How to use webworkers to highlight source code blocks using highlightjs?

How can i use one or more webworkers to highlight multiple small source code blocks on my website?

Example using one webworker

To use only one webworker to highlight multiple code-blocks you might use the following code, where highlight_code_worker_function is the worker function.

<script>

    function highlight_code() {
        if (typeof (Worker) === undefined) return false;
        var workerFunction = new Blob(['(' + highlight_code_worker_function.toString() + ')()'], {type: "text/javascript"});
        var worker = new Worker(URL.createObjectURL(workerFunction));
        var codeBlocks = $('div.readme pre, div.readme code');
        worker.onmessage = function(event) {
            var data = JSON.parse(event.data);
            codeBlocks.eq(data.index).html(data.result).addClass('hljs');
        };
        worker.onerror = function() {
            // do nothing
        };
        codeBlocks.each(function(index) {
            worker.postMessage(JSON.stringify({index: index, code: $(this).text()}));
        });
        worker.postMessage(JSON.stringify({index: -1}));
    }

    function highlight_code_worker_function() {
        onmessage = function(event) {
            var data = JSON.parse(event.data);
            if (data.index === -1) {
                close(); // close worker
            }
            importScripts(''https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.6.0/highlight.min.js'');
            self.hljs.configure({tabReplace:4});
            var result = self.hljs.highlightAuto(data.code);
            postMessage(JSON.stringify({result: result.value, index: data.index}));
        }
    }

    highlight_code();

    </script>

Example using multiple-web workers

    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.6.0/styles/monokai_sublime.min.css">

    <script type="text/javascript">

      function highlight_code()
      {
        if (typeof (Worker) === undefined) return false;
        var workerFunction = new Blob(['(' + highlight_code_worker_function.toString() + ')()'], {type: "text/javascript"});
        var localWorkerURL = URL.createObjectURL(workerFunction);
        $('div.readme pre, div.readme code').each(function() {
          var code = $(this);
          var worker = new Worker(localWorkerURL);
          worker.onmessage = function(event) { code.html(event.data).addClass('hljs'); }
          worker.postMessage(code.text()); // start worker
        });
      }

      function highlight_code_worker_function()
      {
        onmessage = function(event) {
          importScripts('https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.6.0/highlight.min.js');
          self.hljs.configure({tabReplace:4});
          var result = self.hljs.highlightAuto(event.data);
          postMessage(result.value);
          close(); // close worker
        }
      }

      $(window).on('load', highlight_code);

    </script>