Use view buffers during pre-rendering #39465
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| Server, | ||
| WebAssembly, | ||
| ServerAndWebAssembly | ||
| var viewBuffer = new ViewBuffer(_viewBufferScope, nameof(ComponentRenderer), 16); // Preamble is fixed size |
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If we later change the preamble size, and don't realise we should also update this line, will we cause adverse perf effects? Is there any way to make it fail if we do that?
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Maybe the instantiation of the viewbuffer should be done inside WebAssemblyComponentSerializer.AppendPreamble so it's all localized to one bit of code.
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This all looks good to me, even though the concept of MVC view buffers is new to me and so it's possible I might be missing some subtlety. I'm approving based on what I know, but would recommend getting confirmation from @javiercn too.
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@SteveSandersonMS ViewBuffers are an MVC abstraction for ArrayPool<T> that are rented for the duration of view rendering. The view rendering system has some optimizations that makes it efficient to use these when rendering because we know it's safe to transfer ownership of the underlying arrays around since the rented lifetime is well understood:
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* Use view buffers during rendering This change removes about 8kb of string[] allocations per request during pre-rendering and replaces them with a ViewBuffer that uses array pooling. The allocations come from list resizing as part of HtmlRenderer operations (such as https://github.com/dotnet/aspnetcore/blob/main/src/Mvc/Mvc.ViewFeatures/src/RazorComponents/HtmlRenderer.cs#L133-L134). Also includes a couple of other clean up items: * Uses ValueTask instead of `Task<T>` * Moves top-level types to a separate file. * Some formatting cleanup
This change removes about 8kb of string[] allocations per request during pre-rendering and replaces them with a ViewBuffer that uses array pooling. The allocations come from list resizing as part of HtmlRenderer operations (such as https://github.com/dotnet/aspnetcore/blob/main/src/Mvc/Mvc.ViewFeatures/src/RazorComponents/HtmlRenderer.cs#L133-L134). Also includes a couple of other clean up items:
Task<T>Details: https://github.com/dotnet/aspnetcore-internal/issues/3983