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JDBC Type 4 driver for MySQL
/*
* Copyright (c) 2002, 2018, Oracle and/or its affiliates. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License, version 2.0, as published by the
* Free Software Foundation.
*
* This program is also distributed with certain software (including but not
* limited to OpenSSL) that is licensed under separate terms, as designated in a
* particular file or component or in included license documentation. The
* authors of MySQL hereby grant you an additional permission to link the
* program and your derivative works with the separately licensed software that
* they have included with MySQL.
*
* Without limiting anything contained in the foregoing, this file, which is
* part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
* version 1.0, a copy of which can be found at
* http://oss.oracle.com/licenses/universal-foss-exception.
*
* 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 General Public License, version 2.0,
* for more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package com.mysql.cj.protocol.a.result;
import com.mysql.cj.Constants;
import com.mysql.cj.Messages;
import com.mysql.cj.conf.PropertyKey;
import com.mysql.cj.exceptions.CJException;
import com.mysql.cj.exceptions.ExceptionFactory;
import com.mysql.cj.exceptions.ExceptionInterceptor;
import com.mysql.cj.exceptions.StreamingNotifiable;
import com.mysql.cj.log.ProfilerEvent;
import com.mysql.cj.log.ProfilerEventHandler;
import com.mysql.cj.log.ProfilerEventHandlerFactory;
import com.mysql.cj.log.ProfilerEventImpl;
import com.mysql.cj.protocol.ColumnDefinition;
import com.mysql.cj.protocol.ProtocolEntity;
import com.mysql.cj.protocol.ProtocolEntityFactory;
import com.mysql.cj.protocol.Resultset.Concurrency;
import com.mysql.cj.protocol.ResultsetRow;
import com.mysql.cj.protocol.ResultsetRows;
import com.mysql.cj.protocol.a.BinaryRowFactory;
import com.mysql.cj.protocol.a.NativeMessageBuilder;
import com.mysql.cj.protocol.a.NativePacketPayload;
import com.mysql.cj.protocol.a.NativeProtocol;
import com.mysql.cj.protocol.a.TextRowFactory;
import com.mysql.cj.result.Row;
import com.mysql.cj.util.Util;
/**
* Provides streaming of Resultset rows. Each next row is consumed from the
* input stream only on {@link #next()} call. Consumed rows are not cached thus
* we only stream result sets when they are forward-only, read-only, and the
* fetch size has been set to Integer.MIN_VALUE (rows are read one by one).
*
* @param
* ProtocolEntity type
*/
public class ResultsetRowsStreaming extends AbstractResultsetRows implements ResultsetRows {
private NativeProtocol protocol;
private boolean isAfterEnd = false;
private boolean noMoreRows = false;
private boolean isBinaryEncoded = false;
private Row nextRow;
private boolean streamerClosed = false;
private ExceptionInterceptor exceptionInterceptor;
private ProtocolEntityFactory resultSetFactory;
private NativeMessageBuilder commandBuilder = new NativeMessageBuilder(); // TODO use shared builder
/**
* Creates a new RowDataDynamic object.
*
* @param io
* the connection to MySQL that this data is coming from
* @param columnDefinition
* the metadata that describe this data
* @param isBinaryEncoded
* is this data in native format?
* @param resultSetFactory
* {@link ProtocolEntityFactory}
*/
public ResultsetRowsStreaming(NativeProtocol io, ColumnDefinition columnDefinition, boolean isBinaryEncoded,
ProtocolEntityFactory resultSetFactory) {
this.protocol = io;
this.isBinaryEncoded = isBinaryEncoded;
this.metadata = columnDefinition;
this.exceptionInterceptor = this.protocol.getExceptionInterceptor();
this.resultSetFactory = resultSetFactory;
this.rowFactory = this.isBinaryEncoded ? new BinaryRowFactory(this.protocol, this.metadata, Concurrency.READ_ONLY, true)
: new TextRowFactory(this.protocol, this.metadata, Concurrency.READ_ONLY, true);
}
@Override
public void close() {
Object mutex = this.owner != null && this.owner.getSyncMutex() != null ? this.owner.getSyncMutex() : this;
boolean hadMore = false;
int howMuchMore = 0;
synchronized (mutex) {
// drain the rest of the records.
while (next() != null) {
hadMore = true;
howMuchMore++;
if (howMuchMore % 100 == 0) {
Thread.yield();
}
}
if (!this.protocol.getPropertySet().getBooleanProperty(PropertyKey.clobberStreamingResults).getValue()
&& this.protocol.getPropertySet().getIntegerProperty(PropertyKey.netTimeoutForStreamingResults).getValue() > 0) {
int oldValue = this.protocol.getServerSession().getServerVariable("net_write_timeout", 60);
this.protocol.clearInputStream();
try {
this.protocol.sendCommand(this.commandBuilder.buildComQuery(this.protocol.getSharedSendPacket(), "SET net_write_timeout=" + oldValue,
this.protocol.getPropertySet().getStringProperty(PropertyKey.characterEncoding).getValue()), false, 0);
} catch (Exception ex) {
throw ExceptionFactory.createException(ex.getMessage(), ex, this.exceptionInterceptor);
}
}
if (this.protocol.getPropertySet().getBooleanProperty(PropertyKey.useUsageAdvisor).getValue()) {
if (hadMore) {
ProfilerEventHandler eventSink = ProfilerEventHandlerFactory.getInstance(this.owner.getSession());
eventSink.consumeEvent(new ProfilerEventImpl(ProfilerEvent.TYPE_WARN, "", this.owner.getCurrentCatalog(), this.owner.getConnectionId(),
this.owner.getOwningStatementId(), -1, System.currentTimeMillis(), 0, Constants.MILLIS_I18N, null, null,
Messages.getString("RowDataDynamic.2") + howMuchMore + Messages.getString("RowDataDynamic.3")
+ Messages.getString("RowDataDynamic.4") + Messages.getString("RowDataDynamic.5") + Messages.getString("RowDataDynamic.6")
+ this.owner.getPointOfOrigin()));
}
}
}
this.metadata = null;
this.owner = null;
}
@Override
public boolean hasNext() {
boolean hasNext = (this.nextRow != null);
if (!hasNext && !this.streamerClosed) {
this.protocol.closeStreamer(this);
this.streamerClosed = true;
}
return hasNext;
}
@Override
public boolean isAfterLast() {
return this.isAfterEnd;
}
@Override
public boolean isBeforeFirst() {
return this.currentPositionInFetchedRows < 0;
}
@Override
public boolean isEmpty() {
return this.wasEmpty;
}
@Override
public boolean isFirst() {
return this.currentPositionInFetchedRows == 0;
}
@Override
public boolean isLast() {
return !isBeforeFirst() && !isAfterLast() && this.noMoreRows;
}
@SuppressWarnings("unchecked")
@Override
public Row next() {
try {
if (!this.noMoreRows) {
this.nextRow = this.protocol.read(ResultsetRow.class, this.rowFactory);
if (this.nextRow == null) {
this.noMoreRows = true;
this.isAfterEnd = true;
if (this.currentPositionInFetchedRows == -1) {
this.wasEmpty = true;
}
}
} else {
this.nextRow = null;
this.isAfterEnd = true;
}
if (this.nextRow == null && !this.streamerClosed) {
if (this.protocol.getServerSession().hasMoreResults()) {
this.protocol.readNextResultset((T) this.owner, this.owner.getOwningStatementMaxRows(), true, this.isBinaryEncoded, this.resultSetFactory);
} else {
this.protocol.closeStreamer(this);
this.streamerClosed = true;
}
}
if (this.nextRow != null) {
if (this.currentPositionInFetchedRows != Integer.MAX_VALUE) {
this.currentPositionInFetchedRows++;
}
}
return this.nextRow;
} catch (CJException sqlEx) {
if (sqlEx instanceof StreamingNotifiable) {
((StreamingNotifiable) sqlEx).setWasStreamingResults();
}
// There won't be any more rows
this.noMoreRows = true;
// don't wrap SQLExceptions
throw sqlEx;
} catch (Exception ex) {
String exceptionType = ex.getClass().getName();
String exceptionMessage = ex.getMessage();
exceptionMessage += Messages.getString("RowDataDynamic.7");
exceptionMessage += Util.stackTraceToString(ex);
CJException cjEx = ExceptionFactory.createException(
Messages.getString("RowDataDynamic.8") + exceptionType + Messages.getString("RowDataDynamic.9") + exceptionMessage, ex,
this.exceptionInterceptor);
throw cjEx;
}
}
public void afterLast() {
throw ExceptionFactory.createException(Messages.getString("ResultSet.ForwardOnly"));
}
public void beforeFirst() {
throw ExceptionFactory.createException(Messages.getString("ResultSet.ForwardOnly"));
}
public void beforeLast() {
throw ExceptionFactory.createException(Messages.getString("ResultSet.ForwardOnly"));
}
public void moveRowRelative(int rows) {
throw ExceptionFactory.createException(Messages.getString("ResultSet.ForwardOnly"));
}
public void setCurrentRow(int rowNumber) {
throw ExceptionFactory.createException(Messages.getString("ResultSet.ForwardOnly"));
}
}