test_file_structured_clone.html

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<html>

<head>

  <title>Indexed Database Blob Structured Clone Test</title>

  <script src="/tests/SimpleTest/SimpleTest.js"></script>

  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>

  <script type="text/javascript">

/**

   * Test that structured cloning a Blob results in distinct backing files when

   * stored in IndexedDB.

   * Currently, IndexedDB deduplicates blobs based on Blob object identity.

   * Structured cloning creates a new Blob instance with a different identity,

   * so the two blobs are treated as distinct and stored separately on disk.

   * This test verifies that behavior by ensuring the cloned Blob receives a

   * different fileId.

   * TODO: Once IndexedDB switches to using BlobImpl for deduplication,

   * structured-cloned blobs that share the same underlying data should be

   * deduplicated and mapped to the same fileId.

*/

  async function testSteps()

    const name = window.location.pathname;

    const objectStoreName = "Blobs";

    const blob = getRandomBlob(10000);

    const clonedBlob = structuredClone(blob);

    const blobData1 = { key: 1, blob, expectedFileId: 1 };

    // TODO: After switching IndexedDB blob deduplication to use BlobImpl

    // instead of Blob identity, this structured-cloned blob should reuse the

    // same underlying file and have expectedFileId = 1.

    const blobData2 = { key: 2, blob: clonedBlob, expectedFileId: 2 };

    await SpecialPowers.pushPrefEnv({ set: [["dom.indexedDB.dataThreshold", -1]] });

    let request = indexedDB.open(name, 1);

    await expectingUpgrade(request);

    let db = request.result;

    db.onerror = errorHandler;

    let objectStore = db.createObjectStore(objectStoreName, {});

    objectStore.add(blobData1.blob, blobData1.key);

    objectStore.add(blobData2.blob, blobData2.key);

    await expectingSuccess(request);

    objectStore = db.transaction([objectStoreName]).objectStore(objectStoreName);

    request = objectStore.get(blobData1.key);

    await requestSucceeded(request);

    await verifyBlobAsync(request.result, blobData1.blob, blobData1.expectedFileId);

    objectStore = db.transaction([objectStoreName]).objectStore(objectStoreName);

    request = objectStore.get(blobData2.key);

    await requestSucceeded(request);

    await verifyBlobAsync(request.result, blobData2.blob, blobData2.expectedFileId);

    is(bufferCache.length, 2, "Correct length");

  </script>

  <script type="text/javascript" src="file.js"></script>

  <script type="text/javascript" src="helpers.js"></script>

</head>

<body onload="runTest();"></body>

</html>