PPMD String Compression

Demonstrates string compression using PPMD.

Download Chilkat C/C++ Libraries for VC++ 9.0 / Win32

Download Chilkat C/C++ Libraries for VC++ 8.0 / Win32

Download Chilkat C/C++ 64-bit Libraries for VC++ 8.0 / x64

Download Chilkat Visual Studio 2005 C/C++ Libs for Windows Mobile, Pocket PC, SmartPhone, WinCE

Download Chilkat C/C++ Libraries for VC++ 7.0 / Win32

Download Chilkat C/C++ Libraries for VC++ 6.0 / Win32

#include <CkCompression.h>
#include <CkString.h>

void ChilkatSample(void)
    {
    CkCompression compress;

    //  Any string argument automatically begins a 30-day trial.
    bool success;
    success = compress.UnlockComponent("30-day trial");
    if (success != true) {
        printf("Compression component unlock failed\n");
        return;
    }

    compress.put_Algorithm("ppmd");

    CkString strData;
    long i;

    //  Create a long string to compress.
    strData = "abcdefg1122334455667788";
    strData.append("\r\n");
    for (i = 0; i <= 99; i++) {
        strData.append("abcdefg1122334455667788");
        strData.append("\r\n");
    }

    //  Depending on the programming language, the string
    //  may be Unicode.  Tell the component to convert to
    //  ansi (1-byte/char) prior to compression:
    compress.put_Charset("ansi");

    //  Compressed data is binary, meaning that all byte values
    //  from 0 to 255 are possible.  The result would not be
    //  a printable string.  To receive a printable string (us-ascii),
    //  the resultant compressed data should be encoded using
    //  an encoding such as base64.  Set the EncodingMode
    //  property to determine the output encoding:
    //  (Valid choices are "base64", "hex", "url", and others)
    compress.put_EncodingMode("base64");

    //  Note: Base64 encoding expands the compressed data by
    //  4/3rds because each 3 bytes of binary data are represented
    //  by 4 printable chars.  Hex, for example, doubles the output
    //  size because each byte is represented by 2 printable chars.

    //  PPMD compress the string:
    const char * compressedStr;
    compressedStr = compress.compressStringENC(strData);
    if (compressedStr == 0 ) {
        printf("%s\n",compress.lastErrorText());
        return;
    }

    //  Display the compressed string.
    //  The result will be:
    //  ec8YZ5vk9za18d0plwuV7R65em9OZge9gJXht/QAAAAAAAAAABNOZQAAKw==
    printf("%s\n",compressedStr);

    //  Decompress back to the original:
    const char * strOriginal;
    strOriginal = compress.decompressStringENC(compressedStr);

    //  Display the uncompressed original:
    printf("--- Original ---\n");
    printf("%s\n",strOriginal);
    }