Add Heap Space Statistics in v8go

isolate.go

@@ -44,6 +44,14 @@ type HeapStatistics struct {
 	NumberOfDetachedContexts uint64
 }
 
+type HeapSpaceStatistics struct {
+	SpaceName          string
+	SpaceSize          uint64
+	SpaceUsedSize      uint64
+	SpaceAvailableSize uint64
+	PhysicalSpaceSize  uint64
+}
+
 // NewIsolate creates a new V8 isolate. Only one thread may access
 // a given isolate at a time, but different threads may access
 // different isolates simultaneously.
@@ -119,6 +127,23 @@ func (i *Isolate) CompileUnboundScript(source, origin string, opts CompileOption
 	}, nil
 }
 
+// Returns heap statistics segmented by V8 heap spaces.
+func (i *Isolate) GetHeapSpaceStatistics() []HeapSpaceStatistics {
+	spaceStats := []HeapSpaceStatistics{}
+	heapSpaces := int(C.NumberOfHeapSpaces(i.ptr))
+	for space := 0; space < heapSpaces; space++ {
+		stats := C.IsolateGetHeapSpaceStatistics(i.ptr, (C.size_t)(space))
+		spaceStats = append(spaceStats, HeapSpaceStatistics{
+			SpaceName:          C.GoString(stats.space_name),
+			SpaceSize:          uint64(stats.space_size),
+			SpaceUsedSize:      uint64(stats.space_used_size),
+			SpaceAvailableSize: uint64(stats.space_available_size),
+			PhysicalSpaceSize:  uint64(stats.physical_space_size),
+		})
+	}
+	return spaceStats
+}
+
 // GetHeapStatistics returns heap statistics for an isolate.
 func (i *Isolate) GetHeapStatistics() HeapStatistics {
 	hs := C.IsolationGetHeapStatistics(i.ptr)

isolate_test.go

@@ -296,3 +296,29 @@ func makeObject() interface{} {
 		"b": "AAAABBBBAAAABBBBAAAABBBBAAAABBBBAAAABBBB",
 	}
 }
+
+func TestIsolateGetHeapSpaceStatistics(t *testing.T) {
+	t.Parallel()
+	iso := v8.NewIsolate()
+	defer iso.Dispose()
+	printfn := v8.NewFunctionTemplate(iso, func(info *v8.FunctionCallbackInfo) *v8.Value {
+		fmt.Printf("%v", info.Args())
+		return nil
+	})
+	global := v8.NewObjectTemplate(iso)
+	global.Set("print", printfn)
+	ctx := v8.NewContext(iso, global)
+	ctx.RunScript("print('foo')", "print.js")
+
+	heapSpaceStats := iso.GetHeapSpaceStatistics()
+
+	for _, stats := range heapSpaceStats {
+		if stats.SpaceName == "new_space" && (stats.SpaceSize <= 0 || stats.SpaceUsedSize <= 0) {
+			t.Errorf("expected non-zero size for heap space, got %d size for %s", stats.SpaceSize, stats.SpaceName)
+		}
+		if stats.SpaceName == "old_space" && (stats.SpaceSize <= 0 || stats.SpaceUsedSize <= 0) {
+			t.Errorf("expected non-zero size for heap space, got %d size for %s", stats.SpaceSize, stats.SpaceName)
+		}
+	}
+
+}

v8go.cc

@@ -193,6 +193,24 @@ int IsolateIsExecutionTerminating(IsolatePtr iso) {
   return iso->IsExecutionTerminating();
 }
 
+/********** Heap Statistics **********/
+
+size_t NumberOfHeapSpaces(IsolatePtr iso) {
+  return iso->NumberOfHeapSpaces();
+}
+
+IsolateHeapSpaceStatistics IsolateGetHeapSpaceStatistics(IsolatePtr iso,
+                                                         size_t index) {
+  if (iso == nullptr) {
+    return IsolateHeapSpaceStatistics{0};
+  }
+  v8::HeapSpaceStatistics hs;
+  iso->GetHeapSpaceStatistics(&hs, index);
+  return IsolateHeapSpaceStatistics{
+      hs.space_name(), hs.space_size(), hs.space_used_size(),
+      hs.space_available_size(), hs.physical_space_size()};
+}
+
 IsolateHStatistics IsolationGetHeapStatistics(IsolatePtr iso) {
   if (iso == nullptr) {
     return IsolateHStatistics{0};

v8go.h

@@ -129,6 +129,14 @@ typedef struct {
   size_t number_of_detached_contexts;
 } IsolateHStatistics;
 
+typedef struct {
+  const char* space_name;
+  size_t space_size;
+  size_t space_used_size;
+  size_t space_available_size;
+  size_t physical_space_size;
+} IsolateHeapSpaceStatistics;
+
 typedef struct {
   const uint64_t* word_array;
   int word_count;
@@ -142,6 +150,9 @@ extern void IsolateDispose(IsolatePtr ptr);
 extern void IsolateTerminateExecution(IsolatePtr ptr);
 extern int IsolateIsExecutionTerminating(IsolatePtr ptr);
 extern IsolateHStatistics IsolationGetHeapStatistics(IsolatePtr ptr);
+extern size_t NumberOfHeapSpaces(IsolatePtr ptr);
+extern IsolateHeapSpaceStatistics IsolateGetHeapSpaceStatistics(IsolatePtr ptr,
+                                                                size_t index);
 
 extern ValuePtr IsolateThrowException(IsolatePtr iso, ValuePtr value);