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+/* -*- 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/. */
+
+#ifndef mozilla_devtools_DeserializedNode__
+#define mozilla_devtools_DeserializedNode__
+
+#include <utility>
+
+#include "js/UbiNode.h"
+#include "js/UniquePtr.h"
+#include "mozilla/HashFunctions.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/Vector.h"
+#include "mozilla/devtools/CoreDump.pb.h"
+
+// `Deserialized{Node,Edge}` translate protobuf messages from our core dump
+// format into structures we can rely upon for implementing `JS::ubi::Node`
+// specializations on top of. All of the properties of the protobuf messages are
+// optional for future compatibility, and this is the layer where we validate
+// that the properties that do actually exist in any given message fulfill our
+// semantic requirements.
+//
+// Both `DeserializedNode` and `DeserializedEdge` are always owned by a
+// `HeapSnapshot` instance, and their lifetimes must not extend after that of
+// their owning `HeapSnapshot`.
+
+namespace mozilla {
+namespace devtools {
+
+class HeapSnapshot;
+
+using NodeId = uint64_t;
+using StackFrameId = uint64_t;
+
+// A `DeserializedEdge` represents an edge in the heap graph pointing to the
+// node with id equal to `DeserializedEdge::referent` that we deserialized from
+// a core dump.
+struct DeserializedEdge {
+ NodeId referent;
+ // A borrowed reference to a string owned by this node's owning HeapSnapshot.
+ const char16_t* name;
+
+ explicit DeserializedEdge(NodeId referent, const char16_t* edgeName = nullptr)
+ : referent(referent), name(edgeName) {}
+ DeserializedEdge(DeserializedEdge&& rhs);
+ DeserializedEdge& operator=(DeserializedEdge&& rhs);
+
+ private:
+ DeserializedEdge(const DeserializedEdge&) = delete;
+ DeserializedEdge& operator=(const DeserializedEdge&) = delete;
+};
+
+// A `DeserializedNode` is a node in the heap graph that we deserialized from a
+// core dump.
+struct DeserializedNode {
+ using EdgeVector = Vector<DeserializedEdge>;
+ using UniqueStringPtr = UniquePtr<char16_t[]>;
+
+ NodeId id;
+ JS::ubi::CoarseType coarseType;
+ // A borrowed reference to a string owned by this node's owning HeapSnapshot.
+ const char16_t* typeName;
+ uint64_t size;
+ EdgeVector edges;
+ Maybe<StackFrameId> allocationStack;
+ // A borrowed reference to a string owned by this node's owning HeapSnapshot.
+ const char* jsObjectClassName;
+ // A borrowed reference to a string owned by this node's owning HeapSnapshot.
+ const char* scriptFilename;
+ // A borrowed reference to a string owned by this node's owning HeapSnapshot.
+ const char16_t* descriptiveTypeName;
+ // A weak pointer to this node's owning `HeapSnapshot`. Safe without
+ // AddRef'ing because this node's lifetime is equal to that of its owner.
+ HeapSnapshot* owner;
+
+ DeserializedNode(NodeId id, JS::ubi::CoarseType coarseType,
+ const char16_t* typeName, uint64_t size, EdgeVector&& edges,
+ const Maybe<StackFrameId>& allocationStack,
+ const char* className, const char* filename,
+ const char16_t* descriptiveName, HeapSnapshot& owner)
+ : id(id),
+ coarseType(coarseType),
+ typeName(typeName),
+ size(size),
+ edges(std::move(edges)),
+ allocationStack(allocationStack),
+ jsObjectClassName(className),
+ scriptFilename(filename),
+ descriptiveTypeName(descriptiveName),
+ owner(&owner) {}
+ virtual ~DeserializedNode() {}
+
+ DeserializedNode(DeserializedNode&& rhs)
+ : id(rhs.id),
+ coarseType(rhs.coarseType),
+ typeName(rhs.typeName),
+ size(rhs.size),
+ edges(std::move(rhs.edges)),
+ allocationStack(rhs.allocationStack),
+ jsObjectClassName(rhs.jsObjectClassName),
+ scriptFilename(rhs.scriptFilename),
+ descriptiveTypeName(rhs.descriptiveTypeName),
+ owner(rhs.owner) {}
+
+ DeserializedNode& operator=(DeserializedNode&& rhs) {
+ MOZ_ASSERT(&rhs != this);
+ this->~DeserializedNode();
+ new (this) DeserializedNode(std::move(rhs));
+ return *this;
+ }
+
+ // Get a borrowed reference to the given edge's referent. This method is
+ // virtual to provide a hook for gmock and gtest.
+ virtual JS::ubi::Node getEdgeReferent(const DeserializedEdge& edge);
+
+ struct HashPolicy;
+
+ protected:
+ // This is only for use with `MockDeserializedNode` in testing.
+ DeserializedNode(NodeId id, const char16_t* typeName, uint64_t size)
+ : id(id),
+ coarseType(JS::ubi::CoarseType::Other),
+ typeName(typeName),
+ size(size),
+ edges(),
+ allocationStack(Nothing()),
+ jsObjectClassName(nullptr),
+ scriptFilename(nullptr),
+ descriptiveTypeName(nullptr),
+ owner(nullptr) {}
+
+ private:
+ DeserializedNode(const DeserializedNode&) = delete;
+ DeserializedNode& operator=(const DeserializedNode&) = delete;
+};
+
+static inline js::HashNumber hashIdDerivedFromPtr(uint64_t id) {
+ return mozilla::HashGeneric(id);
+}
+
+struct DeserializedNode::HashPolicy {
+ using Lookup = NodeId;
+
+ static js::HashNumber hash(const Lookup& lookup) {
+ return hashIdDerivedFromPtr(lookup);
+ }
+
+ static bool match(const DeserializedNode& existing, const Lookup& lookup) {
+ return existing.id == lookup;
+ }
+};
+
+// A `DeserializedStackFrame` is a stack frame referred to by a thing in the
+// heap graph that we deserialized from a core dump.
+struct DeserializedStackFrame {
+ StackFrameId id;
+ Maybe<StackFrameId> parent;
+ uint32_t line;
+ uint32_t column;
+ // Borrowed references to strings owned by this DeserializedStackFrame's
+ // owning HeapSnapshot.
+ const char16_t* source;
+ const char16_t* functionDisplayName;
+ bool isSystem;
+ bool isSelfHosted;
+ // A weak pointer to this frame's owning `HeapSnapshot`. Safe without
+ // AddRef'ing because this frame's lifetime is equal to that of its owner.
+ HeapSnapshot* owner;
+
+ explicit DeserializedStackFrame(StackFrameId id,
+ const Maybe<StackFrameId>& parent,
+ uint32_t line, uint32_t column,
+ const char16_t* source,
+ const char16_t* functionDisplayName,
+ bool isSystem, bool isSelfHosted,
+ HeapSnapshot& owner)
+ : id(id),
+ parent(parent),
+ line(line),
+ column(column),
+ source(source),
+ functionDisplayName(functionDisplayName),
+ isSystem(isSystem),
+ isSelfHosted(isSelfHosted),
+ owner(&owner) {
+ MOZ_ASSERT(source);
+ }
+
+ JS::ubi::StackFrame getParentStackFrame() const;
+
+ struct HashPolicy;
+
+ protected:
+ // This is exposed only for MockDeserializedStackFrame in the gtests.
+ explicit DeserializedStackFrame()
+ : id(0),
+ parent(Nothing()),
+ line(0),
+ column(0),
+ source(nullptr),
+ functionDisplayName(nullptr),
+ isSystem(false),
+ isSelfHosted(false),
+ owner(nullptr){};
+};
+
+struct DeserializedStackFrame::HashPolicy {
+ using Lookup = StackFrameId;
+
+ static js::HashNumber hash(const Lookup& lookup) {
+ return hashIdDerivedFromPtr(lookup);
+ }
+
+ static bool match(const DeserializedStackFrame& existing,
+ const Lookup& lookup) {
+ return existing.id == lookup;
+ }
+};
+
+} // namespace devtools
+} // namespace mozilla
+
+namespace JS {
+namespace ubi {
+
+using mozilla::devtools::DeserializedNode;
+using mozilla::devtools::DeserializedStackFrame;
+
+template <>
+class Concrete<DeserializedNode> : public Base {
+ protected:
+ explicit Concrete(DeserializedNode* ptr) : Base(ptr) {}
+ DeserializedNode& get() const { return *static_cast<DeserializedNode*>(ptr); }
+
+ public:
+ static void construct(void* storage, DeserializedNode* ptr) {
+ new (storage) Concrete(ptr);
+ }
+
+ CoarseType coarseType() const final { return get().coarseType; }
+ Id identifier() const override { return get().id; }
+ bool isLive() const override { return false; }
+ const char16_t* typeName() const override;
+ Node::Size size(mozilla::MallocSizeOf mallocSizeof) const override;
+ const char* jsObjectClassName() const override {
+ return get().jsObjectClassName;
+ }
+ const char* scriptFilename() const final { return get().scriptFilename; }
+ const char16_t* descriptiveTypeName() const override {
+ return get().descriptiveTypeName;
+ }
+
+ bool hasAllocationStack() const override {
+ return get().allocationStack.isSome();
+ }
+ StackFrame allocationStack() const override;
+
+ // We ignore the `bool wantNames` parameter because we can't control whether
+ // the core dump was serialized with edge names or not.
+ js::UniquePtr<EdgeRange> edges(JSContext* cx, bool) const override;
+
+ static const char16_t concreteTypeName[];
+};
+
+template <>
+class ConcreteStackFrame<DeserializedStackFrame> : public BaseStackFrame {
+ protected:
+ explicit ConcreteStackFrame(DeserializedStackFrame* ptr)
+ : BaseStackFrame(ptr) {}
+
+ DeserializedStackFrame& get() const {
+ return *static_cast<DeserializedStackFrame*>(ptr);
+ }
+
+ public:
+ static void construct(void* storage, DeserializedStackFrame* ptr) {
+ new (storage) ConcreteStackFrame(ptr);
+ }
+
+ uint64_t identifier() const override { return get().id; }
+ uint32_t line() const override { return get().line; }
+ uint32_t column() const override { return get().column; }
+ bool isSystem() const override { return get().isSystem; }
+ bool isSelfHosted(JSContext* cx) const override { return get().isSelfHosted; }
+ void trace(JSTracer* trc) override {}
+ AtomOrTwoByteChars source() const override {
+ return AtomOrTwoByteChars(get().source);
+ }
+ uint32_t sourceId() const override {
+ // Source IDs are local to their host process and are not serialized.
+ return 0;
+ }
+ AtomOrTwoByteChars functionDisplayName() const override {
+ return AtomOrTwoByteChars(get().functionDisplayName);
+ }
+
+ StackFrame parent() const override;
+ bool constructSavedFrameStack(
+ JSContext* cx, MutableHandleObject outSavedFrameStack) const override;
+};
+
+} // namespace ubi
+} // namespace JS
+
+#endif // mozilla_devtools_DeserializedNode__