refhashtableof.c

经典开源游戏glest的源代码

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * $Id: RefHashTableOf.c 568078 2007-08-21 11:43:25Z amassari $
 */


// ---------------------------------------------------------------------------
//  Include
// ---------------------------------------------------------------------------
#if defined(XERCES_TMPLSINC)
#include <xercesc/util/RefHashTableOf.hpp>
#endif

#include <xercesc/util/Janitor.hpp>
#include <xercesc/util/NullPointerException.hpp>
#include <assert.h>
#include <new>

XERCES_CPP_NAMESPACE_BEGIN

// ---------------------------------------------------------------------------
//  RefHashTableOf: Constructors and Destructor
// ---------------------------------------------------------------------------
template <class TVal>
RefHashTableOf<TVal>::RefHashTableOf( const unsigned int modulus
                                    , const bool adoptElems
                                    , MemoryManager* const manager)

    : fMemoryManager(manager)
    , fAdoptedElems(adoptElems)
    , fBucketList(0)
    , fHashModulus(modulus)
    , fInitialModulus(modulus)
    , fCount(0)
    , fHash(0)

{
    initialize(modulus);
	
	// create default hasher
	fHash = new (fMemoryManager) HashXMLCh();
}

template <class TVal>
RefHashTableOf<TVal>::RefHashTableOf( const unsigned int modulus
                                    , const bool adoptElems
                                    , HashBase* hashBase
                                    , MemoryManager* const manager)

    : fMemoryManager(manager)
    , fAdoptedElems(adoptElems)
    , fBucketList(0)
    , fHashModulus(modulus)
    , fInitialModulus(modulus)
    , fCount(0)
    , fHash(0)
{
    initialize(modulus);
    // set hasher
    fHash = hashBase;
}

template <class TVal>
RefHashTableOf<TVal>::RefHashTableOf(const unsigned int modulus
                                     , MemoryManager* const manager)

    : fMemoryManager(manager)
    , fAdoptedElems(true)
    , fBucketList(0)
    , fHashModulus(modulus)
    , fInitialModulus(modulus)
    , fCount(0)
    , fHash(0)
{
    initialize(modulus);

    // create default hasher
    fHash = new (fMemoryManager) HashXMLCh();
}

template <class TVal> void RefHashTableOf<TVal>::initialize(const unsigned int modulus)
{
    if (modulus == 0)
        ThrowXMLwithMemMgr(IllegalArgumentException, XMLExcepts::HshTbl_ZeroModulus, fMemoryManager);

    // Allocate the bucket list and zero them
    fBucketList = (RefHashTableBucketElem<TVal>**) fMemoryManager->allocate
    (
        fHashModulus * sizeof(RefHashTableBucketElem<TVal>*)
    ); //new RefHashTableBucketElem<TVal>*[fHashModulus];
    for (unsigned int index = 0; index < fHashModulus; index++)
        fBucketList[index] = 0;
}

template <class TVal> RefHashTableOf<TVal>::~RefHashTableOf()
{
    cleanup();
}


// ---------------------------------------------------------------------------
//  RefHashTableOf: Element management
// ---------------------------------------------------------------------------
template <class TVal> bool RefHashTableOf<TVal>::isEmpty() const
{
    return fCount==0;
}

template <class TVal> bool RefHashTableOf<TVal>::
containsKey(const void* const key) const
{
    unsigned int hashVal;
    const RefHashTableBucketElem<TVal>* findIt = findBucketElem(key, hashVal);
    return (findIt != 0);
}

template <class TVal> void RefHashTableOf<TVal>::
removeKey(const void* const key)
{
    // Hash the key
    unsigned int hashVal = fHash->getHashVal(key, fHashModulus, fMemoryManager);
    assert(hashVal < fHashModulus);

    //
    //  Search the given bucket for this key. Keep up with the previous
    //  element so we can patch around it.
    //
    RefHashTableBucketElem<TVal>* curElem = fBucketList[hashVal];
    RefHashTableBucketElem<TVal>* lastElem = 0;

    while (curElem)
    {
        if (fHash->equals(key, curElem->fKey))
        {
            if (!lastElem)
            {
                // It was the first in the bucket
                fBucketList[hashVal] = curElem->fNext;
            }
             else
            {
                // Patch around the current element
                lastElem->fNext = curElem->fNext;
            }

            // If we adopted the data, then delete it too
            //    (Note:  the userdata hash table instance has data type of void *.
            //    This will generate compiler warnings here on some platforms, but they
            //    can be ignored since fAdoptedElements is false.
            if (fAdoptedElems)
                delete curElem->fData;

            // Then delete the current element and move forward
 	        // delete curElem;
            // destructor doesn't do anything...
			// curElem->~RefHashTableBucketElem();
            fMemoryManager->deallocate(curElem);            

            fCount--;

            return;
        }

        // Move both pointers upwards
        lastElem = curElem;
        curElem = curElem->fNext;
    }

    // We never found that key
    ThrowXMLwithMemMgr(NoSuchElementException, XMLExcepts::HshTbl_NoSuchKeyExists, fMemoryManager);
}

template <class TVal> void RefHashTableOf<TVal>::removeAll()
{
    if(isEmpty())
        return;

    // Clean up the buckets first
    for (unsigned int buckInd = 0; buckInd < fHashModulus; buckInd++)
    {
        // Get the bucket list head for this entry
        RefHashTableBucketElem<TVal>* curElem = fBucketList[buckInd];
        RefHashTableBucketElem<TVal>* nextElem;
        while (curElem)
        {
            // Save the next element before we hose this one
            nextElem = curElem->fNext;

            // If we adopted the data, then delete it too
            //    (Note:  the userdata hash table instance has data type of void *.
            //    This will generate compiler warnings here on some platforms, but they
            //    can be ignored since fAdoptedElements is false.
            if (fAdoptedElems)
                delete curElem->fData;

            // Then delete the current element and move forward
 	        // delete curElem;
            // destructor doesn't do anything...
			// curElem->~RefHashTableBucketElem();
            fMemoryManager->deallocate(curElem);            
            curElem = nextElem;
        }

        // Clean out this entry
        fBucketList[buckInd] = 0;
    }

    fCount = 0;
}

// This method returns the data associated with a key. The key entry is deleted. The caller
// now owns the returned data (case of hashtable adopting the data).
// This function is called by transferElement so that the undeleted data can be transferred
// to a new key which will own that data.
template <class TVal> TVal* RefHashTableOf<TVal>::
orphanKey(const void* const key)
{
    // Hash the key
    TVal* retVal = 0;
    unsigned int hashVal = fHash->getHashVal(key, fHashModulus, fMemoryManager);
    assert(hashVal < fHashModulus);

    //
    //  Search the given bucket for this key. Keep up with the previous
    //  element so we can patch around it.
    //
    RefHashTableBucketElem<TVal>* curElem = fBucketList[hashVal];
    RefHashTableBucketElem<TVal>* lastElem = 0;

    while (curElem)
    {
        if (fHash->equals(key, curElem->fKey))
        {
            if (!lastElem)
            {
                // It was the first in the bucket
                fBucketList[hashVal] = curElem->fNext;
            }
            else
            {
                // Patch around the current element
                lastElem->fNext = curElem->fNext;
            }

            retVal = curElem->fData;

            // Delete the current element
            // delete curElem;
            // destructor doesn't do anything...
			// curElem->~RefHashTableBucketElem();
            fMemoryManager->deallocate(curElem);            
            break;
        }

        // Move both pointers upwards
        lastElem = curElem;
        curElem = curElem->fNext;
    }

    // We never found that key
    if (!retVal)
        ThrowXMLwithMemMgr(NoSuchElementException, XMLExcepts::HshTbl_NoSuchKeyExists, fMemoryManager);

    return retVal;
}

//
// cleanup():
//   similar to destructor
//   called to cleanup the memory, in case destructor cannot be called
//
template <class TVal> void RefHashTableOf<TVal>::cleanup()
{
    removeAll();

    // Then delete the bucket list & hasher
    fMemoryManager->deallocate(fBucketList); //delete [] fBucketList;
    fBucketList = 0;
    delete fHash;
}

//
// reinitialize():
//   similar to constructor
//   called to re-construct the fElemList from scratch again
//
template <class TVal> void RefHashTableOf<TVal>::reinitialize(HashBase* hashBase)
{
    if (fBucketList || fHash)
        cleanup();

    fHashModulus = fInitialModulus;
    initialize(fHashModulus);

    if (hashBase)
        fHash = hashBase;
    else
        fHash = new (fMemoryManager) HashXMLCh();   // create default hasher
}



// this function transfer the data from key1 to key2
// this is equivalent to calling
//  1.  get(key1) to retrieve the data,
//  2.  removeKey(key1),
//  3.  and then put(key2, data)
// except that the data is not deleted in "removeKey" even it is adopted so that it
// can be transferred to key2.