(PureBasic) Async SFTP Progress Info

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

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkTask.pb"
IncludeFile "CkGlobal.pb"
IncludeFile "CkSFtp.pb"

Procedure ChilkatExample()

    ; All Chilkat classes can be unlocked at once at the beginning of a program
    ; by calling UnlockBundle.  It requires a Bundle unlock code.
    chilkatGlob.i = CkGlobal::ckCreate()
    If chilkatGlob.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i = CkGlobal::ckUnlockBundle(chilkatGlob,"Anything for 30-day trial.")
    If success <> 1
        Debug CkGlobal::ckLastErrorText(chilkatGlob)
        CkGlobal::ckDispose(chilkatGlob)
        ProcedureReturn
    EndIf

    sftp.i = CkSFtp::ckCreate()
    If sftp.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Set some timeouts, in milliseconds:
    CkSFtp::setCkConnectTimeoutMs(sftp, 15000)
    CkSFtp::setCkIdleTimeoutMs(sftp, 15000)

    ; Connect to the SSH server.  
    ; The standard SSH port = 22
    ; The hostname may be a hostname or IP address.
    hostname.s = "www.my-ssh-server.com"
    port.i = 22
    success = CkSFtp::ckConnect(sftp,hostname,port)
    If success <> 1
        Debug CkSFtp::ckLastErrorText(sftp)
        CkGlobal::ckDispose(chilkatGlob)
        CkSFtp::ckDispose(sftp)
        ProcedureReturn
    EndIf

    ; Authenticate with the SSH server.  Chilkat SFTP supports
    ; both password-based authenication as well as public-key
    ; authentication.  This example uses password authenication.
    success = CkSFtp::ckAuthenticatePw(sftp,"myLogin","myPassword")
    If success <> 1
        Debug CkSFtp::ckLastErrorText(sftp)
        CkGlobal::ckDispose(chilkatGlob)
        CkSFtp::ckDispose(sftp)
        ProcedureReturn
    EndIf

    ; After authenticating, the SFTP subsystem must be initialized:
    success = CkSFtp::ckInitializeSftp(sftp)
    If success <> 1
        Debug CkSFtp::ckLastErrorText(sftp)
        CkGlobal::ckDispose(chilkatGlob)
        CkSFtp::ckDispose(sftp)
        ProcedureReturn
    EndIf

    ; --------------------
    ; Download a file
    ; --------------------
    localFilePath.s = "c:/temp/hamlet.xml"
    remoteFilePath.s = "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.
    task.i = CkSFtp::ckDownloadFileByNameAsync(sftp,remoteFilePath,localFilePath)
    If CkSFtp::ckLastMethodSuccess(sftp) = 0
        Debug CkSFtp::ckLastErrorText(sftp)
        CkGlobal::ckDispose(chilkatGlob)
        CkSFtp::ckDispose(sftp)
        ProcedureReturn
    EndIf

    ; Before starting the task, tell it to keep an in-memory log of what would've been
    ; ProgressInfo callbacks.
    CkTask::setCkKeepProgressLog(task, 1)

    ; Schedule the task for running on the thread pool.  This changes the task's state
    ; from Inert to Live.
    success = CkTask::ckRun(task)
    If success <> 1
        Debug CkTask::ckLastErrorText(task)
        CkTask::ckDispose(task)

        CkGlobal::ckDispose(chilkatGlob)
        CkSFtp::ckDispose(sftp)
        ProcedureReturn
    EndIf

    ; 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.
    curPctDone.i = 0
    name.s
    value.s

    While CkTask::ckFinished(task) <> 1

        If CkTask::ckPercentDone(task) <> curPctDone
            curPctDone = CkTask::ckPercentDone(task)
            Debug Str(curPctDone) + " percent done"
        EndIf

        ; Check the progress info log.
        ; Emit any log entries..
        While (CkTask::ckProgressLogSize(task) > 0)
            ; Get the 1st entry, emit it, and then remove it..
            name = CkTask::ckProgressInfoName(task,0)
            value = CkTask::ckProgressInfoValue(task,0)

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

            Debug name + ": " + value
            CkTask::ckRemoveProgressInfo(task,0)
        Wend

        ; Sleep 100 ms.
        CkTask::ckSleepMs(task,100)

    Wend

    ; Just in case there are any remaining entries...
    While (CkTask::ckProgressLogSize(task) > 0)
        ; Get the 1st entry, emit it, and then remove it..
        name = CkTask::ckProgressInfoName(task,0)
        value = CkTask::ckProgressInfoValue(task,0)
        Debug name + ": " + value
        CkTask::ckRemoveProgressInfo(task,0)
    Wend

    ; 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 CkTask::ckStatusInt(task) <> 7
        Debug "Task did not complete."
        Debug "task status: " + CkTask::ckStatus(task)
        CkTask::ckDispose(task)

        CkGlobal::ckDispose(chilkatGlob)
        CkSFtp::ckDispose(sftp)
        ProcedureReturn
    EndIf

    ; 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 = CkTask::ckGetResultBool(task)
    If success <> 1
        ; The task's ResultErrorText contains what would have been in the LastErrorText property had
        ; the DownloadFileByName method been called synchronously.
        Debug CkTask::ckResultErrorText(task)
    Else
        Debug "File downloaded asynchronously."
    EndIf

    CkTask::ckDispose(task)



    CkGlobal::ckDispose(chilkatGlob)
    CkSFtp::ckDispose(sftp)


    ProcedureReturn
EndProcedure