private RenderBatch GetRenderedBatch(RenderTreeBuilder from, RenderTreeBuilder to)
{
var batchBuilder = new RenderBatchBuilder();
diff.ApplyNewRenderTreeVersion(batchBuilder, 0, from.GetFrames(), to.GetFrames());
return(batchBuilder.ToBatch());
}
public void RecognizesComponentTypeChangesAtSameSequenceNumber()
{
// Arrange
oldTree.OpenComponent <FakeComponent>(123);
oldTree.CloseComponent();
GetRenderedBatch(new RenderTreeBuilder(renderer), oldTree); // Assign initial IDs
newTree.OpenComponent <FakeComponent2>(123);
newTree.CloseComponent();
var batchBuilder = new RenderBatchBuilder();
// Act
var diff = RenderTreeDiffBuilder.ComputeDiff(renderer, batchBuilder, 0, oldTree.GetFrames(), newTree.GetFrames());
// Assert: We're going to dispose the old component, and render the new one
Assert.Equal(new[] { 0 }, batchBuilder.ComponentDisposalQueue);
Assert.Equal(new[] { 1 }, batchBuilder.ComponentRenderQueue);
// Assert: Got correct info in diff
Assert.Collection(diff.Edits,
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 0),
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 0);
Assert.IsType <FakeComponent2>(batchBuilder.ReferenceFramesBuffer.Buffer[entry.ReferenceFrameIndex].Component);
});
}
public RenderTreeDiffBuilderBenchmark()
{
builder = new RenderBatchBuilder();
renderer = new FakeRenderer();
// A simple component for basic tests -- this is similar to what MVC scaffolding generates
// for bootstrap3 form fields, but modified to be more Blazorey.
original = new RenderTreeBuilder(renderer);
original.OpenElement(0, "div");
original.AddAttribute(1, "class", "form-group");
original.OpenElement(2, "label");
original.AddAttribute(3, "class", "control-label");
original.AddAttribute(4, "for", "name");
original.AddAttribute(5, "data-unvalidated", true);
original.AddContent(6, "Car");
original.CloseElement();
original.OpenElement(7, "input");
original.AddAttribute(8, "class", "form-control");
original.AddAttribute(9, "type", "text");
original.AddAttribute(10, "name", "name"); // Notice the gap in sequence numbers
original.AddAttribute(12, "value", "");
original.CloseElement();
original.OpenElement(13, "span");
original.AddAttribute(14, "class", "text-danger field-validation-valid");
original.AddContent(15, "");
original.CloseElement();
original.CloseElement();
// Now simulate some input
modified = new RenderTreeBuilder(renderer);
modified.OpenElement(0, "div");
modified.AddAttribute(1, "class", "form-group");
modified.OpenElement(2, "label");
modified.AddAttribute(3, "class", "control-label");
modified.AddAttribute(4, "for", "name");
modified.AddAttribute(5, "data-unvalidated", false);
modified.AddContent(6, "Car");
modified.CloseElement();
modified.OpenElement(7, "input");
modified.AddAttribute(8, "class", "form-control");
modified.AddAttribute(9, "type", "text");
modified.AddAttribute(10, "name", "name");
modified.AddAttribute(11, "data-validation-state", "invalid");
modified.AddAttribute(12, "value", "Lamborghini");
modified.CloseElement();
modified.OpenElement(13, "span");
modified.AddAttribute(14, "class", "text-danger field-validation-invalid"); // changed
modified.AddContent(15, "No, you can't afford that.");
modified.CloseElement();
modified.CloseElement();
}
private RenderBatch GetRenderedBatch(RenderTreeBuilder from, RenderTreeBuilder to)
{
var batchBuilder = new RenderBatchBuilder();
var diff = RenderTreeDiffBuilder.ComputeDiff(renderer, batchBuilder, 0, from.GetFrames(), to.GetFrames());
batchBuilder.UpdatedComponentDiffs.Append(diff);
return(batchBuilder.ToBatch());
}
private void CleanupComponentStateResources(RenderBatchBuilder batchBuilder)
{
// We don't expect these things to throw.
RenderTreeDiffBuilder.DisposeFrames(batchBuilder, CurrentRenderTree.GetFrames());
if (_hasAnyCascadingParameterSubscriptions)
{
RemoveCascadingParameterSubscriptions();
}
DisposeBuffers();
}
public DiffContext(
Renderer renderer,
RenderBatchBuilder batchBuilder,
RenderTreeFrame[] oldTree, RenderTreeFrame[] newTree)
{
Renderer = renderer;
BatchBuilder = batchBuilder;
OldTree = oldTree;
NewTree = newTree;
Edits = batchBuilder.EditsBuffer;
ReferenceFrames = batchBuilder.ReferenceFramesBuffer;
SiblingIndex = 0;
}
private RenderBatch GetRenderedBatch(RenderTreeBuilder from, RenderTreeBuilder to, bool initializeFromFrames)
{
if (initializeFromFrames)
{
var emptyFrames = new RenderTreeBuilder(renderer).GetFrames();
var oldFrames = from.GetFrames();
RenderTreeDiffBuilder.ComputeDiff(renderer, new RenderBatchBuilder(), 0, emptyFrames, oldFrames);
}
var batchBuilder = new RenderBatchBuilder();
var diff = RenderTreeDiffBuilder.ComputeDiff(renderer, batchBuilder, 0, from.GetFrames(), to.GetFrames());
batchBuilder.UpdatedComponentDiffs.Append(diff);
return(batchBuilder.ToBatch());
}
public DiffContext(
Renderer renderer,
RenderBatchBuilder batchBuilder,
int componentId,
RenderTreeFrame[] oldTree,
RenderTreeFrame[] newTree)
{
Renderer = renderer;
BatchBuilder = batchBuilder;
ComponentId = componentId;
OldTree = oldTree;
NewTree = newTree;
Edits = batchBuilder.EditsBuffer;
ReferenceFrames = batchBuilder.ReferenceFramesBuffer;
AttributeDiffSet = batchBuilder.AttributeDiffSet;
SiblingIndex = 0;
}
/// <summary>
/// As well as computing the diff between the two trees, this method also has the side-effect
/// of instantiating child components on newly-inserted Component frames, and copying the existing
/// component instances onto retained Component frames. It's particularly convenient to do that
/// here because we have the right information and are already walking the trees to do the diff.
/// </summary>
public void ApplyNewRenderTreeVersion(
RenderBatchBuilder batchBuilder,
int componentId,
ArrayRange <RenderTreeFrame> oldTree,
ArrayRange <RenderTreeFrame> newTree)
{
_entries.Clear();
_referenceFrames.Clear();
var siblingIndex = 0;
var slotId = batchBuilder.ReserveUpdatedComponentSlotId();
AppendDiffEntriesForRange(batchBuilder, oldTree.Array, 0, oldTree.Count, newTree.Array, 0, newTree.Count, ref siblingIndex);
batchBuilder.SetUpdatedComponent(
slotId,
new RenderTreeDiff(componentId, _entries.ToRange(), _referenceFrames.ToRange()));
}
public static RenderTreeDiff ComputeDiff(
Renderer renderer,
RenderBatchBuilder batchBuilder,
int componentId,
ArrayRange <RenderTreeFrame> oldTree,
ArrayRange <RenderTreeFrame> newTree)
{
var editsBuffer = batchBuilder.EditsBuffer;
var editsBufferStartLength = editsBuffer.Count;
var diffContext = new DiffContext(renderer, batchBuilder, oldTree.Array, newTree.Array);
AppendDiffEntriesForRange(ref diffContext, 0, oldTree.Count, 0, newTree.Count);
var editsSegment = editsBuffer.ToSegment(editsBufferStartLength, editsBuffer.Count);
return(new RenderTreeDiff(componentId, editsSegment));
}
public void RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, out Exception?renderFragmentException)
{
renderFragmentException = null;
// A component might be in the render queue already before getting disposed by an
// earlier entry in the render queue. In that case, rendering is a no-op.
if (_componentWasDisposed)
{
return;
}
_nextRenderTree.Clear();
try
{
renderFragment(_nextRenderTree);
}
catch (Exception ex)
{
// If an exception occurs in the render fragment delegate, we won't process the diff in any way, so child components,
// event handlers, etc., will all be left untouched as if this component didn't re-render at all. The Renderer will
// then forcibly clear the descendant subtree by rendering an empty fragment for this component.
renderFragmentException = ex;
return;
}
// We don't want to make errors from this be recoverable, because there's no legitimate reason for them to happen
_nextRenderTree.AssertTreeIsValid(Component);
// Swap the old and new tree builders
(CurrentRenderTree, _nextRenderTree) = (_nextRenderTree, CurrentRenderTree);
var diff = RenderTreeDiffBuilder.ComputeDiff(
_renderer,
batchBuilder,
ComponentId,
_nextRenderTree.GetFrames(),
CurrentRenderTree.GetFrames());
batchBuilder.UpdatedComponentDiffs.Append(diff);
batchBuilder.InvalidateParameterViews();
}
public bool TryDisposeInBatch(RenderBatchBuilder batchBuilder, [NotNullWhen(false)] out Exception?exception)
{
_componentWasDisposed = true;
exception = null;
try
{
if (Component is IDisposable disposable)
{
disposable.Dispose();
}
}
catch (Exception ex)
{
exception = ex;
}
CleanupComponentStateResources(batchBuilder);
return(exception == null);
}
public void QueuesRemovedChildComponentsForDisposal()
{
// Arrange
oldTree.OpenComponent <DisposableComponent>(10); // <DisposableComponent>
oldTree.CloseComponent(); // </DisposableComponent>
oldTree.OpenComponent <NonDisposableComponent>(20); // <NonDisposableComponent>
oldTree.CloseComponent(); // </NonDisposableComponent>
oldTree.OpenComponent <DisposableComponent>(30); // <DisposableComponent>
oldTree.CloseComponent(); // </DisposableComponent>
newTree.OpenComponent <DisposableComponent>(30); // <DisposableComponent>
newTree.CloseComponent(); // </DisposableComponent>
var batchBuilder = new RenderBatchBuilder();
RenderTreeDiffBuilder.ComputeDiff(renderer, batchBuilder, 0, new RenderTreeBuilder(renderer).GetFrames(), oldTree.GetFrames());
// Act/Assert
// Note that we track NonDisposableComponent was disposed even though it's not IDisposable,
// because it's up to the upstream renderer to decide what "disposing" a component means
Assert.Empty(batchBuilder.ComponentDisposalQueue);
RenderTreeDiffBuilder.ComputeDiff(renderer, batchBuilder, 0, oldTree.GetFrames(), newTree.GetFrames());
Assert.Equal(new[] { 0, 1 }, batchBuilder.ComponentDisposalQueue);
}
public static void DisposeFrames(RenderBatchBuilder batchBuilder, ArrayRange <RenderTreeFrame> frames) => DisposeFramesInRange(batchBuilder, frames.Array, 0, frames.Count);
public ParameterViewLifetime(RenderBatchBuilder owner)
{
_owner = owner;
_stamp = owner.ParameterViewValidityStamp;
}
private void AppendDiffEntriesForRange(
RenderBatchBuilder batchBuilder,
RenderTreeFrame[] oldTree, int oldStartIndex, int oldEndIndexExcl,
RenderTreeFrame[] newTree, int newStartIndex, int newEndIndexExcl,
ref int siblingIndex)
{
var hasMoreOld = oldEndIndexExcl > oldStartIndex;
var hasMoreNew = newEndIndexExcl > newStartIndex;
var prevOldSeq = -1;
var prevNewSeq = -1;
while (hasMoreOld || hasMoreNew)
{
var oldSeq = hasMoreOld ? oldTree[oldStartIndex].Sequence : int.MaxValue;
var newSeq = hasMoreNew ? newTree[newStartIndex].Sequence : int.MaxValue;
if (oldSeq == newSeq)
{
AppendDiffEntriesForFramesWithSameSequence(batchBuilder, oldTree, oldStartIndex, newTree, newStartIndex, ref siblingIndex);
oldStartIndex = NextSiblingIndex(oldTree[oldStartIndex], oldStartIndex);
newStartIndex = NextSiblingIndex(newTree[newStartIndex], newStartIndex);
hasMoreOld = oldEndIndexExcl > oldStartIndex;
hasMoreNew = newEndIndexExcl > newStartIndex;
prevOldSeq = oldSeq;
prevNewSeq = newSeq;
}
else
{
bool treatAsInsert;
var oldLoopedBack = oldSeq <= prevOldSeq;
var newLoopedBack = newSeq <= prevNewSeq;
if (oldLoopedBack == newLoopedBack)
{
// Both sequences are proceeding through the same loop block, so do a simple
// preordered merge join (picking from whichever side brings us closer to being
// back in sync)
treatAsInsert = newSeq < oldSeq;
if (oldLoopedBack)
{
// If both old and new have now looped back, we must reset their 'looped back'
// tracker so we can treat them as proceeding through the same loop block
prevOldSeq = prevNewSeq = -1;
}
}
else if (oldLoopedBack)
{
// Old sequence looped back but new one didn't
// The new sequence either has some extra trailing elements in the current loop block
// which we should insert, or omits some old trailing loop blocks which we should delete
// TODO: Find a way of not recomputing this next flag on every iteration
var newLoopsBackLater = false;
for (var testIndex = newStartIndex + 1; testIndex < newEndIndexExcl; testIndex++)
{
if (newTree[testIndex].Sequence < newSeq)
{
newLoopsBackLater = true;
break;
}
}
// If the new sequence loops back later to an earlier point than this,
// then we know it's part of the existing loop block (so should be inserted).
// If not, then it's unrelated to the previous loop block (so we should treat
// the old items as trailing loop blocks to be removed).
treatAsInsert = newLoopsBackLater;
}
else
{
// New sequence looped back but old one didn't
// The old sequence either has some extra trailing elements in the current loop block
// which we should delete, or the new sequence has extra trailing loop blocks which we
// should insert
// TODO: Find a way of not recomputing this next flag on every iteration
var oldLoopsBackLater = false;
for (var testIndex = oldStartIndex + 1; testIndex < oldEndIndexExcl; testIndex++)
{
if (oldTree[testIndex].Sequence < oldSeq)
{
oldLoopsBackLater = true;
break;
}
}
// If the old sequence loops back later to an earlier point than this,
// then we know it's part of the existing loop block (so should be removed).
// If not, then it's unrelated to the previous loop block (so we should treat
// the new items as trailing loop blocks to be inserted).
treatAsInsert = !oldLoopsBackLater;
}
if (treatAsInsert)
{
ref var newFrame = ref newTree[newStartIndex];
var newFrameType = newFrame.FrameType;
if (newFrameType == RenderTreeFrameType.Attribute)
{
var referenceFrameIndex = _referenceFrames.Append(newFrame);
Append(RenderTreeEdit.SetAttribute(siblingIndex, referenceFrameIndex));
newStartIndex++;
}
else
{
if (newFrameType == RenderTreeFrameType.Element || newFrameType == RenderTreeFrameType.Component)
{
InstantiateChildComponents(batchBuilder, newTree, newStartIndex);
}
var referenceFrameIndex = AppendSubtreeToReferenceFrames(newTree, newStartIndex);
Append(RenderTreeEdit.PrependFrame(siblingIndex, referenceFrameIndex));
newStartIndex = NextSiblingIndex(newFrame, newStartIndex);
siblingIndex++;
}
hasMoreNew = newEndIndexExcl > newStartIndex;
prevNewSeq = newSeq;
}