third_party/WebKit/LayoutTests/storage/indexeddb/key-cursor-request-cycle.html

   1 <!DOCTYPE html>
   2 <script src="../../resources/js-test.js"></script>
   3 <script src="resources/shared.js"></script>
   4 <script>
   5
   6 description("Verify that that key cursors weakly hold request, and work if request is GC'd");
   7
   8 indexedDBTest(prepareDatabase, onOpen);
   9
  10 function prepareDatabase(evt)
  11 {
  12     preamble(evt);
  13     evalAndLog("db = event.target.result");
  14     evalAndLog("store = db.createObjectStore('store')");
  15     store.put("value1", "key1");
  16     store.put("value2", "key2");
  17 }
  18
  19 function onOpen(evt)
  20 {
  21     preamble(evt);
  22     evalAndLog("db = event.target.result");
  23     evalAndLog("tx = db.transaction('store')");
  24     evalAndLog("store = tx.objectStore('store')");
  25
  26     evalAndLog("cursorRequest = store.openKeyCursor()");
  27     cursorRequest.onsuccess = function openCursorRequestSuccess(evt) {
  28         preamble(evt);
  29         debug("Result will be checked later, to ensure that lazy access is safe");
  30     };
  31
  32     evalAndLog("otherRequest = store.get(0)");
  33     otherRequest.onsuccess = function otherRequestSuccess(evt) {
  34         preamble(evt);
  35
  36         debug("Verify that the request's result can be accessed lazily:");
  37         evalAndLog("gc()");
  38
  39         evalAndLog("cursor = cursorRequest.result");
  40         shouldBeNonNull("cursor");
  41         shouldBeEqualToString("cursor.key", "key1");
  42         evalAndLog("cursorRequest.extra = 123");
  43         evalAndLog("cursor.extra = 456");
  44
  45         // Assign a new handler to inspect the request and cursor indirectly.
  46         cursorRequest.onsuccess = function cursorContinueSuccess(evt) {
  47             preamble(evt);
  48             evalAndLog("cursor = event.target.result");
  49             shouldBeNonNull("cursor");
  50             shouldBeEqualToString("cursor.key", "key2");
  51             shouldBe("event.target.extra", "123");
  52             shouldBe("cursor.extra", "456");
  53         };
  54
  55         debug("Ensure request is not released if cursor is still around.");
  56         cursorRequestObservation = internals.observeGC(cursorRequest);
  57         evalAndLog("cursorRequest = null");
  58         evalAndLog("gc()");
  59         shouldBeFalse("cursorRequestObservation.wasCollected");
  60
  61         evalAndLog("cursor.continue()");
  62
  63         cursorObservation = internals.observeGC(cursor);
  64         evalAndLog("cursor = null");
  65         evalAndLog("gc()");
  66         shouldBeFalse("cursorObservation.wasCollected");
  67
  68         evalAndLog("finalRequest = store.get(0)");
  69         finalRequest.onsuccess = function finalRequestSuccess(evt) {
  70             preamble(evt);
  71             shouldBeEqualToString("cursor.key", "key2");
  72
  73             cursorObservation = internals.observeGC(cursor);
  74             evalAndLog("cursor = null");
  75             evalAndLog("gc()");
  76             shouldBeTrue("cursorRequestObservation.wasCollected");
  77             shouldBeTrue("cursorObservation.wasCollected");
  78         };
  79     };
  80
  81     tx.oncomplete = finishJSTest;
  82 }
  83
  84
  85 </script>