buffer.h

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]

#ifndef __storagemanager_buffer_h
#define __storagemanager_buffer_h

#include <cstring>

namespace SpatialIndex
{
	namespace StorageManager
	{
		class Buffer : public IBuffer
		{
		public:
			Buffer(IStorageManager& sm, Tools::PropertySet& ps);
				// String                   Value     Description
				// ----------------------------------------------
				// Capacity		VT_ULONG	Buffer maximum capacity.
				// WriteThrough	VT_BOOL	Enable or disable write through policy.

			virtual ~Buffer();

			virtual void loadByteArray(const long id, unsigned long& len, byte** data);
			virtual void storeByteArray(long& id, const unsigned long len, const byte* const data);
			virtual void deleteByteArray(const long id);

			virtual void clear();
			virtual unsigned long getHits();

		protected:
			class Entry
			{
			public:
				Entry(unsigned long l, const byte* const d) : m_pData(0), m_length(l), m_bDirty(false)
				{
					m_pData = new byte[m_length];
					memcpy(m_pData, d, m_length);
				}

				~Entry() { delete[] m_pData; }

				byte* m_pData;
				unsigned long m_length;
				bool m_bDirty;
			}; // Entry

			virtual void addEntry(long id, Entry* pEntry) = 0;
			virtual void removeEntry() = 0;

			unsigned long m_capacity;
			bool m_bWriteThrough;
			IStorageManager* m_pStorageManager;
			std::map<long, Entry*> m_buffer;
			unsigned long m_hits;
		}; // Buffer
	}
}

#endif /*__storagemanager_buffer_h*/