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/*
* Copyright 2004-2021 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.expression.condition;
import java.util.ArrayList;
import java.util.TreeSet;
import org.h2.engine.SessionLocal;
import org.h2.expression.Expression;
import org.h2.expression.ExpressionColumn;
import org.h2.expression.ExpressionVisitor;
import org.h2.index.IndexCondition;
import org.h2.message.DbException;
import org.h2.table.ColumnResolver;
import org.h2.table.TableFilter;
import org.h2.value.TypeInfo;
import org.h2.value.Value;
import org.h2.value.ValueBoolean;
import org.h2.value.ValueNull;
/**
* Used for optimised IN(...) queries where the contents of the IN list are all
* constant and of the same type.
*/
public final class ConditionInConstantSet extends Condition {
private Expression left;
private final boolean not;
private final boolean whenOperand;
private final ArrayList valueList;
// HashSet cannot be used here, because we need to compare values of
// different type or scale properly.
private final TreeSet valueSet;
private boolean hasNull;
private final TypeInfo type;
/**
* Create a new IN(..) condition.
*
* @param session the session
* @param left
* the expression before IN. Cannot have {@link Value#UNKNOWN}
* data type and {@link Value#ENUM} type is also supported only
* for {@link ExpressionColumn}.
* @param not whether the result should be negated
* @param whenOperand whether this is a when operand
* @param valueList
* the value list (at least two elements); all values must be
* comparable with left value
*/
ConditionInConstantSet(SessionLocal session, Expression left, boolean not, boolean whenOperand,
ArrayList valueList) {
this.left = left;
this.not = not;
this.whenOperand = whenOperand;
this.valueList = valueList;
this.valueSet = new TreeSet<>(session.getDatabase().getCompareMode());
TypeInfo type = left.getType();
for (Expression expression : valueList) {
type = TypeInfo.getHigherType(type, expression.getType());
}
this.type = type;
for (Expression expression : valueList) {
add(expression.getValue(session), session);
}
}
private void add(Value v, SessionLocal session) {
if ((v = v.convertTo(type, session)).containsNull()) {
hasNull = true;
} else {
valueSet.add(v);
}
}
@Override
public Value getValue(SessionLocal session) {
return getValue(left.getValue(session), session);
}
@Override
public boolean getWhenValue(SessionLocal session, Value left) {
if (!whenOperand) {
return super.getWhenValue(session, left);
}
return getValue(left, session).isTrue();
}
private Value getValue(Value left, SessionLocal session) {
if ((left = left.convertTo(type, session)).containsNull()) {
return ValueNull.INSTANCE;
}
boolean result = valueSet.contains(left);
if (!result && hasNull) {
return ValueNull.INSTANCE;
}
return ValueBoolean.get(not ^ result);
}
@Override
public boolean isWhenConditionOperand() {
return whenOperand;
}
@Override
public void mapColumns(ColumnResolver resolver, int level, int state) {
left.mapColumns(resolver, level, state);
}
@Override
public Expression optimize(SessionLocal session) {
left = left.optimize(session);
return this;
}
@Override
public Expression getNotIfPossible(SessionLocal session) {
if (whenOperand) {
return null;
}
return new ConditionInConstantSet(session, left, !not, false, valueList);
}
@Override
public void createIndexConditions(SessionLocal session, TableFilter filter) {
if (not || whenOperand || !(left instanceof ExpressionColumn)) {
return;
}
ExpressionColumn l = (ExpressionColumn) left;
if (filter != l.getTableFilter()) {
return;
}
if (session.getDatabase().getSettings().optimizeInList) {
TypeInfo colType = l.getType();
if (TypeInfo.haveSameOrdering(colType, TypeInfo.getHigherType(colType, type))) {
filter.addIndexCondition(IndexCondition.getInList(l, valueList));
}
}
}
@Override
public void setEvaluatable(TableFilter tableFilter, boolean b) {
left.setEvaluatable(tableFilter, b);
}
@Override
public boolean needParentheses() {
return true;
}
@Override
public StringBuilder getUnenclosedSQL(StringBuilder builder, int sqlFlags) {
return getWhenSQL(left.getSQL(builder, sqlFlags, AUTO_PARENTHESES), sqlFlags);
}
@Override
public StringBuilder getWhenSQL(StringBuilder builder, int sqlFlags) {
if (not) {
builder.append(" NOT");
}
return writeExpressions(builder.append(" IN("), valueList, sqlFlags).append(')');
}
@Override
public void updateAggregate(SessionLocal session, int stage) {
left.updateAggregate(session, stage);
}
@Override
public boolean isEverything(ExpressionVisitor visitor) {
if (!left.isEverything(visitor)) {
return false;
}
switch (visitor.getType()) {
case ExpressionVisitor.OPTIMIZABLE_AGGREGATE:
case ExpressionVisitor.DETERMINISTIC:
case ExpressionVisitor.READONLY:
case ExpressionVisitor.INDEPENDENT:
case ExpressionVisitor.EVALUATABLE:
case ExpressionVisitor.SET_MAX_DATA_MODIFICATION_ID:
case ExpressionVisitor.NOT_FROM_RESOLVER:
case ExpressionVisitor.GET_DEPENDENCIES:
case ExpressionVisitor.QUERY_COMPARABLE:
case ExpressionVisitor.GET_COLUMNS1:
case ExpressionVisitor.GET_COLUMNS2:
return true;
default:
throw DbException.getInternalError("type=" + visitor.getType());
}
}
@Override
public int getCost() {
return left.getCost();
}
/**
* Add an additional element if possible. Example: given two conditions
* A IN(1, 2) OR A=3, the constant 3 is added: A IN(1, 2, 3).
*
* @param session the session
* @param other the second condition
* @return null if the condition was not added, or the new condition
*/
Expression getAdditional(SessionLocal session, Comparison other) {
if (!not && !whenOperand && left.isEverything(ExpressionVisitor.DETERMINISTIC_VISITOR)) {
Expression add = other.getIfEquals(left);
if (add != null) {
if (add.isConstant()) {
ArrayList list = new ArrayList<>(valueList.size() + 1);
list.addAll(valueList);
list.add(add);
return new ConditionInConstantSet(session, left, false, false, list);
}
}
}
return null;
}
@Override
public int getSubexpressionCount() {
return 1 + valueList.size();
}
@Override
public Expression getSubexpression(int index) {
if (index == 0) {
return left;
} else if (index > 0 && index <= valueList.size()) {
return valueList.get(index - 1);
}
throw new IndexOutOfBoundsException();
}
}
