/*
* Copyright 2004-2023 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.schema;
import java.sql.Connection;
import java.sql.SQLException;
import org.h2.api.Aggregate;
import org.h2.api.AggregateFunction;
import org.h2.engine.DbObject;
import org.h2.engine.SessionLocal;
import org.h2.message.DbException;
import org.h2.message.Trace;
import org.h2.util.JdbcUtils;
import org.h2.util.StringUtils;
import org.h2.value.DataType;
import org.h2.value.TypeInfo;
/**
* Represents a user-defined aggregate function.
*/
public final class UserAggregate extends UserDefinedFunction {
private Class<?> javaClass;
public UserAggregate(Schema schema, int id, String name, String className,
boolean force) {
super(schema, id, name, Trace.FUNCTION);
this.className = className;
if (!force) {
getInstance();
}
}
public Aggregate getInstance() {
if (javaClass == null) {
javaClass = JdbcUtils.loadUserClass(className);
}
Object obj;
try {
obj = javaClass.getDeclaredConstructor().newInstance();
Aggregate agg;
if (obj instanceof Aggregate) {
agg = (Aggregate) obj;
} else {
agg = new AggregateWrapper((AggregateFunction) obj);
}
return agg;
} catch (Exception e) {
throw DbException.convert(e);
}
}
@Override
public String getDropSQL() {
StringBuilder builder = new StringBuilder("DROP AGGREGATE IF EXISTS ");
return getSQL(builder, DEFAULT_SQL_FLAGS).toString();
}
@Override
public String getCreateSQL() {
StringBuilder builder = new StringBuilder("CREATE FORCE AGGREGATE ");
getSQL(builder, DEFAULT_SQL_FLAGS).append(" FOR ");
return StringUtils.quoteStringSQL(builder, className).toString();
}
@Override
public int getType() {
return DbObject.AGGREGATE;
}
@Override
public synchronized void removeChildrenAndResources(SessionLocal session) {
database.removeMeta(session, getId());
className = null;
javaClass = null;
invalidate();
}
/**
* Wrap {@link AggregateFunction} in order to behave as
* {@link org.h2.api.Aggregate}
**/
private static class AggregateWrapper implements Aggregate {
private final AggregateFunction aggregateFunction;
AggregateWrapper(AggregateFunction aggregateFunction) {
this.aggregateFunction = aggregateFunction;
}
@Override
public void init(Connection conn) throws SQLException {
aggregateFunction.init(conn);
}
@Override
public int getInternalType(int[] inputTypes) throws SQLException {
int[] sqlTypes = new int[inputTypes.length];
for (int i = 0; i < inputTypes.length; i++) {
sqlTypes[i] = DataType.convertTypeToSQLType(TypeInfo.getTypeInfo(inputTypes[i]));
}
return DataType.convertSQLTypeToValueType(aggregateFunction.getType(sqlTypes));
}
@Override
public void add(Object value) throws SQLException {
aggregateFunction.add(value);
}
@Override
public Object getResult() throws SQLException {
return aggregateFunction.getResult();
}
}
}