Xojo Plugin

File Read Blocks

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

Dim success As Boolean
success = False

// 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.

Dim dataBlock As MemoryBlock

Dim facSrc As New Chilkat.FileAccess
Dim facDest As New Chilkat.FileAccess

Dim srcPath As String
srcPath = "qa_data/xml/hamlet.xml"
Dim destPath As String
destPath = "qa_output/hamletOut.xml"

success = facSrc.OpenForRead(srcPath)
success = facDest.OpenForWrite(destPath)
// Assuming success for the example..

// How many 1024-byte blocks?  (Including 1 for the last partial block)
Dim numBlocks As Int32
numBlocks = facSrc.GetNumBlocks(1024)

Dim i As Int32
i = 0
While (i < numBlocks)
    dataBlock = facSrc.ReadBlock(i,1024)
    If (facSrc.LastMethodSuccess <> True) Then
        System.DebugLog(facSrc.LastErrorText)
        Return
    End If

    success = facDest.FileWrite(dataBlock)
    If (success <> True) Then
        System.DebugLog(facDest.LastErrorText)
        Return
    End If

    i = i + 1
Wend

facSrc.FileClose 
facDest.FileClose 

Dim bEqual As Boolean
bEqual = facSrc.FileContentsEqual(srcPath,destPath)
If (bEqual <> True) Then
    System.DebugLog("Something went wrong!")
    Return
End If

System.DebugLog("File successfully copied by blocks.")