element-ios/BroadcastUploadExtension/Sources/SampleHandler.swift

//
// License from the original repository:
// https://github.com/jitsi/jitsi-meet-sdk-samples/blob/master/LICENSE
//
//  SampleHandler.swift
//  Broadcast Extension
//
//  Created by Alex-Dan Bumbu on 04.06.2021.
//

import ReplayKit

import MatrixSDK

private enum Constants {
    // the App Group ID value that the app and the broadcast extension targets are setup with. It differs for each app.
    static let appGroupIdentifier = BuildSettings.applicationGroupIdentifier
}

class SampleHandler: RPBroadcastSampleHandler {
    
    private var clientConnection: SocketConnection?
    private var uploader: SampleUploader?
    
    private var frameCount: Int = 0
    
    private var socketFilePath: String {
      let sharedContainer = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: Constants.appGroupIdentifier)
        return sharedContainer?.appendingPathComponent("rtc_SSFD").path ?? ""
    }
    
    override init() {
        super.init()
        setupLogger()

        if let connection = SocketConnection(filePath: socketFilePath) {
          clientConnection = connection
          setupConnection()
          
          uploader = SampleUploader(connection: connection)
        }
    }

    override func broadcastStarted(withSetupInfo setupInfo: [String: NSObject]?) {
        // User has requested to start the broadcast. Setup info from the UI extension can be supplied but optional.
        frameCount = 0
        
        DarwinNotificationCenter.shared.postNotification(.broadcastStarted)
        openConnection()
    }
    
    override func broadcastPaused() {
        // User has requested to pause the broadcast. Samples will stop being delivered.
    }
    
    override func broadcastResumed() {
        // User has requested to resume the broadcast. Samples delivery will resume.
    }
    
    override func broadcastFinished() {
        // User has requested to finish the broadcast.
        DarwinNotificationCenter.shared.postNotification(.broadcastStopped)
        clientConnection?.close()
    }
    
    override func processSampleBuffer(_ sampleBuffer: CMSampleBuffer, with sampleBufferType: RPSampleBufferType) {
        switch sampleBufferType {
        case RPSampleBufferType.video:
            // very simple mechanism for adjusting frame rate by using every third frame
            frameCount += 1
            if frameCount % 3 == 0 {
                uploader?.send(sample: sampleBuffer)
            }
        default:
            break
        }
    }
}

private extension SampleHandler {
  
    func setupConnection() {
        clientConnection?.didClose = { [weak self] error in
            MXLog.error("client connection did close", context: error)
          
            if let error = error {
                self?.finishBroadcastWithError(error)
            } else {
                // the displayed failure message is more user friendly when using NSError instead of Error
                let JMScreenSharingStopped = 10001
                let customError = NSError(domain: RPRecordingErrorDomain, code: JMScreenSharingStopped, userInfo: [NSLocalizedDescriptionKey: "Screen sharing stopped"])
                self?.finishBroadcastWithError(customError)
            }
        }
    }
    
    func openConnection() {
        let queue = DispatchQueue(label: "broadcast.connectTimer")
        let timer = DispatchSource.makeTimerSource(queue: queue)
        timer.schedule(deadline: .now(), repeating: .milliseconds(100), leeway: .milliseconds(500))
        timer.setEventHandler { [weak self] in
            guard self?.clientConnection?.open() == true else {
                return
            }
            
            timer.cancel()
        }
        
        timer.resume()
    }

    func setupLogger() {
        let configuration = MXLogConfiguration()
        configuration.logLevel = .verbose
        configuration.maxLogFilesCount = 100
        configuration.logFilesSizeLimit = 10 * 1024 * 1024; // 10MB
        configuration.subLogName = "broadcastUploadExtension"

        if isatty(STDERR_FILENO) == 0 {
            configuration.redirectLogsToFiles = true
        }

        MXLog.configure(configuration)
    }
}