(Visual FoxPro) Compress Text Feed to Binary

This example receives incoming text data in chunks, compresses as a stream, and accumulates the compressed binary data.

The purpose is to demonstrate the BeginCompressString, MoreCompressString, and EndCompressString methods.

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

LOCAL lnSuccess
LOCAL loCompressedData
LOCAL loCompressedBytes
LOCAL loCompress
LOCAL loSbIndex
LOCAL i
LOCAL lcOriginalText

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.BinData')
loCompressedData = CreateObject('Chilkat.BinData')

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Compression')
loCompress = CreateObject('Chilkat.Compression')
loCompress.Algorithm = "deflate"
loCompress.Charset = "utf-8"

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbIndex = CreateObject('Chilkat.StringBuilder')

FOR i = 0 TO 24
    * Note: It is possible (and normal) for a BeginCompress* or MoreCompress* method to return
    * an empty string (or 0 bytes).  When this happens, the input data is not lost.  It will be flushed
    * in a subsequent call.
    loSbIndex.Clear()
    loSbIndex.AppendInt(i)
    IF (i = 0) THEN
        loCompressedBytes = loCompress.BeginCompressString(loSbIndex.GetAsString())
    ELSE
        loCompressedBytes = loCompress.MoreCompressString(loSbIndex.GetAsString())
    ENDIF

    loCompressedData.AppendBinary(loCompressedBytes)
    loCompressedBytes = loCompress.MoreCompressString(": This is a line of data to be compressed..." + CHR(13) + CHR(10))
    loCompressedData.AppendBinary(loCompressedBytes)
NEXT

* Flush any remaining output.
loCompressedBytes = loCompress.EndCompressString()
loCompressedData.AppendBinary(loCompressedBytes)

* Show the compressed data in hex format:
? "The hex encoded compressed text:"
? loCompressedData.GetEncoded("hex")

* Now decompress in one call:
loCompressedBytes = loCompressedData.GetBinary()
lcOriginalText = loCompress.DecompressString(loCompressedBytes)
? lcOriginalText

RELEASE loCompressedData
RELEASE loCompress
RELEASE loSbIndex