ossimRefPtr<ossimElevCellHandler> ossimElevationCellDatabase::getOrCreateCellHandler(const ossimGpt& gpt)
{
ossimRefPtr<ossimElevCellHandler> result = 0;
ossim_uint64 id = createId(gpt);
{
OpenThreads::ScopedLock<OpenThreads::Mutex> lock(m_cacheMapMutex);
CellMap::iterator iter = m_cacheMap.find(id);
if(iter != m_cacheMap.end())
{
iter->second->updateTimestamp();
result = iter->second->m_handler.get();
return result.get();
}
}
result = createCell(gpt);
{
OpenThreads::ScopedLock<OpenThreads::Mutex> lock(m_cacheMapMutex);
if(result.valid())
{
m_cacheMap.insert(std::make_pair(id, new CellInfo(id, result.get())));
// Check the map size and purge cells if needed.
if(m_cacheMap.size() > m_maxOpenCells)
{
flushCacheToMinOpenCells();
}
}
}
return result;
}
ossimRefPtr<ossimElevCellHandler> ossimImageElevationDatabase::getOrCreateCellHandler(
const ossimGpt& gpt)
{
ossimRefPtr<ossimElevCellHandler> result = 0;
// Note: Must do mutex lock / unlock around any cach map access.
m_cacheMapMutex.lock();
if ( m_cacheMap.size() )
{
//---
// Look in existing map for handler.
//
// Note: Cannot key off of id from gpt as cells can be any arbituary dimensions.
//---
CellMap::iterator lastAccessedCellIter = m_cacheMap.find(m_lastAccessedId);
CellMap::iterator iter = lastAccessedCellIter;
// Check from last accessed to end.
while ( iter != m_cacheMap.end() )
{
if ( iter->second->m_handler->pointHasCoverage(gpt) )
{
result = iter->second->m_handler.get();
break;
}
++iter;
}
if ( result.valid() == false )
{
iter = m_cacheMap.begin();
// Beginning to last accessed.
while ( iter != lastAccessedCellIter)
{
if ( iter->second->m_handler->pointHasCoverage(gpt) )
{
result = iter->second->m_handler.get();
break;
}
++iter;
}
}
if ( result.valid() )
{
m_lastAccessedId = iter->second->m_id;
iter->second->updateTimestamp();
}
}
m_cacheMapMutex.unlock();
if ( result.valid() == false )
{
// Not in m_cacheMap. Create a new cell for point if we have coverage.
result = createCell(gpt);
if(result.valid())
{
OpenThreads::ScopedLock<OpenThreads::Mutex> lock(m_cacheMapMutex);
//---
// Add the cell to map.
// NOTE: ossimImageElevationDatabase::createCell sets m_lastAccessedId to that of
// the entries map key.
//---
m_cacheMap.insert(std::make_pair(m_lastAccessedId,
new CellInfo(m_lastAccessedId, result.get())));
++m_lastMapKey;
// Check the map size and purge cells if needed.
if(m_cacheMap.size() > m_maxOpenCells)
{
flushCacheToMinOpenCells();
}
}
}
return result;
}
