(Unicode 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.

Chilkat C/C++ Library Downloads
MS Visual C/C++ C++ Builder Linux C/C++ Alpine Linux C/C++	MacOS C/C++ iOS C/C++ Android C/C++ MinGW C/C++

#include <C_CkCompressionW.h>
#include <C_CkBinDataW.h>

void ChilkatSample(void)
    {
    BOOL success;
    const wchar_t *strBase64;
    HCkCompressionW compress;
    HCkBinDataW binDat;
    const wchar_t *compressedBase64;
    const wchar_t *decompressedBase64;

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

    strBase64 = L"VGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NClRoZSBxdWljayBicm93biBmb3gganVtcGVkIG92ZXIgdGhlIGxhenkgZG9nLg0KVGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NCg0K";

    compress = CkCompressionW_Create();
    CkCompressionW_putAlgorithm(compress,L"deflate");

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

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

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

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

    // Now decompress:
    CkBinDataW_Clear(binDat);
    CkBinDataW_AppendEncoded(binDat,compressedBase64,L"base64");
    CkCompressionW_DecompressBd(compress,binDat);

    decompressedBase64 = CkBinDataW_getEncoded(binDat,L"base64");
    wprintf(L"decompressed base64:\n");
    wprintf(L"%s\n",decompressedBase64);

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


    CkCompressionW_Dispose(compress);
    CkBinDataW_Dispose(binDat);

    }