// 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/extensions/statistics-extension.h"

#include "src/counters.h"
#include "src/heap/heap-inl.h"
#include "src/isolate.h"

namespace v8 {
namespace internal {

const char* const StatisticsExtension::kSource =
    "native function getV8Statistics();";


v8::Local<v8::FunctionTemplate> StatisticsExtension::GetNativeFunctionTemplate(
    v8::Isolate* isolate, v8::Local<v8::String> str) {
  DCHECK_EQ(strcmp(*v8::String::Utf8Value(isolate, str), "getV8Statistics"), 0);
  return v8::FunctionTemplate::New(isolate, StatisticsExtension::GetCounters);
}


static void AddCounter(v8::Isolate* isolate,
                       v8::Local<v8::Object> object,
                       StatsCounter* counter,
                       const char* name) {
  if (counter->Enabled()) {
    object->Set(isolate->GetCurrentContext(),
                v8::String::NewFromUtf8(isolate, name, NewStringType::kNormal)
                    .ToLocalChecked(),
                v8::Number::New(isolate, *counter->GetInternalPointer()))
        .FromJust();
  }
}

static void AddNumber(v8::Isolate* isolate, v8::Local<v8::Object> object,
                      double value, const char* name) {
  object
      ->Set(isolate->GetCurrentContext(),
            v8::String::NewFromUtf8(isolate, name, NewStringType::kNormal)
                .ToLocalChecked(),
            v8::Number::New(isolate, value))
      .FromJust();
}


static void AddNumber64(v8::Isolate* isolate,
                        v8::Local<v8::Object> object,
                        int64_t value,
                        const char* name) {
  object->Set(isolate->GetCurrentContext(),
              v8::String::NewFromUtf8(isolate, name, NewStringType::kNormal)
                  .ToLocalChecked(),
              v8::Number::New(isolate, static_cast<double>(value))).FromJust();
}


void StatisticsExtension::GetCounters(
    const v8::FunctionCallbackInfo<v8::Value>& args) {
  Isolate* isolate = reinterpret_cast<Isolate*>(args.GetIsolate());
  Heap* heap = isolate->heap();

  if (args.Length() > 0) {  // GC if first argument evaluates to true.
    if (args[0]->IsBoolean() &&
        args[0]
            ->BooleanValue(args.GetIsolate()->GetCurrentContext())
            .FromMaybe(false)) {
      heap->CollectAllGarbage(Heap::kNoGCFlags,
                              GarbageCollectionReason::kCountersExtension);
    }
  }

  Counters* counters = isolate->counters();
  v8::Local<v8::Object> result = v8::Object::New(args.GetIsolate());

  struct StatisticsCounter {
    v8::internal::StatsCounter* counter;
    const char* name;
  };
  const StatisticsCounter counter_list[] = {
#define ADD_COUNTER(name, caption) \
  { counters->name(), #name }      \
  ,

      STATS_COUNTER_LIST_1(ADD_COUNTER) STATS_COUNTER_LIST_2(ADD_COUNTER)
#undef ADD_COUNTER
  };  // End counter_list array.

  for (size_t i = 0; i < arraysize(counter_list); i++) {
    AddCounter(args.GetIsolate(), result, counter_list[i].counter,
               counter_list[i].name);
  }

  struct StatisticNumber {
    size_t number;
    const char* name;
  };

  const StatisticNumber numbers[] = {
      {heap->memory_allocator()->Size(), "total_committed_bytes"},
      {heap->new_space()->Size(), "new_space_live_bytes"},
      {heap->new_space()->Available(), "new_space_available_bytes"},
      {heap->new_space()->CommittedMemory(), "new_space_commited_bytes"},
      {heap->old_space()->Size(), "old_space_live_bytes"},
      {heap->old_space()->Available(), "old_space_available_bytes"},
      {heap->old_space()->CommittedMemory(), "old_space_commited_bytes"},
      {heap->code_space()->Size(), "code_space_live_bytes"},
      {heap->code_space()->Available(), "code_space_available_bytes"},
      {heap->code_space()->CommittedMemory(), "code_space_commited_bytes"},
      {heap->lo_space()->Size(), "lo_space_live_bytes"},
      {heap->lo_space()->Available(), "lo_space_available_bytes"},
      {heap->lo_space()->CommittedMemory(), "lo_space_commited_bytes"},
  };

  for (size_t i = 0; i < arraysize(numbers); i++) {
    AddNumber(args.GetIsolate(), result, numbers[i].number, numbers[i].name);
  }

  AddNumber64(args.GetIsolate(), result, heap->external_memory(),
              "amount_of_external_allocated_memory");
  args.GetReturnValue().Set(result);

  HeapIterator iterator(reinterpret_cast<Isolate*>(args.GetIsolate())->heap());
  HeapObject* obj;
  int reloc_info_total = 0;
  int source_position_table_total = 0;
  while ((obj = iterator.next()) != nullptr) {
    if (obj->IsCode()) {
      Code* code = Code::cast(obj);
      reloc_info_total += code->relocation_info()->Size();
      ByteArray* source_position_table = code->SourcePositionTable();
      if (source_position_table->length() > 0) {
        source_position_table_total += code->SourcePositionTable()->Size();
      }
    } else if (obj->IsBytecodeArray()) {
      source_position_table_total +=
          BytecodeArray::cast(obj)->SourcePositionTable()->Size();
    }
  }

  AddNumber(args.GetIsolate(), result, reloc_info_total,
            "reloc_info_total_size");
  AddNumber(args.GetIsolate(), result, source_position_table_total,
            "source_position_table_total_size");
}

}  // namespace internal
}  // namespace v8