memorystoragemanager.cc

一个非常好的GIS开源新版本

// Spatial Index Library
//
// Copyright (C) 2002 Navel Ltd.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
//  Email:
//    [e-mail]

#include <stdexcept>

#include "../spatialindex/SpatialIndexImpl.h"

#include "MemoryStorageManager.h"

using namespace SpatialIndex;
using namespace SpatialIndex::StorageManager;
using std::stack;
using std::vector;

SpatialIndex::IStorageManager* SpatialIndex::StorageManager::returnMemoryStorageManager(Tools::PropertySet& ps)
{
	IStorageManager* sm = new MemoryStorageManager(ps);
	return sm;
}

SpatialIndex::IStorageManager* SpatialIndex::StorageManager::createNewMemoryStorageManager()
{
	Tools::PropertySet ps;
	return returnMemoryStorageManager(ps);
}

MemoryStorageManager::MemoryStorageManager(Tools::PropertySet& ps)
{
}

MemoryStorageManager::~MemoryStorageManager()
{
	for (vector<Entry*>::iterator it = m_buffer.begin(); it != m_buffer.end(); it++) delete *it;
}

void MemoryStorageManager::loadByteArray(const long id, unsigned long& len, byte** data)
{
	Entry* e;
	try
	{
		e = m_buffer.at(id);
		if (e == 0) throw Tools::InvalidPageException(id);
	}
	catch (std::out_of_range)
	{
		throw Tools::InvalidPageException(id);
	}

	len = e->m_length;
	*data = new byte[len];

	memcpy(*data, e->m_pData, len);
}

void MemoryStorageManager::storeByteArray(long& id, const unsigned long len, const byte* const data)
{
	if (id == NewPage)
	{
		Entry* e = new Entry(len, data);

		if (m_emptyPages.empty())
		{
			m_buffer.push_back(e);
			id = m_buffer.size() - 1;
		}
		else
		{
			id = m_emptyPages.top(); m_emptyPages.pop();
			m_buffer[id] = e;
		}
	}
	else
	{
		Entry* e_old;
		try
		{
			e_old = m_buffer.at(id);
			if (e_old == 0) throw Tools::InvalidPageException(id);
		}
		catch (std::out_of_range)
		{
			throw Tools::InvalidPageException(id);
		}

		Entry* e = new Entry(len, data);

		delete e_old;
		m_buffer[id] = e;
	}
}

void MemoryStorageManager::deleteByteArray(const long id)
{
	Entry* e;
	try
	{
		e = m_buffer.at(id);
		if (e == 0) throw Tools::InvalidPageException(id);
	}
	catch (std::out_of_range)
	{
		throw Tools::InvalidPageException(id);
	}

	m_buffer[id] = 0;
	m_emptyPages.push(id);

	delete e;
}