/**
* 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.server.service.dxl;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import com.foundationdb.ais.model.AbstractVisitor;
import com.foundationdb.ais.model.AkibanInformationSchema;
import com.foundationdb.ais.model.Join;
import com.foundationdb.ais.model.Table;
import com.foundationdb.qp.operator.API;
import com.foundationdb.qp.operator.Operator;
import com.foundationdb.qp.operator.QueryContext;
import com.foundationdb.qp.operator.SimpleQueryContext;
import com.foundationdb.qp.operator.StoreAdapter;
import com.foundationdb.qp.row.Row;
import com.foundationdb.qp.rowtype.TableRowType;
import com.foundationdb.qp.util.SchemaCache;
import com.foundationdb.server.api.DMLFunctions;
import com.foundationdb.server.service.listener.ListenerService;
import com.foundationdb.server.service.listener.TableListener;
import com.foundationdb.server.service.session.Session;
import com.foundationdb.server.store.SchemaManager;
import com.foundationdb.server.store.Store;
import com.google.inject.Inject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
class BasicDMLFunctions implements DMLFunctions {
private final static Logger logger = LoggerFactory.getLogger(BasicDMLFunctions.class);
private final SchemaManager schemaManager;
private final Store store;
private final ListenerService listenerService;
@Inject
BasicDMLFunctions(SchemaManager schemaManager, Store store, ListenerService listenerService) {
this.schemaManager = schemaManager;
this.store = store;
this.listenerService = listenerService;
}
/**
* Determine if a Table can be truncated 'quickly' through the Store interface.
* This is possible if the entire group can be truncated. Specifically, all other
* tables in the group must have no rows.
* @param session Session to operation on
* @param table Table to determine if a fast truncate is possible on
* @param descendants <code>true</code> to ignore descendants of
* <code>table</code> in the check
* @return true if store.truncateGroup() used, false otherwise
*/
private boolean canFastTruncate(Session session, Table table, boolean descendants) {
if(!table.getFullTextIndexes().isEmpty()) {
return false;
}
List<Table> tableList = new ArrayList<>();
tableList.add(table.getGroup().getRoot());
while(!tableList.isEmpty()) {
Table aTable = tableList.remove(tableList.size() - 1);
if(aTable != table) {
if(aTable.rowDef().getTableStatus().getRowCount(session) > 0) {
return false;
}
}
if((aTable != table) || !descendants) {
for(Join join : aTable.getChildJoins()) {
tableList.add(join.getChild());
}
}
}
return true;
}
@Override
public void truncateTable(final Session session, final int tableId)
{
truncateTable(session, tableId, false);
}
@Override
public void truncateTable(final Session session, final int tableId, final boolean descendants)
{
logger.trace("truncating tableId={}", tableId);
final AkibanInformationSchema ais = schemaManager.getAis(session);
final Table table = ais.getTable(tableId);
if(canFastTruncate(session, table, descendants)) {
store.truncateGroup(session, table.getGroup());
// All other tables in the group have no rows. Only need to truncate this table.
for(TableListener listener : listenerService.getTableListeners()) {
listener.onTruncate(session, table, true);
}
return;
}
slowTruncate(session, table, descendants);
}
private void slowTruncate(Session session, Table table, boolean descendants) {
final com.foundationdb.qp.rowtype.Schema schema = SchemaCache.globalSchema(table.getAIS());
final Set<TableRowType> filterTypes;
if(descendants) {
filterTypes = new HashSet<>();
table.visit(new AbstractVisitor() {
@Override
public void visit(Table t) {
TableRowType rowType = schema.tableRowType(t);
assert rowType != null : t;
filterTypes.add(rowType);
}
});
} else {
filterTypes = Collections.singleton(schema.tableRowType(table));
}
// We can't do a "fast truncate" for whatever reason so do so with a full scan.
Operator plan =
API.delete_Returning(
API.filter_Default(
API.groupScan_Default(table.getGroup()), filterTypes),
false
);
StoreAdapter adapter = store.createAdapter(session, schema);
QueryContext context = new SimpleQueryContext(adapter);
com.foundationdb.qp.operator.Cursor cursor = API.cursor(plan, context, context.createBindings());
cursor.openTopLevel();
try {
Row row;
do {
row = cursor.next();
}
while(row != null);
} finally {
cursor.closeTopLevel();
}
for(TableListener listener : listenerService.getTableListeners()) {
listener.onTruncate(session, table, false);
}
}
}