/**
* 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.sql.pg;
import com.foundationdb.ais.model.Column;
import com.foundationdb.sql.optimizer.plan.CostEstimate;
import com.foundationdb.qp.operator.*;
import com.foundationdb.qp.row.Row;
import com.foundationdb.qp.rowtype.RowType;
import com.foundationdb.util.tap.InOutTap;
import com.foundationdb.util.tap.Tap;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static com.foundationdb.server.service.dxl.DXLFunctionsHook.DXLFunction;
import java.util.*;
import java.io.IOException;
/**
* An SQL SELECT transformed into an operator tree
* @see PostgresOperatorCompiler
*/
public class PostgresOperatorStatement extends PostgresBaseOperatorStatement
implements PostgresCursorGenerator<Cursor>
{
private Operator resultOperator;
private CostEstimate costEstimate;
private static final Logger logger = LoggerFactory.getLogger(PostgresOperatorStatement.class);
private static final InOutTap EXECUTE_TAP = Tap.createTimer("PostgresOperatorStatement: execute shared");
public PostgresOperatorStatement(PostgresOperatorCompiler compiler) {
super(compiler);
}
public void init(Operator resultOperator,
RowType resultRowType,
List<String> columnNames,
List<PostgresType> columnTypes,
List<Column> aisColumns,
PostgresType[] parameterTypes,
CostEstimate costEstimate) {
super.init(resultRowType, columnNames, columnTypes, aisColumns, parameterTypes);
this.resultOperator = resultOperator;
this.costEstimate = costEstimate;
}
@Override
public TransactionMode getTransactionMode() {
return TransactionMode.READ;
}
@Override
public TransactionAbortedMode getTransactionAbortedMode() {
return TransactionAbortedMode.NOT_ALLOWED;
}
@Override
public AISGenerationMode getAISGenerationMode() {
return AISGenerationMode.NOT_ALLOWED;
}
@Override
public boolean canSuspend(PostgresServerSession server) {
return server.isTransactionActive();
}
@Override
public Cursor openCursor(PostgresQueryContext context, QueryBindings bindings) {
Cursor cursor = API.cursor(resultOperator, context, bindings);
cursor.openTopLevel();
return cursor;
}
public void closeCursor(Cursor cursor) {
if (cursor != null) {
cursor.closeTopLevel();
}
}
@Override
public int execute(PostgresQueryContext context, QueryBindings bindings, int maxrows) throws IOException {
PostgresServerSession server = context.getServer();
PostgresMessenger messenger = server.getMessenger();
int nrows = 0;
Cursor cursor = null;
IOException exceptionDuringExecution = null;
RuntimeException runtimeExDuringExecution = null;
boolean suspended = false;
try {
preExecute(context, DXLFunction.UNSPECIFIED_DML_READ);
context.initStore(getSchema());
cursor = context.startCursor(this, bindings);
PostgresOutputter<Row> outputter = getRowOutputter(context);
outputter.beforeData();
if (cursor != null) {
Row row;
while ((row = cursor.next()) != null) {
assert (getResultRowType() == null) || (row.rowType() == getResultRowType()) : row;
outputter.output(row);
nrows++;
if ((maxrows > 0) && (nrows >= maxrows)) {
suspended = true;
break;
}
}
}
outputter.afterData();
}
catch (IOException e) {
exceptionDuringExecution = e;
} catch (RuntimeException e) {
logger.error("Caught unexpected runtime exception during execution {}", e);
runtimeExDuringExecution = e;
}
finally {
RuntimeException exceptionDuringCleanup = null;
try {
suspended = context.finishCursor(this, cursor, nrows, suspended);
}
catch (RuntimeException e) {
exceptionDuringCleanup = e;
logger.error("Caught exception while cleaning up cursor for {} : {}", resultOperator.describePlan(), e);
}
finally {
postExecute(context, DXLFunction.UNSPECIFIED_DML_READ);
}
if (exceptionDuringExecution != null) {
throw exceptionDuringExecution;
} else if (runtimeExDuringExecution != null) {
throw runtimeExDuringExecution;
} else if (exceptionDuringCleanup != null) {
throw exceptionDuringCleanup;
}
}
if (suspended) {
messenger.beginMessage(PostgresMessages.PORTAL_SUSPENDED_TYPE.code());
messenger.sendMessage();
}
else {
messenger.beginMessage(PostgresMessages.COMMAND_COMPLETE_TYPE.code());
messenger.writeString("SELECT " + nrows);
messenger.sendMessage();
}
return nrows;
}
@Override
protected InOutTap executeTap()
{
return EXECUTE_TAP;
}
@Override
public CostEstimate getCostEstimate() {
return costEstimate;
}
}