(PowerBuilder) Unzip Binary File to Stream

Demonstrates how to unzip a large binary file to a stream to allow the application to process the uncompressed bytes chunk by chunk.

Note: This example requires Chilkat v9.5.0.67 or greater.

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

integer li_rc
oleobject loo_Zip
integer li_Success
oleobject loo_Entry
oleobject loo_DataStream
oleobject loo_UnzipTask
oleobject loo_Fac
oleobject loo_Bd

// This requires the Chilkat Zip API to have been previously unlocked.
// See Unlock Chilkat Zip for sample code.

loo_Zip = create oleobject
// Use "Chilkat_9_5_0.Zip" for versions of Chilkat < 10.0.0
li_rc = loo_Zip.ConnectToNewObject("Chilkat.Zip")
if li_rc < 0 then
    destroy loo_Zip
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// First open a .zip.
li_Success = loo_Zip.OpenZip("qa_data/zips/big.zip")
if li_Success <> 1 then
    Write-Debug loo_Zip.LastErrorText
    destroy loo_Zip
    return
end if

// Get the entry to be unzipped to a stream..
loo_Entry = loo_Zip.GetEntryByIndex(0)
if loo_Zip.LastMethodSuccess <> 1 then
    Write-Debug loo_Zip.LastErrorText
    destroy loo_Zip
    return
end if

loo_DataStream = create oleobject
// Use "Chilkat_9_5_0.Stream" for versions of Chilkat < 10.0.0
li_rc = loo_DataStream.ConnectToNewObject("Chilkat.Stream")

loo_UnzipTask = loo_Entry.UnzipToStreamAsync(loo_DataStream)
if loo_Entry.LastMethodSuccess <> 1 then
    Write-Debug loo_Entry.LastErrorText
    destroy loo_Entry
    destroy loo_Zip
    destroy loo_DataStream
    return
end if

// Start the background unzip thread.
loo_UnzipTask.Run()

// We'll read the uncompressed data chunk-by-chunk and write to an output file.
loo_Fac = create oleobject
// Use "Chilkat_9_5_0.FileAccess" for versions of Chilkat < 10.0.0
li_rc = loo_Fac.ConnectToNewObject("Chilkat.FileAccess")

li_Success = loo_Fac.OpenForWrite("qa_output/out.dat")
if li_Success <> 1 then
    Write-Debug loo_Fac.LastErrorText
    destroy loo_Entry
    destroy loo_Zip
    destroy loo_DataStream
    destroy loo_Fac
    return
end if

// Read the stream.  (this is reading the unzipped file data)
loo_Bd = create oleobject
// Use "Chilkat_9_5_0.BinData" for versions of Chilkat < 10.0.0
li_rc = loo_Bd.ConnectToNewObject("Chilkat.BinData")

do while loo_DataStream.EndOfStream <> 1
    // Get the next chunk of decompressed bytes.
    loo_DataStream.ReadBd(loo_Bd)
    // Do something with it..
    // In this simple example, we'll just write to the file.
    loo_Fac.FileWriteBd(loo_Bd,0,0)
    // Clear for the next read.
    loo_Bd.Clear()
loop

loo_Fac.FileClose()

destroy loo_Entry
destroy loo_UnzipTask
Write-Debug "Success."


destroy loo_Zip
destroy loo_DataStream
destroy loo_Fac
destroy loo_Bd