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 5445 matching lines @@
 }
 
 
 HeapStatistics::HeapStatistics(): total_heap_size_(0),
                                   total_heap_size_executable_(0),
                                   total_physical_size_(0),
                                   used_heap_size_(0),
                                   heap_size_limit_(0) { }
 
 
+HeapSpaceStatistics::HeapSpaceStatistics(): space_name_(0),
+                                            space_size_(0),
+                                            space_used_size_(0),
+                                            space_avalable_size_(0),
+                                            physical_space_size_(0) { }
+
+
 bool v8::V8::InitializeICU(const char* icu_data_file) {
   return i::InitializeICU(icu_data_file);
 }
 
 
 const char* v8::V8::GetVersion() {
   return i::Version::GetVersion();
 }
 
 
@@ skipping 1517 matching lines @@
   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();
 }
 
 
+int Isolate::NumberOfHeapSpaces() {
+  return i::LAST_SPACE - i::FIRST_SPACE + 1;
+}
+
+
+bool Isolate::GetHeapSpaceStatistics(HeapSpaceStatistics* space_statistics,
+                                     int index) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  i::Heap* heap = isolate->heap();
+  if (index > i::LAST_SPACE || index < i::FIRST_SPACE || !space_statistics)

[rmcilroy, 2015/04/16 13:49:05]

nit - move the '!space_statistics' check out to a seperate if block (just for
code clarity).

[ssid, 2015/04/16 16:40:29]

Done.

+    return false;
+
+  space_statistics->space_name_ = heap->GetSpaceName(index);
+  space_statistics->space_size_ = heap->space(index)->CommittedMemory();

[rmcilroy, 2015/04/16 13:49:05]

nit - factor out:
 Space space = heap->space(index);
and use the 'space' local variable for these lookups to avoid having to call
space(index) multiple times.

[ssid, 2015/04/16 16:40:29]

Done.

+  space_statistics->space_used_size_ = heap->space(index)->Size();
+  space_statistics->space_avalable_size_ = heap->space(index)->Available();
+  space_statistics->physical_space_size_ =
+      heap->space(index)->CommittedPhysicalMemory();
+  return true;
+}
+
+
 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);
 }
 
 
 void Isolate::SetEventLogger(LogEventCallback that) {
   // Do not overwrite the event logger if we want to log explicitly.
@@ skipping 1097 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