buffer_manager.h

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#ifndef BUFFER_MANAGER_CLASS
#define BUFFER_MANAGER_CLASS

/*****************************************************************************\
*                                                                             *
*  Name   : buffer_manager                                                    *
*  Author : Chris Koeritz                                                     *
*                                                                             *
*******************************************************************************
* Copyright (c) 1992-$now By Author.  This program is free software; you can  *
* redistribute it and/or modify it under the terms of the GNU General Public  *
* License as published by the Free Software Foundation; either version 2 of   *
* the License or (at your option) any later version.  This is online at:      *
*     http://www.fsf.org/copyleft/gpl.html                                    *
* Please send any updates to: fred@gruntose.com                               *
\*****************************************************************************/

#include "buffer_base.h"

// forward.
class internal_buffer_list;
class memory_limiter;


class BUFFERS_CLASS_STYLE buffer_manager
{
public:
  buffer_manager(int total_memory, int connection_memory);

  virtual ~buffer_manager();

  IMPLEMENT_CLASS_NAME("buffer_manager");

  int buffers() const;

  int total_memory_allowed() const;
  int total_allocated() const;
  inline int space_left() const
          { return total_memory_allowed() - total_allocated(); }

  outcome add_buffer(buffer_base *to_add);

  outcome extract(buffer_key &key, byte_array &to_fill,
        byte_array &attachment, int offset = 0, bool remove_buffer = true);

  buffer_base *disengage(buffer_key &key);

  void show_buffers(istring &dump, int indentation = 0);

  buffer_base *lock_buffer(int &start, const buffer_key &key);

  void unlock_buffer(buffer_base *to_unlock);

  bool zap(buffer_id to_whack);

  bool zap_match(int &start, const buffer_key &key);

  bool zap_all_matches(const buffer_key &key);

  void zap_all();

  enum kind_to_find { EITHER, WHOLE, NON_WHOLE };
  bool zap_expired(istring &text_form, buffer_key &dead_key, int &start,
          int age, kind_to_find which);

private:
  mutex *_buffer_lock;  
  internal_buffer_list *_buffer_list;  
  memory_limiter *_space_minder;  

  buffer_base *locked_locate(int &start, const buffer_key &key);

  int locked_find(int &start, const buffer_key &key);

  bool okay_addition(buffer_base &to_check);
  void record_subtraction(buffer_base &check_out);
  void find_space();
};

#endif

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