/**
* Creates a partial mapping.
*
* <p>Initially, no element is mapped to any other:
*
* <table border="1">
* <caption>Example</caption>
* <tr>
* <th>source</th>
* <td>0</td>
* <td>1</td>
* <td>2</td>
* </tr>
* <tr>
* <th>target</th>
* <td>-1</td>
* <td>-1</td>
* <td>-1</td>
* </tr>
* </table>
*
* <table border="1">
* <caption>Example</caption>
* <tr>
* <th>target</th>
* <td>0</td>
* <td>1</td>
* <td>2</td>
* <td>3</td>
* </tr>
* <tr>
* <th>source</th>
* <td>-1</td>
* <td>-1</td>
* <td>-1</td>
* <td>-1</td>
* </tr>
* </table>
*
* @param sourceCount Number of source elements
* @param targetCount Number of target elements
* @param mappingType Mapping type; must not allow multiple sources per target or multiple
* targets per source
*/
public PartialMapping(int sourceCount, int targetCount, MappingType mappingType) {
this.mappingType = mappingType;
assert mappingType.isSingleSource() : mappingType;
assert mappingType.isSingleTarget() : mappingType;
this.sources = new int[targetCount];
this.targets = new int[sourceCount];
Arrays.fill(sources, -1);
Arrays.fill(targets, -1);
}
public PartialFunctionImpl(int sourceCount, int targetCount, MappingType mappingType) {
super();
if (sourceCount < 0) {
throw new IllegalArgumentException("Sources must be finite");
}
this.sourceCount = sourceCount;
this.targetCount = targetCount;
this.mappingType = mappingType;
if (!mappingType.isSingleTarget()) {
throw new IllegalArgumentException("Must have at most one target");
}
this.targets = new int[sourceCount];
Arrays.fill(targets, -1);
}
public void onMatch(RelOptRuleCall call) {
JoinRel join = (JoinRel) call.rels[0];
List<RexNode> expList = new ArrayList<RexNode>(Arrays.asList(join.getChildExps()));
if (reduceExpressions(join, expList)) {
call.transformTo(
new JoinRel(
join.getCluster(),
join.getLeft(),
join.getRight(),
expList.get(0),
join.getJoinType(),
join.getVariablesStopped()));
// New plan is absolutely better than old plan.
call.getPlanner().setImportance(join, 0.0);
}
}
public void onMatch(RelOptRuleCall call) {
ProjectRel project = (ProjectRel) call.rels[0];
List<RexNode> expList = new ArrayList<RexNode>(Arrays.asList(project.getChildExps()));
if (reduceExpressions(project, expList)) {
call.transformTo(
new ProjectRel(
project.getCluster(),
project.getChild(),
expList.toArray(new RexNode[expList.size()]),
project.getRowType(),
ProjectRel.Flags.Boxed,
Collections.<RelCollation>emptyList()));
// New plan is absolutely better than old plan.
call.getPlanner().setImportance(project, 0.0);
}
}
/**
* Creates a partial mapping from a list. For example, <code>
* PartialMapping({1, 2, 4}, 6)</code> creates the mapping
*
* <table border="1">
* <caption>Example</caption>
* <tr>
* <th>source</th>
* <td>0</td>
* <td>1</td>
* <td>2</td>
* <td>3</td>
* <td>4</td>
* <td>5</td>
* </tr>
* <tr>
* <th>target</th>
* <td>-1</td>
* <td>0</td>
* <td>1</td>
* <td>-1</td>
* <td>2</td>
* <td>-1</td>
* </tr>
* </table>
*
* @param sourceList List whose i'th element is the source of target #i
* @param sourceCount Number of elements in the source domain
* @param mappingType Mapping type, must be {@link
* org.eigenbase.util.mapping.MappingType#PARTIAL_SURJECTION} or stronger.
*/
public PartialMapping(List<Integer> sourceList, int sourceCount, MappingType mappingType) {
this.mappingType = mappingType;
assert mappingType.isSingleSource();
assert mappingType.isSingleTarget();
int targetCount = sourceList.size();
this.targets = new int[sourceCount];
this.sources = new int[targetCount];
Arrays.fill(sources, -1);
for (int i = 0; i < sourceList.size(); ++i) {
final int source = sourceList.get(i);
sources[i] = source;
if (source >= 0) {
targets[source] = i;
} else {
assert !this.mappingType.isMandatorySource();
}
}
}
public void onMatch(RelOptRuleCall call) {
FilterRel filter = (FilterRel) call.rels[0];
List<RexNode> expList = new ArrayList<RexNode>(Arrays.asList(filter.getChildExps()));
RexNode newConditionExp;
boolean reduced;
if (reduceExpressions(filter, expList)) {
assert (expList.size() == 1);
newConditionExp = expList.get(0);
reduced = true;
} else {
// No reduction, but let's still test the original
// predicate to see if it was already a constant,
// in which case we don't need any runtime decision
// about filtering.
newConditionExp = filter.getChildExps()[0];
reduced = false;
}
if (newConditionExp.isAlwaysTrue()) {
call.transformTo(filter.getChild());
} else if ((newConditionExp instanceof RexLiteral)
|| RexUtil.isNullLiteral(newConditionExp, true)) {
call.transformTo(new EmptyRel(filter.getCluster(), filter.getRowType()));
} else if (reduced) {
call.transformTo(CalcRel.createFilter(filter.getChild(), expList.get(0)));
} else {
if (newConditionExp instanceof RexCall) {
RexCall rexCall = (RexCall) newConditionExp;
boolean reverse = (rexCall.getOperator() == SqlStdOperatorTable.notOperator);
if (reverse) {
rexCall = (RexCall) rexCall.getOperands()[0];
}
reduceNotNullableFilter(call, filter, rexCall, reverse);
}
return;
}
// New plan is absolutely better than old plan.
call.getPlanner().setImportance(filter, 0.0);
}
public void clear() {
Arrays.fill(sources, -1);
Arrays.fill(targets, -1);
}