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/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001-2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xerces" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache\@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation, and was
* originally based on software copyright (c) 2001, International
* Business Machines, Inc., http://www.ibm.com . For more information
* on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
/*
* $Id$
*/
#include "DOMAttrImpl.hpp"
#include "DOMDocumentImpl.hpp"
#include "DOMNodeIDMap.hpp"
#include <xercesc/util/XMLString.hpp>
#include <xercesc/util/RuntimeException.hpp>
#include <stdio.h>
static const int gPrimes[] = {997, 9973, 99991, 999983, 0 }; // To do - add a few more.
static const float gMaxFill = 0.8f; // The maximum fraction of the total
// table entries to consume before exanding.
DOMNodeIDMap::DOMNodeIDMap(int initialSize, DOMDocument *doc)
{
fDoc = doc;
for (fSizeIndex = 0; gPrimes[fSizeIndex] < initialSize; fSizeIndex++)
{
if (gPrimes[fSizeIndex] == 0)
{
// We need a bigger size than the largest available one.
// Big trouble.
fSizeIndex--;
David Abram Cargill
committed
ThrowXMLwithMemMgr(RuntimeException, XMLExcepts::NodeIDMap_GrowErr, ((DOMDocumentImpl *)fDoc)->getMemoryManager());
}
}
fSize = gPrimes[fSizeIndex];
fNumEntries = 0;
fMaxEntries = (XMLSize_t)(float(fSize) * gMaxFill);
//fTable = new (fDoc) DOMAttr*[fSize];
fTable = (DOMAttr**) ((DOMDocumentImpl *)fDoc)->allocate(sizeof(DOMAttr*) * fSize);
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for (i=0; i<fSize; i++)
fTable[i] = 0;
};
DOMNodeIDMap::~DOMNodeIDMap()
{
// don't delete - the document owns the storage.
fTable = 0;
};
void DOMNodeIDMap::add(DOMAttr *attr)
{
//
// If the table is getting too full, grow it. We arbitrarily limit
// the table to 80 full, which should limit the average number of
// rehashes to a reasonable value.
//
if (fNumEntries >= fMaxEntries)
growTable();
fNumEntries++;
//
// Hash the value string from the ID attribute being added to the table
// 0 < Initial hash value < table size.
// An initial hash of zero would cause the rehash to fail.
//
const XMLCh *id=attr->getValue();
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XMLSize_t initalHash = XMLString::hash(id, fSize-1, ((DOMDocumentImpl *)fDoc)->getMemoryManager());
initalHash++;
XMLSize_t currentHash = initalHash;
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//
// Loop looking for an empty slot for this ID.
// Don't even bother checking to see if the ID is already there -
// the table is only filled by the parser from valid documents, which
// can not have duplicates. Behavior of invalid docs is not defined.
//
while (true)
{
DOMAttr *tableSlot = fTable[currentHash];
if (tableSlot == 0 ||
tableSlot == (DOMAttr *)-1)
break;
currentHash += initalHash; // rehash
if (currentHash >= fSize)
currentHash = currentHash % fSize;
}
//
// We've found our slot. Stick the pointer to the attr into it.
//
fTable[currentHash] = attr;
};
void DOMNodeIDMap::remove(DOMAttr *attr)
{
//
// Hash the value string from the ID attribute being added to the table
// 0 < Initial hash value < table size.
// An initial hash of zero would cause the rehash to fail.
//
const XMLCh *id=attr->getValue();
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XMLSize_t initalHash = XMLString::hash(id, fSize-1, ((DOMDocumentImpl *)fDoc)->getMemoryManager());
initalHash++;
XMLSize_t currentHash = initalHash;
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//
// Loop looking for a slot pointing to an attr with this id.
//
while (true)
{
DOMAttr *tableSlot = fTable[currentHash];
if (tableSlot == 0)
{
// There is no matching entry in the table
return;
}
if (tableSlot == attr)
{
// Found the attribute. Set the slot to -1 to indicate
// that it was once used, meaning that lookups, while never
// matching here, can not stop either, but must rehash again
// and continue searching.
fTable[currentHash] = (DOMAttr *)-1;
return;
}
currentHash += initalHash; // rehash.
if (currentHash >= fSize)
currentHash = currentHash % fSize;
}
};
DOMAttr *DOMNodeIDMap::find(const XMLCh *id)
{
//
// Get the hashcode for the supplied string.
//
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XMLSize_t initalHash = XMLString::hash(id, fSize-1, ((DOMDocumentImpl *)fDoc)->getMemoryManager());
initalHash++;
XMLSize_t currentHash = initalHash;
//
// Loop looking for a slot pointing to an attr with this id.
//
while (true)
{
DOMAttr *tableSlot = fTable[currentHash];
if (tableSlot == 0)
{
// There is no matching entry in the table
return 0;
}
if ((tableSlot != (DOMAttr *)-1) && XMLString::equals(tableSlot->getValue(), id))
return tableSlot;
currentHash += initalHash; // rehash
if (currentHash >= fSize)
currentHash = currentHash % fSize;
}
return 0; // Never gets here, but keeps some compilers happy.
};
//
// Grow the table to the next larger size.
// It has gotten too full for efficient operation.
// (We never fill it all the way)
//
void DOMNodeIDMap::growTable()
{
DOMAttr **oldTable = fTable;
XMLSize_t oldSize = fSize;
//
// Figure the new table size.
//
#if defined(XERCES_DEBUG)
fprintf(stderr, "growing...\n");
#endif
fSizeIndex++;
fSize = gPrimes[fSizeIndex];
if (fSize == 0)
{
// We need to grow bigger than the largest available size.
// Big trouble.
fSizeIndex--;
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ThrowXMLwithMemMgr(RuntimeException, XMLExcepts::NodeIDMap_GrowErr, ((DOMDocumentImpl *)fDoc)->getMemoryManager());
}
//
// Allocate the new table.
//
//fTable = new (fDoc) DOMAttr *[fSize];
fTable = (DOMAttr**) ((DOMDocumentImpl *)fDoc)->allocate(sizeof(DOMAttr*) * fSize);
for (i=0; i<fSize; i++)
fTable[i] = 0;
fMaxEntries = (XMLSize_t)(float(fSize) * gMaxFill);
//
// Move entries over from the old table to the new one.
//
for (i=0; i<oldSize; i++)
{
if ((oldTable[i] != 0) && (oldTable[i] != (DOMAttr *)-1))
add(oldTable[i]);
}
// delete [] oldTable; (The document owns the storage. The old table will just
// need to leak until until the document is discarded.)
};