/**
* Copyright (C) 2009-2013 FoundationDB, LLC
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.foundationdb.qp.util;
import com.foundationdb.qp.operator.QueryBindings;
import com.foundationdb.qp.row.Row;
import com.foundationdb.qp.rowtype.RowType;
import com.foundationdb.server.collation.AkCollator;
import com.foundationdb.server.types.TClass;
import com.foundationdb.server.types.TComparison;
import com.foundationdb.server.types.texpressions.TEvaluatableExpression;
import com.foundationdb.server.types.value.Value;
import com.foundationdb.server.types.value.ValueSource;
import com.foundationdb.server.types.value.ValueSources;
import com.foundationdb.server.types.value.ValueTargets;
import com.google.common.collect.ArrayListMultimap;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class HashTable {
private ArrayListMultimap<KeyWrapper, Row> hashTable = ArrayListMultimap.create();
private RowType hashedRowType;
private List<TComparison> tComparisons;
private List<AkCollator> collators;
private boolean matchNulls;
public List<Row> getMatchingRows(Row row, List<TEvaluatableExpression> evaluatableComparisonFields, QueryBindings bindings){
KeyWrapper key = new KeyWrapper(row, evaluatableComparisonFields, bindings);
if (!matchNulls && key.isNull())
return Collections.emptyList();
return hashTable.get(key);
}
public void put(Row row, List<TEvaluatableExpression> evaluatableComparisonFields, QueryBindings bindings){
KeyWrapper key = new KeyWrapper(row, evaluatableComparisonFields, bindings);
if (matchNulls || !key.isNull()) {
hashTable.put(key, row);
}
}
public RowType getRowType() {
return hashedRowType;
}
public void setRowType(RowType rowType) {
hashedRowType = rowType;
}
public void setTComparisons(List<TComparison> tComparisons) {
this.tComparisons = tComparisons;
}
public void setCollators(List<AkCollator> collators) {
this.collators = collators;
}
public void setMatchNulls(boolean matchNulls) {
this.matchNulls = matchNulls;
}
public class KeyWrapper implements Comparable<KeyWrapper> {
List<ValueSource> values = new ArrayList<>();
int hashKey = 0;
boolean isNull;
@Override
public int hashCode() {
return hashKey;
}
@Override
public boolean equals(Object x) {
if ( !(x instanceof KeyWrapper) || ((KeyWrapper)x).values.size() != values.size() )
return false;
return (compareTo((KeyWrapper)x) == 0);
}
@Override
public int compareTo(KeyWrapper other) {
for (int i = 0; i < values.size(); i++) {
int compare;
if (tComparisons != null && tComparisons.get(i) != null) {
compare = tComparisons.get(i).compare(values.get(i).getType(), values.get(i), other.values.get(i).getType(), other.values.get(i));
}
else {
compare = TClass.compare(values.get(i).getType(), values.get(i), other.values.get(i).getType(), other.values.get(i));
}
if (compare != 0) {
return compare;
}
}
return 0;
}
public boolean isNull() {
return isNull;
}
public KeyWrapper(Row row, List<TEvaluatableExpression> comparisonExpressions, QueryBindings bindings){
int i = 0;
for (TEvaluatableExpression expression : comparisonExpressions) {
if (row != null)
expression.with(row);
if (bindings != null)
expression.with(bindings);
expression.evaluate();
ValueSource columnValue = expression.resultValue();
if (columnValue.isNull())
isNull = true;
Value valueCopy = new Value(columnValue.getType());
ValueTargets.copyFrom(columnValue, valueCopy);
AkCollator collator = (collators != null) ? collators.get(i) : null;
hashKey ^= ValueSources.hash(valueCopy, collator);
values.add(valueCopy);
i++;
}
}
}
}