(Visual FoxPro) Stream a file to compression to encryption to an output file.

Runs a chain of streams to read a source file, compress, encrypt, and write an output file.

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

LOCAL lnSuccess
LOCAL loCompress
LOCAL loCrypt
LOCAL lcIvHex
LOCAL lcKeyHex
LOCAL loStreamC
LOCAL loStreamE
LOCAL loTaskC
LOCAL loTaskE
LOCAL loBinData

* This requires the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* Initialize the compression object.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Compression')
loCompress = CreateObject('Chilkat.Compression')
loCompress.Algorithm = "deflate"

* Initialize the encryption object.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Crypt2')
loCrypt = CreateObject('Chilkat.Crypt2')
loCrypt.CryptAlgorithm = "chacha20"
loCrypt.KeyLength = 256
loCrypt.EncodingMode = "hex"
lcIvHex = "000000000000000000000002"
loCrypt.SetEncodedIV(lcIvHex,"hex")
loCrypt.InitialCount = 42
lcKeyHex = "1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0"
loCrypt.SetEncodedKey(lcKeyHex,"hex")

* Setup the streams.  
* streamC is for compression
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Stream')
loStreamC = CreateObject('Chilkat.Stream')
* streamE is for encryption
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Stream')
loStreamE = CreateObject('Chilkat.Stream')

* The source for the compressor is a file.
loStreamC.SourceFile = "qa_data/hamlet.xml"
* The source for the encryptor is the output of the compressor stream.
lnSuccess = loStreamE.SetSourceStream(loStreamC)

* The sink for the encryptor is the output file.
loStreamE.SinkFile = "qa_output/compressed_encrypted.dat"

* Start the compression and encryption streams in background threads..
loTaskC = loCompress.CompressStreamAsync(loStreamC)
loTaskE = loCrypt.EncryptStreamAsync(loStreamE)
lnSuccess = loTaskC.Run()
lnSuccess = loTaskE.Run()

* Let the streams run until finished.
* Let's make sure the background task finished.
* It should already be the case that the task is finished.
DO WHILE ((loTaskE.Finished <> 1) OR (loTaskC.Finished <> 1))
    loTaskE.SleepMs(20)
ENDDO

* check for success..
IF (loTaskE.TaskSuccess <> 1) THEN
    ? "async encryption failed:"
    ? loTaskE.ResultErrorText
    lnSuccess = 0
ENDIF

* check for success..
IF (loTaskC.TaskSuccess <> 1) THEN
    ? "async compression failed:"
    ? loTaskC.ResultErrorText
    lnSuccess = 0
ENDIF

RELEASE loTaskE
RELEASE loTaskC

* Load the file that was produced and decrypt/decompress to verify.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.BinData')
loBinData = CreateObject('Chilkat.BinData')
lnSuccess = loBinData.LoadFile("qa_output/compressed_encrypted.dat")
lnSuccess = loCrypt.DecryptBd(loBinData)
lnSuccess = loCompress.DecompressBd(loBinData)

* binData should contain the original data..
lnSuccess = loBinData.WriteFile("qa_output/original_hamlet.xml")

? "Finished."

RELEASE loCompress
RELEASE loCrypt
RELEASE loStreamC
RELEASE loStreamE
RELEASE loBinData