(SQL Server) Wait for Async Method to Complete

Demonstrates using the Wait method to wait for an asynchronous method to complete. This example will do an SFTP upload (over SSH) and will use the Async version of each method. Obviously, waiting for the async method to complete is the same as making a synchronous call, but an application wouldn't typically do this. An application might, for example, do other things as a background task is running, and then later wait for the task to complete.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    DECLARE @iTmp1 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @sftp int
    -- Use "Chilkat_9_5_0.SFtp" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.SFtp', @sftp OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- Set some timeouts, in milliseconds:
    EXEC sp_OASetProperty @sftp, 'ConnectTimeoutMs', 15000
    EXEC sp_OASetProperty @sftp, 'IdleTimeoutMs', 15000
    DECLARE @waitMaxMs int
    SELECT @waitMaxMs = 30000

    -- Connect to the SSH server.  
    -- The standard SSH port = 22
    -- The hostname may be a hostname or IP address.
    DECLARE @port int
    SELECT @port = 22
    DECLARE @domain nvarchar(4000)
    SELECT @domain = 'sftp.example.com'

    DECLARE @task int
    EXEC sp_OAMethod @sftp, 'ConnectAsync', @task OUT, @domain, @port
    EXEC sp_OAGetProperty @sftp, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sftp
        RETURN
      END
    -- Start the background task.
    DECLARE @success int
    EXEC sp_OAMethod @task, 'Run', @success OUT
    IF Not @success
      BEGIN
        EXEC sp_OAGetProperty @task, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
      END

    -- Wait for the connect task to finish.
    -- The 1/0 returned by Wait applies to the Wait method call, not the task.
    EXEC sp_OAMethod @task, 'Wait', @success OUT, @waitMaxMs
    EXEC sp_OAGetProperty @task, 'StatusInt', @iTmp0 OUT
    EXEC sp_OAGetProperty @task, 'TaskSuccess', @iTmp1 OUT
    IF Not @success or (@iTmp0 <> 7) or (@iTmp1 <> 1)
      BEGIN
        IF Not @success
          BEGIN
            -- The task.LastErrorText applies to the Wait method call.
            EXEC sp_OAGetProperty @task, 'LastErrorText', @sTmp0 OUT
            PRINT @sTmp0
          END
        ELSE
          BEGIN
            -- The ResultErrorText applies to the underlying task method call (i.e. the Connect)
            EXEC sp_OAGetProperty @task, 'Status', @sTmp0 OUT
            PRINT @sTmp0
            EXEC sp_OAGetProperty @task, 'ResultErrorText', @sTmp0 OUT
            PRINT @sTmp0
          END
        EXEC @hr = sp_OADestroy @task

        EXEC @hr = sp_OADestroy @sftp
        RETURN
      END

    EXEC @hr = sp_OADestroy @task

    -- Authenticate with the SSH server.  Chilkat SFTP supports
    -- both password-based authenication as well as public-key
    -- authentication.  This example uses password authenication.
    EXEC sp_OAMethod @sftp, 'AuthenticatePwAsync', @task OUT, 'myLogin', 'myPassword'
    -- To keep the example short, we'll skip handling failures.
    -- The failures would be handled in the same way as shown above.

    EXEC sp_OAMethod @task, 'Run', @success OUT
    EXEC sp_OAMethod @task, 'Wait', @success OUT, @waitMaxMs
    EXEC @hr = sp_OADestroy @task

    -- After authenticating, the SFTP subsystem must be initialized:
    EXEC sp_OAMethod @sftp, 'InitializeSftpAsync', @task OUT
    EXEC sp_OAMethod @task, 'Run', @success OUT
    EXEC sp_OAMethod @task, 'Wait', @success OUT, @waitMaxMs
    EXEC @hr = sp_OADestroy @task

    -- Upload from the local file to the SSH server.
    -- Important -- the remote filepath is the 1st argument,
    -- the local filepath is the 2nd argument;
    DECLARE @remoteFilePath nvarchar(4000)
    SELECT @remoteFilePath = 'hamlet.xml'
    DECLARE @localFilePath nvarchar(4000)
    SELECT @localFilePath = 'c:/temp/hamlet.xml'

    EXEC sp_OAMethod @sftp, 'UploadFileByNameAsync', @task OUT, @remoteFilePath, @localFilePath
    EXEC sp_OAGetProperty @sftp, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @sftp, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sftp
        RETURN
      END

    EXEC sp_OAMethod @task, 'Run', @success OUT
    EXEC sp_OAMethod @task, 'Wait', @success OUT, @waitMaxMs
    EXEC sp_OAGetProperty @task, 'StatusInt', @iTmp0 OUT
    EXEC sp_OAGetProperty @task, 'TaskSuccess', @iTmp1 OUT
    IF Not @success or (@iTmp0 <> 7) or (@iTmp1 <> 1)
      BEGIN
        IF Not @success
          BEGIN
            -- The task.LastErrorText applies to the Wait method call.
            EXEC sp_OAGetProperty @task, 'LastErrorText', @sTmp0 OUT
            PRINT @sTmp0
          END
        ELSE
          BEGIN
            -- The ResultErrorText applies to the underlying task method call (i.e. the Connect)
            EXEC sp_OAGetProperty @task, 'Status', @sTmp0 OUT
            PRINT @sTmp0
            EXEC sp_OAGetProperty @task, 'ResultErrorText', @sTmp0 OUT
            PRINT @sTmp0
          END
        EXEC @hr = sp_OADestroy @task

        EXEC @hr = sp_OADestroy @sftp
        RETURN
      END

    EXEC @hr = sp_OADestroy @task


    PRINT 'File uploaded.'

    EXEC @hr = sp_OADestroy @sftp


END
GO