[heap] Separate ObjectStats out into its own class.

src/heap/object-stats.h

+// Copyright 2015 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.
+
+#ifndef V8_HEAP_OBJECT_STATS_H_
+#define V8_HEAP_OBJECT_STATS_H_
+
+#include "src/heap/heap.h"
+#include "src/objects.h"
+
+namespace v8 {
+namespace internal {
+
+class ObjectStats {
+ public:
+  explicit ObjectStats(Heap* heap) : heap_(heap) {}
+
+  // ObjectStats are kept in two arrays, counts and sizes. Related stats are
+  // stored in a contiguous linear buffer. Stats groups are stored one after
+  // another.
+  enum {
+    FIRST_CODE_KIND_SUB_TYPE = LAST_TYPE + 1,
+    FIRST_FIXED_ARRAY_SUB_TYPE =
+        FIRST_CODE_KIND_SUB_TYPE + Code::NUMBER_OF_KINDS,
+    FIRST_CODE_AGE_SUB_TYPE =
+        FIRST_FIXED_ARRAY_SUB_TYPE + LAST_FIXED_ARRAY_SUB_TYPE + 1,
+    OBJECT_STATS_COUNT = FIRST_CODE_AGE_SUB_TYPE + Code::kCodeAgeCount + 1
+  };
+
+  void ClearObjectStats(bool clear_last_time_stats = false);
+
+  void TraceObjectStats();
+  void TraceObjectStat(const char* name, int count, int size, double time);
+  void CheckpointObjectStats();
+
+  void RecordObjectStats(InstanceType type, size_t size) {
+    DCHECK(type <= LAST_TYPE);
+    object_counts_[type]++;
+    object_sizes_[type] += size;
+  }
+
+  void RecordCodeSubTypeStats(int code_sub_type, int code_age, size_t size) {
+    int code_sub_type_index = FIRST_CODE_KIND_SUB_TYPE + code_sub_type;
+    int code_age_index =
+        FIRST_CODE_AGE_SUB_TYPE + code_age - Code::kFirstCodeAge;
+    DCHECK(code_sub_type_index >= FIRST_CODE_KIND_SUB_TYPE &&
+           code_sub_type_index < FIRST_CODE_AGE_SUB_TYPE);
+    DCHECK(code_age_index >= FIRST_CODE_AGE_SUB_TYPE &&
+           code_age_index < OBJECT_STATS_COUNT);
+    object_counts_[code_sub_type_index]++;
+    object_sizes_[code_sub_type_index] += size;
+    object_counts_[code_age_index]++;
+    object_sizes_[code_age_index] += size;
+  }
+
+  void RecordFixedArraySubTypeStats(int array_sub_type, size_t size) {
+    DCHECK(array_sub_type <= LAST_FIXED_ARRAY_SUB_TYPE);
+    object_counts_[FIRST_FIXED_ARRAY_SUB_TYPE + array_sub_type]++;
+    object_sizes_[FIRST_FIXED_ARRAY_SUB_TYPE + array_sub_type] += size;
+  }
+
+  size_t object_count_last_gc(size_t index) {
+    return object_counts_last_time_[index];
+  }
+
+  size_t object_size_last_gc(size_t index) {
+    return object_sizes_last_time_[index];
+  }
+
+  Isolate* isolate();
+  Heap* heap() { return heap_; }
+
+ private:
+  Heap* heap_;
+
+  // Object counts and used memory by InstanceType
+  size_t object_counts_[OBJECT_STATS_COUNT];
+  size_t object_counts_last_time_[OBJECT_STATS_COUNT];
+  size_t object_sizes_[OBJECT_STATS_COUNT];
+  size_t object_sizes_last_time_[OBJECT_STATS_COUNT];
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_HEAP_OBJECT_STATS_H_