/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.ignite.internal.processors.query.h2;
import java.lang.reflect.Field;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.NoSuchElementException;
import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.internal.processors.cache.GridCacheContext;
import org.apache.ignite.internal.processors.query.IgniteSQLException;
import org.apache.ignite.internal.processors.query.h2.opt.GridH2ValueCacheObject;
import org.apache.ignite.internal.util.GridCloseableIteratorAdapter;
import org.apache.ignite.internal.util.typedef.internal.S;
import org.apache.ignite.internal.util.typedef.internal.U;
import org.h2.jdbc.JdbcResultSet;
import org.h2.result.ResultInterface;
import org.h2.value.Value;
/**
* Iterator over result set.
*/
public abstract class GridH2ResultSetIterator<T> extends GridCloseableIteratorAdapter<T> {
/** */
private static final Field RESULT_FIELD;
/**
* Initialize.
*/
static {
try {
RESULT_FIELD = JdbcResultSet.class.getDeclaredField("result");
RESULT_FIELD.setAccessible(true);
}
catch (NoSuchFieldException e) {
throw new IllegalStateException("Check H2 version in classpath.", e);
}
}
/** */
private static final long serialVersionUID = 0L;
/** */
private final ResultInterface res;
/** */
private final ResultSet data;
/** */
protected final Object[] row;
/** */
private final boolean closeStmt;
/** */
private boolean hasRow;
/**
* @param data Data array.
* @param closeStmt If {@code true} closes result set statement when iterator is closed.
* @param needCpy {@code True} if need copy cache object's value.
* @throws IgniteCheckedException If failed.
*/
protected GridH2ResultSetIterator(ResultSet data, boolean closeStmt, boolean needCpy) throws IgniteCheckedException {
this.data = data;
this.closeStmt = closeStmt;
try {
res = needCpy ? (ResultInterface)RESULT_FIELD.get(data) : null;
}
catch (IllegalAccessException e) {
throw new IllegalStateException(e); // Must not happen.
}
if (data != null) {
try {
row = new Object[data.getMetaData().getColumnCount()];
}
catch (SQLException e) {
throw new IgniteCheckedException(e);
}
}
else
row = null;
}
/**
* @return {@code true} If next row was fetched successfully.
*/
private boolean fetchNext() {
if (data == null)
return false;
try {
if (!data.next())
return false;
if (res != null) {
Value[] values = res.currentRow();
for (int c = 0; c < row.length; c++) {
Value val = values[c];
if (val instanceof GridH2ValueCacheObject) {
GridH2ValueCacheObject valCacheObj = (GridH2ValueCacheObject)values[c];
GridCacheContext cctx = valCacheObj.getCacheContext();
row[c] = valCacheObj.getObject(cctx != null && cctx.needValueCopy());
}
else
row[c] = val.getObject();
}
}
else {
for (int c = 0; c < row.length; c++)
row[c] = data.getObject(c + 1);
}
return true;
}
catch (SQLException e) {
throw new IgniteSQLException(e);
}
}
/** {@inheritDoc} */
@Override public boolean onHasNext() {
return hasRow || (hasRow = fetchNext());
}
/** {@inheritDoc} */
@SuppressWarnings("IteratorNextCanNotThrowNoSuchElementException")
@Override public T onNext() {
if (!hasNext())
throw new NoSuchElementException();
hasRow = false;
return createRow();
}
/**
* @return Row.
*/
protected abstract T createRow();
/** {@inheritDoc} */
@Override public void onRemove() {
throw new UnsupportedOperationException();
}
/** {@inheritDoc} */
@Override public void onClose() throws IgniteCheckedException {
if (data == null)
// Nothing to close.
return;
if (closeStmt) {
try {
U.closeQuiet(data.getStatement());
}
catch (SQLException e) {
throw new IgniteCheckedException(e);
}
}
U.closeQuiet(data);
}
/** {@inheritDoc} */
@Override public String toString() {
return S.toString(GridH2ResultSetIterator.class, this);
}
}