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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__