forked from mirrors/gecko-dev
		
	
		
			
				
	
	
		
			133 lines
		
	
	
	
		
			4.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			133 lines
		
	
	
	
		
			4.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
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| /* This Source Code Form is subject to the terms of the Mozilla Public
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|  * License, v. 2.0. If a copy of the MPL was not distributed with this
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|  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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| 
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| #include "mozilla/devtools/DominatorTree.h"
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| #include "mozilla/dom/DominatorTreeBinding.h"
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| #include "mozilla/ErrorResult.h"
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| 
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| namespace mozilla {
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| namespace devtools {
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| 
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| dom::Nullable<uint64_t> DominatorTree::GetRetainedSize(uint64_t aNodeId,
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|                                                        ErrorResult& aRv) {
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|   JS::ubi::Node::Id id(aNodeId);
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|   auto node = mHeapSnapshot->getNodeById(id);
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|   if (node.isNothing()) return dom::Nullable<uint64_t>();
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| 
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|   auto mallocSizeOf = GetCurrentThreadDebuggerMallocSizeOf();
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|   JS::ubi::Node::Size size = 0;
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|   if (!mDominatorTree.getRetainedSize(*node, mallocSizeOf, size)) {
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|     aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
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|     return dom::Nullable<uint64_t>();
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|   }
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| 
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|   MOZ_ASSERT(size != 0,
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|              "The node should not have been unknown since we got it from the "
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|              "heap snapshot.");
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|   return dom::Nullable<uint64_t>(size);
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| }
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| 
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| struct NodeAndRetainedSize {
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|   JS::ubi::Node mNode;
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|   JS::ubi::Node::Size mSize;
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| 
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|   NodeAndRetainedSize(const JS::ubi::Node& aNode, JS::ubi::Node::Size aSize)
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|       : mNode(aNode), mSize(aSize) {}
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| 
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|   struct Comparator {
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|     static bool Equals(const NodeAndRetainedSize& aLhs,
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|                        const NodeAndRetainedSize& aRhs) {
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|       return aLhs.mSize == aRhs.mSize;
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|     }
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| 
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|     static bool LessThan(const NodeAndRetainedSize& aLhs,
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|                          const NodeAndRetainedSize& aRhs) {
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|       // Use > because we want to sort from greatest to least retained size.
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|       return aLhs.mSize > aRhs.mSize;
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|     }
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|   };
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| };
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| 
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| void DominatorTree::GetImmediatelyDominated(
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|     uint64_t aNodeId, dom::Nullable<nsTArray<uint64_t>>& aOutResult,
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|     ErrorResult& aRv) {
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|   MOZ_ASSERT(aOutResult.IsNull());
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| 
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|   JS::ubi::Node::Id id(aNodeId);
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|   Maybe<JS::ubi::Node> node = mHeapSnapshot->getNodeById(id);
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|   if (node.isNothing()) return;
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| 
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|   // Get all immediately dominated nodes and their retained sizes.
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|   MallocSizeOf mallocSizeOf = GetCurrentThreadDebuggerMallocSizeOf();
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|   Maybe<JS::ubi::DominatorTree::DominatedSetRange> range =
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|       mDominatorTree.getDominatedSet(*node);
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|   MOZ_ASSERT(
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|       range.isSome(),
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|       "The node should be known, since we got it from the heap snapshot.");
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|   size_t length = range->length();
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|   nsTArray<NodeAndRetainedSize> dominatedNodes(length);
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|   for (const JS::ubi::Node& dominatedNode : *range) {
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|     JS::ubi::Node::Size retainedSize = 0;
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|     if (NS_WARN_IF(!mDominatorTree.getRetainedSize(dominatedNode, mallocSizeOf,
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|                                                    retainedSize))) {
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|       aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
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|       return;
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|     }
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|     MOZ_ASSERT(retainedSize != 0,
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|                "retainedSize should not be zero since we know the node is in "
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|                "the dominator tree.");
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| 
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|     dominatedNodes.AppendElement(
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|         NodeAndRetainedSize(dominatedNode, retainedSize));
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|   }
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| 
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|   // Sort them by retained size.
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|   NodeAndRetainedSize::Comparator comparator;
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|   dominatedNodes.Sort(comparator);
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| 
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|   // Fill the result with the nodes' ids.
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|   JS::ubi::Node root = mDominatorTree.root();
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|   aOutResult.SetValue(nsTArray<uint64_t>(length));
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|   for (const NodeAndRetainedSize& entry : dominatedNodes) {
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|     // The root dominates itself, but we don't want to expose that to JS.
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|     if (entry.mNode == root) continue;
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| 
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|     aOutResult.Value().AppendElement(entry.mNode.identifier());
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|   }
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| }
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| 
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| dom::Nullable<uint64_t> DominatorTree::GetImmediateDominator(
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|     uint64_t aNodeId) const {
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|   JS::ubi::Node::Id id(aNodeId);
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|   Maybe<JS::ubi::Node> node = mHeapSnapshot->getNodeById(id);
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|   if (node.isNothing()) return dom::Nullable<uint64_t>();
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| 
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|   JS::ubi::Node dominator = mDominatorTree.getImmediateDominator(*node);
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|   if (!dominator || dominator == *node) return dom::Nullable<uint64_t>();
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| 
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|   return dom::Nullable<uint64_t>(dominator.identifier());
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| }
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| 
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| /*** Cycle Collection Boilerplate
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|  * *****************************************************************/
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| 
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| NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DominatorTree, mParent, mHeapSnapshot)
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| 
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| NS_IMPL_CYCLE_COLLECTING_ADDREF(DominatorTree)
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| NS_IMPL_CYCLE_COLLECTING_RELEASE(DominatorTree)
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| 
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| NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DominatorTree)
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|   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
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|   NS_INTERFACE_MAP_ENTRY(nsISupports)
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| NS_INTERFACE_MAP_END
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| 
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| /* virtual */
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| JSObject* DominatorTree::WrapObject(JSContext* aCx,
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|                                     JS::HandleObject aGivenProto) {
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|   return dom::DominatorTree_Binding::Wrap(aCx, this, aGivenProto);
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| }
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| 
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| }  // namespace devtools
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| }  // namespace mozilla
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