/**
* Copyright (c) 2013, Institute of Information Systems (Sven Groppe and contributors of LUPOSDATE), University of Luebeck
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this list of conditions and the following
* disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other materials provided with the distribution.
* - Neither the name of the University of Luebeck nor the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package lupos.engine.operators;
import java.util.List;
import lupos.datastructures.queryresult.QueryResult;
import lupos.datastructures.queryresult.QueryResultDebug;
import lupos.misc.debug.DebugStep;
/**
* This class is the super class for all operators, which process bindings.
*/
public class Operator extends BasicOperator {
/**
*
*/
private static final long serialVersionUID = -8701923927442894567L;
/**
* This method is overridden by derived classes. The overridden methods
* should process a received QueryResult object (from a preceding operator).
* Additionally the operand number is available. Let us assume that the
* current operator is C, another operator is A and a succeeding operator is
* B = A OPTIONAL C. Note that it is important to know that A is the left
* operand and C is the right operand of B. Then a succeeding operator of C
* is B with operand number 1 (A has a succeeding operator B with operand
* number 0).
*
* @param queryResult
* The received QueryResult
* @param operandID
* The operand number
* @return
*/
public QueryResult process(final QueryResult queryResult, final int operandID) {
throw (new UnsupportedOperationException("This Operator(" + this + ") should have been replaced before being used."));
}
public QueryResult deleteQueryResult(final QueryResult queryResult, final int operandID) {
// in the typical case, just apply the normal process method
// this works well e.g. for filter operators, but does not work well
// for those operators, which intermediately save the query results
// as well as pipeline breakers...
return this.process(queryResult, operandID);
}
public void deleteQueryResult(final int operandID) {
// to be overriden if an operator intermediately stores a QueryResult (e.g. pipeline-breakers) and a QueryResult must be deleted...
}
/**
* The standard constructor
*/
public Operator() {
// no initialization
}
/**
* The constructor, which sets the succeeding operators
*
* @param succeedingOperators
* the succeeding operators
*/
public Operator(final List<OperatorIDTuple> succeedingOperators) {
super(succeedingOperators);
}
/**
* This constructor can be used to set only one succeeding operator
*
* @param succeedingOperator
* the one and only succeeding operator
*/
public Operator(final OperatorIDTuple succeedingOperator) {
super(succeedingOperator);
}
/**
* This method processes a received QueryResult with operand number and
* forwards the result to the succeeding operators.
*
* @param queryResult
* the received QueryResult
* @param operandID
* the operand number
*/
public void processAll(final QueryResult queryResult, final int operandID) {
final QueryResult opp = this.process(queryResult, operandID);
if (opp == null) {
return;
}
if (this.succeedingOperators.size() > 1) {
opp.materialize();
}
for (final OperatorIDTuple opId : this.succeedingOperators) {
((Operator) opId.getOperator()).processAll(opp, opId.getId());
}
}
/**
* This method processes a received QueryResult with operand number and
* forwards the result to the succeeding operators.
*
* @param queryResult
* the received QueryResult
* @param operandID
* the operand number
*/
public void deleteAll(final QueryResult queryResult, final int operandID) {
final QueryResult opp = this.deleteQueryResult(queryResult, operandID);
if (!this.isPipelineBreaker()) {
if (opp == null) {
return;
}
if (this.succeedingOperators.size() > 1) {
opp.materialize();
}
}
for (final OperatorIDTuple opId : this.succeedingOperators) {
if (this.isPipelineBreaker()) {
((Operator) opId.getOperator()).deleteAll(opId.getId());
} else {
((Operator) opId.getOperator()).deleteAll(opp, opId.getId());
}
}
}
public void deleteAll(final int operandID) {
this.deleteQueryResult(operandID);
this.deleteAllAtSucceedingOperators();
}
public void deleteAllAtSucceedingOperators() {
for (final OperatorIDTuple opId : this.succeedingOperators) {
((Operator) opId.getOperator()).deleteAll(opId.getId());
}
}
protected boolean isPipelineBreaker() {
return false;
}
/**
* This method processes a received QueryResult with operand number and
* forwards the result to the succeeding operators. It further sends debug
* messages for stepwise debugging!
*
* @param queryResult
* the received QueryResult
* @param operandID
* the operand number
*/
public void deleteAllDebug(final int operandID, final DebugStep debugstep) {
this.deleteQueryResult(operandID);
this.deleteAllDebugAtSucceedingOperators(debugstep);
}
/**
* This method processes a received QueryResult with operand number and
* forwards the result to the succeeding operators. It further sends debug
* messages for stepwise debugging!
*
* @param queryResult
* the received QueryResult
* @param operandID
* the operand number
*/
public void deleteAllDebug(final QueryResult queryResult,
final int operandID, final DebugStep debugstep) {
final QueryResult opp = this.deleteQueryResult(queryResult, operandID);
if (!this.isPipelineBreaker()) {
if (opp == null) {
return;
}
if (this.succeedingOperators.size() > 1) {
opp.materialize();
}
}
for (final OperatorIDTuple opId : this.succeedingOperators) {
if (this.isPipelineBreaker()) {
debugstep.stepDeleteAll(this, opId.getOperator());
((Operator) opId.getOperator()).deleteAllDebug(opId.getId(),
debugstep);
} else {
final QueryResultDebug qrDebug = new QueryResultDebug(opp,
debugstep, this, opId.getOperator(), false);
((Operator) opId.getOperator()).deleteAllDebug(qrDebug, opId
.getId(), debugstep);
}
}
}
public void deleteAllDebugAtSucceedingOperators(final DebugStep debugstep) {
for (final OperatorIDTuple opId : this.succeedingOperators) {
debugstep.stepDeleteAll(this, opId.getOperator());
((Operator) opId.getOperator()).deleteAllDebug(opId.getId(),
debugstep);
}
}
/**
* This method processes a received QueryResult with operand number and
* forwards the result to the succeeding operators. It further sends debug
* messages for stepwise debugging!
*
* @param queryResult
* the received QueryResult
* @param operandID
* the operand number
*/
public void processAllDebug(final QueryResult queryResult, final int operandID, final DebugStep debugstep) {
final QueryResult opp = this.process(queryResult, operandID);
if (opp == null){
return;
}
if (this.succeedingOperators.size() > 1) {
opp.materialize();
}
for (final OperatorIDTuple opId : this.succeedingOperators) {
final QueryResultDebug qrDebug = new QueryResultDebug(opp, debugstep, this, opId.getOperator(), true);
((Operator) opId.getOperator()).processAllDebug(qrDebug, opId.getId(), debugstep);
}
}
}