stringpool.hxx

C++ 编写的EROS RTOS

#ifndef __STRINGPOOL_HXX__
#define __STRINGPOOL_HXX__
/*
 * Copyright (C) 1998, 1999, Jonathan S. Shapiro.
 *
 * This file is part of the EROS Operating System.
 *
 * 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,
 * or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

class InternedString;

/* A StringPool manages a dense collection of unique strings */

class StringPool {
  char *pool;
  int poolsz;
  int poolLimit;
  
  struct PoolEntry {
    uint32_t signature;
    int offset;			/* into pool buffer */
    PoolEntry *pNext;
  };
  
  enum {
    nPockets = 256,
  };
  
  PoolEntry *poolTable[nPockets];

  int Lookup(const InternedString& is);
  void reinit();
public:
  StringPool();
  ~StringPool();
  
  int Add(const InternedString&);
  InternedString Get(int offset) const;

  int Size() const
  { return poolsz; }

  const char *GetPoolBuffer() const
  { return pool; }

  int WriteToFile(int fd);	/* returns number of bytes written */
  bool ReadFromFile(int fd, int len);
};

#endif /* __STRINGPOOL_HXX__ */