gecko-dev/devtools/shared/heapsnapshot/DeserializedNode.cpp

127 строки
3.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/devtools/DeserializedNode.h"
#include "mozilla/devtools/HeapSnapshot.h"
#include "nsCRTGlue.h"
namespace mozilla {
namespace devtools {
DeserializedEdge::DeserializedEdge(DeserializedEdge&& rhs) {
referent = rhs.referent;
name = rhs.name;
}
DeserializedEdge& DeserializedEdge::operator=(DeserializedEdge&& rhs) {
MOZ_ASSERT(&rhs != this);
this->~DeserializedEdge();
new (this) DeserializedEdge(std::move(rhs));
return *this;
}
JS::ubi::Node DeserializedNode::getEdgeReferent(const DeserializedEdge& edge) {
auto ptr = owner->nodes.lookup(edge.referent);
MOZ_ASSERT(ptr);
// `HashSets` only provide const access to their values, because mutating a
// value might change its hash, rendering it unfindable in the set.
// Unfortunately, the `ubi::Node` constructor requires a non-const pointer to
// its referent. However, the only aspect of a `DeserializedNode` we hash on
// is its id, which can't be changed via `ubi::Node`, so this cast can't cause
// the trouble `HashSet` is concerned a non-const reference would cause.
return JS::ubi::Node(const_cast<DeserializedNode*>(&*ptr));
}
JS::ubi::StackFrame DeserializedStackFrame::getParentStackFrame() const {
MOZ_ASSERT(parent.isSome());
auto ptr = owner->frames.lookup(parent.ref());
MOZ_ASSERT(ptr);
// See above comment in DeserializedNode::getEdgeReferent about why this
// const_cast is needed and safe.
return JS::ubi::StackFrame(const_cast<DeserializedStackFrame*>(&*ptr));
}
} // namespace devtools
} // namespace mozilla
namespace JS {
namespace ubi {
using mozilla::devtools::DeserializedEdge;
const char16_t Concrete<DeserializedNode>::concreteTypeName[] =
u"mozilla::devtools::DeserializedNode";
const char16_t* Concrete<DeserializedNode>::typeName() const {
return get().typeName;
}
Node::Size Concrete<DeserializedNode>::size(
mozilla::MallocSizeOf mallocSizeof) const {
return get().size;
}
class DeserializedEdgeRange : public EdgeRange {
DeserializedNode* node;
Edge currentEdge;
size_t i;
void settle() {
if (i >= node->edges.length()) {
front_ = nullptr;
return;
}
auto& edge = node->edges[i];
auto referent = node->getEdgeReferent(edge);
currentEdge = Edge(edge.name ? NS_xstrdup(edge.name) : nullptr, referent);
front_ = &currentEdge;
}
public:
explicit DeserializedEdgeRange(DeserializedNode& node) : node(&node), i(0) {
settle();
}
void popFront() override {
i++;
settle();
}
};
StackFrame Concrete<DeserializedNode>::allocationStack() const {
MOZ_ASSERT(hasAllocationStack());
auto id = get().allocationStack.ref();
auto ptr = get().owner->frames.lookup(id);
MOZ_ASSERT(ptr);
// See above comment in DeserializedNode::getEdgeReferent about why this
// const_cast is needed and safe.
return JS::ubi::StackFrame(const_cast<DeserializedStackFrame*>(&*ptr));
}
js::UniquePtr<EdgeRange> Concrete<DeserializedNode>::edges(JSContext* cx,
bool) const {
js::UniquePtr<DeserializedEdgeRange> range(
js_new<DeserializedEdgeRange>(get()));
if (!range) return nullptr;
return js::UniquePtr<EdgeRange>(range.release());
}
StackFrame ConcreteStackFrame<DeserializedStackFrame>::parent() const {
return get().parent.isNothing() ? StackFrame() : get().getParentStackFrame();
}
bool ConcreteStackFrame<DeserializedStackFrame>::constructSavedFrameStack(
JSContext* cx, MutableHandleObject outSavedFrameStack) const {
StackFrame f(&get());
return ConstructSavedFrameStackSlow(cx, f, outSavedFrameStack);
}
} // namespace ubi
} // namespace JS