element-ios/Riot/Modules/Room/VoiceMessages/VoiceMessageAttachmentCache...

323 lines
15 KiB
Swift

//
// Copyright 2021-2024 New Vector Ltd.
//
// SPDX-License-Identifier: AGPL-3.0-only
// Please see LICENSE in the repository root for full details.
//
import Foundation
import DSWaveformImage
enum VoiceMessageAttachmentCacheManagerError: Error {
case invalidEventId
case invalidAttachmentType
case decryptionError(Error)
case preparationError(Error)
case conversionError(Error)
case durationError(Error?)
case invalidNumberOfSamples
case samplingError
case cancelled
}
/**
Swift optimizes the callbacks to be the same instance. Wrap them so we can store them in an array.
*/
private class CompletionWrapper {
let completion: (Result<VoiceMessageAttachmentCacheManagerLoadResult, Error>) -> Void
init(_ completion: @escaping (Result<VoiceMessageAttachmentCacheManagerLoadResult, Error>) -> Void) {
self.completion = completion
}
}
private struct CompletionCallbackKey: Hashable {
let eventIdentifier: String
let requiredNumberOfSamples: Int
}
struct VoiceMessageAttachmentCacheManagerLoadResult {
let eventIdentifier: String
let url: URL
let duration: TimeInterval
let samples: [Float]
}
@objc class VoiceMessageAttachmentCacheManagerBridge: NSObject {
@objc static func clearCache() {
VoiceMessageAttachmentCacheManager.sharedManager.clearCache()
}
}
class VoiceMessageAttachmentCacheManager {
private struct Constants {
static let taskSemaphoreTimeout = 5.0
}
static let sharedManager = VoiceMessageAttachmentCacheManager()
private var completionCallbacks = [CompletionCallbackKey: [CompletionWrapper]]()
private var samples = [String: [Int: [Float]]]()
private var durations = [String: TimeInterval]()
private var finalURLs = [String: URL]()
private let workQueue: DispatchQueue
private let operationQueue: OperationQueue
private var temporaryFilesFolderURL: URL {
return URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true).appendingPathComponent("VoiceMessages")
}
private init() {
workQueue = DispatchQueue(label: "io.element.VoiceMessageAttachmentCacheManager.queue", qos: .userInitiated)
operationQueue = OperationQueue()
operationQueue.maxConcurrentOperationCount = 1
}
func loadAttachment(_ attachment: MXKAttachment, numberOfSamples: Int, completion: @escaping (Result<VoiceMessageAttachmentCacheManagerLoadResult, Error>) -> Void) {
guard attachment.type == .voiceMessage || attachment.type == .audio else {
completion(Result.failure(VoiceMessageAttachmentCacheManagerError.invalidAttachmentType))
MXLog.error("[VoiceMessageAttachmentCacheManager] Invalid attachment type, ignoring request.")
return
}
guard let identifier = attachment.eventId else {
completion(Result.failure(VoiceMessageAttachmentCacheManagerError.invalidEventId))
MXLog.error("[VoiceMessageAttachmentCacheManager] Invalid event id, ignoring request.")
return
}
guard numberOfSamples > 0 else {
completion(Result.failure(VoiceMessageAttachmentCacheManagerError.invalidNumberOfSamples))
MXLog.error("[VoiceMessageAttachmentCacheManager] Invalid number of samples, ignoring request.")
return
}
do {
try setupTemporaryFilesFolder()
} catch {
completion(Result.failure(VoiceMessageAttachmentCacheManagerError.preparationError(error)))
MXLog.error("[VoiceMessageAttachmentCacheManager] Failed creating temporary files folder", context: error)
return
}
operationQueue.addOperation {
MXLog.debug("[VoiceMessageAttachmentCacheManager] Started task")
if let finalURL = self.finalURLs[identifier], let duration = self.durations[identifier], let samples = self.samples[identifier]?[numberOfSamples] {
MXLog.debug("[VoiceMessageAttachmentCacheManager] Finished task - using cached results")
let result = VoiceMessageAttachmentCacheManagerLoadResult(eventIdentifier: identifier, url: finalURL, duration: duration, samples: samples)
DispatchQueue.main.async {
completion(Result.success(result))
}
return
}
self.enqueueLoadAttachment(attachment, identifier: identifier, numberOfSamples: numberOfSamples, completion: completion)
}
}
func clearCache() {
for key in completionCallbacks.keys {
invokeFailureCallbacksForIdentifier(key.eventIdentifier, requiredNumberOfSamples: key.requiredNumberOfSamples, error: VoiceMessageAttachmentCacheManagerError.cancelled)
}
operationQueue.cancelAllOperations()
samples.removeAll()
durations.removeAll()
finalURLs.removeAll()
if FileManager.default.fileExists(atPath: temporaryFilesFolderURL.path) {
do {
try FileManager.default.removeItem(at: temporaryFilesFolderURL)
} catch {
MXLog.error("[VoiceMessageAttachmentCacheManager] Failed clearing cached disk files", context: error)
}
}
}
private func enqueueLoadAttachment(_ attachment: MXKAttachment, identifier: String, numberOfSamples: Int, completion: @escaping (Result<VoiceMessageAttachmentCacheManagerLoadResult, Error>) -> Void) {
let callbackKey = CompletionCallbackKey(eventIdentifier: identifier, requiredNumberOfSamples: numberOfSamples)
if var callbacks = completionCallbacks[callbackKey] {
MXLog.debug("[VoiceMessageAttachmentCacheManager] Finished task - cached completion callback")
callbacks.append(CompletionWrapper(completion))
completionCallbacks[callbackKey] = callbacks
return
} else {
completionCallbacks[callbackKey] = [CompletionWrapper(completion)]
}
let semaphore = DispatchSemaphore(value: 0)
if let finalURL = finalURLs[identifier], let duration = durations[identifier] {
sampleFileAtURL(finalURL, duration: duration, numberOfSamples: numberOfSamples, identifier: identifier, semaphore: semaphore)
let result = semaphore.wait(timeout: .now() + Constants.taskSemaphoreTimeout)
if case DispatchTimeoutResult.timedOut = result {
MXLog.error("[VoiceMessageAttachmentCacheManager] Timed out waiting for tasks to finish.")
}
return
}
DispatchQueue.main.async { // These don't behave accordingly if called from a background thread
if attachment.isEncrypted {
attachment.decrypt(toTempFile: { filePath in
self.workQueue.async {
self.convertFileAtPath(filePath, numberOfSamples: numberOfSamples, identifier: identifier, semaphore: semaphore)
}
}, failure: { error in
// A nil error in this case is a cancellation on the MXMediaLoader
if let error = error {
MXLog.error("[VoiceMessageAttachmentCacheManager] Failed decrypting attachment", context: error)
self.invokeFailureCallbacksForIdentifier(identifier, requiredNumberOfSamples: numberOfSamples, error: VoiceMessageAttachmentCacheManagerError.decryptionError(error))
}
semaphore.signal()
})
} else {
attachment.prepare({
self.workQueue.async {
self.convertFileAtPath(attachment.cacheFilePath, numberOfSamples: numberOfSamples, identifier: identifier, semaphore: semaphore)
}
}, failure: { error in
// A nil error in this case is a cancellation on the MXMediaLoader
if let error = error {
MXLog.error("[VoiceMessageAttachmentCacheManager] Failed preparing attachment", context: error)
self.invokeFailureCallbacksForIdentifier(identifier, requiredNumberOfSamples: numberOfSamples, error: VoiceMessageAttachmentCacheManagerError.preparationError(error))
}
semaphore.signal()
})
}
}
let result = semaphore.wait(timeout: .now() + Constants.taskSemaphoreTimeout)
if case DispatchTimeoutResult.timedOut = result {
MXLog.error("[VoiceMessageAttachmentCacheManager] Timed out waiting for tasks to finish.")
}
}
private func convertFileAtPath(_ path: String?, numberOfSamples: Int, identifier: String, semaphore: DispatchSemaphore) {
guard let path else {
return
}
let filePath = URL(fileURLWithPath: path)
let fileExtension = filePath.hasSupportedAudioExtension ? filePath.pathExtension : "m4a"
let newURL = temporaryFilesFolderURL.appendingPathComponent(identifier).appendingPathExtension(fileExtension)
let conversionCompletion: (Result<Void, VoiceMessageAudioConverterError>) -> Void = { result in
self.workQueue.async {
switch result {
case .success:
MXLog.debug("[VoiceMessageAttachmentCacheManager] Finished converting voice message")
self.finalURLs[identifier] = newURL
VoiceMessageAudioConverter.mediaDurationAt(newURL) { result in
self.workQueue.async {
MXLog.debug("[VoiceMessageAttachmentCacheManager] Finished retrieving media duration")
switch result {
case .success:
if let duration = try? result.get() {
self.durations[identifier] = duration
self.sampleFileAtURL(newURL, duration: duration, numberOfSamples: numberOfSamples, identifier: identifier, semaphore: semaphore)
} else {
MXLog.error("[VoiceMessageAttachmentCacheManager] Failed retrieving media duration")
self.invokeFailureCallbacksForIdentifier(identifier, requiredNumberOfSamples: numberOfSamples, error: VoiceMessageAttachmentCacheManagerError.durationError(nil))
semaphore.signal()
}
case .failure(let error):
MXLog.error("[VoiceMessageAttachmentCacheManager] Failed retrieving audio duration", context: error)
self.invokeFailureCallbacksForIdentifier(identifier, requiredNumberOfSamples: numberOfSamples, error: VoiceMessageAttachmentCacheManagerError.durationError(error))
semaphore.signal()
}
}
}
case .failure(let error):
MXLog.error("[VoiceMessageAttachmentCacheManager] Failed converting voice message", context: error)
self.invokeFailureCallbacksForIdentifier(identifier, requiredNumberOfSamples: numberOfSamples, error: VoiceMessageAttachmentCacheManagerError.conversionError(error))
semaphore.signal()
}
}
}
if FileManager.default.fileExists(atPath: newURL.path) {
conversionCompletion(Result.success(()))
} else {
VoiceMessageAudioConverter.convertToMPEG4AACIfNeeded(sourceURL: filePath, destinationURL: newURL, completion: conversionCompletion)
}
}
private func sampleFileAtURL(_ url: URL, duration: TimeInterval, numberOfSamples: Int, identifier: String, semaphore: DispatchSemaphore) {
let analyser = WaveformAnalyzer(audioAssetURL: url)
analyser?.samples(count: numberOfSamples, completionHandler: { samples in
self.workQueue.async {
guard let samples = samples else {
MXLog.debug("[VoiceMessageAttachmentCacheManager] Failed sampling voice message")
self.invokeFailureCallbacksForIdentifier(identifier, requiredNumberOfSamples: numberOfSamples, error: VoiceMessageAttachmentCacheManagerError.samplingError)
semaphore.signal()
return
}
MXLog.debug("[VoiceMessageAttachmentCacheManager] Finished sampling voice message")
if var existingSamples = self.samples[identifier] {
existingSamples[numberOfSamples] = samples
self.samples[identifier] = existingSamples
} else {
self.samples[identifier] = [numberOfSamples: samples]
}
self.invokeSuccessCallbacksForIdentifier(identifier, url: url, duration: duration, samples: samples)
semaphore.signal()
}
})
}
private func invokeSuccessCallbacksForIdentifier(_ identifier: String, url: URL, duration: TimeInterval, samples: [Float]) {
let callbackKey = CompletionCallbackKey(eventIdentifier: identifier, requiredNumberOfSamples: samples.count)
guard let callbacks = completionCallbacks[callbackKey] else {
return
}
let result = VoiceMessageAttachmentCacheManagerLoadResult(eventIdentifier: identifier, url: url, duration: duration, samples: samples)
let copy = callbacks.map { $0 }
DispatchQueue.main.async {
for wrapper in copy {
wrapper.completion(Result.success(result))
}
}
self.completionCallbacks[callbackKey] = nil
MXLog.debug("[VoiceMessageAttachmentCacheManager] Successfully finished task")
}
private func invokeFailureCallbacksForIdentifier(_ identifier: String, requiredNumberOfSamples: Int, error: Error) {
let callbackKey = CompletionCallbackKey(eventIdentifier: identifier, requiredNumberOfSamples: requiredNumberOfSamples)
guard let callbacks = completionCallbacks[callbackKey] else {
return
}
let copy = callbacks.map { $0 }
DispatchQueue.main.async {
for wrapper in copy {
wrapper.completion(Result.failure(error))
}
}
self.completionCallbacks[callbackKey] = nil
MXLog.debug("[VoiceMessageAttachmentCacheManager] Failed task with error: \(error)")
}
private func setupTemporaryFilesFolder() throws {
let url = temporaryFilesFolderURL
try FileManager.default.createDirectory(at: url, withIntermediateDirectories: true, attributes: nil)
}
}