sqlitemem.h

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#ifndef CVMFS_SQLITEMEM_H_
#define CVMFS_SQLITEMEM_H_

#include <inttypes.h>
#include <pthread.h>
#include <stdint.h>

#include <cassert>
#include <cstdlib>
#include <vector>

#include "duplex_sqlite3.h"
#include "gtest/gtest_prod.h"

class MallocArena;


class SqliteMemoryManager {
  FRIEND_TEST(T_Sqlitemem, LookasideBuffer);
  FRIEND_TEST(T_Sqlitemem, Malloc);
  FRIEND_TEST(T_Sqlitemem, Realloc);
  FRIEND_TEST(T_Sqlitemem, ReallocStress);

 public:
  static const unsigned kScratchSlotSize = 8192;
  static const unsigned kScratchNoSlots = 8;
  static const unsigned kScratchSize = kScratchSlotSize * kScratchNoSlots;

  static const unsigned kPageCacheSlotSize = 1300;
  static const unsigned kPageCacheNoSlots = 4000;
  static const unsigned kPageCacheSize = kPageCacheSlotSize * kPageCacheNoSlots;

  static const unsigned kLookasideSlotSize = 32;
  static const unsigned kLookasideSlotsPerDb = 128;


  class LookasideBufferArena {
   public:
    static const unsigned kBufferSize =
      kLookasideSlotSize * kLookasideSlotsPerDb;

    static const unsigned kBuffersPerArena = 128;
    static const unsigned kArenaSize = kBuffersPerArena * kBufferSize;
    static const unsigned kNoBitmaps = kBuffersPerArena / (sizeof(int) * 8);

    LookasideBufferArena();
    ~LookasideBufferArena();

    void *GetBuffer();
    void PutBuffer(void *buffer);
    bool IsEmpty();
    bool Contains(void *buffer);

   private:
    void *arena_;

    int freemap_[kNoBitmaps];
  };


  static SqliteMemoryManager *GetInstance() {
    if (instance_ == NULL)
      instance_ = new SqliteMemoryManager();
    return instance_;
  }
  static void CleanupInstance();
  static bool HasInstance() { return instance_ != NULL; }
  ~SqliteMemoryManager();

  void AssignGlobalArenas();
  void *AssignLookasideBuffer(sqlite3 *db);
  void ReleaseLookasideBuffer(void *buffer);

 private:
  static const unsigned kArenaSize = 8 * 1024 * 1024;
  static SqliteMemoryManager *instance_;

  static void *xMalloc(int size);
  static void xFree(void *ptr);
  static void *xRealloc(void *ptr, int new_size);
  static int xSize(void *ptr);
  static int xRoundup(int size);
  static int xInit(void *app_data);
  static void xShutdown(void *app_data);


  SqliteMemoryManager();

  void *GetLookasideBuffer();
  void PutLookasideBuffer(void *buffer);

  void *GetMemory(int size);
  void PutMemory(void *ptr);
  int GetMemorySize(void *ptr);

  pthread_mutex_t lock_;

  bool assigned_;

  struct sqlite3_mem_methods sqlite3_mem_vanilla_;

  struct sqlite3_mem_methods mem_methods_;
  void *page_cache_memory_;
  std::vector<LookasideBufferArena *> lookaside_buffer_arenas_;
  std::vector<MallocArena *> malloc_arenas_;
  unsigned idx_last_arena_;
};  // class SqliteMemoryManager

#endif  // CVMFS_SQLITEMEM_H_