(DataFlex) File Read Blocks

Demonstrates how to read a file in fixed-size blocks (except for the very last block).

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

Use ChilkatAx-9.5.0-win32.pkg

Procedure Test
    Variant hoDataBlock
    Handle hoFacSrc
    Handle hoFacDest
    String sSrcPath
    String sDestPath
    Boolean iSuccess
    Integer iNumBlocks
    Integer i
    Boolean iBEqual
    String sTemp1
    Boolean bTemp1

    // Demonstrates how to read a file in blocks,
    // which can be useful when uploading to cloud storage
    // services such as Azure, S3, Google, etc.

    // For this example, we're simply writing the blocks
    // to an output file, and then checking to see if the
    // resulting file contents equals the original file contents.

    Get Create (RefClass(cComCkFileAccess)) To hoFacSrc
    If (Not(IsComObjectCreated(hoFacSrc))) Begin
        Send CreateComObject of hoFacSrc
    End
    Get Create (RefClass(cComCkFileAccess)) To hoFacDest
    If (Not(IsComObjectCreated(hoFacDest))) Begin
        Send CreateComObject of hoFacDest
    End

    Move "qa_data/xml/hamlet.xml" To sSrcPath
    Move "qa_output/hamletOut.xml" To sDestPath

    Get ComOpenForRead Of hoFacSrc sSrcPath To iSuccess
    Get ComOpenForWrite Of hoFacDest sDestPath To iSuccess
    // Assuming success for the example..

    // How many 1024-byte blocks?  (Including 1 for the last partial block)
    Get ComGetNumBlocks Of hoFacSrc 1024 To iNumBlocks

    Move 0 To i
    While (i < iNumBlocks)
        Get ComReadBlock Of hoFacSrc i 1024 To hoDataBlock
        Get ComLastMethodSuccess Of hoFacSrc To bTemp1
        If (bTemp1 <> True) Begin
            Get ComLastErrorText Of hoFacSrc To sTemp1
            Showln sTemp1
            Procedure_Return
        End

        Get ComFileWrite Of hoFacDest vDataBlock To iSuccess
        If (iSuccess <> True) Begin
            Get ComLastErrorText Of hoFacDest To sTemp1
            Showln sTemp1
            Procedure_Return
        End

        Move (i + 1) To i
    Loop

    Send ComFileClose To hoFacSrc
    Send ComFileClose To hoFacDest

    Get ComFileContentsEqual Of hoFacSrc sSrcPath sDestPath To iBEqual
    If (iBEqual <> True) Begin
        Showln "Something went wrong!"
        Procedure_Return
    End

    Showln "File successfully copied by blocks."


End_Procedure