Adding V8 api to get memory statistics of spaces in V8::Heap.

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 12 matching lines @@
 #include "src/code-stubs.h"
 #include "src/compiler.h"
 #include "src/contexts.h"
 #include "src/conversions-inl.h"
 #include "src/counters.h"
 #include "src/cpu-profiler.h"
 #include "src/debug.h"
 #include "src/deoptimizer.h"
 #include "src/execution.h"
 #include "src/global-handles.h"
+#include "src/heap/spaces.h"
 #include "src/heap-profiler.h"
 #include "src/heap-snapshot-generator-inl.h"
 #include "src/icu_util.h"
 #include "src/json-parser.h"
 #include "src/messages.h"
 #include "src/parser.h"
 #include "src/pending-compilation-error-handler.h"
 #include "src/profile-generator-inl.h"
 #include "src/property.h"
 #include "src/property-details.h"
@@ skipping 6907 matching lines @@
     : isolate_(reinterpret_cast<i::Isolate*>(isolate)) {
   isolate_->handle_scope_implementer()->IncrementCallDepth();
 }
 
 
 Isolate::SuppressMicrotaskExecutionScope::~SuppressMicrotaskExecutionScope() {
   isolate_->handle_scope_implementer()->DecrementCallDepth();
 }
 
 
+class HeapStatisticsHelper {

[rmcilroy, 2015/04/13 12:48:23]

I don't think we should have a seperate class just for this, and in any case it
probably shouldn't be in api.cc. Could you move the filling-in of these stats to
heap.cc (I'm not sure about how the public / internal dependencies would look
though)?

+ public:
+  static void ExtractHeapStatistics(HeapStatistics* heap_statistics,
+                                    i::Heap* heap) {
+    heap_statistics->total_heap_size_ = heap->CommittedMemory();
+    heap_statistics->total_heap_size_executable_ =
+        heap->CommittedMemoryExecutable();
+    heap_statistics->total_physical_size_ = heap->CommittedPhysicalMemory();
+    heap_statistics->used_heap_size_ = heap->SizeOfObjects();
+    heap_statistics->heap_size_limit_ = heap->MaxReserved();
+
+    heap_statistics->new_space_statistics()->size_of_objects_ =
+        heap->new_space()->Size();
+    heap_statistics->new_space_statistics()->available_memory_ =
+        heap->new_space()->Available();
+    heap_statistics->new_space_statistics()->committed_memory_ =
+        heap->new_space()->CommittedMemory();
+
+    heap_statistics->lo_space_statistics()->size_of_objects_ =
+        heap->lo_space()->SizeOfObjects();
+    heap_statistics->lo_space_statistics()->available_memory_ =
+        heap->lo_space()->Available();
+    heap_statistics->lo_space_statistics()->committed_memory_ =
+        heap->lo_space()->CommittedMemory();
+
+    ExtractSpaceStatisticsFromPagedSpace(
+        heap->old_space(), heap_statistics->old_space_statistics());
+    ExtractSpaceStatisticsFromPagedSpace(
+        heap->code_space(), heap_statistics->code_space_statistics());
+    ExtractSpaceStatisticsFromPagedSpace(
+        heap->map_space(), heap_statistics->map_space_statistics());
+    ExtractSpaceStatisticsFromPagedSpace(
+        heap->cell_space(), heap_statistics->cell_space_statistics());
+  }
+
+  static void ExtractSpaceStatisticsFromPagedSpace(
+      i::PagedSpace* paged_space,
+      HeapStatistics::SpaceStatistics* space_stats) {
+    space_stats->size_of_objects_ = paged_space->SizeOfObjects();
+    space_stats->committed_memory_ = paged_space->CommittedMemory();
+    space_stats->available_memory_ = paged_space->Available();
+  }
+};
+
+
 void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   i::Heap* heap = isolate->heap();
-  heap_statistics->total_heap_size_ = heap->CommittedMemory();
-  heap_statistics->total_heap_size_executable_ =
-      heap->CommittedMemoryExecutable();
-  heap_statistics->total_physical_size_ = heap->CommittedPhysicalMemory();
-  heap_statistics->used_heap_size_ = heap->SizeOfObjects();
-  heap_statistics->heap_size_limit_ = heap->MaxReserved();
+  HeapStatisticsHelper::ExtractHeapStatistics(heap_statistics, heap);
 }
 
 
 void Isolate::GetStackSample(const RegisterState& state, void** frames,
                              size_t frames_limit, SampleInfo* sample_info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   i::TickSample::GetStackSample(isolate, state, i::TickSample::kSkipCEntryFrame,
                                 frames, frames_limit, sample_info);
 }
 
@@ skipping 1100 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal