C++ KeySet::Unify方法代码示例

bool QueryProcessor::
DoQuery( Rectangles &window, KeySet &result )
{
	AllDimensions::iterator		aitr;
	OneDimension::iterator		oitr;
	Indexes::iterator			iitr;
	KeySet						deviantExportedSet;
	KeySet						tmpResult;
	QueryOutcome				qo;
	string						demangled;
	DimRectangleMap::iterator	ditr, daxitr;
	KeySet::iterator			ksitr;
	int							tmp;
	Rectangles					*rec = summarize ? &summaries : rectangles;

	numQueries++;

	//printf( "Doing query\n" );
		// Phase 0: Initialize 
	for( int i = 0; i <= window.rId ; i++ ) {
		qo[i].MakeUniversal( );
	}

		// Phase 1:  Process imported intervals
	for( aitr=window.importedBoxes.begin( ); aitr!=window.importedBoxes.end( );
			aitr++ ) {

		demangled.assign( aitr->first, 2, aitr->first.size( ) - 2 );
		ditr = rec->unexported.find( demangled );

		for( oitr=aitr->second.begin( ); oitr!=aitr->second.end( ); oitr++ ) {
			tmpResult.Clear( );
				// include all rectangles whose constraints are satisfied
			if( ( iitr = exported.find( aitr->first ) ) != exported.end( ) ) {
				if( !iitr->second->Filter( oitr->second, tmpResult ) ) {
					printf( "Failed exported index lookup\n" );
					return( false );
				}
			}

				// include deviant exported rectangles and all rectangles
				// which do not constrain this attribute (if any)
			if( ditr == rec->unexported.end( ) ) {
				qo[oitr->first].IntersectWithUnionOf( tmpResult, 
					rec->deviantExported );
			} else {
				qo[oitr->first].IntersectWithUnionOf( tmpResult, ditr->second,
					rec->deviantExported );
			}
		}
	}

		// Phase 2:  Remove candidates which constrain absent attributes
	for(ditr=window.unimported.begin();ditr!=window.unimported.end();ditr++) {
			// find all rectangles which constrain this particular attribute
		daxitr = rec->allExported.find( ditr->first );
		if( daxitr == rec->allExported.end( ) ) continue;
			// remove this set from the solution for each query rectangle
		ksitr.Initialize( ditr->second );
		while( ksitr.Next( tmp ) ) {
			qo[tmp].Subtract( daxitr->second );
		}
	}

		// Phase 3:  Process exported dimensions
	for( aitr=window.exportedBoxes.begin( ); aitr!=window.exportedBoxes.end( );
			aitr++ ) {
			// need to include rectangles which are deviant on this attribute
		demangled.assign( aitr->first, 2, aitr->first.size( ) - 2 );
		ditr = rec->deviantImported.find( demangled );

		for( oitr=aitr->second.begin( ); oitr!=aitr->second.end( ); oitr++ ) {
			tmpResult.Clear( );
				// include all rectangles which satisfy this constraint
			if( ( iitr = imported.find( aitr->first ) ) != imported.end( ) ) {
				if( !iitr->second->Filter( oitr->second, tmpResult ) ) {
					printf( "Failed imported index lookup\n" );
					return( false );
				}
			}
				// check if there are relevant deviant imported rectangles
			if( ditr == rec->deviantImported.end( ) ) {
					// ... if not, just intersect with filtered results
				qo[oitr->first].Intersect( tmpResult );
			} else {
					// ... otherwise, include deviant imported rectangles
				qo[oitr->first].IntersectWithUnionOf(ditr->second,tmpResult);
			}
		}
	}

		// Phase 4:  Aggregate results for all query rectangles
	result.Clear( );
	for( int i = 0 ; i <= window.rId ; i++ ) {
		result.Unify( qo[i] );
	}

		// done
	return( true );
}