(C++) Chunked Compression Using CompressBd2 with FirstChunk and LastChunk

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The example shows how to correctly mark the first, middle, and final chunks so that the compression stream is properly initialized and finalized. The compressed output is accumulated in a separate BinData object without modifying the input chunks. Finally, the example decompresses the combined result to verify that the original data is restored correctly.

This approach is ideal for scenarios where data is received incrementally, such as reading from a network stream, processing large files in parts, or handling real-time data feeds.

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

void ChilkatSample(void)
    {
    bool success = false;

    // This example assumes the Chilkat API has already been unlocked.
    // See Global Unlock Sample for sample code.

    CkCompression compress;
    compress.put_Algorithm("zlib");

    // This will accumulate the compressed output.
    CkBinData bdOut;

    // ------------------------------------------------------------------
    // Simulate input arriving in chunks.
    // ------------------------------------------------------------------

    const char *part1 = "The quick brown fox ";
    const char *part2 = "jumps over the lazy dog. ";
    const char *part3 = "This text is split into chunks.";

    // ------------------------------------------------------------------
    // Compress the first chunk
    // ------------------------------------------------------------------

    compress.put_FirstChunk(true);
    compress.put_LastChunk(false);

    CkBinData bdIn;
    bdIn.AppendString(part1,"utf-8");

    success = compress.CompressBd2(bdIn,bdOut);
    if (success == false) {
        std::cout << compress.lastErrorText() << "\r\n";
        return;
    }

    // ------------------------------------------------------------------
    // Compress a middle chunk
    // ------------------------------------------------------------------

    compress.put_FirstChunk(false);
    compress.put_LastChunk(false);

    bdIn.Clear();
    bdIn.AppendString(part2,"utf-8");

    success = compress.CompressBd2(bdIn,bdOut);
    if (success == false) {
        std::cout << compress.lastErrorText() << "\r\n";
        return;
    }

    // ------------------------------------------------------------------
    // Compress the final chunk
    // ------------------------------------------------------------------

    compress.put_FirstChunk(false);
    compress.put_LastChunk(true);

    bdIn.Clear();
    bdIn.AppendString(part3,"utf-8");

    success = compress.CompressBd2(bdIn,bdOut);
    if (success == false) {
        std::cout << compress.lastErrorText() << "\r\n";
        return;
    }

    // Get the final compressed result as base64 for display
    const char *compressedBase64 = bdOut.getEncoded("base64");

    std::cout << "Compressed data (base64):" << "\r\n";
    std::cout << compressedBase64 << "\r\n";

    // ------------------------------------------------------------------
    // Decompress to verify correctness
    // ------------------------------------------------------------------

    CkBinData bdDecompressed;

    compress.put_FirstChunk(true);
    compress.put_LastChunk(true);

    success = compress.DecompressBd2(bdOut,bdDecompressed);
    if (success == false) {
        std::cout << compress.lastErrorText() << "\r\n";
        return;
    }

    // Convert decompressed bytes back to a string
    const char *resultText = bdDecompressed.getString("utf-8");

    std::cout << "Decompressed text:" << "\r\n";
    std::cout << resultText << "\r\n";
    }