(C) Compress and Decompress Base64

Imagine we have data represented as a base64 string. This example demonstrates how to decode, compress, and re-encode to smaller base64 representing the compressed data.

Note: This example requires Chilkat v9.5.0.66 or greater.

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#include <C_CkCompression.h>
#include <C_CkBinData.h>

void ChilkatSample(void)
    {
    BOOL success;
    const char *strBase64;
    HCkCompression compress;
    HCkBinData binDat;
    const char *compressedBase64;
    const char *decompressedBase64;

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

    strBase64 = "VGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NClRoZSBxdWljayBicm93biBmb3gganVtcGVkIG92ZXIgdGhlIGxhenkgZG9nLg0KVGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NCg0K";

    compress = CkCompression_Create();
    CkCompression_putAlgorithm(compress,"deflate");

    binDat = CkBinData_Create();
    // Load the base64 data into a BinData object.
    // This decodes the base64. The decoded bytes will be contained in the BinData.
    CkBinData_AppendEncoded(binDat,strBase64,"base64");

    // Compress the BinData.
    CkCompression_CompressBd(compress,binDat);

    // Get the compressed data in base64 format:
    compressedBase64 = CkBinData_getEncoded(binDat,"base64");
    printf("compressed base64:\n");
    printf("%s\n",compressedBase64);

    // The compressed base64 is: C8lIVSgszUzOVkgqyi/PU0jLr1DIKs0tSE1RyC9LLVIoAcrnJFZVKqTkp+vxcoUMYeW8XAA=

    // Now decompress:
    CkBinData_Clear(binDat);
    CkBinData_AppendEncoded(binDat,compressedBase64,"base64");
    CkCompression_DecompressBd(compress,binDat);

    decompressedBase64 = CkBinData_getEncoded(binDat,"base64");
    printf("decompressed base64:\n");
    printf("%s\n",decompressedBase64);

    // The output is the original data:
    // VGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NClRoZSBxdWljayBicm93biBmb3gganVtcGVkIG92ZXIgdGhlIGxhenkgZG9nLg0KVGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NCg0K


    CkCompression_Dispose(compress);
    CkBinData_Dispose(binDat);

    }