michael@0: /* Any copyright is dedicated to the Public Domain.
michael@0:    http://creativecommons.org/publicdomain/zero/1.0/ 
michael@0: */
michael@0: /* This testcase triggers two telemetry pings.
michael@0:  *
michael@0:  * Telemetry code keeps histograms of past telemetry pings. The first
michael@0:  * ping populates these histograms. One of those histograms is then
michael@0:  * checked in the second request.
michael@0:  */
michael@0: 
michael@0: const Cc = Components.classes;
michael@0: const Ci = Components.interfaces;
michael@0: const Cu = Components.utils;
michael@0: const Cr = Components.results;
michael@0: 
michael@0: Cu.import("resource://testing-common/httpd.js", this);
michael@0: Cu.import("resource://gre/modules/Services.jsm");
michael@0: Cu.import("resource://gre/modules/LightweightThemeManager.jsm", this);
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);
michael@0: Cu.import("resource://gre/modules/TelemetryPing.jsm", this);
michael@0: Cu.import("resource://gre/modules/TelemetryFile.jsm", this);
michael@0: Cu.import("resource://gre/modules/Task.jsm", this);
michael@0: Cu.import("resource://gre/modules/Promise.jsm", this);
michael@0: 
michael@0: const IGNORE_HISTOGRAM = "test::ignore_me";
michael@0: const IGNORE_HISTOGRAM_TO_CLONE = "MEMORY_HEAP_ALLOCATED";
michael@0: const IGNORE_CLONED_HISTOGRAM = "test::ignore_me_also";
michael@0: const ADDON_NAME = "Telemetry test addon";
michael@0: const ADDON_HISTOGRAM = "addon-histogram";
michael@0: // Add some unicode characters here to ensure that sending them works correctly.
michael@0: const FLASH_VERSION = "\u201c1.1.1.1\u201d";
michael@0: const SHUTDOWN_TIME = 10000;
michael@0: const FAILED_PROFILE_LOCK_ATTEMPTS = 2;
michael@0: 
michael@0: // Constants from prio.h for nsIFileOutputStream.init
michael@0: const PR_WRONLY = 0x2;
michael@0: const PR_CREATE_FILE = 0x8;
michael@0: const PR_TRUNCATE = 0x20;
michael@0: const RW_OWNER = 0600;
michael@0: 
michael@0: const NUMBER_OF_THREADS_TO_LAUNCH = 30;
michael@0: let gNumberOfThreadsLaunched = 0;
michael@0: 
michael@0: const Telemetry = Cc["@mozilla.org/base/telemetry;1"].getService(Ci.nsITelemetry);
michael@0: 
michael@0: let gHttpServer = new HttpServer();
michael@0: let gServerStarted = false;
michael@0: let gRequestIterator = null;
michael@0: 
michael@0: function sendPing () {
michael@0:   TelemetryPing.gatherStartup();
michael@0:   if (gServerStarted) {
michael@0:     return TelemetryPing.testPing("http://localhost:" + gHttpServer.identity.primaryPort);
michael@0:   } else {
michael@0:     return TelemetryPing.testPing("http://doesnotexist");
michael@0:   }
michael@0: }
michael@0: 
michael@0: function wrapWithExceptionHandler(f) {
michael@0:   function wrapper(...args) {
michael@0:     try {
michael@0:       f(...args);
michael@0:     } catch (ex if typeof(ex) == 'object') {
michael@0:       dump("Caught exception: " + ex.message + "\n");
michael@0:       dump(ex.stack);
michael@0:       do_test_finished();
michael@0:     }
michael@0:   }
michael@0:   return wrapper;
michael@0: }
michael@0: 
michael@0: function registerPingHandler(handler) {
michael@0:   gHttpServer.registerPrefixHandler("/submit/telemetry/",
michael@0: 				   wrapWithExceptionHandler(handler));
michael@0: }
michael@0: 
michael@0: function setupTestData() {
michael@0:   Telemetry.newHistogram(IGNORE_HISTOGRAM, "never", 1, 2, 3, Telemetry.HISTOGRAM_BOOLEAN);
michael@0:   Telemetry.histogramFrom(IGNORE_CLONED_HISTOGRAM, IGNORE_HISTOGRAM_TO_CLONE);
michael@0:   Services.startup.interrupted = true;
michael@0:   Telemetry.registerAddonHistogram(ADDON_NAME, ADDON_HISTOGRAM, 1, 5, 6,
michael@0:                                    Telemetry.HISTOGRAM_LINEAR);
michael@0:   h1 = Telemetry.getAddonHistogram(ADDON_NAME, ADDON_HISTOGRAM);
michael@0:   h1.add(1);
michael@0: }
michael@0: 
michael@0: function getSavedHistogramsFile(basename) {
michael@0:   let tmpDir = Services.dirsvc.get("ProfD", Ci.nsIFile);
michael@0:   let histogramsFile = tmpDir.clone();
michael@0:   histogramsFile.append(basename);
michael@0:   if (histogramsFile.exists()) {
michael@0:     histogramsFile.remove(true);
michael@0:   }
michael@0:   do_register_cleanup(function () {
michael@0:     try {
michael@0:       histogramsFile.remove(true);
michael@0:     } catch (e) {
michael@0:     }
michael@0:   });
michael@0:   return histogramsFile;
michael@0: }
michael@0: 
michael@0: function decodeRequestPayload(request) {
michael@0:   let s = request.bodyInputStream;
michael@0:   let payload = null;
michael@0:   let decoder = Cc["@mozilla.org/dom/json;1"].createInstance(Ci.nsIJSON)
michael@0: 
michael@0:   if (request.getHeader("content-encoding") == "gzip") {
michael@0:     let observer = {
michael@0:       buffer: "",
michael@0:       onStreamComplete: function(loader, context, status, length, result) {
michael@0:         this.buffer = String.fromCharCode.apply(this, result);
michael@0:       }
michael@0:     };
michael@0: 
michael@0:     let scs = Cc["@mozilla.org/streamConverters;1"]
michael@0:               .getService(Ci.nsIStreamConverterService);
michael@0:     let listener = Cc["@mozilla.org/network/stream-loader;1"]
michael@0:                   .createInstance(Ci.nsIStreamLoader);
michael@0:     listener.init(observer);
michael@0:     let converter = scs.asyncConvertData("gzip", "uncompressed",
michael@0:                                          listener, null);
michael@0:     converter.onStartRequest(null, null);
michael@0:     converter.onDataAvailable(null, null, s, 0, s.available());
michael@0:     converter.onStopRequest(null, null, null);
michael@0:     let unicodeConverter = Cc["@mozilla.org/intl/scriptableunicodeconverter"]
michael@0:                     .createInstance(Ci.nsIScriptableUnicodeConverter);
michael@0:     unicodeConverter.charset = "UTF-8";
michael@0:     let utf8string = unicodeConverter.ConvertToUnicode(observer.buffer);
michael@0:     utf8string += unicodeConverter.Finish();
michael@0:     payload = decoder.decode(utf8string);
michael@0:   } else {
michael@0:     payload = decoder.decodeFromStream(s, s.available());
michael@0:   }
michael@0: 
michael@0:   return payload;
michael@0: }
michael@0: 
michael@0: function checkPayloadInfo(payload, reason) {
michael@0:   // get rid of the non-deterministic field
michael@0:   const expected_info = {
michael@0:     OS: "XPCShell", 
michael@0:     appID: "xpcshell@tests.mozilla.org", 
michael@0:     appVersion: "1", 
michael@0:     appName: "XPCShell", 
michael@0:     appBuildID: "2007010101",
michael@0:     platformBuildID: "2007010101",
michael@0:     flashVersion: FLASH_VERSION
michael@0:   };
michael@0: 
michael@0:   for (let f in expected_info) {
michael@0:     do_check_eq(payload.info[f], expected_info[f]);
michael@0:   }
michael@0: 
michael@0:   do_check_eq(payload.info.reason, reason);
michael@0:   do_check_true("appUpdateChannel" in payload.info);
michael@0:   do_check_true("locale" in payload.info);
michael@0:   do_check_true("revision" in payload.info);
michael@0:   do_check_true(payload.info.revision.startsWith("http"));
michael@0: 
michael@0:   try {
michael@0:     // If we've not got nsIGfxInfoDebug, then this will throw and stop us doing
michael@0:     // this test.
michael@0:     let gfxInfo = Cc["@mozilla.org/gfx/info;1"].getService(Ci.nsIGfxInfoDebug);
michael@0:     let isWindows = ("@mozilla.org/windows-registry-key;1" in Components.classes);
michael@0:     let isOSX = ("nsILocalFileMac" in Components.interfaces);
michael@0: 
michael@0:     if (isWindows || isOSX) {
michael@0:       do_check_true("adapterVendorID" in payload.info);
michael@0:       do_check_true("adapterDeviceID" in payload.info);
michael@0:     }
michael@0:   }
michael@0:   catch (x) {
michael@0:   }
michael@0: }
michael@0: 
michael@0: function checkPayload(request, reason, successfulPings) {
michael@0:   let payload = decodeRequestPayload(request);
michael@0:   // Take off ["","submit","telemetry"].
michael@0:   let pathComponents = request.path.split("/").slice(3);
michael@0: 
michael@0:   checkPayloadInfo(payload, reason);
michael@0:   do_check_eq(reason, pathComponents[1]);
michael@0:   do_check_eq(request.getHeader("content-type"), "application/json; charset=UTF-8");
michael@0:   do_check_true(payload.simpleMeasurements.uptime >= 0);
michael@0:   do_check_true(payload.simpleMeasurements.startupInterrupted === 1);
michael@0:   do_check_eq(payload.simpleMeasurements.shutdownDuration, SHUTDOWN_TIME);
michael@0:   do_check_eq(payload.simpleMeasurements.savedPings, 1);
michael@0:   do_check_true("maximalNumberOfConcurrentThreads" in payload.simpleMeasurements);
michael@0:   do_check_true(payload.simpleMeasurements.maximalNumberOfConcurrentThreads >= gNumberOfThreadsLaunched);
michael@0: 
michael@0:   do_check_eq(payload.simpleMeasurements.failedProfileLockCount,
michael@0:               FAILED_PROFILE_LOCK_ATTEMPTS);
michael@0:   let profileDirectory = Services.dirsvc.get("ProfD", Ci.nsIFile);
michael@0:   let failedProfileLocksFile = profileDirectory.clone();
michael@0:   failedProfileLocksFile.append("Telemetry.FailedProfileLocks.txt");
michael@0:   do_check_true(!failedProfileLocksFile.exists());
michael@0: 
michael@0: 
michael@0:   let isWindows = ("@mozilla.org/windows-registry-key;1" in Components.classes);
michael@0:   if (isWindows) {
michael@0:     do_check_true(payload.simpleMeasurements.startupSessionRestoreReadBytes > 0);
michael@0:     do_check_true(payload.simpleMeasurements.startupSessionRestoreWriteBytes > 0);
michael@0:   }
michael@0: 
michael@0:   const TELEMETRY_PING = "TELEMETRY_PING";
michael@0:   const TELEMETRY_SUCCESS = "TELEMETRY_SUCCESS";
michael@0:   const TELEMETRY_TEST_FLAG = "TELEMETRY_TEST_FLAG";
michael@0:   const READ_SAVED_PING_SUCCESS = "READ_SAVED_PING_SUCCESS";
michael@0:   do_check_true(TELEMETRY_PING in payload.histograms);
michael@0:   do_check_true(READ_SAVED_PING_SUCCESS in payload.histograms);
michael@0:   let rh = Telemetry.registeredHistograms([]);
michael@0:   for (let name of rh) {
michael@0:     if (/SQLITE/.test(name) && name in payload.histograms) {
michael@0:       do_check_true(("STARTUP_" + name) in payload.histograms); 
michael@0:     }
michael@0:   }
michael@0:   do_check_false(IGNORE_HISTOGRAM in payload.histograms);
michael@0:   do_check_false(IGNORE_CLONED_HISTOGRAM in payload.histograms);
michael@0: 
michael@0:   // Flag histograms should automagically spring to life.
michael@0:   const expected_flag = {
michael@0:     range: [1, 2],
michael@0:     bucket_count: 3,
michael@0:     histogram_type: 3,
michael@0:     values: {0:1, 1:0},
michael@0:     sum: 0,
michael@0:     sum_squares_lo: 0,
michael@0:     sum_squares_hi: 0
michael@0:   };
michael@0:   let flag = payload.histograms[TELEMETRY_TEST_FLAG];
michael@0:   do_check_eq(uneval(flag), uneval(expected_flag));
michael@0: 
michael@0:   // There should be one successful report from the previous telemetry ping.
michael@0:   const expected_tc = {
michael@0:     range: [1, 2],
michael@0:     bucket_count: 3,
michael@0:     histogram_type: 2,
michael@0:     values: {0:1, 1:successfulPings, 2:0},
michael@0:     sum: successfulPings,
michael@0:     sum_squares_lo: successfulPings,
michael@0:     sum_squares_hi: 0
michael@0:   };
michael@0:   let tc = payload.histograms[TELEMETRY_SUCCESS];
michael@0:   do_check_eq(uneval(tc), uneval(expected_tc));
michael@0: 
michael@0:   let h = payload.histograms[READ_SAVED_PING_SUCCESS];
michael@0:   do_check_eq(h.values[0], 1);
michael@0: 
michael@0:   // The ping should include data from memory reporters.  We can't check that
michael@0:   // this data is correct, because we can't control the values returned by the
michael@0:   // memory reporters.  But we can at least check that the data is there.
michael@0:   //
michael@0:   // It's important to check for the presence of reporters with a mix of units,
michael@0:   // because TelemetryPing has separate logic for each one.  But we can't
michael@0:   // currently check UNITS_COUNT_CUMULATIVE or UNITS_PERCENTAGE because
michael@0:   // Telemetry doesn't touch a memory reporter with these units that's
michael@0:   // available on all platforms.
michael@0: 
michael@0:   do_check_true('MEMORY_JS_GC_HEAP' in payload.histograms); // UNITS_BYTES
michael@0:   do_check_true('MEMORY_JS_COMPARTMENTS_SYSTEM' in payload.histograms); // UNITS_COUNT
michael@0: 
michael@0:   // We should have included addon histograms.
michael@0:   do_check_true("addonHistograms" in payload);
michael@0:   do_check_true(ADDON_NAME in payload.addonHistograms);
michael@0:   do_check_true(ADDON_HISTOGRAM in payload.addonHistograms[ADDON_NAME]);
michael@0: 
michael@0:   do_check_true(("mainThread" in payload.slowSQL) &&
michael@0:                 ("otherThreads" in payload.slowSQL));
michael@0: }
michael@0: 
michael@0: function dummyTheme(id) {
michael@0:   return {
michael@0:     id: id,
michael@0:     name: Math.random().toString(),
michael@0:     headerURL: "http://lwttest.invalid/a.png",
michael@0:     footerURL: "http://lwttest.invalid/b.png",
michael@0:     textcolor: Math.random().toString(),
michael@0:     accentcolor: Math.random().toString()
michael@0:   };
michael@0: }
michael@0: 
michael@0: // A fake plugin host for testing flash version telemetry
michael@0: let PluginHost = {
michael@0:   getPluginTags: function(countRef) {
michael@0:     let plugins = [{name: "Shockwave Flash", version: FLASH_VERSION}];
michael@0:     countRef.value = plugins.length;
michael@0:     return plugins;
michael@0:   },
michael@0: 
michael@0:   QueryInterface: function(iid) {
michael@0:     if (iid.equals(Ci.nsIPluginHost)
michael@0:      || iid.equals(Ci.nsISupports))
michael@0:       return this;
michael@0:   
michael@0:     throw Components.results.NS_ERROR_NO_INTERFACE;
michael@0:   }
michael@0: }
michael@0: 
michael@0: let PluginHostFactory = {
michael@0:   createInstance: function (outer, iid) {
michael@0:     if (outer != null)
michael@0:       throw Components.results.NS_ERROR_NO_AGGREGATION;
michael@0:     return PluginHost.QueryInterface(iid);
michael@0:   }
michael@0: };
michael@0: 
michael@0: const PLUGINHOST_CONTRACTID = "@mozilla.org/plugin/host;1";
michael@0: const PLUGINHOST_CID = Components.ID("{2329e6ea-1f15-4cbe-9ded-6e98e842de0e}");
michael@0: 
michael@0: function registerFakePluginHost() {
michael@0:   let registrar = Components.manager.QueryInterface(Ci.nsIComponentRegistrar);
michael@0:   registrar.registerFactory(PLUGINHOST_CID, "Fake Plugin Host",
michael@0:                             PLUGINHOST_CONTRACTID, PluginHostFactory);
michael@0: }
michael@0: 
michael@0: function writeStringToFile(file, contents) {
michael@0:   let ostream = Cc["@mozilla.org/network/safe-file-output-stream;1"]
michael@0:                 .createInstance(Ci.nsIFileOutputStream);
michael@0:   ostream.init(file, PR_WRONLY | PR_CREATE_FILE | PR_TRUNCATE,
michael@0: 	       RW_OWNER, ostream.DEFER_OPEN);
michael@0:   ostream.write(contents, contents.length);
michael@0:   ostream.QueryInterface(Ci.nsISafeOutputStream).finish();
michael@0:   ostream.close();
michael@0: }
michael@0: 
michael@0: function write_fake_shutdown_file() {
michael@0:   let profileDirectory = Services.dirsvc.get("ProfD", Ci.nsIFile);
michael@0:   let file = profileDirectory.clone();
michael@0:   file.append("Telemetry.ShutdownTime.txt");
michael@0:   let contents = "" + SHUTDOWN_TIME;
michael@0:   writeStringToFile(file, contents);
michael@0: }
michael@0: 
michael@0: function write_fake_failedprofilelocks_file() {
michael@0:   let profileDirectory = Services.dirsvc.get("ProfD", Ci.nsIFile);
michael@0:   let file = profileDirectory.clone();
michael@0:   file.append("Telemetry.FailedProfileLocks.txt");
michael@0:   let contents = "" + FAILED_PROFILE_LOCK_ATTEMPTS;
michael@0:   writeStringToFile(file, contents);
michael@0: }
michael@0: 
michael@0: function run_test() {
michael@0:   do_test_pending();
michael@0:   try {
michael@0:     let gfxInfo = Cc["@mozilla.org/gfx/info;1"].getService(Ci.nsIGfxInfoDebug);
michael@0:     gfxInfo.spoofVendorID("0xabcd");
michael@0:     gfxInfo.spoofDeviceID("0x1234");
michael@0:   } catch (x) {
michael@0:     // If we can't test gfxInfo, that's fine, we'll note it later.
michael@0:   }
michael@0: 
michael@0:   // Addon manager needs a profile directory
michael@0:   do_get_profile();
michael@0:   createAppInfo("xpcshell@tests.mozilla.org", "XPCShell", "1", "1.9.2");
michael@0: 
michael@0:   // Make it look like we've previously failed to lock a profile a couple times.
michael@0:   write_fake_failedprofilelocks_file();
michael@0: 
michael@0:   // Make it look like we've shutdown before.
michael@0:   write_fake_shutdown_file();
michael@0: 
michael@0:   let currentMaxNumberOfThreads = Telemetry.maximalNumberOfConcurrentThreads;
michael@0:   do_check_true(currentMaxNumberOfThreads > 0);
michael@0: 
michael@0:   // Try to augment the maximal number of threads currently launched
michael@0:   let threads = [];
michael@0:   try {
michael@0:     for (let i = 0; i < currentMaxNumberOfThreads + 10; ++i) {
michael@0:       threads.push(Services.tm.newThread(0));
michael@0:     }
michael@0:   } catch (ex) {
michael@0:     // If memory is too low, it is possible that not all threads will be launched.
michael@0:   }
michael@0:   gNumberOfThreadsLaunched = threads.length;
michael@0: 
michael@0:   do_check_true(Telemetry.maximalNumberOfConcurrentThreads >= gNumberOfThreadsLaunched);
michael@0: 
michael@0:   do_register_cleanup(function() {
michael@0:     threads.forEach(function(thread) {
michael@0:       thread.shutdown();
michael@0:     });
michael@0:   });
michael@0: 
michael@0:   Telemetry.asyncFetchTelemetryData(wrapWithExceptionHandler(actualTest));
michael@0: }
michael@0: 
michael@0: function actualTest() {
michael@0:   // try to make LightweightThemeManager do stuff
michael@0:   let gInternalManager = Cc["@mozilla.org/addons/integration;1"]
michael@0:                          .getService(Ci.nsIObserver)
michael@0:                          .QueryInterface(Ci.nsITimerCallback);
michael@0: 
michael@0:   gInternalManager.observe(null, "addons-startup", null);
michael@0:   LightweightThemeManager.currentTheme = dummyTheme("1234");
michael@0: 
michael@0:   // fake plugin host for consistent flash version data
michael@0:   registerFakePluginHost();
michael@0: 
michael@0:   run_next_test();
michael@0: }
michael@0: 
michael@0: // Ensure that not overwriting an existing file fails silently
michael@0: add_task(function* test_overwritePing() {
michael@0:   let ping = {slug: "foo"}
michael@0:   yield TelemetryFile.savePing(ping, true);
michael@0:   yield TelemetryFile.savePing(ping, false);
michael@0:   yield TelemetryFile.cleanupPingFile(ping);
michael@0: });
michael@0: 
michael@0: // Ensures that expired histograms are not part of the payload.
michael@0: add_task(function* test_expiredHistogram() {
michael@0:   let histogram_id = "FOOBAR";
michael@0:   let dummy = Telemetry.newHistogram(histogram_id, "30", 1, 2, 3, Telemetry.HISTOGRAM_EXPONENTIAL);
michael@0: 
michael@0:   dummy.add(1);
michael@0: 
michael@0:   do_check_eq(TelemetryPing.getPayload()["histograms"][histogram_id], undefined);
michael@0:   do_check_eq(TelemetryPing.getPayload()["histograms"]["TELEMETRY_TEST_EXPIRED"], undefined);
michael@0: });
michael@0: 
michael@0: // Checks that an invalid histogram file is deleted if TelemetryFile fails to parse it.
michael@0: add_task(function* test_runInvalidJSON() {
michael@0:   let histogramsFile = getSavedHistogramsFile("invalid-histograms.dat");
michael@0: 
michael@0:   writeStringToFile(histogramsFile, "this.is.invalid.JSON");
michael@0:   do_check_true(histogramsFile.exists());
michael@0: 
michael@0:   yield TelemetryPing.testLoadHistograms(histogramsFile);
michael@0:   do_check_false(histogramsFile.exists());
michael@0: });
michael@0: 
michael@0: // Sends a ping to a non existing server.
michael@0: add_task(function* test_noServerPing() {
michael@0:   yield sendPing();
michael@0: });
michael@0: 
michael@0: // Checks that a sent ping is correctly received by a dummy http server.
michael@0: add_task(function* test_simplePing() {
michael@0:   gHttpServer.start(-1);
michael@0:   gServerStarted = true;
michael@0:   gRequestIterator = Iterator(new Request());
michael@0: 
michael@0:   yield sendPing();
michael@0:   decodeRequestPayload(yield gRequestIterator.next());
michael@0: });
michael@0: 
michael@0: // Saves the current session histograms, reloads them, perfoms a ping
michael@0: // and checks that the dummy http server received both the previously
michael@0: // saved histograms and the new ones.
michael@0: add_task(function* test_saveLoadPing() {
michael@0:   let histogramsFile = getSavedHistogramsFile("saved-histograms.dat");
michael@0: 
michael@0:   setupTestData();
michael@0:   yield TelemetryPing.testSaveHistograms(histogramsFile);
michael@0:   yield TelemetryPing.testLoadHistograms(histogramsFile);
michael@0:   yield sendPing();
michael@0:   checkPayload((yield gRequestIterator.next()), "test-ping", 1);
michael@0:   checkPayload((yield gRequestIterator.next()), "saved-session", 1);
michael@0: });
michael@0: 
michael@0: // Checks that an expired histogram file is deleted when loaded.
michael@0: add_task(function* test_runOldPingFile() {
michael@0:   let histogramsFile = getSavedHistogramsFile("old-histograms.dat");
michael@0: 
michael@0:   yield TelemetryPing.testSaveHistograms(histogramsFile);
michael@0:   do_check_true(histogramsFile.exists());
michael@0:   let mtime = histogramsFile.lastModifiedTime;
michael@0:   histogramsFile.lastModifiedTime = mtime - (14 * 24 * 60 * 60 * 1000 + 60000); // 14 days, 1m
michael@0: 
michael@0:   yield TelemetryPing.testLoadHistograms(histogramsFile);
michael@0:   do_check_false(histogramsFile.exists());
michael@0: });
michael@0: 
michael@0: add_task(function* stopServer(){
michael@0:   gHttpServer.stop(do_test_finished);
michael@0: });
michael@0: 
michael@0: // An iterable sequence of http requests
michael@0: function Request() {
michael@0:   let defers = [];
michael@0:   let current = 0;
michael@0: 
michael@0:   function RequestIterator() {}
michael@0: 
michael@0:   // Returns a promise that resolves to the next http request
michael@0:   RequestIterator.prototype.next = function() {
michael@0:     let deferred = defers[current++];
michael@0:     return deferred.promise;
michael@0:   }
michael@0: 
michael@0:   this.__iterator__ = function(){
michael@0:     return new RequestIterator();
michael@0:   }
michael@0: 
michael@0:   registerPingHandler((request, response) => {
michael@0:     let deferred = defers[defers.length - 1];
michael@0:     defers.push(Promise.defer());
michael@0:     deferred.resolve(request);
michael@0:   });
michael@0: 
michael@0:   defers.push(Promise.defer());
michael@0: }