DataFlex

Clear the SFTP File-Attribute Cache

Demonstrates the Chilkat SFtp.ClearCache method, which clears the internal remote file-attribute cache used when the EnableCache property is enabled. It takes no arguments.

Background: When caching is on, Chilkat remembers file attributes it has already fetched so that repeated lookups — common when listing then stat-ing many files — avoid extra round trips. The trade-off is staleness: if files change on the server, the cache can report old sizes or timestamps. ClearCache discards those remembered values so the next lookup queries the server fresh, which you would do after a known change or before a check that must be current.

Chilkat DataFlex Downloads

Download Chilkat for DataFlex

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoSftp
    Integer iPort
    String sPassword
    String sTemp1

    Move False To iSuccess

    //  Demonstrates the SFtp.ClearCache method, which clears the internal remote file-attribute cache
    //  used when the EnableCache property is True.  It takes no arguments.

    Get Create (RefClass(cComChilkatSFtp)) To hoSftp
    If (Not(IsComObjectCreated(hoSftp))) Begin
        Send CreateComObject of hoSftp
    End

    //  Connect, authenticate, and initialize the SFTP subsystem.
    Move 22 To iPort
    Get ComConnect Of hoSftp "sftp.example.com" iPort To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSftp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  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.
    Move "mySshPassword" To sPassword

    Get ComAuthenticatePw Of hoSftp "mySshLogin" sPassword To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSftp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComInitializeSftp Of hoSftp To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSftp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  With caching enabled, repeated attribute lookups for the same file are served from memory.
    Set ComEnableCache Of hoSftp To True

    //  ... perform operations that populate the cache ...

    //  Clear the cache so that subsequent attribute lookups query the server again, for example
    //  after files on the server are known to have changed.
    Send ComClearCache To hoSftp
    Showln "Attribute cache cleared."

    Send ComDisconnect To hoSftp


End_Procedure