(MFC) 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 C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkBinData.h>
#include <CkByteData.h>
#include <CkCompression.h>
#include <CkStringBuilder.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    bool success;
    CkBinData compressedData;
    CkByteData compressedBytes;

    CkCompression compress;
    compress.put_Algorithm("deflate");
    compress.put_Charset("utf-8");

    CkStringBuilder sbIndex;

    int i;
    for (i = 0; i <= 24; i++) {
        // 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.
        sbIndex.Clear();
        sbIndex.AppendInt(i);
        if (i == 0) {
            success = compress.BeginCompressString(sbIndex.getAsString(),compressedBytes);
        }
        else {
            success = compress.MoreCompressString(sbIndex.getAsString(),compressedBytes);
        }

        compressedData.AppendBinary(compressedBytes);
        success = compress.MoreCompressString(": This is a line of data to be compressed...\r\n",compressedBytes);
        compressedData.AppendBinary(compressedBytes);
    }

    // Flush any remaining output.
    success = compress.EndCompressString(compressedBytes);
    compressedData.AppendBinary(compressedBytes);

    // Show the compressed data in hex format:
    strOut.append("The hex encoded compressed text:");
    strOut.append("\r\n");
    strOut.append(compressedData.getEncoded("hex"));
    strOut.append("\r\n");

    // Now decompress in one call:
    success = compressedData.GetBinary(compressedBytes);
    const char *originalText = compress.decompressString(compressedBytes);
    strOut.append(originalText);
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }