spiegel-keyman/ios/engine/KMEI/KeymanEngine/Classes/KeyboardRepository/ResourceDownloadQueue.swift

555 lines
21 KiB
Swift

//
// ResourceDownloadQueue.swift
// KeymanEngine
//
// Created by Joshua Horton on 8/20/19.
// Copyright © 2019 SIL International. All rights reserved.
//
import Foundation
import Reachability
protocol DownloadNode {
var resources: [LanguageResource]? { get }
}
class DownloadTask: DownloadNode {
public enum Resource {
case keyboard, lexicalModel, other
}
public final var type: Resource
public final var resources: [LanguageResource]?
public final var request: HTTPDownloadRequest
public init(do request: HTTPDownloadRequest, for resources: [LanguageResource]?, type: DownloadTask.Resource) {
self.request = request
self.type = type
self.resources = resources
}
}
/**
* Represents one overall resource-related command for requests against the Keyman Cloud API.
*/
class DownloadBatch: DownloadNode {
public enum Activity {
case download, update, composite
}
/*
* Three main cases so far:
* - [.download, .keyboard]: download new Keyboard (possibly with an associated lexical model)
* - [.download, .lexicalModel]: download new LexicalModel.
* - [.composite, .other]: batch update of all resources, containing the following within its compositeQueue
* - [.update, .keyboard]: updates one Keyboard
* - [.update, .lexicalModel]: updates one LexicalModel
* - Depending on needs, this may be extended to allow 'nested' .composite instances.
*/
public final var activity: Activity
public final var type: DownloadTask.Resource
public final var tasks: [DownloadNode]
var errors: [Error?] // Only used by the ResourceDownloadQueue.
//public final var promise: Int
public init?(do tasks: [DownloadTask], as activity: Activity, ofType type: DownloadTask.Resource) {
self.activity = activity
self.type = type
self.tasks = tasks
self.errors = Array(repeating: nil, count: tasks.count)
// Indicates 'composite' mode, which should use the other initializer.
if activity == .composite {
return nil
}
// A batch containing tasks should always be targeting a 'primary' language resource.
// .other exists to handle fonts packaged with keyboards, not our primary resources.
if type == .other {
return nil
}
}
public init(queue: [DownloadBatch]) {
self.activity = .composite
self.type = .other
self.tasks = queue
self.errors = Array(repeating: nil, count: tasks.count)
}
public var resources: [LanguageResource]? {
get {
var resArray: [LanguageResource] = []
tasks.forEach{ task in
resArray.append(contentsOf: task.resources ?? [])
}
return resArray
}
}
}
// This is a private class used internally by ResourceDownloadQueue to track progress through
// the queue and its DownloadBatches. We need a stack scheme - each instance of this corresponds
// to one frame of the stack.
private class DownloadQueueFrame {
public var nodes: [DownloadNode] = []
public var index: Int = 0
public final var batch: DownloadBatch?
private(set) var isComposite = false
public init() {
batch = nil
}
public init? (from batch: DownloadBatch) {
if batch.activity != .composite {
return nil
}
self.isComposite = true
self.batch = batch
nodes.append(contentsOf: batch.tasks)
}
}
// The other half of ResourceDownloadManager, this class is responsible for executing the downloads
// and handling the results.
class ResourceDownloadQueue: HTTPDownloadDelegate {
private var queueRoot: DownloadQueueFrame
private var queueStack: [DownloadQueueFrame]
private var downloader: HTTPDownloader?
private var reachability: Reachability!
private let keymanHostName = "api.keyman.com"
public init() {
reachability = Reachability(hostname: keymanHostName)
queueRoot = DownloadQueueFrame()
queueStack = [queueRoot] // queueRoot will always be the bottom frame of the stack.
}
public func hasConnection() -> Bool {
return reachability.connection != Reachability.Connection.none
}
// Might should add a "withNotification: Bool" option for clarity.
public func canExecute(_ batch: DownloadBatch) -> Bool {
guard reachability.connection != Reachability.Connection.none else {
let error = NSError(domain: "Keyman", code: 0,
userInfo: [NSLocalizedDescriptionKey: "No internet connection"])
downloadFailed(forBatch: batch, error: error)
return false
}
// At this stage, we now have everything needed to generate download requests.
guard currentBatch == nil else { // Original behavior - only one download operation is permitted at a time.
let error = NSError(domain: "Keyman", code: 0,
userInfo: [NSLocalizedDescriptionKey: "Download queue is busy"])
downloadFailed(forBatch: batch, error: error)
return false
}
return true
}
public var currentBatch: DownloadBatch? {
get {
let frame = currentFrame
if(frame.nodes.count == 0) {
return nil // Nothing's downloading.
} else {
return (frame.nodes[frame.index] as! DownloadBatch) // Return the currently processing DownloadBatch.
}
}
}
private var currentFrame: DownloadQueueFrame {
get {
return queueStack[queueStack.count - 1]
}
}
private func finalizeCurrentBatch() {
let frame = queueStack[queueStack.count - 1]
if queueStack.count == 1 {
// Batches in the root may be safely dumped from the queue.
// This automatically cleans out old top-level commands once done, instead of maintaining a persistent history.
//
// We _could_ keep the full history until the last command in the queue is done and empty the root's node list
// when everything's done instead. Might be worth a thought.
frame.nodes.remove(at: 0)
} else {
// Batches in subframes should be kept so that we can report progress; increment the index instead.
frame.index += 1
}
}
private func executeNext() {
let frame = queueStack[queueStack.count - 1]
// If nothing's in the queue, this will be straight-forward.
if queueStack.count == 1 { // Are we on the root frame?
// Is the root frame out of commands?
if frame.nodes.count == 0 {
return
} // else
let batch = frame.nodes[0] as! DownloadBatch
innerExecute(batch)
} else { // We're in a queue stack frame; check our state!
if frame.index == frame.nodes.count {
// We've hit the end of this stack frame's commands; time to pop and continue from the previous frame's perspective.
_ = queueStack.popLast()
// In the current state of the app, this is only the case for batch updates.
if frame.isComposite {
let parentFrame = queueStack[queueStack.count - 1]
updateBatchFinished(parentFrame.nodes[parentFrame.index] as! DownloadBatch)
}
// Of course, this means we've "finished" a batch download. We can use the same handlers as before.
finalizeCurrentBatch()
executeNext()
return
} else {
// We've got more batches left within this stack frame. Continue.
let batch = frame.nodes[frame.index] as! DownloadBatch
innerExecute(batch)
}
}
}
private func innerExecute(_ batch: DownloadBatch) {
if batch.activity == .composite {
if batch.type == .other {
// It's the top level of an update operation. Time to make a correpsonding notification.
updateBatchStarted(batch)
}
// We're a batch composed of multiple sub-batches. Time to set that up on the queue!
let frame = DownloadQueueFrame(from: batch)!
queueStack.append(frame)
// TODO: Notify about the new batch being started!
innerExecute(batch.tasks[0] as! DownloadBatch)
return
} else {
// Make a separate one for each batch; this simplifies event handling when multiple batches are in queue,
// as the old downloader will have a final event left to trigger at this point. (downloadQueueFinished)
downloader = HTTPDownloader(self)
let tasks = batch.tasks as! [DownloadTask]
downloader!.userInfo = [Key.downloadBatch: batch]
tasks.forEach { task in
downloader!.addRequest(task.request)
}
downloader!.run()
// TODO: Notify about the new batch being started!
}
}
public func queue(_ batch: DownloadBatch) {
queueRoot.nodes.append(batch)
// If the queue was empty before this...
if queueRoot.nodes.count == 1 {
executeNext()
}
}
// MARK - helper methods for ResourceDownloadManager
// TODO: Eliminate this property coompletely.
var currentRequest: HTTPDownloadRequest? {
get {
// This was literally the state of this property when the refactor producing this class was performed.
return nil;
}
}
// TODO: Needs validation.
func keyboardIdForCurrentRequest() -> String? {
if let currentRequest = currentRequest {
let tmpStr = currentRequest.url.lastPathComponent
if tmpStr.hasJavaScriptExtension {
return String(tmpStr.dropLast(3))
}
} else {
// TODO: search the queue instead.
// let kbInfo = downloader!.userInfo[Key.keyboardInfo]
// if let keyboards = kbInfo as? [InstallableKeyboard], let keyboard = keyboards.first {
// return keyboard.id
// }
}
return nil
}
func lexicalModelIdForCurrentRequest() -> String? {
if let currentRequest = currentRequest {
let tmpStr = currentRequest.url.lastPathComponent
if tmpStr.hasJavaScriptExtension {
return String(tmpStr.dropLast(3))
}
} else {
// TODO: search the queue instead.
// let kbInfo = downloader!.userInfo[Key.lexicalModelInfo]
// if let lexicalModels = kbInfo as? [InstallableLexicalModel], let lexicalModel = lexicalModels.first {
// return lexicalModel.id
// }
}
return nil
}
// MARK - notification methods
private func downloadFailed(forBatch batch: DownloadBatch, error: Error) {
let tasks = batch.tasks as! [DownloadTask]
if batch.activity == .composite {
// It's an update operation.
// Not yet called in this case.
} else if batch.type == .keyboard {
let keyboards = tasks.compactMap { task in
return task.resources as? [InstallableKeyboard]
}.flatMap {$0}
downloadFailed(forKeyboards: keyboards, error: error)
} else if batch.type == .lexicalModel {
let lexModels = tasks.compactMap { task in
return task.resources as? [InstallableLexicalModel]
}.flatMap {$0}
downloadFailed(forLanguageID: lexModels[0].languageID, error: error)
}
}
public func downloadFailed(forKeyboards keyboards: [InstallableKeyboard], error: Error) {
let notification = KeyboardDownloadFailedNotification(keyboards: keyboards, error: error)
NotificationCenter.default.post(name: Notifications.keyboardDownloadFailed,
object: self,
value: notification)
}
public func downloadFailed(forLanguageID languageID: String, error: Error) {
let notification = LexicalModelDownloadFailedNotification(lmOrLanguageID: languageID, error: error)
NotificationCenter.default.post(name: Notifications.lexicalModelDownloadFailed,
object: self,
value: notification)
}
public func downloadFailed(forLexicalModelPackage packageURL: String, error: Error) {
let notification = LexicalModelDownloadFailedNotification(lmOrLanguageID: packageURL, error: error)
NotificationCenter.default.post(name: Notifications.lexicalModelDownloadFailed,
object: self,
value: notification)
}
public func downloadSucceeded(forKeyboards keyboards: [InstallableKeyboard]) {
let notification = KeyboardDownloadCompletedNotification(keyboards)
NotificationCenter.default.post(name: Notifications.keyboardDownloadCompleted,
object: self,
value: notification)
}
public func downloadSucceeded(forLexicalModel lm: InstallableLexicalModel) {
let notification = LexicalModelDownloadCompletedNotification([lm])
NotificationCenter.default.post(name: Notifications.lexicalModelDownloadCompleted,
object: self,
value: notification)
}
public func updateBatchStarted(_ batch: DownloadBatch) {
let notification = BatchUpdateStartedNotification(batch.resources!)
NotificationCenter.default.post(name: Notifications.batchUpdateStarted,
object: self,
value: notification)
}
public func updateBatchFinished(_ batch: DownloadBatch) {
var successes: [[LanguageResource]] = []
var failures: [[LanguageResource]] = []
var errors: [Error] = []
// Remember, since this is for .composite batches, batch.tasks is of type [DownloadBatch].
for (index, res) in batch.tasks.enumerated() {
if batch.errors[index] == nil {
successes.append(res.resources!)
} else {
failures.append(res.resources!)
errors.append(batch.errors[index]!)
}
}
let notification = BatchUpdateCompletedNotification(successes: successes, failures: failures, errors: errors)
NotificationCenter.default.post(name: Notifications.batchUpdateCompleted,
object: self,
value: notification)
}
//MARK: - HTTPDownloadDelegate methods
func downloadQueueFinished(_ queue: HTTPDownloader) {
// We can use the properties of the current "batch" to generate specialized notifications.
let batch = queue.userInfo[Key.downloadBatch] as! DownloadBatch
// Due to how the queue operates, batch.activity != .composite. That case is handled elsewhere.
if(batch.activity == .composite) {
// Composite indicates that a batch is made of multiple sub-batches, not individual
// DownloadTasks that the HTTPDownloader can handle, which are 1-to-1 with its requests.
fatalError("HTTPDownloader should never be assigned a .composite-type DownloadBatch.")
} else {
let isUpdate = batch.activity == .update
if batch.type == .keyboard {
// The request has succeeded.
if downloader!.requestsCount == 0 { // Download queue finished.
let keyboards = batch.resources as! [InstallableKeyboard]
FontManager.shared.registerCustomFonts()
log.info("Downloaded keyboard: \(keyboards[0].id).")
if(!isUpdate) {
downloadSucceeded(forKeyboards: keyboards)
}
let userDefaults = Storage.active.userDefaults
userDefaults.set([Date()], forKey: Key.synchronizeSWKeyboard)
userDefaults.synchronize()
}
} else if batch.type == .lexicalModel {
let task = batch.tasks[0] as! DownloadTask // It's always at this index.
if let lm = installLexicalModelPackage(downloadedPackageFile: URL.init(string: task.request.destinationFile!)!) {
if !isUpdate {
downloadSucceeded(forLexicalModel: lm)
}
} else if !isUpdate {
let installError = NSError(domain: "Keyman", code: 0,
userInfo: [NSLocalizedDescriptionKey: "installError"])
downloadFailed(forLexicalModelPackage: "\(task.request.url)", error: installError)
currentFrame.batch?.errors[currentFrame.index] = installError
}
}
}
// Completing the queue means having completed a batch. We should only move forward in this class's
// queue at this time, once a batch's task queue is complete.
finalizeCurrentBatch()
executeNext()
}
func downloadQueueCancelled(_ queue: HTTPDownloader) {
//
// In case we're part of a 'composite' operation, we should still keep the queue moving.
finalizeCurrentBatch()
executeNext()
}
func downloadRequestStarted(_ request: HTTPDownloadRequest) {
// If we're downloading a new keyboard.
// The extra check is there to filter out other potential request types in the future.
let batch = request.userInfo[Key.downloadBatch] as! DownloadBatch
if request.tag == 0 && batch.activity != .update {
let task = request.userInfo[Key.downloadTask] as! DownloadTask
if task.type == .keyboard {
NotificationCenter.default.post(name: Notifications.keyboardDownloadStarted,
object: self,
value: task.resources as! [InstallableKeyboard])
} else if task.type == .lexicalModel {
NotificationCenter.default.post(name: Notifications.lexicalModelDownloadStarted,
object: self,
value: task.resources as! [InstallableLexicalModel])
}
}
}
func downloadRequestFinished(_ request: HTTPDownloadRequest) {
// Did we finish, but with an request error code?
if request.responseStatusCode != 200 {
// Possible request error (400 Bad Request, 404 Not Found, etc.)
let errorMessage = "\(request.responseStatusMessage ?? ""): \(request.url)"
let error = NSError(domain: "Keyman", code: 0,
userInfo: [NSLocalizedDescriptionKey: errorMessage])
currentFrame.batch?.errors[currentFrame.index] = error
// Now that we've synthesized an appropriate error instance, use the same handler
// as for HTTPDownloader's 'failed' condition.
downloadRequestFailed(request, with: error)
} // else - handled once the entire queue is completed without errors.
// This particularly matters for keyboards.
}
func downloadRequestFailed(_ request: HTTPDownloadRequest) {
// We should never be in a state to return 'Unknown error", but better safe than sorry.
downloadRequestFailed(request, with: request.error ?? NSError(domain: "Keyman", code: 0,
userInfo: [NSLocalizedDescriptionKey: "Unknown error"]))
}
func downloadRequestFailed(_ request: HTTPDownloadRequest, with error: Error) {
currentFrame.batch?.errors[currentFrame.index] = error
let task = request.userInfo[Key.downloadTask] as! DownloadTask
let batch = request.userInfo[Key.downloadBatch] as! DownloadBatch
let isUpdate = batch.activity == .update
if task.type == .keyboard {
log.error("Keyboard download failed: \(error).")
let keyboards = task.resources as? [InstallableKeyboard]
if !isUpdate {
// Clean up keyboard file if anything fails
// TODO: Also clean up remaining fonts
try? FileManager.default.removeItem(at: Storage.active.keyboardURL(for: keyboards![0]))
downloadFailed(forKeyboards: keyboards ?? [], error: error as NSError)
}
} else if task.type == .lexicalModel {
log.error("Lexical model download failed: \(error).")
let lexicalModels = task.resources as? [InstallableLexicalModel]
if !isUpdate {
// Clean up model file if anything fails
try? FileManager.default.removeItem(at: Storage.active.lexicalModelURL(for: lexicalModels![0]))
downloadFailed(forLanguageID: lexicalModels?[0].languageID ?? "", error: error as NSError)
}
}
downloader!.cancelAllOperations()
}
// MARK - Language resource installation methods
// Processes fetched lexical models.
// return a lexical model so caller can use it in a downloadSucceeded call
// is called by other class funcs
public func installLexicalModelPackage(downloadedPackageFile: URL) -> InstallableLexicalModel? {
var installedLexicalModel: InstallableLexicalModel? = nil
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
var destination = documentsDirectory
destination.appendPathComponent("temp/\(downloadedPackageFile.lastPathComponent)")
KeymanPackage.extract(fileUrl: downloadedPackageFile, destination: destination, complete: { kmp in
if let kmp = kmp as! LexicalModelKeymanPackage? {
do {
try Manager.parseLMKMP(kmp.sourceFolder)
log.info("successfully parsed the lexical model in: \(kmp.sourceFolder)")
installedLexicalModel = kmp.models[0].installableLexicalModels[0]
//this can fail gracefully and not show errors to users
try FileManager.default.removeItem(at: downloadedPackageFile)
} catch {
log.error("Error installing the lexical model: \(error)")
}
} else {
log.error("Error extracting the lexical model from the package: \(KMPError.invalidPackage)")
}
})
return installedLexicalModel
}
}