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class QgsAbstractCacheIndex
{
%TypeHeaderCode
#include <qgscacheindex.h>
%End
public:
QgsAbstractCacheIndex();
virtual ~QgsAbstractCacheIndex();
/**
* Is called, whenever a feature is removed from the cache. You should update your indexes, so
* they become invalid in case this feature was required to successfuly answer a request.
*/
virtual void flushFeature( const QgsFeatureId fid ) = 0;
/**
* Sometimes, the whole cache changes its state and its easier to just withdraw everything.
* In this case, this method is issued. Be sure to clear all cache information in here.
*/
virtual void flush() = 0;
/**
* @brief
* Implement this method to update the the indices, in case you need information contained by the request
* to properly index. (E.g. spatial index)
* Does nothing by default
*
* @param featureRequest The feature request that was answered
* @param fids The feature ids that have been returned
*/
virtual void requestCompleted( QgsFeatureRequest featureRequest, QgsFeatureIds fids );
/**
* Is called, when a feature request is issued on a cached layer.
* If this cache index is able to completely answer the feature request, it will return true
* and write the list of feature ids of cached features to cachedFeatures. If it is not able
* it will return false and the cachedFeatures state is undefined.
*
* @param featureIterator A reference to a {@link QgsFeatureIterator}. A valid featureIterator will
* be assigned in case this index is able to answer the request and the return
* value is true.
* @param featureRequest The feature request, for which this index is queried.
*
* @return True, if this index holds the information to answer the request.
*
*/
virtual bool getCacheIterator( QgsFeatureIterator& featureIterator, const QgsFeatureRequest& featureRequest ) = 0;
};
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