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1// Copyright 2021 the V8 project authors. All rights reserved.2// Use of this source code is governed by a BSD-style license that can be3// found in the LICENSE file.4 5#ifndef INCLUDE_CPPGC_HEAP_STATISTICS_H_6#define INCLUDE_CPPGC_HEAP_STATISTICS_H_7 8#include <cstddef>9#include <cstdint>10#include <string>11#include <vector>12 13namespace cppgc {14 15/**16 * `HeapStatistics` contains memory consumption and utilization statistics for a17 * cppgc heap.18 */19struct HeapStatistics final {20  /**21   * Specifies the detail level of the heap statistics. Brief statistics contain22   * only the top-level allocated and used memory statistics for the entire23   * heap. Detailed statistics also contain a break down per space and page, as24   * well as freelist statistics and object type histograms. Note that used25   * memory reported by brief statistics and detailed statistics might differ26   * slightly.27   */28  enum DetailLevel : uint8_t {29    kBrief,30    kDetailed,31  };32 33  /**34   * Object statistics for a single type.35   */36  struct ObjectStatsEntry {37    /**38     * Number of allocated bytes.39     */40    size_t allocated_bytes;41    /**42     * Number of allocated objects.43     */44    size_t object_count;45  };46 47  /**48   * Page granularity statistics. For each page the statistics record the49   * allocated memory size and overall used memory size for the page.50   */51  struct PageStatistics {52    /** Overall committed amount of memory for the page. */53    size_t committed_size_bytes = 0;54    /** Resident amount of memory held by the page. */55    size_t resident_size_bytes = 0;56    /** Amount of memory actually used on the page. */57    size_t used_size_bytes = 0;58    /** Statistics for object allocated on the page. Filled only when59     * NameProvider::SupportsCppClassNamesAsObjectNames() is true. */60    std::vector<ObjectStatsEntry> object_statistics;61  };62 63  /**64   * Statistics of the freelist (used only in non-large object spaces). For65   * each bucket in the freelist the statistics record the bucket size, the66   * number of freelist entries in the bucket, and the overall allocated memory67   * consumed by these freelist entries.68   */69  struct FreeListStatistics {70    /** bucket sizes in the freelist. */71    std::vector<size_t> bucket_size;72    /** number of freelist entries per bucket. */73    std::vector<size_t> free_count;74    /** memory size consumed by freelist entries per size. */75    std::vector<size_t> free_size;76  };77 78  /**79   * Space granularity statistics. For each space the statistics record the80   * space name, the amount of allocated memory and overall used memory for the81   * space. The statistics also contain statistics for each of the space's82   * pages, its freelist and the objects allocated on the space.83   */84  struct SpaceStatistics {85    /** The space name */86    std::string name;87    /** Overall committed amount of memory for the heap. */88    size_t committed_size_bytes = 0;89    /** Resident amount of memory held by the heap. */90    size_t resident_size_bytes = 0;91    /** Amount of memory actually used on the space. */92    size_t used_size_bytes = 0;93    /** Statistics for each of the pages in the space. */94    std::vector<PageStatistics> page_stats;95    /** Statistics for the freelist of the space. */96    FreeListStatistics free_list_stats;97  };98 99  /** Overall committed amount of memory for the heap. */100  size_t committed_size_bytes = 0;101  /** Resident amount of memory held by the heap. */102  size_t resident_size_bytes = 0;103  /** Amount of memory actually used on the heap. */104  size_t used_size_bytes = 0;105  /** Memory retained in the page pool, not used directly by the heap. */106  size_t pooled_memory_size_bytes = 0;107  /** Detail level of this HeapStatistics. */108  DetailLevel detail_level;109 110  /** Statistics for each of the spaces in the heap. Filled only when111   * `detail_level` is `DetailLevel::kDetailed`. */112  std::vector<SpaceStatistics> space_stats;113 114  /**115   * Vector of `cppgc::GarbageCollected` type names.116   */117  std::vector<std::string> type_names;118};119 120}  // namespace cppgc121 122#endif  // INCLUDE_CPPGC_HEAP_STATISTICS_H_123