(PowerShell) Async SFTP Progress Info

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

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

$sftp = New-Object Chilkat.SFtp

# Set some timeouts, in milliseconds:
$sftp.ConnectTimeoutMs = 15000
$sftp.IdleTimeoutMs = 15000

# Connect to the SFTP server.  
$success = $sftp.Connect("sftp.example.com",22)
if ($success -ne $true) {
    $($sftp.LastErrorText)
    exit
}

# Authenticate with the SSH server.  Chilkat SFTP supports
# both password-based authenication as well as public-key
# authentication.  This example uses password authenication.
$success = $sftp.AuthenticatePw("myLogin","myPassword")
if ($success -ne $true) {
    $($sftp.LastErrorText)
    exit
}

# After authenticating, the SFTP subsystem must be initialized:
$success = $sftp.InitializeSftp()
if ($success -ne $true) {
    $($sftp.LastErrorText)
    exit
}

# --------------------
# Download a file
# --------------------
$localFilePath = "c:/temp/hamlet.xml"
$remoteFilePath = "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 = $sftp.DownloadFileByNameAsync($remoteFilePath,$localFilePath)
if ($sftp.LastMethodSuccess -eq $false) {
    $($sftp.LastErrorText)
    exit
}

# 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 -ne $true) {
    $($task.LastErrorText)

    exit
}

# 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 = 0

while ($task.Finished -ne $true) {

    if ($task.PercentDone -ne $curPctDone) {
        $curPctDone = $task.PercentDone
        $([string]$curPctDone + " percent done")
    }

    # Check the progress info log.
    # Emit any log entries..
    while (($task.ProgressLogSize -gt 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"

        $($name + ": " + $value)
        $task.RemoveProgressInfo(0)
    }

    # Sleep 100 ms.
    $task.SleepMs(100)

}

# Just in case there are any remaining entries...
while (($task.ProgressLogSize -gt 0)) {
    # Get the 1st entry, emit it, and then remove it..
    $name = $task.ProgressInfoName(0)
    $value = $task.ProgressInfoValue(0)
    $($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 -ne 7) {
    $("Task did not complete.")
    $("task status: " + $task.Status)

    exit
}

# 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 -ne $true) {
    # The task's ResultErrorText contains what would have been in the LastErrorText property had
    # the DownloadFileByName method been called synchronously.
    $($task.ResultErrorText)
}
else {
    $("File downloaded asynchronously.")
}