
|
||
|
||
}
|
||
}
|
||
}
|
||
|
||
func readFromDisk(_ completion: @escaping (RSImage?) -> Void) {
|
||
|
||
guard diskStatus != .notOnDisk else {
|
||
completion(nil)
|
||
return
|
||
}
|
||
|
||
queue.async {
|
||
|
||
if let data = self.diskCache[self.diskKey], !data.isEmpty {
|
||
RSImage.rs_image(with: data, imageResultBlock: completion)
|
||
return
|
||
}
|
||
|
||
DispatchQueue.main.async {
|
||
completion(nil)
|
||
}
|
||
}
|
||
}
|
||
|
||
func saveToDisk(_ data: Data) {
|
||
|
||
queue.async {
|
||
|
||
do {
|
||
try self.diskCache.setData(data, forKey: self.diskKey)
|
||
DispatchQueue.main.async {
|
||
self.diskStatus = .onDisk
|
||
}
|
||
}
|
||
catch {}
|
||
}
|
||
}
|
||
|
||
func downloadFavicon(_ completion: @escaping (RSImage?) -> Void) {
|
||
|
||
guard let url = URL(string: faviconURL) else {
|
||
completion(nil)
|
||
return
|
||
}
|
||
|
||
downloadUsingCache(url) { (data, response, error) in
|
||
|
||
if let data = data, !data.isEmpty, let response = response, response.statusIsOK, error == nil {
|
||
self.saveToDisk(data)
|
||
RSImage.rs_image(with: data, imageResultBlock: completion)
|
||
return
|
||
}
|
||
|
||
if let error = error {
|
||
appDelegate.logMessage("Error downloading favicon at \(url): \(error)", type: .warning)
|
||
}
|
||
|
||
completion(nil)
|
||
}
|
||
}
|
||
|
||
func postDidLoadFaviconNotification() {
|
||
|
||
assert(Thread.isMainThread)
|
||
NotificationCenter.default.post(name: .DidLoadFavicon, object: self)
|
||
}
|
||
|
||
}
|