src: export v8.GetHeapCodeAndMetadataStatistics()

Export statistic provided by V8 through HeapCodeStatistics class and
and GetHeapCodeAndMetadataStatistics function to v8 Node.js module

PR-URL: nodejs#27978
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

doc/api/v8.md

@@ -166,6 +166,28 @@ being non-zero indicates a potential memory leak.
 }
 ```
 
+## v8.getHeapCodeStatistics()
+<!-- YAML
+added: REPLACEME
+-->
+
+* Returns: {Object}
+
+Returns an object with the following properties:
+
+* `code_and_metadata_size` {number}
+* `bytecode_and_metadata_size` {number}
+* `external_script_source_size` {number}
+
+<!-- eslint-skip -->
+```js
+{
+  code_and_metadata_size: 212208,
+  bytecode_and_metadata_size: 161368,
+  external_script_source_size: 1410794
+}
+```
+
 ## v8.setFlagsFromString(flags)
 <!-- YAML
 added: v1.0.0

lib/v8.js

@@ -91,10 +91,12 @@ const {
   setFlagsFromString: _setFlagsFromString,
   heapStatisticsArrayBuffer,
   heapSpaceStatisticsArrayBuffer,
+  heapCodeStatisticsArrayBuffer,
   updateHeapStatisticsArrayBuffer,
   updateHeapSpaceStatisticsArrayBuffer,
+  updateHeapCodeStatisticsArrayBuffer,
 
-  // Properties for heap and heap space statistics buffer extraction.
+  // Properties for heap statistics buffer extraction.
   kTotalHeapSizeIndex,
   kTotalHeapSizeExecutableIndex,
   kTotalPhysicalSizeIndex,
@@ -104,14 +106,21 @@ const {
   kDoesZapGarbageIndex,
   kMallocedMemoryIndex,
   kPeakMallocedMemoryIndex,
+  kNumberOfNativeContextsIndex,
+  kNumberOfDetachedContextsIndex,
+
+  // Properties for heap spaces statistics buffer extraction.
   kHeapSpaces,
   kHeapSpaceStatisticsPropertiesCount,
   kSpaceSizeIndex,
   kSpaceUsedSizeIndex,
   kSpaceAvailableSizeIndex,
   kPhysicalSpaceSizeIndex,
-  kNumberOfNativeContextsIndex,
-  kNumberOfDetachedContextsIndex
+
+  // Properties for heap code statistics buffer extraction.
+  kCodeAndMetadataSizeIndex,
+  kBytecodeAndMetadataSizeIndex,
+  kExternalScriptSourceSizeIndex
 } = internalBinding('v8');
 
 const kNumberOfHeapSpaces = kHeapSpaces.length;
@@ -122,6 +131,9 @@ const heapStatisticsBuffer =
 const heapSpaceStatisticsBuffer =
     new Float64Array(heapSpaceStatisticsArrayBuffer);
 
+const heapCodeStatisticsBuffer =
+    new Float64Array(heapCodeStatisticsArrayBuffer);
+
 function setFlagsFromString(flags) {
   validateString(flags, 'flags');
   _setFlagsFromString(flags);
@@ -166,6 +178,17 @@ function getHeapSpaceStatistics() {
   return heapSpaceStatistics;
 }
 
+function getHeapCodeStatistics() {
+  const buffer = heapCodeStatisticsBuffer;
+
+  updateHeapCodeStatisticsArrayBuffer();
+  return {
+    'code_and_metadata_size': buffer[kCodeAndMetadataSizeIndex],
+    'bytecode_and_metadata_size': buffer[kBytecodeAndMetadataSizeIndex],
+    'external_script_source_size': buffer[kExternalScriptSourceSizeIndex]
+  };
+}
+
 /* V8 serialization API */
 
 /* JS methods for the base objects */
@@ -272,6 +295,7 @@ module.exports = {
   getHeapSnapshot,
   getHeapStatistics,
   getHeapSpaceStatistics,
+  getHeapCodeStatistics,
   setFlagsFromString,
   Serializer,
   Deserializer,

src/env-inl.h

@@ -569,6 +569,16 @@ inline void Environment::set_heap_space_statistics_buffer(double* pointer) {
   heap_space_statistics_buffer_ = pointer;
 }
 
+inline double* Environment::heap_code_statistics_buffer() const {
+  CHECK_NOT_NULL(heap_code_statistics_buffer_);
+  return heap_code_statistics_buffer_;
+}
+
+inline void Environment::set_heap_code_statistics_buffer(double* pointer) {
+  CHECK_NULL(heap_code_statistics_buffer_);  // Should be set only once.
+  heap_code_statistics_buffer_ = pointer;
+}
+
 inline char* Environment::http_parser_buffer() const {
   return http_parser_buffer_;
 }

src/env.cc

@@ -414,6 +414,7 @@ Environment::~Environment() {
   delete[] heap_statistics_buffer_;
   delete[] heap_space_statistics_buffer_;
   delete[] http_parser_buffer_;
+  delete[] heap_code_statistics_buffer_;
 
   TRACE_EVENT_NESTABLE_ASYNC_END0(
     TRACING_CATEGORY_NODE1(environment), "Environment", this);

src/env.h

@@ -1023,6 +1023,9 @@ class Environment : public MemoryRetainer {
   inline double* heap_space_statistics_buffer() const;
   inline void set_heap_space_statistics_buffer(double* pointer);
 
+  inline double* heap_code_statistics_buffer() const;
+  inline void set_heap_code_statistics_buffer(double* pointer);
+
   inline char* http_parser_buffer() const;
   inline void set_http_parser_buffer(char* buffer);
   inline bool http_parser_buffer_in_use() const;
@@ -1345,6 +1348,7 @@ class Environment : public MemoryRetainer {
 
   double* heap_statistics_buffer_ = nullptr;
   double* heap_space_statistics_buffer_ = nullptr;
+  double* heap_code_statistics_buffer_ = nullptr;
 
   char* http_parser_buffer_ = nullptr;
   bool http_parser_buffer_in_use_ = false;

src/node_v8.cc

@@ -30,6 +30,7 @@ using v8::Array;
 using v8::ArrayBuffer;
 using v8::Context;
 using v8::FunctionCallbackInfo;
+using v8::HeapCodeStatistics;
 using v8::HeapSpaceStatistics;
 using v8::HeapStatistics;
 using v8::Integer;
@@ -43,6 +44,7 @@ using v8::Uint32;
 using v8::V8;
 using v8::Value;
 
+
 #define HEAP_STATISTICS_PROPERTIES(V)                                         \
   V(0, total_heap_size, kTotalHeapSizeIndex)                                  \
   V(1, total_heap_size_executable, kTotalHeapSizeExecutableIndex)             \
@@ -61,6 +63,7 @@ static const size_t kHeapStatisticsPropertiesCount =
     HEAP_STATISTICS_PROPERTIES(V);
 #undef V
 
+
 #define HEAP_SPACE_STATISTICS_PROPERTIES(V)                                   \
   V(0, space_size, kSpaceSizeIndex)                                           \
   V(1, space_used_size, kSpaceUsedSizeIndex)                                  \
@@ -73,6 +76,16 @@ static const size_t kHeapSpaceStatisticsPropertiesCount =
 #undef V
 
 
+#define HEAP_CODE_STATISTICS_PROPERTIES(V)                                    \
+  V(0, code_and_metadata_size, kCodeAndMetadataSizeIndex)                    \
+  V(1, bytecode_and_metadata_size, kBytecodeAndMetadataSizeIndex)             \
+  V(2, external_script_source_size, kExternalScriptSourceSizeIndex)
+
+#define V(a, b, c) +1
+static const size_t kHeapCodeStatisticsPropertiesCount =
+    HEAP_CODE_STATISTICS_PROPERTIES(V);
+#undef V
+
 void CachedDataVersionTag(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
   Local<Integer> result =
@@ -111,6 +124,18 @@ void UpdateHeapSpaceStatisticsBuffer(const FunctionCallbackInfo<Value>& args) {
 }
 
 
+void UpdateHeapCodeStatisticsArrayBuffer(
+    const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+  HeapCodeStatistics s;
+  env->isolate()->GetHeapCodeAndMetadataStatistics(&s);
+  double* const buffer = env->heap_code_statistics_buffer();
+#define V(index, name, _) buffer[index] = static_cast<double>(s.name());
+  HEAP_CODE_STATISTICS_PROPERTIES(V)
+#undef V
+}
+
+
 void SetFlagsFromString(const FunctionCallbackInfo<Value>& args) {
   CHECK(args[0]->IsString());
   String::Utf8Value flags(args.GetIsolate(), args[0]);
@@ -127,6 +152,7 @@ void Initialize(Local<Object> target,
   env->SetMethodNoSideEffect(target, "cachedDataVersionTag",
                              CachedDataVersionTag);
 
+  // Export symbols used by v8.getHeapStatistics()
   env->SetMethod(target,
                  "updateHeapStatisticsArrayBuffer",
                  UpdateHeapStatisticsArrayBuffer);
@@ -151,6 +177,35 @@ void Initialize(Local<Object> target,
   HEAP_STATISTICS_PROPERTIES(V)
 #undef V
 
+  // Export symbols used by v8.getHeapCodeStatistics()
+  env->SetMethod(target,
+                 "updateHeapCodeStatisticsArrayBuffer",
+                 UpdateHeapCodeStatisticsArrayBuffer);
+
+  env->set_heap_code_statistics_buffer(
+    new double[kHeapCodeStatisticsPropertiesCount]);
+
+  const size_t heap_code_statistics_buffer_byte_length =
+      sizeof(*env->heap_code_statistics_buffer())
+      * kHeapCodeStatisticsPropertiesCount;
+
+  target->Set(env->context(),
+              FIXED_ONE_BYTE_STRING(env->isolate(),
+                                    "heapCodeStatisticsArrayBuffer"),
+              ArrayBuffer::New(env->isolate(),
+                               env->heap_code_statistics_buffer(),
+                               heap_code_statistics_buffer_byte_length))
+  .Check();
+
+#define V(i, _, name)                                                         \
+  target->Set(env->context(),                                                 \
+              FIXED_ONE_BYTE_STRING(env->isolate(), #name),                   \
+              Uint32::NewFromUnsigned(env->isolate(), i)).Check();
+
+  HEAP_CODE_STATISTICS_PROPERTIES(V)
+#undef V
+
+  // Export symbols used by v8.getHeapSpaceStatistics()
   target->Set(env->context(),
               FIXED_ONE_BYTE_STRING(env->isolate(),
                                     "kHeapSpaceStatisticsPropertiesCount"),
@@ -205,6 +260,7 @@ void Initialize(Local<Object> target,
   HEAP_SPACE_STATISTICS_PROPERTIES(V)
 #undef V
 
+  // Export symbols used by v8.setFlagsFromString()
   env->SetMethod(target, "setFlagsFromString", SetFlagsFromString);
 }
 

test/parallel/test-v8-stats.js

@@ -22,6 +22,18 @@ keys.forEach(function(key) {
 });
 
 
+const heapCodeStatistics = v8.getHeapCodeStatistics();
+const heapCodeStatisticsKeys = [
+  'bytecode_and_metadata_size',
+  'code_and_metadata_size',
+  'external_script_source_size'];
+assert.deepStrictEqual(Object.keys(heapCodeStatistics).sort(),
+                       heapCodeStatisticsKeys);
+heapCodeStatisticsKeys.forEach(function(key) {
+  assert.strictEqual(typeof heapCodeStatistics[key], 'number');
+});
+
+
 const expectedHeapSpaces = [
   'code_large_object_space',
   'code_space',