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HSQLDB - Lightweight 100% Java SQL Database Engine
/* Copyright (c) 2001-2020, The HSQL Development Group
* 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 HSQL Development Group 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 HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* 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
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*/
package org.hsqldb;
import java.util.Arrays;
import org.hsqldb.lib.HsqlArrayList;
import org.hsqldb.lib.HsqlList;
import org.hsqldb.lib.Iterator;
import org.hsqldb.lib.OrderedHashSet;
/**
* Transforms a tree of GROUPING SETS variants into normalised form for
* building the result of GROUP BY queries.
*
* Code modifications to ParserDQL, QuerySpecification, RowSetNavigatorData,
* SetFunctionValueAggregate and other classes by the author form parts of
* added support for GROUPING SETS, ROLLUP, CUBE and GROUPING functionality.
*
* @author Nicholas Quek (kocolipy@users dot sourceforge.net)
* @version 2.5.1
* @since 2.5.1
*/
public class GroupSet {
Expression[] groupExpressions;
HsqlArrayList sets = new HsqlArrayList();
int nullSets = 0;
boolean isDistinctGroups;
public GroupSet(Expression[] expressions, boolean isDistinct) {
groupExpressions = expressions;
isDistinctGroups = isDistinct;
}
public Iterator getIterator() {
return sets.iterator();
}
public int isGrouped(HsqlList current, Expression e) {
int count = 0;
if (current == null) {
return (1 << (e.nodes.length)) - 1; //Total Aggregate case
}
for (int i = 0; i < e.nodes.length; i++) {
count = count << 1;
int colIndex = e.nodes[i].columnIndex;
if (!current.contains(colIndex)) {
count += 1;
}
}
return count;
}
public void process() {
// columns in grouping sets by name
HsqlArrayList tmp = evaluate(groupExpressions);
Iterator it = tmp.iterator();
outerloop:
while (it.hasNext()) {
HsqlList set = (HsqlList) it.next();
if (set.isEmpty()) {
if (isDistinctGroups) {
nullSets = 1;
} else {
nullSets++;
}
} else {
if (isDistinctGroups) {
OrderedHashSet newSet = new OrderedHashSet();
newSet.addAll(set);
for (int i = 0; i < sets.size(); i++) {
HsqlList current = (HsqlList) sets.get(i);
if (current.size() == newSet.size()) {
if (newSet.containsAll(current)) {
continue outerloop;
}
}
}
set = newSet;
}
sets.add(set);
}
}
}
private int getColumnIndex(Expression e) {
return e.resultTableColumnIndex;
}
private HsqlArrayList evaluate(Expression e) {
if (e.opType == OpTypes.NONE) {
HsqlArrayList sets = new HsqlArrayList();
sets.add(new HsqlArrayList());
return sets;
}
Expression[] exprs = e.nodes;
if (exprs.length == 0
|| (e.opType != OpTypes.VALUELIST
&& e.opType != OpTypes.ROW)) {
exprs = new Expression[1];
exprs[0] = e;
}
switch (e.groupingType) {
case Tokens.CUBE :
return powerSet(exprs);
case Tokens.ROLLUP :
return rollUp(exprs);
case Tokens.SETS :
return grouping(exprs);
default :
if (e.nodes.length == 0) {
HsqlArrayList sets = new HsqlArrayList();
HsqlArrayList inner = new HsqlArrayList();
inner.add(getColumnIndex(e));
sets.add(inner);
return sets;
}
return evaluate(e.nodes);
}
}
private HsqlArrayList evaluate(Expression[] e) {
HsqlArrayList sets = new HsqlArrayList();
if (e.length == 0) {
HsqlArrayList inner = new HsqlArrayList();
sets.add(inner);
return sets;
}
HsqlArrayList first = evaluate(e[0]);
HsqlArrayList results = evaluate(Arrays.copyOfRange(e, 1, e.length));
Iterator it = results.iterator();
while (it.hasNext()) {
HsqlArrayList current = (HsqlArrayList) it.next();
Iterator itFirst = first.iterator();
while (itFirst.hasNext()) {
HsqlArrayList newSet = new HsqlArrayList();
HsqlArrayList next = (HsqlArrayList) itFirst.next();
newSet.addAll(next);
newSet.addAll(current);
sets.add(newSet);
}
}
return sets;
}
private HsqlArrayList powerSet(Expression[] expressions) {
HsqlArrayList sets = new HsqlArrayList();
if (expressions.length == 0) {
sets.add(new HsqlArrayList());
return sets;
}
HsqlArrayList first;
if (expressions[0].nodes.length != 0
&& (expressions[0].opType == OpTypes.VALUELIST
|| expressions[0].opType == OpTypes.ROW)) {
first = evaluate(expressions[0]);
} else {
first = new HsqlArrayList();
HsqlArrayList tmp = new HsqlArrayList();
tmp.add(getColumnIndex(expressions[0]));
first.add(tmp);
}
HsqlArrayList results = powerSet(Arrays.copyOfRange(expressions, 1,
expressions.length));
Iterator itFirst = first.iterator();
while (itFirst.hasNext()) {
HsqlArrayList current = (HsqlArrayList) itFirst.next();
Iterator it = results.iterator();
while (it.hasNext()) {
HsqlArrayList newSet = new HsqlArrayList();
HsqlArrayList next = (HsqlArrayList) it.next();
newSet.addAll(current);
newSet.addAll(next);
if (!newSet.isEmpty()) {
sets.add(newSet);
}
}
}
sets.addAll(results);
return sets;
}
private HsqlArrayList rollUp(Expression[] expressions) {
HsqlArrayList sets = new HsqlArrayList();
if (expressions.length == 0) {
sets.add(new HsqlArrayList());
return sets;
}
HsqlArrayList first;
if (expressions[0].nodes.length != 0
&& (expressions[0].opType == OpTypes.VALUELIST
|| expressions[0].opType == OpTypes.ROW)) {
first = evaluate(expressions[0]);
} else {
first = new HsqlArrayList();
HsqlArrayList tmp = new HsqlArrayList();
tmp.add(getColumnIndex(expressions[0]));
first.add(tmp);
}
HsqlArrayList results = rollUp(Arrays.copyOfRange(expressions, 1,
expressions.length));
Iterator it = results.iterator();
while (it.hasNext()) {
HsqlArrayList current = (HsqlArrayList) it.next();
Iterator itFirst = first.iterator();
while (itFirst.hasNext()) {
HsqlArrayList next = (HsqlArrayList) itFirst.next();
HsqlArrayList newSet = new HsqlArrayList();
newSet.addAll(next);
newSet.addAll(current);
sets.add(newSet);
}
}
sets.add(new HsqlArrayList());
return sets;
}
private HsqlArrayList grouping(Expression[] expressions) {
HsqlArrayList sets = new HsqlArrayList();
if (expressions.length == 0) {
return sets;
}
if (expressions[0].nodes.length != 0
&& (expressions[0].opType == OpTypes.VALUELIST
|| expressions[0].opType == OpTypes.ROW)) {
sets = evaluate(expressions[0]);
} else {
sets = new HsqlArrayList();
HsqlArrayList tmp = new HsqlArrayList();
if (expressions[0].opType != OpTypes.NONE) {
tmp.add(getColumnIndex(expressions[0]));
}
sets.add(tmp);
}
HsqlArrayList results = grouping(Arrays.copyOfRange(expressions, 1,
expressions.length));
sets.addAll(results);
return sets;
}
}
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