(Node.js) Compress Text Feed to Binary

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

The purpose is to demonstrate the BeginCompressString, MoreCompressString, and EndCompressString methods.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    var success;
    var compressedData = new chilkat.BinData();

    var compress = new chilkat.Compression();
    compress.Algorithm = "deflate";
    compress.Charset = "utf-8";

    var sbIndex = new chilkat.StringBuilder();

    var 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) {
            compressedBytes = compress.BeginCompressString(sbIndex.GetAsString());
        }
        else {
            compressedBytes = compress.MoreCompressString(sbIndex.GetAsString());
        }

        compressedData.AppendBinary(compressedBytes);
        compressedBytes = compress.MoreCompressString(": This is a line of data to be compressed...\r\n");
        compressedData.AppendBinary(compressedBytes);
    }

    // Flush any remaining output.
    compressedBytes = compress.EndCompressString();
    compressedData.AppendBinary(compressedBytes);

    // Show the compressed data in hex format:
    console.log("The hex encoded compressed text:");
    console.log(compressedData.GetEncoded("hex"));

    // Now decompress in one call:
    compressedBytes = compressedData.GetBinary();
    var originalText = compress.DecompressString(compressedBytes);
    console.log(originalText);

}

chilkatExample();