/*

 * Copyright (C) 2012 David Anderson

 *

 * This file is part of JITCraft.

 *

 * JITCraft 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 3 of the License, or (at your option)

 * any later version.

 * 

 * Foobar 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

 * JITCraft. If not, see http://www.gnu.org/licenses/.

 */

#ifndef _include_jitcraft_string_pool_h_

#define _include_jitcraft_string_pool_h_

#include <string.h>

#include "AllocatorPolicies.h"

#include "HashTable.h"

#include "Strings.h"

namespace ke {

class Zone;

class String;

// Guarantee that strings with the same contents will map to one pointer. 

class StringPool

{

    class CharsAndLength {

        const char *str_;

        size_t length_;

      public:

        CharsAndLength(const char *str, size_t length)

          : str_(str),

            length_(length)

        {

        }

        const char *str() const {

            return str_;

        }

        size_t length() const {

            return length_;

        }

    };

    struct Policy

    {

        typedef String * Payload;

        static uint32 hash(const CharsAndLength &key) {

            return HashCharSequence(key.str(), key.length());

        }

        static bool matches(const CharsAndLength &key, String *string) {

            if (string->length() != key.length())

                return false;

            return memcmp(string->chars(), key.str(), key.length() * sizeof(char)) == 0;

        }

    };

    typedef HashTable<Policy, ZoneAllocatorPolicy> StringSet;

  public:

    StringPool(Zone *zone);

    ~StringPool();

    bool initialize();

  public:

    String *add(const char *str, size_t len);

    void sweep();

  private:

    Zone *zone_;

    StringSet set_;

};

}

#endif // _include_jitcraft_string_pool_h_