# InvalidateMask(ulong)

> Invalidate all properties stored from multiple documents that match a document key mask.

## Definition

* **Type:** Method
* **Namespace:** [UnityEditor.Search](/engine/6000.6/script-reference/unityeditor/search.md)
* **Assembly:** UnityEditor

```csharp
void InvalidateMask(ulong documentKeyMask)
```

### Parameters

**** (\[ulong]\(https\://learn.microsoft.com/dotnet/api/system.uint64)): A document key mask.

### Remarks

This operation is slower than the simpler [IPropertyDatabaseView.Invalidate](/engine/6000.6/script-reference/unityeditor/search/ipropertydatabaseview/invalidate.md) since we cannot rely on a binary search to find all keys that match the mask.

```csharp
using (var view = propertyDatabase.GetView())
{
    // Store properties of multiple documents.
    for (ulong i = 0; i < 10; ++i)
    {
        for (var j = 0; j < 10; ++j)
            view.Store(i, view.CreatePropertyHash($"prop{j}"), $"value{j}");
    }

    // Invalidate all documents that match any set bits of the mask.
    ulong invalidatedDocumentMask = 2;
    view.InvalidateMask(invalidatedDocumentMask);

    // The invalidated documents can no longer be retrieved.
    for (ulong i = 0; i < 10; ++i)
    {
        if ((i & invalidatedDocumentMask) == 0)
            continue;
        if (view.TryLoad(i, out IEnumerable<object> invalidatedDocumentValues))
            Assert.Fail("TryLoad should have failed to retrieve the invalidated document values.");
    }
}
```

Additional Resources: [IPropertyDatabaseView.CreateDocumentKey](/engine/6000.6/script-reference/unityeditor/search/ipropertydatabaseview/createdocumentkey.md).