gecko-dev/dom/base/test/file_bug945152_worker.js

var gData1 = "TEST_DATA_1:ABCDEFGHIJKLMNOPQRSTUVWXYZ";
var gData2 = "TEST_DATA_2:1234567890";
var gPaddingChar = ".";
var gPaddingSize = 10000;
var gPadding = "";

for (var i = 0; i < gPaddingSize; i++) {
  gPadding += gPaddingChar;
}

function ok(a, msg) {
  postMessage({ type: "status", status: !!a, msg });
}

function is(a, b, msg) {
  postMessage({ type: "status", status: a === b, msg });
}

function checkData(response, data_head, cb) {
  ok(response, "Data is non-null");
  var str = String.fromCharCode.apply(null, new Uint8Array(response));
  ok(str.length == data_head.length + gPaddingSize, "Data size is correct");
  ok(str.slice(0, data_head.length) == data_head, "Data head is correct");
  ok(str.slice(data_head.length) == gPadding, "Data padding is correct");
  cb();
}

self.onmessage = function onmessage(event) {
  var jar = event.data;

  function makeJarURL(entry) {
    return "jar:" + jar + "!/" + entry;
  }

  function test_mapped_sync() {
    var xhr = new XMLHttpRequest({ mozAnon: true, mozSystem: true });
    xhr.open("GET", makeJarURL("data_1.txt"), false);
    xhr.responseType = "arraybuffer";
    xhr.send();
    if (xhr.status) {
      ok(xhr.status == 200, "Status is 200");
      var ct = xhr.getResponseHeader("Content-Type");
      ok(ct.includes("mem-mapped"), "Data is memory-mapped");
      checkData(xhr.response, gData1, runTests);
    }
  }

  function test_mapped_async() {
    var xhr = new XMLHttpRequest({ mozAnon: true, mozSystem: true });
    xhr.open("GET", makeJarURL("data_1.txt"));
    xhr.responseType = "arraybuffer";
    xhr.onreadystatechange = function() {
      if (xhr.readyState !== xhr.DONE) {
        return;
      }
      if (xhr.status) {
        ok(xhr.status == 200, "Status is 200");
        var ct = xhr.getResponseHeader("Content-Type");
        ok(ct.includes("mem-mapped"), "Data is memory-mapped");
        checkData(xhr.response, gData1, runTests);
      }
    };
    xhr.send();
  }

  // Make sure array buffer retrieved from compressed file in package is
  // handled by memory allocation instead of memory mapping.
  function test_non_mapped() {
    var xhr = new XMLHttpRequest({ mozAnon: true, mozSystem: true });
    xhr.open("GET", makeJarURL("data_2.txt"));
    xhr.responseType = "arraybuffer";
    xhr.onreadystatechange = function() {
      if (xhr.readyState !== xhr.DONE) {
        return;
      }
      if (xhr.status) {
        ok(xhr.status == 200, "Status is 200");
        var ct = xhr.getResponseHeader("Content-Type");
        ok(!ct.includes("mem-mapped"), "Data is not memory-mapped");
        checkData(xhr.response, gData2, runTests);
      }
    };
    xhr.send();
  }

  var tests = [test_mapped_sync, test_mapped_async, test_non_mapped];

  function runTests() {
    if (!tests.length) {
      postMessage({ type: "finish" });
      return;
    }

    var test = tests.shift();
    test();
  }

  runTests();
};