(Swift 3,4,5...) Async SFTP Progress Info

Demonstrates checking for progress info updates when running a task asynchronously. This example demonstrates an SFTP download.

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    let sftp = CkoSFtp()!

    // Set some timeouts, in milliseconds:
    sftp.connectTimeoutMs = 15000
    sftp.idleTimeoutMs = 15000

    // Connect to the SFTP server.  
    var success: Bool = sftp.connect("sftp.example.com", port: 22)
    if success != true {
        print("\(sftp.lastErrorText!)")
        return
    }

    // Authenticate with the SSH server.  Chilkat SFTP supports
    // both password-based authenication as well as public-key
    // authentication.  This example uses password authenication.
    success = sftp.authenticatePw("myLogin", password: "myPassword")
    if success != true {
        print("\(sftp.lastErrorText!)")
        return
    }

    // After authenticating, the SFTP subsystem must be initialized:
    success = sftp.initializeSftp()
    if success != true {
        print("\(sftp.lastErrorText!)")
        return
    }

    // --------------------
    // Download a file
    // --------------------
    var localFilePath: String? = "c:/temp/hamlet.xml"
    var remoteFilePath: String? = "subdir1/subdir2/hamlet.xml"

    // Call the async version of the DownloadFileByName method to return a task object.
    // The task object is loaded, but is in the Inert state -- meaning it is
    // not yet scheduled to run on Chilkat's background thread pool.
    var task: CkoTask? = sftp.downloadFile(byNameAsync: remoteFilePath, localFilePath: localFilePath)
    if sftp.lastMethodSuccess == false {
        print("\(sftp.lastErrorText!)")
        return
    }

    // Before starting the task, tell it to keep an in-memory log of what would've been
    // ProgressInfo callbacks.
    task.keepProgressLog = true

    // Schedule the task for running on the thread pool.  This changes the task's state
    // from Inert to Live.
    success = task!.run()
    if success != true {
        print("\(task!.lastErrorText!)")
        task = nil
        return
    }

    // The application is now free to do anything else
    // while the file is being downloaded.

    // For this example, we'll simply sleep and periodically
    // check to see if the download is finished, and report the progress
    // along the way.
    var curPctDone: Int = 0
    var name: String?
    var value: String?

    while task!.finished != true {

        if task!.percentDone.intValue != curPctDone {
            curPctDone = task!.percentDone.intValue
            print("\(curPctDone) percent done")
        }

        // Check the progress info log.
        // Emit any log entries..
        while (task!.progressLogSize.intValue > 0) {
            // Get the 1st entry, emit it, and then remove it..
            name = task!.progressInfoName(0)
            value = task!.progressInfoValue(0)

            // Entries reporting the received byte count will have the name "RcvByteCount"
            // Entries reporting the current bytes-per-second will have the name "RcvBytesPerSec"

            print("\(name!): \(value!)")
            task!.removeProgressInfo(0)
        }

        // Sleep 100 ms.
        task!.sleepMs(100)

    }

    // Just in case there are any remaining entries...
    while (task!.progressLogSize.intValue > 0) {
        // Get the 1st entry, emit it, and then remove it..
        name = task!.progressInfoName(0)
        value = task!.progressInfoValue(0)
        print("\(name!): \(value!)")
        task!.removeProgressInfo(0)
    }

    // A finished task could be one that was canceled, aborted, or truly finished.  

    // If the task was "canceled", it was canceled prior to actually starting.  This could
    // happen if the task was canceled while waiting in a thread pool queue to be scheduled by Chilkat's
    // background thread pool scheduler.  

    // If the task was "aborted", it indicates that it was canceled while running in a background thread.  
    // The ResultErrorText will likely indicate that the task was aborted.

    // If the task "completed", then it ran to completion, but the actual success/failure of the method
    // is determined by the result obtained via a GetResult* method.  (A "completed" task will
    // have a StatusInt equal to 7.   If the task finished, but was not completed, then it must've
    // been aborted or canceled:
    if task!.statusInt.intValue != 7 {
        print("Task did not complete.")
        print("task status: \(task!.status!)")
        task = nil
        return
    }

    // The DownloadFileByName method returns a boolean.  Therefore, after the task is finished,
    // we can get the boolean result by calling GetResultBool.  This is the return value had
    // we called DownloadFileByName synchronously.
    success = task!.getResultBool()
    if success != true {
        // The task's ResultErrorText contains what would have been in the LastErrorText property had
        // the DownloadFileByName method been called synchronously.
        print("\(task!.resultErrorText!)")
    }
    else {
        print("File downloaded asynchronously.")
    }

    task = nil

}