//  Microsoft Windows
//  Copyright (C) Microsoft Corporation, 1992 - 1994.

//  File:       strhash.hxx

//  Contents:   A hash table for strings

//  History:    7-Nov-94    BruceFo Created



#ifndef __STRHASH_HXX__
#define __STRHASH_HXX__


#define HASH_DEFAULT_NUM_BUCKETS    47


// Forward definitions

class CStrHashBucketElem;
class CStrHashBucket;
class CStrHashTable;


// Class definitions

#define ITERATE_END ((DWORD)-1)

class CIterateData
{
    friend class CStrHashTable;

public:
    CIterateData(
        VOID
        )
        :
        m_pCurrentElem(NULL),
        m_CurrentBucket(0)
    {
    }

private:
    CStrHashBucketElem* m_pCurrentElem;
    DWORD               m_CurrentBucket;
};



class CStrHashBucketElem
{
    DECLARE_SIG;

    friend class CStrHashBucket;
    friend class CStrHashTable;

public:

    CStrHashBucketElem(
        IN const WCHAR* pszKey
        );

    ~CStrHashBucketElem();

    BOOL
    IsEqual(
        IN const WCHAR* pszKey
        );

#if DBG == 1
    VOID Print()
    {
        appAssert(NULL != m_pszKey);
        appDebugOut((DEB_TRACE,"%ws\n", m_pszKey));
    }
#endif DBG == 1

private:

    CStrHashBucketElem* m_next;
    const WCHAR*        m_pszKey;
};



class CStrHashBucket
{
    DECLARE_SIG;

    friend class CStrHashTable;

public:

    CStrHashBucket(VOID);

    ~CStrHashBucket();

    HRESULT Insert(IN const WCHAR* pszKey);
    BOOL     Remove(IN const WCHAR* pszKey);
    BOOL IsMember(IN const WCHAR* pszKey);

#if DBG == 1
    VOID Print()
    {
        for (CStrHashBucketElem* x = m_head; NULL != x; x = x->m_next)
        {
            x->Print();
        }
    }
#endif DBG == 1

private:
    CStrHashBucketElem* m_head;
};



class CStrHashTable
{
    DECLARE_SIG;

public:
    CStrHashTable(IN DWORD cNumBuckets = HASH_DEFAULT_NUM_BUCKETS);

    // Returns the status of the object after construction: S_OK or an error
    // code.
    HRESULT QueryError(VOID);

    ~CStrHashTable();

    // Three basic operations: insert, remove, and check membership. The
    // strings may not be NULL.

    HRESULT     Insert(IN const WCHAR* pszKey);
    HRESULT     Remove(IN const WCHAR* pszKey);
    BOOL IsMember(IN const WCHAR* pszKey);
    DWORD Count(VOID);

    // Iteration routines

    CIterateData* IterateStart(VOID);
    VOID IterateGetNext(IN OUT CIterateData* pCurrent);
    VOID IterateEnd(IN CIterateData* pCurrent);
    BOOL     IterateDone(IN CIterateData* pCurrent);
    const WCHAR* IterateGetData(IN OUT CIterateData* pCurrent);

#if DBG == 1
    VOID Print()
    {
        appAssert(NULL != m_ht);

        for (DWORD i = 0; i < m_cNumBuckets; i++)
        {
            appDebugOut((DEB_TRACE,"======== bucket %d\n",i));
            m_ht[i].Print();
        }
    }
#endif DBG == 1

private:

    VOID IterateGetBucket(IN OUT CIterateData* pCurrent);
    DWORD     HashFunction(IN const WCHAR* pszKey);
    HRESULT CheckRehash(VOID);
    HRESULT Rehash(IN DWORD cNumBuckets);

    CStrHashBucket*     m_ht;
    DWORD               m_cMinNumBuckets;
    DWORD               m_cNumBuckets;
    DWORD               m_cElems;
};

#endif // __STRHASH_HXX__