third_party/WebKit/LayoutTests/storage/indexeddb/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 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.openCursor()");
  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         shouldBeEqualToString("cursor.value", "value1");
  43         evalAndLog("cursorRequest.extra = 123");
  44         evalAndLog("cursor.extra = 456");
  45
  46         // Assign a new handler to inspect the request and cursor indirectly.
  47         cursorRequest.onsuccess = function cursorContinueSuccess(evt) {
  48             preamble(evt);
  49             evalAndLog("cursor = event.target.result");
  50             shouldBeNonNull("cursor");
  51             shouldBeEqualToString("cursor.key", "key2");
  52             shouldBeEqualToString("cursor.value", "value2");
  53             shouldBe("event.target.extra", "123");
  54             shouldBe("cursor.extra", "456");
  55         };
  56
  57         debug("Ensure request is not released if cursor is still around.");
  58         cursorRequestObservation = internals.observeGC(cursorRequest);
  59         evalAndLog("cursorRequest = null");
  60         evalAndLog("gc()");
  61         shouldBeFalse("cursorRequestObservation.wasCollected");
  62
  63         evalAndLog("cursor.continue()");
  64
  65         cursorObservation = internals.observeGC(cursor);
  66         evalAndLog("cursor = null");
  67         evalAndLog("gc()");
  68         shouldBeFalse("cursorObservation.wasCollected");
  69
  70         evalAndLog("finalRequest = store.get(0)");
  71         finalRequest.onsuccess = function finalRequestSuccess(evt) {
  72             preamble(evt);
  73             shouldBeEqualToString("cursor.key", "key2");
  74             shouldBeEqualToString("cursor.value", "value2");
  75
  76             cursorObservation = internals.observeGC(cursor);
  77             evalAndLog("cursor = null");
  78             evalAndLog("gc()");
  79             shouldBeTrue("cursorRequestObservation.wasCollected");
  80             shouldBeTrue("cursorObservation.wasCollected");
  81         };
  82     };
  83
  84     tx.oncomplete = finishJSTest;
  85 }
  86
  87
  88 </script>