//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
// $NoKeywords: $
//=============================================================================//

#ifndef STRINGPOOL_H
#define STRINGPOOL_H

#if defined(_WIN32)
#pragma once
#endif

#include "utlrbtree.h"
#include "utlvector.h"

//-----------------------------------------------------------------------------
// Purpose: Allocates memory for strings, checking for duplicates first,
//			reusing exising strings if duplicate found.
//-----------------------------------------------------------------------------

class CStringPool {
   public:
    CStringPool();
    ~CStringPool();

    unsigned int Count() const;

    const char* Allocate(const char* pszValue);
    void FreeAll();

    // searches for a string already in the pool
    const char* Find(const char* pszValue);

   protected:
    typedef CUtlRBTree<const char*, unsigned short> CStrSet;

    CStrSet m_Strings;
};

//-----------------------------------------------------------------------------
// Purpose: A reference counted string pool.
//
// Elements are stored more efficiently than in the conventional string pool,
// quicker to look up, and storage is tracked via reference counts.
//
// At some point this should replace CStringPool
//-----------------------------------------------------------------------------
class CCountedStringPool {
   public:  // HACK, hash_item_t structure should not be public.
    struct hash_item_t {
        char* pString;
        unsigned short nNextElement;
        unsigned char nReferenceCount;
        unsigned char pad;
    };

    enum { INVALID_ELEMENT = 0, MAX_REFERENCE = 0xFF, HASH_TABLE_SIZE = 1024 };

    CUtlVector<unsigned short> m_HashTable;  // Points to each element
    CUtlVector<hash_item_t> m_Elements;
    unsigned short m_FreeListStart;

   public:
    CCountedStringPool();
    virtual ~CCountedStringPool();

    void FreeAll();

    char* FindString(const char* pIntrinsic);
    char* ReferenceString(const char* pIntrinsic);
    void DereferenceString(const char* pIntrinsic);

    // These are only reliable if there are less than 64k strings in your string
    // pool
    unsigned short FindStringHandle(const char* pIntrinsic);
    unsigned short ReferenceStringHandle(const char* pIntrinsic);
    char* HandleToString(unsigned short handle);
    void SpewStrings();
};

#endif  // STRINGPOOL_H