Download remote files simultaneously

Downloading files and directories from the remote SFTP server to the local disk is quite simple. All that needs to occur is passing appropriate server information such as hostname, port, username, password/private key and the number of threads to the Download method of the Sftp class.

The following steps illustrate how to use the Download to download files and directories.

using System;
using System.Threading;
using ComponentPro.IO;
using ComponentPro.Net;

...

static void Main()
{
    // Create a new class instance. 
    Sftp client = new Sftp();

    // Connect to the server. 
    client.Connect("server");

    // Authenticate. 
    client.Authenticate("user", "pass");

    client.CommandResponse += client_ResponseRead;

    // You can register the ThreadStateChanged event here or in the client_Progress event handler as shown below. 
    client.ThreadStateChanged += Thread_StateChanged;
    client.Progress += client_Progress;

    // ... 
 
    // Download files and subdirectories from "/my folder" to "c:\\my folder" using 3 threads. This waits untils these threads complete. 
    client.Download("/my folder", "c:\\my folder", 3, true);

    // ... 
 
    client.Disconnect();
}

static void client_Progress(object sender, FileSystemProgressEventArgs e)
{
    // You can access the threads used for the multi-thread file operation here. 
    // Uncomment the following code to register the StateChanged event of each thread. 
    //if (e.State == TransferState.DirectoryStructureBuilt) 
    //{ 
    //    for (int i = 0; i < e.TransferStatistics.Threads.Count; i++) 
    //    { 
    //        e.TransferStatistics.Threads[i].StateChanged += Thread_StateChanged; 
    //    } 
    //} 
 
    // When the multi-thread operation completes the status is MultiFileOperationCompleted. 
    if (e.State == TransferState.MultiFileOperationCompleted)
        Console.WriteLine("File transfer completed");
}

static long _threadsCompleted;
static void Thread_StateChanged(object sender, TransferThreadStateChangedEventArgs e)
{
    if (e.State == TransferThreadState.Stopped) // The thread is stopped 
    {
        TransferThreadInfo info = (TransferThreadInfo)sender;

        Console.WriteLine(string.Format("Thread ID {0} completed", info.ThreadId));

        Interlocked.Increment(ref _threadsCompleted);
        if (Interlocked.Read(ref _threadsCompleted) == 3)
        {
            Console.WriteLine("Multi-threads file transfer completed");
        }
    }
}

static void client_ResponseRead(object sender, CommandResponseEventArgs e)
{
    Sftp client = (Sftp)sender;

    if (client.ThreadId >= 0)
        if (e.Command != null)
            Console.WriteLine("Thread: {0} - CMD>       {1}", client.ThreadId,
                e.Command);
        else 
            Console.WriteLine("Thread: {0} - RESPONSE>  {1}", client.ThreadId,
                e.Response);
}

Imports System.Threading
Imports ComponentPro.IO
Imports ComponentPro.Net

...

Shared Sub Main()
    ' Create a new class instance. 
    Dim client As New Sftp()

    ' Connect to the server. 
    client.Connect("server")

    ' Authenticate. 
    client.Authenticate("user", "pass")

    AddHandler client.CommandResponse, AddressOf client_ResponseRead

    ' You can register the ThreadStateChanged event here or in the client_Progress event handler as shown below. 
    AddHandler client.ThreadStateChanged, AddressOf Thread_StateChanged
    AddHandler client.Progress, AddressOf client_Progress

    ' ... 
 
    ' Download files and subdirectories from "/my folder" to "c:\\my folder" using 3 threads. This waits untils these threads complete. 
    client.Download("/my folder", "c:\my folder", 3, True)

    ' ... 
 
    client.Disconnect()
End Sub 
 
Private Shared Sub client_Progress(ByVal sender As Object, ByVal e As FileSystemProgressEventArgs)
    ' You can access the threads used for the multi-thread file operation here. 
    ' Uncomment the following code to register the StateChanged event of each thread. 
    'if (e.State == TransferState.DirectoryStructureBuilt) 
    '{ 
    '    for (int i = 0; i < e.TransferStatistics.Threads.Count; i++) 
    '    { 
    '        e.TransferStatistics.Threads[i].StateChanged += Thread_StateChanged; 
    '    } 
    '} 
 
    ' When the multi-thread operation completes the status is MultiFileOperationCompleted. 
    If e.State = TransferState.MultiFileOperationCompleted Then 
        Console.WriteLine("File transfer completed")
    End If 
End Sub 
 
Private Shared _threadsCompleted As Long 
Private Shared Sub Thread_StateChanged(ByVal sender As Object, ByVal e As TransferThreadStateChangedEventArgs)
    If e.State = TransferThreadState.Stopped Then ' The thread is stopped 
        Dim info As TransferThreadInfo = CType(sender, TransferThreadInfo)

        Console.WriteLine(String.Format("Thread ID {0} completed", info.ThreadId))

        Interlocked.Increment(_threadsCompleted)
        If Interlocked.Read(_threadsCompleted) = 3 Then 
            Console.WriteLine("Multi-threads file transfer completed")
        End If 
    End If 
End Sub 
 
Private Shared Sub client_ResponseRead(ByVal sender As Object, ByVal e As CommandResponseEventArgs)
    Dim client As Sftp = CType(sender, Sftp)

    If client.ThreadId >= 0 Then 
        If e.Command IsNot Nothing Then 
            Console.WriteLine("Thread: {0} - CMD>       {1}", client.ThreadId, e.Command)
        Else 
            Console.WriteLine("Thread: {0} - RESPONSE>  {1}", client.ThreadId, e.Response)
        End If 
    End If 
End Sub