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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	node_snapshotable.h	Lines:	14	14	100.0 %
Date:	2022-09-22 04:22:24	Branches:	0	0	- %



#ifndef SRC_NODE_SNAPSHOTABLE_H_
#define SRC_NODE_SNAPSHOTABLE_H_

#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#include "base_object.h"
#include "util.h"

namespace node {

class Environment;
struct EnvSerializeInfo;
struct SnapshotData;
class ExternalReferenceRegistry;

using SnapshotIndex = size_t;

struct PropInfo {
  std::string name;     // name for debugging
  uint32_t id;          // In the list - in case there are any empty entries
  SnapshotIndex index;  // In the snapshot
};

#define SERIALIZABLE_OBJECT_TYPES(V)                                           \
  V(fs_binding_data, fs::BindingData)                                          \
  V(v8_binding_data, v8_utils::BindingData)                                    \
  V(blob_binding_data, BlobBindingData)                                        \
  V(process_binding_data, process::BindingData)                                \
  V(util_weak_reference, util::WeakReference)

enum class EmbedderObjectType : uint8_t {
#define V(PropertyName, NativeType) k_##PropertyName,
  SERIALIZABLE_OBJECT_TYPES(V)
#undef V
};

typedef size_t SnapshotIndex;

// When serializing an embedder object, we'll serialize the native states
// into a chunk that can be mapped into a subclass of InternalFieldInfoBase,
// and pass it into the V8 callback as the payload of StartupData.
// The memory chunk looks like this:
//
// [   type   ] - EmbedderObjectType (a uint8_t)
// [  length  ] - a size_t
// [    ...   ] - custom bytes of size |length - header size|
struct InternalFieldInfoBase {
 public:
  EmbedderObjectType type;
  size_t length;

  template <typename T>
  static T* New(EmbedderObjectType type) {
    static_assert(std::is_base_of_v<InternalFieldInfoBase, T> ||
                      std::is_same_v<InternalFieldInfoBase, T>,
                  "Can only accept InternalFieldInfoBase subclasses");
    void* buf = ::operator new[](sizeof(T));
    T* result = new (buf) T;
    result->type = type;
    result->length = sizeof(T);
    return result;
  }

  template <typename T>
  T* Copy() const {
    static_assert(std::is_base_of_v<InternalFieldInfoBase, T> ||
                      std::is_same_v<InternalFieldInfoBase, T>,
                  "Can only accept InternalFieldInfoBase subclasses");
    static_assert(std::is_trivially_copyable_v<T>,
                  "Can only memcpy trivially copyable class");
    void* buf = ::operator new[](sizeof(T));
    T* result = new (buf) T;
    memcpy(result, this, sizeof(T));
    return result;
  }

  void Delete() { ::operator delete[](this); }

  InternalFieldInfoBase() = default;
};

// An interface for snapshotable native objects to inherit from.
// Use the SERIALIZABLE_OBJECT_METHODS() macro in the class to define
// the following methods to implement:
//
// - PrepareForSerialization(): This would be run prior to context
//   serialization. Use this method to e.g. release references that
//   can be re-initialized, or perform property store operations
//   that needs a V8 context.
// - Serialize(): This would be called during context serialization,
//   once for each embedder field of the object.
//   Allocate and construct an InternalFieldInfoBase object that contains
//   data that can be used to deserialize native states.
// - Deserialize(): This would be called after the context is
//   deserialized and the object graph is complete, once for each
//   embedder field of the object. Use this to restore native states
//   in the object.
class SnapshotableObject : public BaseObject {
 public:
  SnapshotableObject(Environment* env,
                     v8::Local<v8::Object> wrap,
                     EmbedderObjectType type);
  const char* GetTypeNameChars() const;

  // If returns false, the object will not be serialized.
  virtual bool PrepareForSerialization(v8::Local<v8::Context> context,
                                       v8::SnapshotCreator* creator) = 0;
  virtual InternalFieldInfoBase* Serialize(int index) = 0;
  bool is_snapshotable() const override { return true; }
  // We'll make sure that the type is set in the constructor
  EmbedderObjectType type() { return type_; }

 private:
  EmbedderObjectType type_;
};

#define SERIALIZABLE_OBJECT_METHODS()                                          \
  bool PrepareForSerialization(v8::Local<v8::Context> context,                 \
                               v8::SnapshotCreator* creator) override;         \
  InternalFieldInfoBase* Serialize(int index) override;                        \
  static void Deserialize(v8::Local<v8::Context> context,                      \
                          v8::Local<v8::Object> holder,                        \
                          int index,                                           \
                          InternalFieldInfoBase* info);

v8::StartupData SerializeNodeContextInternalFields(v8::Local<v8::Object> holder,
                                                   int index,
                                                   void* env);
void DeserializeNodeInternalFields(v8::Local<v8::Object> holder,
                                   int index,
                                   v8::StartupData payload,
                                   void* env);
void SerializeSnapshotableObjects(Environment* env,
                                  v8::SnapshotCreator* creator,
                                  EnvSerializeInfo* info);
}  // namespace node

#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#endif  // SRC_NODE_SNAPSHOTABLE_H_


Generated by: GCOVR (Version 4.2)

Line	Branch	Exec	Source
1
2			#ifndef SRC_NODE_SNAPSHOTABLE_H_
3			#define SRC_NODE_SNAPSHOTABLE_H_
4
5			#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
6
7			#include "base_object.h"
8			#include "util.h"
9
10			namespace node {
11
12			class Environment;
13			struct EnvSerializeInfo;
14			struct SnapshotData;
15			class ExternalReferenceRegistry;
16
17			using SnapshotIndex = size_t;
18
19			struct PropInfo {
20			std::string name; // name for debugging
21			uint32_t id; // In the list - in case there are any empty entries
22			SnapshotIndex index; // In the snapshot
23			};
24
25			#define SERIALIZABLE_OBJECT_TYPES(V) \
26			V(fs_binding_data, fs::BindingData) \
27			V(v8_binding_data, v8_utils::BindingData) \
28			V(blob_binding_data, BlobBindingData) \
29			V(process_binding_data, process::BindingData) \
30			V(util_weak_reference, util::WeakReference)
31
32			enum class EmbedderObjectType : uint8_t {
33			#define V(PropertyName, NativeType) k_##PropertyName,
34			SERIALIZABLE_OBJECT_TYPES(V)
35			#undef V
36			};
37
38			typedef size_t SnapshotIndex;
39
40			// When serializing an embedder object, we'll serialize the native states
41			// into a chunk that can be mapped into a subclass of InternalFieldInfoBase,
42			// and pass it into the V8 callback as the payload of StartupData.
43			// The memory chunk looks like this:
44			//
45			// [ type ] - EmbedderObjectType (a uint8_t)
46			// [ length ] - a size_t
47			// [ ... ] - custom bytes of size \|length - header size\|
48			struct InternalFieldInfoBase {
49			public:
50			EmbedderObjectType type;
51			size_t length;
52
53			template <typename T>
54		24	static T* New(EmbedderObjectType type) {
55			static_assert(std::is_base_of_v<InternalFieldInfoBase, T> \|\|
56			std::is_same_v<InternalFieldInfoBase, T>,
57			"Can only accept InternalFieldInfoBase subclasses");
58		24	void* buf = ::operator new[](sizeof(T));
59		24	T* result = new (buf) T;
60		24	result->type = type;
61		24	result->length = sizeof(T);
62		24	return result;
63			}
64
65			template <typename T>
66		44160	T* Copy() const {
67			static_assert(std::is_base_of_v<InternalFieldInfoBase, T> \|\|
68			std::is_same_v<InternalFieldInfoBase, T>,
69			"Can only accept InternalFieldInfoBase subclasses");
70			static_assert(std::is_trivially_copyable_v<T>,
71			"Can only memcpy trivially copyable class");
72		44160	void* buf = ::operator new[](sizeof(T));
73		44160	T* result = new (buf) T;
74		44160	memcpy(result, this, sizeof(T));
75		44160	return result;
76			}
77
78		22076	void Delete() { ::operator delete[](this); }
79
80			InternalFieldInfoBase() = default;
81			};
82
83			// An interface for snapshotable native objects to inherit from.
84			// Use the SERIALIZABLE_OBJECT_METHODS() macro in the class to define
85			// the following methods to implement:
86			//
87			// - PrepareForSerialization(): This would be run prior to context
88			// serialization. Use this method to e.g. release references that
89			// can be re-initialized, or perform property store operations
90			// that needs a V8 context.
91			// - Serialize(): This would be called during context serialization,
92			// once for each embedder field of the object.
93			// Allocate and construct an InternalFieldInfoBase object that contains
94			// data that can be used to deserialize native states.
95			// - Deserialize(): This would be called after the context is
96			// deserialized and the object graph is complete, once for each
97			// embedder field of the object. Use this to restore native states
98			// in the object.
99			class SnapshotableObject : public BaseObject {
100			public:
101			SnapshotableObject(Environment* env,
102			v8::Local<v8::Object> wrap,
103			EmbedderObjectType type);
104			const char* GetTypeNameChars() const;
105
106			// If returns false, the object will not be serialized.
107			virtual bool PrepareForSerialization(v8::Local<v8::Context> context,
108			v8::SnapshotCreator* creator) = 0;
109			virtual InternalFieldInfoBase* Serialize(int index) = 0;
110		24	bool is_snapshotable() const override { return true; }
111			// We'll make sure that the type is set in the constructor
112		24	EmbedderObjectType type() { return type_; }
113
114			private:
115			EmbedderObjectType type_;
116			};
117
118			#define SERIALIZABLE_OBJECT_METHODS() \
119			bool PrepareForSerialization(v8::Local<v8::Context> context, \
120			v8::SnapshotCreator* creator) override; \
121			InternalFieldInfoBase* Serialize(int index) override; \
122			static void Deserialize(v8::Local<v8::Context> context, \
123			v8::Local<v8::Object> holder, \
124			int index, \
125			InternalFieldInfoBase* info);
126
127			v8::StartupData SerializeNodeContextInternalFields(v8::Local<v8::Object> holder,
128			int index,
129			void* env);
130			void DeserializeNodeInternalFields(v8::Local<v8::Object> holder,
131			int index,
132			v8::StartupData payload,
133			void* env);
134			void SerializeSnapshotableObjects(Environment* env,
135			v8::SnapshotCreator* creator,
136			EnvSerializeInfo* info);
137			} // namespace node
138
139			#endif // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
140
141			#endif // SRC_NODE_SNAPSHOTABLE_H_