Xojo Plugin

Upload a Large File in Chunks (FTP)

Demonstrates the Chilkat Ftp2.LargeFileUpload method, which uploads a local file as a sequence of transfers, each up to a given chunk size. The arguments are the local path, the remote path, and the chunk size in bytes.

Note: The local paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: Some servers, proxies, or firewalls impose a limit on the size or duration of a single data transfer, which a very large file can exceed. This method sidesteps that by sending the file in pieces — the first with STOR to create or replace the file, each subsequent one appended — so no single transfer is oversized. Choose a chunk size comfortably under whatever limit you are working around.

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Xojo Plugin

Dim success As Boolean
success = False

//  Demonstrates the Ftp2.LargeFileUpload method, which uploads a local file as a sequence of
//  transfers, each up to a given chunk size.  The 1st argument is the local path, the 2nd is the
//  remote path, and the 3rd is the chunk size in bytes.

Dim ftp As New Chilkat.Ftp2

ftp.Hostname = "ftp.example.com"
ftp.Username = "myFtpLogin"

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
ftp.Password = "myPassword"

success = ftp.Connect()
If (success = False) Then
    System.DebugLog(ftp.LastErrorText)
    Return
End If

//  The first chunk is sent with STOR (creating/replacing the remote file); each later chunk is
//  appended.  Uploading in chunks can work around server or network limits on a single transfer.
Dim chunkSize As Int32
chunkSize = 10485760
success = ftp.LargeFileUpload("qa_data/bigfile.zip","uploads/bigfile.zip",chunkSize)
If (success = False) Then
    System.DebugLog(ftp.LastErrorText)
    Return
End If

System.DebugLog("Large file uploaded.")

success = ftp.Disconnect()
If (success = False) Then
    System.DebugLog(ftp.LastErrorText)
    Return
End If