(MFC) Compress String Feed to Base64

This example receives incoming text data in chunks, compresses as a stream, and accumulates the compressed data in base64.

The purpose is to demonstrate the BeginCompressStringENC, MoreCompressStringENC, and EndCompressStringENC methods.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkStringBuilder.h>
#include <CkCompression.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;
    CkStringBuilder sbCompressedBase64;

    CkCompression compress;
    compress.put_Algorithm("deflate");
    compress.put_Charset("utf-8");
    compress.put_EncodingMode("base64");

    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) {
            sbCompressedBase64.Append(compress.beginCompressStringENC(sbIndex.getAsString()));
        }
        else {
            sbCompressedBase64.Append(compress.moreCompressStringENC(sbIndex.getAsString()));
        }

        sbCompressedBase64.Append(compress.moreCompressStringENC(": This is a line of data to be compressed...\r\n"));
    }

    // Flush any remaining output.
    sbCompressedBase64.Append(compress.endCompressStringENC());

    strOut.append("The base64 encoded compressed text:");
    strOut.append("\r\n");
    strOut.append(sbCompressedBase64.getAsString());
    strOut.append("\r\n");

    // Now decompress in one call:
    const char *originalText = compress.decompressStringENC(sbCompressedBase64.getAsString());
    strOut.append(originalText);
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }